Patent Application
20140309295
The present invention relates to the prevention and/or the treatment of neurodegenerative diseases or of diseases associated with an unwanted oxidation or of age-associated pathological processes, as well as to the prevention and/or the treatment of epilepsy, of epileptic seizures or of convulsions, to the decrease of LDL cholesterol levels and to the inhibition of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase for the prevention of dyslipemia and of cardiovascular diseases.
The high incidence of neurodegenerative diseases and of age-associated diseases is a problem of the first order worldwide. It is therefore necessary to search for neuroprotective compounds preventing or palliating said diseases. Of all of them, Alzheimer's disease (AD) is the most prevalent, it being estimated that 81 million people will suffer from this disease in 2040 (Blennow et al., Lancet 2006; 368: 387-403). It is estimated that half a million people are currently suffering from AD in Spain alone. The costs associated to this disease are proportionally high, and it is calculated that the total cost derived from caring for Alzheimer's patients is 81,000 and 22,000 million in the United States and in the United Kingdom, respectively. Currently there are no effective drugs which prevent or impede this disease, therefore it is necessary to search for and validate novel neuroprotective compounds which prevent neuronal damage.
Different strategies are currently being followed for obtaining novel compounds, since it has been seen that the current drugs offer little benefits to the patients. These drugs temporarily delay (one year, at best) some symptoms of the illness but do not prevent their evolution. The current therapeutic options are based on the inhibition of acetyl-cholinesterase with drugs such as donepezil, galantamine or rivastigmine, or on the capacity of memantine in antagonizing a glutamate receptor, NMDA (N-methyl-D-aspartic acid).
Due to the low success of these drugs new lines of research have opened up and among them, research on inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) enzyme (known as statins) as therapeutic agents stands out in recent years. HMGR is the enzyme which catalyzes the limiting step in cholesterol biosynthesis; therefore its inhibition by statins is a usual therapeutic strategy to reduce the high cholesterol levels associated to the low density lipoproteins (LDL). These drugs reduce the risk of myocardial infarction and coronary death, and are considered safe. Moreover, hypercholesterolemia (defined as a high blood cholesterol level) is the main risk factor for ischemic cardiovascular disease, such as atherosclerosis.
Several genetic and environmental factors affecting cholesterol metabolism are associated with AD. For example, the apolipoprotein E ε4 (apoE4) isoform is a risk factor for AD and is linked to an increase in cholesterol levels. Atherosclerosis, which has hypercholesterolemia as the main risk factor, also seems to be associated to AD. Furthermore, epidemiological studies indicate that high serum cholesterol levels increase the risk of AD, and it has been proposed that homeostatic regulation of cholesterol metabolism can be altered in Alzheimer's. On the other hand, a significant reduction of the risk of Alzheimer's in patients treated with statins has been described. All these studies jointly suggest that the reduction of cholesterol levels can inhibit the pathogenesis of Alzheimer's disease (Cole & Vassar; Neurobiol Dis 2006; 22[2]:209-22).
Cholesterol is transported through blood by means of different types of lipoproteins, in which the major cholesterol carriers are low density lipoproteins (LDL) and high density lipoproteins (HDL). LDLs are lipoproteins specialized in transporting cholesterol and triglycerides from the liver to peripheral tissues, in which they are captured by the cells through the LDL receptors (LDL-R) in cell membrane. LDLs also regulate cholesterol synthesis, and high LDL cholesterol levels have been associated to the risk of suffering from cardiovascular diseases (CVD). In turn, HDLs are lipoproteins which transport cholesterol from the different tissues to the liver. Due to the fact that HDLs can remove cholesterol from arteries and transport it back to the liver for its excretion, they are given a protective role against cardiovascular diseases. HMGR inhibitors are the most successful hypolipidemic agents in history, being capable of reducing total cholesterol levels based on decreasing LDL cholesterol levels without altering HDL cholesterol levels.
New properties of the statins have recently been described, especially at the level of brain damage caused by trauma or in dementias, new antioxidant and anti-inflammatory activities being proposed (Pahan, Cell Mol Life Sci. 2006; 63[10]:1165-78), and certain statins (e.g., simvastatin) have been demonstrated to intensify the learning and memory capacity in mice (Ling et al., Ann Neurol. 2006; 60[6]:729-39) or protect them against convulsive seizures associated to epileptic phenomena (Lee et al., Neurosci Lett. 2008; 440: 260-4). Moreover, the statins have also demonstrated their effectiveness in phase II clinical trials which suggest positive results against the treatment of cerebral vasospasm (Fandino et al., Neurocirugia. 2007; 18: 16-27), as well as against neuronal death induced by ischemic damage in the retina (Honjo et al., Arch. Ophthalmol. 2002; 120: 1707-13). Nevertheless, it is currently being discussed whether the neuroprotective effects of the different commercial statins (e.g., atorvastatin, lovastatin, simvastatin, etc.) are due to a direct effect on the lipid metabolism, or whether in contrast they are a result of alternative routes.
Patent application WO 99/11258 describes a compound with a structure similar to the one of the present invention. Nevertheless, this document does not specify the configuration of the different chiral centers present in the compound.
Although there is literature on the potential neuroprotective effect of statins, the authors of this invention have found that a derivative of a non-commercial monacolin J, specifically (1S,2S,6R,8S,8aR)-1,2,6,7,8,8a-hexahydro-3,7-dimethyl-8-[2-[(2R,4R)-tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl]ethyl]-1-naphthalenyl-2-ethyl-butyrate (also sometimes identified as NST0037 in this patent application) is an agent with a surprisingly neuroprotective potential, in addition to having a high capacity of reducing blood lipid (cholesterol and triglycerides) levels, very effectively inhibiting HMGR, and protecting against epilepsy, epileptic seizures and convulsions. Furthermore, and surprisingly, this compound is safer than commercial statins, showing toxicity levels under the levels of the statin showing the highest level of biosafety, simvastatin. Additionally, it refers to a compound which is less expensive to synthesize due to the low cost of the side chain to be added to the monacolin J molecule.
The neuroprotective activity of said compound has been clearly shown against different aggressions which cause neuronal death in human cell lines of cholinergic origin by means of different types of aggressions which cause oxidative stress, reticular stress or apoptosis (Example 2,
The neuroprotective activity of said compound has been confirmed in a mouse model of Alzheimer's disease, in which this compound exerts a neuroprotective effect against neuronal death in the hippocampus caused by an excitotoxic substance (Example 3,
The antiepileptic and anticonvulsant activity of said compound has been clearly shown by means of the determination of the protection against epileptic seizures and convulsions in an epilepsy model in mice (Example 4,
The hypolipidemic activity of said compound has been clearly shown by means of the determination of the HMGR inhibition in comparison to two commercial statins, simvastatin and atorvastatin (Example 5,
The hypolipidemic capacity of said compound has additionally been demonstrated in an endogenous hyperlipidemia model in mice, an effect similar to simvastatin in reducing total plasma cholesterol levels, LDL cholesterol levels, VLDL cholesterol levels and esterified cholesterol fraction levels being observed. In contrast, and like with simvastatin, it alters neither HDL cholesterol levels nor free cholesterol fraction levels, giving it a protective role against cardiovascular diseases (CVD) (Example 5,
The hypolipidemic activity of said compound has been confirmed in an induced hyperlipidemia model in mice (Example 6,
The biosafety of said compound has been clearly shown by means of the evaluation of its toxicity in a zebrafish embryo model in comparison with a commercial statin, simvastatin, observing that it is less toxic than simvastatin at different concentrations since a lower mortality occurs (Example 7,
Therefore, one aspect of the present invention relates to a compound of formula (I) [also identified on occasions in this patent application as NST0037]:
its hydroxy acid form, the pharmaceutically acceptable salts of said hydroxy acid and pharmaceutically acceptable prodrugs and solvates of the compound and of its hydroxy acid form.
Another aspect of the present invention is a pharmaceutical composition comprising a compound of formula (I) and/or its hydroxy acid form and/or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form, and at least one pharmaceutically acceptable adjuvant, carrier and/or vehicle.
Another aspect of the present invention relates to a compound of formula (I), its hydroxy acid form or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form for its use as medicament.
According to another aspect, the present invention relates to a compound of formula (I), its hydroxy acid form or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form for its use as a neuroprotective agent, in particular in the prevention and/or the treatment of:
One aspect of the present invention relates to the use of a compound of formula (I), of its hydroxy acid form, of a pharmaceutically acceptable salt of said hydroxy acid and/or of a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form in the manufacture of a medicament. According to a particular embodiment, the medicament is for being used as a neuroprotective agent, in particular in the prevention and/or the treatment of:
Another aspect of the present invention is a compound of formula (I), its hydroxy acid form or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form for its use in increasing seladin-1/DHCR24 gene expression.
Another aspect of the present invention is a compound of formula (I), its hydroxy acid form or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form for its use in the prevention and/or treatment of diseases related to the seladin-1/DHCR24 gene.
Another aspect of the present invention relates to the use of a compound of formula (I), of its hydroxy acid form, of a pharmaceutically acceptable salt of said hydroxy acid and/or of a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form in the manufacture of a medicament characterized by increasing seladin-1/DHCR24 gene expression.
In another aspect, the invention relates to a method for the prevention and/or treatment of neurodegenerative diseases, cognitive deterioration, diseases associated with undesired oxidation, age-associated pathological processes and progeria, epilepsy, epileptic seizures and convulsions, cardiovascular diseases such as atherosclerosis, atrial fibrillation, dyslipemia, hypercholesterolemia, hyperlipidemia and hypertriglyceridemia, or fungal or viral infections in a subject in need of treatment, comprising administering to said subject a therapeutically effective amount of a compound of formula (I), its hydroxy acid form or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form.
To aid in understanding the invention object of this patent application, the meaning of some terms and expressions used in the context of the invention is explained below.
The term “neuroprotective agent”, as it is used herein, relates to any substance capable of causing the attenuation or disappearance of the effects of neuronal degeneration or death by means of any mechanism known or to be known, for example, necrosis, apoptosis, autophagia, oxidative damage, excitotoxicity, endoplasmic reticulum damage, deposition of byproducts, loss of cell architecture, etc., or to the reduction or disappearance of the side effects thereof.
The term “statin”, as it is used herein, relates to an inhibitor of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) enzyme, which catalyzes the limiting step of cholesterol biosynthesis and includes any natural, synthetic or semi-synthetic statin. Some statins can be in the closed form (lactone) or in the open form (hydroxy acid). Hydroxy acids (open form) can be prepared from the corresponding lactones by conventional hydrolysis, for example, with sodium hydroxide in methanol, sodium hydroxide in tetrahydrofuran-water and the like. In the open form (hydroxy acid), the statins react to form salts with pharmaceutically acceptable metal and amine cations formed from organic or inorganic bases. The pharmaceutically acceptable salts of the statins can differ from the corresponding free acids in some physical characteristics such as solubility and melting point, but they are considered equivalent to the free acid form for the purposes of this invention. The free open form (hydroxy acid) of the statins can be regenerated from the salt form, if desired, by contacting the salt with a diluted aqueous solution of an acid such as hydrochloric acid and the like. The closed form (lactone) of the statins can be regenerated by dissolving the open form (hydroxy acid) in an inert solvent such as, for example, toluene, benzene, ethyl acetate and the like, at temperatures comprised between approximately 0° C. and approximately the boiling point of the solvent, typically (although not necessarily) with simultaneous separation of the resulting water and catalysis with strong acids, e.g., hydrochloric acid and the like. Likewise, the statins can exist in a solvated or non-solvated form and such forms are equivalent to the non-solvated form for the purposes of this invention.
The term “cardioprotective”, as it is used herein, relates to any substance capable of causing the attenuation or disappearance of the underlying effects of cardiovascular diseases or cardiopathies or of cardiac damage by means of any mechanism known or to be known, for example, necrosis, apoptosis, ischemia, arrhythmia, deposition of byproducts, loss of cell architecture, etc., or to the reduction or disappearance of the side effects thereof.
The term “hypolipidemic”, as it is used herein, relates to any pharmacologically active substance having the property of reducing blood lipid levels or lipid levels in other tissues. The importance of these substances is due to the fact that the excess of some types of lipids (cholesterol or triglycerides) or lipoproteins is one of the main risk factors for cardiovascular diseases.
The term “hypocholesterolemic”, as it is used herein, relates to any pharmacologically active substance having the property of reducing blood cholesterol levels or cholesterol levels in other tissues.
The term “hypotriglyceridemic”, as it is used herein, relates to any pharmacologically active substance having the property of reducing blood triglyceride levels or triglyceride levels in other tissues.
The term “antiepileptic or anticonvulsant”, as it is used herein, relates to the attenuation of epileptic or convulsive seizures, for example, in the duration and/or in the intensity, or to the disappearance of epileptic or convulsive seizures, or to the reduction or disappearance of the side effects thereof.
The term “biosafe” as it is used herein, relates to the absence of toxic effects, generation of tumors, alterations in embryologic development (teratogenesis) or other adverse effects.
The term “neurodegenerative disease”, as it is used herein, includes diseases which result from the degeneration or deterioration of nervous tissue, particularly of neurons, leading over time to a dysfunction or to a disability; the term degeneration includes loss of cell viability, loss of cell function and/or loss of the number of cells (neurons or others). Illustrative, non-limiting, examples of neurodegenerative diseases include Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS), multiple sclerosis, etc. In a particular embodiment, said neurodegenerative disease is a disease related to neuronal death caused by a substance which, for example, causes oxidative stress or endoplasmic reticulum stress or apoptosis or excitotoxicity or neuronal death in general.
The term “disease associated with undesired oxidation”, as it is used herein, relates to a disease caused by undesired oxidation (e.g., excessive oxidation) or in which said undesired oxidation is a symptom. Said undesired oxidation can be a result of the damage caused by free radicals on proteins, DNA and/or lipids independently from the specific free radical involved or from the target. Undesired oxidation involves an excessive generation of free radicals which can cause a dysfunction in cells, tissues or organs and can therefore form a potential mechanism of a disease. In a particular embodiment, said undesired oxidation can be caused by age (aging) or by a neurodegenerative process and can cause by itself or in combination with other factors the onset of several diseases. In a specific embodiment, said undesired oxidation relates to the oxidative damage caused by a substance which causes oxidative stress.
The term “age-associated pathological process”, as it is used herein, relates to any age-related event or combination of events causing loss of cell viability of the nervous tissue or cell sensitization of the nervous tissue, loss of cell function and/or loss of the number of cells (neurons or others), including cell metabolic dysfunction, stress processes, infections by pathogens, genetic alterations, genetic susceptibility, trauma, ischemia, epilepsy, etc.
The term “cardiovascular disease”, as it is used herein, relates to any disease or dysfunction or alteration of the heart or of the rest of the cardiovascular system or of the blood.
The term “epilepsy”, as it is used herein, relates to a chronic brain syndrome having varied causes, characterized by recurrent seizures due to excessive hypersynchronic discharges of nervous impulses by the brain neurons, associated eventually with several clinical and paraclinical manifestations. The seizures can be convulsive or non-convulsive. Epilepsy can have many causes; in some cases it can be due to different types of brain injuries (e.g., brain traumas, sequelae of meningitis, tumors, etc.); in other cases there is no injury but a genetic predisposition to seizures; in other cases, the etiology of the epilepsy can be environmental, due to pharmacological treatments, due to excitotoxicity, trauma, stress processes, aging, development problems, neurological diseases, psychological crises, problems during gestation, problems during labor, etc.
The term “epileptic or convulsant”, as it is used herein, relates to any epileptic seizure or convulsion of any etiology, for example, genetic, environmental, due to pharmacological treatments, due to excitotoxicity, due to trauma, due to stress processes, due to aging, due to development problems, due to neurological diseases, due to psychological crises, due to problems during gestation, due to problems during labor, etc. An epileptic seizure occurs when an abnormal electrical activity in the brain causes an involuntary change of body movement or function, feeling, in the capacity of being alert or in behavior, and can be partial or generalized (convulsive or non-convulsive).
The term “cognitive deterioration”, as it is used herein, relates to the loss or alteration of mental functions, such as memory, orientation, language, visual recognition or conduct which interfere with the social activity and interaction of the person affected persistently over time.
The term “fungal or viral infections”, as it is used herein, relates to any colonization of a microscopic fungus or virus which is harmful for the normal functioning or for the survival of the colonized organism or host.
The term “subject”, as it is used herein, relates to a member of a mammal species and includes but is not limited to domestic animals, primates and humans; preferably, the subject is a male or female human being of any age or race. In a particular embodiment, said subject is a mammal which suffers, or is susceptible of suffering, age-associated pathological processes, such as aging, or a neurodegenerative disease, such as a chronic neurodegenerative disease.
The term “pharmaceutically acceptable”, as it is used herein, relates to the fact that the compound is physiologically tolerable and generally does not cause an allergic reaction or a similar unfavorable reaction, such as a gastric disorder, dizziness or the like, when administered to a subject; said term “pharmaceutically acceptable” preferably means approved by a government regulatory agency or listed in the United States Pharmacopoeia or in another generally recognized pharmacopoeia for use in animals (e.g., European Pharmacopoeia, etc.).
The term “pharmaceutically acceptable salt”, as it is used herein, includes “pharmaceutically acceptable metal salts” as well as “pharmaceutically acceptable amine salts”. The term “pharmaceutically acceptable metal salt” contemplates salts formed with sodium, potassium, calcium, magnesium, aluminum, iron or zinc ions. The term “pharmaceutically acceptable amine salt” contemplates salts with ammonia and organic nitrogen bases strong enough to form salts with carboxylic acids. Said pharmaceutically acceptable salts can be obtained by conventional methods known by persons skilled in the art.
The compound (1S,2S,6R,8S,8aR)-1,2,6,7,8,8a-hexahydro-3,7-dimethyl-8-[2-[(2R,4R)-tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl]ethyl]-1-naphthalenyl-2-ethyl-butyrate can be obtained by semisynthesis methods, such as those described for other compounds of the same family in U.S. Pat. No. 4,866,090.
A number of assays performed by the inventors have clearly shown the neuroprotective effect of compound NST0037 against the action of a substance causing oxidative stress, as well as its neuroprotective effect against the action of a substance causing endoplasmic reticulum stress, and its neuroprotective effect against the action of a substance causing apoptosis in human cholinergic neurons, as well as its neuroprotective effect against a substance causing excitotoxicity, oxidative damage, apoptosis, hippocampal atrophy, neuronal death, cognitive deterioration, temporal memory loss, spatial memory loss, etc.
The neuroprotective effect against the action of a substance causing oxidative stress, such as xanthine/xanthine oxidase (XXO), is described in Example 2. It is observed in said example that compound NST0037 is capable of significantly and quantitatively reducing neuronal death caused by oxidative stress, which clearly shows the neuroprotective capacity of this compound (
For the purpose of better defining the neuroprotective effect of the compound, the inventors analyzed the neurodegenerative process with greater detail by means of the analysis of neuronal death caused by an excitotoxic substance (kainate) in the hippocampal neurons of mice, as described in Example 3. It is observed in said example that compound NST0037 is capable of significantly and quantitatively reducing neuronal death caused by an excitotoxic substance, which clearly shows the neuroprotective capacity of said compound (
Likewise, as is known, the administration of an excitotoxic substance induces convulsive seizures and epilepsy in the animal in some cases; for this reason, the inventors analyzed if the neuroprotective effect of compound NST0037 was accompanied by an antiepileptic and anticonvulsant effect caused by an excitotoxic substance (Example 4), observing that the administration of NST0037 delayed the time of onset of the first convulsion (latency) (
Furthermore, and due to the nature of compound NST0037, the inhibitory capacity of the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) enzyme was studied. Surprisingly, and as is shown in Example 5, the results demonstrate that compound NST0037 has an evident hypocholesterolemic effect. It can be seen in the obtained results and as shown in
For the purpose of better defining the hypocholesterolemic effect of the compound, the inventors analyzed the hypocholesterolemic activity with greater detail by means of the analysis of the variations of the plasma cholesterol fractions in mice with endogenous hypercholesterolemia, as described in Example 5. To that end, the effect of compound NST0037 and of simvastatin was compared in two groups of mice, the total cholesterol levels being determined after the administration of the compounds (
For the purpose of better defining the hypocholesterolemic effect of the compound, the inventors analyzed the hypocholesterolemic activity with greater detail by means of the analysis of the variations of plasma cholesterol fractions in mice with induced hypercholesterolemia, as is described in Example 6. To that end, the effect of compound NST0037 and of simvastatin was compared in two groups of mice, the total cholesterol levels being determined after the administration of the compounds (
In order for a compound to be administered to the human population, it is necessary that its innocuousness and safety be demonstrated. For this purpose, the inventors analyzed the biosafety of compound NST0037 in a widely used toxicological model, the zebrafish embryo, following the methodology described in the OECD C15 protocol, as described in Example 7. In this model, the inventors compared the effect of the compound with simvastatin at concentrations greater than the doses used in clinical practice for the purpose of causing evident damage in the embryos in order to be able to better define the adverse effects of said compound. Thus, the administration of a high dose of NST0037 caused the mortality of all the embryos of the assay, as occurred with the same dose of simvastatin, although the latter was more toxic, since the reduction of the survival rate started earlier in time (
The antifungal activity of compound NST0037 was also studied by means of bioassay against statins (lovastatin, atorvastatin and simvastatin). The obtained results showed that compound NST0037 was the only one capable of causing inhibition halos in the entire assayed concentration range, even at the lowest concentrations (
In addition, the capacity of compound NST0037 to increase seladin-1/DHCR24 gene expression was studied since the neuroprotective effects of the increased expression of this gene against Alzheimer's disease have been demonstrated (Cechi et al., J. Cell. Mol. Med. 2008; 12: 1990-2002). It has been described (Greeve et al., J. Neurosci. 2000; 20: 7345-52) that the product of the seladin-1/DHCR24 gene exerts its neuroprotective power by means of the antiapoptotic effect by inhibition of caspase-3, and regulating cholesterol synthesis from desmosterol, which determinates the generation of a barrier against the neurotoxic injuries and prevents the production of β-amyloid. These mechanisms of action indicate that the increase of seladin-1/DHCR24 gene expression has a general neuroprotective effect, therefore those drugs that cause an increase of the expression of this gene can potentially be used in the prevention and/or treatment of neuronal death associated to neurodegenerative diseases (e.g., Alzheimer's, Parkinson's, multiple sclerosis, amyotrophic lateral sclerosis, status epilepticus, Huntington's, etc.) or of diseases associated with undesired oxidation or of age-associated pathological processes. The capacity of increasing seladin-1/DHCR24 gene expression by means of the administration of NST0037 is described in Example 9, in comparison with memantine (one of the drugs normally used to treat AD). It is observed in said example that compound NST0037 is capable of increasing quantitatively, significantly and in a dose-dependent manner the seladin-1/DHCR24 gene expression, which is demonstrated both by means of gene expression analysis using microarray technology and by means of relative expression analysis using real time quantitative PCR. Said results clearly show the neuroprotective capacity of compound NST0037 (
Additionally, the neuroprotective effect in human neuronal cultures of compound NST0037 against aggressions which mimic some neurodegenerative diseases, such as AD by means of the inhibition of protein phosphatase 1 (
For the purpose of better defining the neuroprotective effect of the compound, the inventors analyzed the neurodegenerative process with greater detail by means of the analysis of the histopathological signs associated with neuronal death caused by an excitotoxic substance (kainate) in the hippocampal neurons of mice, as described in Example 15. In said example it is observed that compound NST0037 is capable of preventing or improving neuritic dystrophy (
For the purpose of better defining the neuroprotective effect of the compound, the inventors analyzed the potential therapeutic effect of the treatment with NST0037 in a model of acute Parkinson's disease in mice as described in Example 16. To that end, and after the acute administration of a dopaminergic neuron-specific parkinsonian neurotoxin (MPTP), it was observed that NST0037 was capable of modifying the deleterious effects caused by the neurotoxin such as mortality (
For the purpose of better defining the neuroprotective effect of the compound, the inventors analyzed the potential therapeutic effect of the treatment with NST0037 in a model of subchronic Parkinson's disease in mice as described in Example 17. To that end, and after the subchronic administration of a dopaminergic neuron-specific parkinsonian neurotoxin (MPTP), it was observed that NST0037 was capable of modifying the deleterious effects caused by the neurotoxin such as the locomotor deficit in relation to the motor resistance (
For the purpose of better defining the blood-brain barrier passage of compound NST0037, the inventors analyzed different parameters such as the theoretical lipophilicity, the percentage of passage and the effective permeability (
For the purpose of better defining the hypocholesterolemic effect of the compound, the inventors analyzed the hypocholesterolemic activity with greater detail by means of the analysis of the reductions of cholesterol in two human cells lines of hepatic and neuronal origin (
For the purpose of better defining the hypocholesterolemic effect of the compound, the inventors analyzed the hypocholesterolemic activity with greater detail by means of reductions of cholesterol and of the associated fractions (
For the purpose of better defining the modulation of the seladin-1/DHCR24 gene by compound NST0037, the inventors analyzed its regulation in the brain of mice treated orally with NST0037 (
For the purpose of better defining the innocuousness and safety of compound NST0037 and to corroborate the studies performed in Example 7 with zebrafish embryo, the inventors decided to analyzed the biosafety of compound NST0037 in larvae as described in Example 24. In this model, the inventors compared the effect of the compound in comparison with simvastatin by making increasing concentration curves, which revealed a high safety of the compound since there was no mortality with any of the two treatments (Table II), and where simvastatin produced a smaller percentage of healthy larvae than NST0037 (
For the purpose of better defining the innocuousness and safety of compound NST0037 and to corroborate the studies performed in previous examples, the inventors decided to analyze the biosafety of NST0037 after treatment in adult fish in comparison with simvastatin, as described in Example 25. The results indicated that while simvastatin causes a significant weight loss in the animals, NST0037 does not significantly vary said parameter (
For the purpose of better defining the innocuousness and safety of the compound NST0037 and to corroborate the studies performed in previous examples, the inventors decided to analyze the biosafety of NST0037 after treatment in adult fish in comparison with simvastatin, as described in Example 26. The results indicated that while simvastatin caused a significant mortality at 4 days of treatment, the mortality associated with NST0037 was residual (Table III). Furthermore, while simvastatin caused clear histopathological variations in the ovary of the animals treated with 100 mg/Kg, NST0037 did not cause any deleterious effect at this dose (
The pharmaceutical composition provided by this invention can contain compound NST0037, and/or its hydroxy acid form and/or a pharmaceutically acceptable salt of said hydroxy acid and/or a pharmaceutically acceptable prodrug or solvate of the compound or of its hydroxy acid form together with one or more pharmaceutically acceptable adjuvants, vehicles or excipients.
The term pharmaceutically acceptable “salt, prodrug or solvate” relates to any pharmaceutically acceptable salt, solvate or any other compound which is capable of providing (directly or indirectly) a compound as has been described in the present invention in its administration to the recipient. Nevertheless, pharmaceutically unacceptable salts also fall within the scope of the invention, since the latter can be useful for the preparation of pharmaceutically acceptable salts. The salts and prodrugs can be prepared by means of methods known in the state of the art.
Any compound which is a prodrug of the compound of formula (I) or of its hydroxy acid form is within the scope of the invention. The term “prodrug” is used in its broadest meaning and encompasses those derivates which are converted in vivo into the compounds of the invention. Such derivates would be evident to a person with average skilled in the art and include the following derivatives of the present compounds: esters, amino acid esters, phosphate esters, metal sulfonate salt esters, carbamates and amides. The compounds according to the invention can be in a crystalline form or as free compounds or as solvates (for example, hydrates) and it is intended that both forms are within the scope of the present invention. Solvation methods are generally known in the state of the art. In a particular embodiment the solvate is a hydrate.
The pharmaceutical compositions containing compound NST0037, or a hydroxy acid form thereof or a pharmaceutically acceptable salt of said hydroxy acid, can be formulated in any pharmaceutical dosage form suitable for its administration by the chosen administration route, e.g., oral, parenteral (subcutaneous, intramuscular, intravenous, intraperitoneal route, etc.), topical, rectal route, etc. By way of a non-limiting illustration, the pharmaceutical compositions provided by this invention can be formulated in a solid pharmaceutical dosage form administered by the oral route (e.g., granules, tablets, capsules, etc.), in a liquid pharmaceutical dosage form administered by the oral route (e.g., solutions, suspensions, emulsions, etc.), in a pharmaceutical dosage form administered by the parenteral route (e.g., solutions, suspensions, emulsions, etc.). To that end, in each case, the suitable pharmaceutically acceptable vehicles and excipients will be chosen for the chosen pharmaceutical dosage form and route of administration, for example, binding agents, diluents, disintegrating agents, lubricants, wetting agents, etc., for the formulation of solid pharmaceutical dosage forms, and buffers, surfactants, etc., for the formulation of liquid pharmaceutical dosage forms. Said vehicles and excipients must be pharmaceutically acceptable and pharmacologically tolerable and have to be able to be combined with other components of the formulation without exerting any adverse effect on the subject treated. Information on said vehicles and excipients, as well as on said pharmaceutical dosage forms of said active ingredient can be found in Galenic Pharmacy treatises. A review of the different pharmaceutical dosage forms of drugs, in general, and of their methods of preparation can be found in the book “Treated de Farmacia Galènica” (“Galenic Pharmacy Treatise”), by C. Faulì i Trillo, 1st Edition, 1993, Luzàn 5, S. A. de Ediciones.
The pharmaceutical composition provided by this invention comprises, compound NST0037, or a hydroxy acid form thereof or a pharmaceutically acceptable salt of said hydroxy acid, in a therapeutically effective amount. In the way used in this description, the expression “therapeutically effective amount” relates to the amount of compound calculated to cause the desired effect. The dose of compound NST0037, or a hydroxy acid form thereof or a pharmaceutically acceptable salt of said hydroxy acid, to be administered to a subject can vary within a wide range depending on a number of factors, including the characteristics of the compound used, e.g., its biological half-life and activity, the concentration of the compound in the pharmaceutical composition, the clinical situation of the subject, the severity of the pathology, the chosen pharmaceutical dosage form, etc. The pharmaceutical composition provided by this invention can be administered one or more times a day for preventive or therapeutic purposes or, alternatively, others administration regimens can be followed, not necessarily daily but also at precise times, weekly, etc.
If desired, the pharmaceutical composition provided by this invention can be used together with other drugs, for example, drugs useful in the treatment of neurodegenerative diseases, cognitive deterioration, diseases associated with undesired oxidation, age-associated pathological processes and progeria, epilepsy, epileptic seizures, convulsions, cardiovascular diseases, or fungal or viral infections for the purpose of increasing the efficacy of the pharmaceutical composition provided by this invention, a combination therapy thus being generated. Said additional drugs can form part of the same pharmaceutical composition or, alternatively, can be provided as a separate pharmaceutical composition for its administration at the same time (simultaneous administration) as the pharmaceutical composition provided by this invention or at different times (sequential administration) with respect to the administration of the pharmaceutical composition provided by this invention.
The following examples serve to illustrate the invention and must not be considered as limiting thereof.
The compound identified as NST0037 was prepared following the methodology described in Hoffman, et al. (J. Med. Chem., 1986, 29, 849-852) for similar compounds.
Lovastatin was purified from an extract of natural origin by column chromatography using a hexane and ethyl acetate gradient as eluent.
A solution of 0.7 g of potassium hydroxide in 0.5 ml of water is prepared and 3 ml of methanol are added little by little. 0.5 g of Lovastatin are subsequently added and the solution is placed under reflux for 21 hours. After the treatment of the reaction, a 50% mixture of monacolin J and the opened product is obtained.
A solution of 0.5 g of Monacolin J in 10 ml of dichloromethane is prepared. 0.4345 g of imidazol are added and it is stirred until dissolution. Then 0.4835 g of tert-butyl-dimethylsilane chloride dissolved in 5 ml of dichloromethane are added, and stirring is continued for 24 hours. The reaction is followed by TLC using dichloromethane-methanol (10:1) as eluent. Yield: 96%.
0.3 g of the protected derivative previously obtained are dissolved in a flask with inert atmosphere in 2 ml of pyridine. 0.06 g of DMAP dissolved in 2 mL of pyridine are subsequently added. The reaction flask is placed in an ice bath and 0.378 ml of 2-ethylbutyryl chloride are added. Then it is stirred for one hour at 0° C. and at room temperature for 18 hours. The reaction is followed by TLC using hexane-ethyl acetate (2:1) as eluent. Yield: 95%.
0.368 g of the derivative previously obtained are dissolved in 2 ml of THF. Then a solution of 0.16 ml of acetic acid and 2.16 ml of 1M tetrabutylammonium fluoride is added to the reaction medium. The reaction mixture is stirred at room temperature for 16 hours. The reaction is followed by TLC using dichloromethane-acetone (6:1) as eluent. Yield: 75%.
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 of cell death caused by treatment with xanthine/xanthine oxidase which generates oxidative damage (causes free radicals such as hydrogen peroxide, superoxide anion, hydroxyl radical), which triggers cell death, was analyzed. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 22 hours, after which time the WST-1 reagent (Roche) was added. The Test WST-1 is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth, therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan which is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 of cell death caused by treatment with tunicamycin generating reticular stress was analyzed. Tunicamycin is an inhibitor of protein N-glycosylation, causing abnormal protein folding in the endoplasmic reticulum, therefore said proteins are accumulated and cause stress, resulting in cell death. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 22 hours, after which time WST-1 reagent (Roche) was added. The WST-1 Test is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth; therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan that is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 of cell death caused by treatment with camptothecin generating cell cycle arrest was analyzed. Camptothecin is an inhibitor of Topoisomerase I, it therefore prevents DNA duplication and triggers cell cycle arrest and death due to apoptosis. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 22 hours, after which time the WST-1 reagent (Roche) was added. The Test WST-1 is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth, therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan which is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 against apoptosis (programmed cell death) caused by treatment with camptothecin which inhibits the enzyme Topoisomerase I, which prevents DNA duplication and triggers apoptotic cell death, was analyzed. These cells, not exceeding 15 passages, were seeded on 6-well plates treated for adherent cells with a cell concentration of 8×105 cells/well and 7×105 cells/well for the assay with pretreatment; 2 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 2 ml of total volume for the following conditions:
In the assay with pretreatment, the cells were previously treated with 40 μM of NST0037, 100 μM of mevalonate or both together for 24 hours and then they were treated with 50 μM camptothecin, the rest of the procedure was similar to the assay without pretreatment.
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 6 hours, after which time they were collected along with their culture medium and centrifuged at 300×g for 5 minutes. The medium was removed, a washing was performed with PBS and the cells were fixed for 2 minutes with 500 μl of 70% ethanol at −20° C. Once fixed, they were centrifuged at 400×g for 5 minutes, washed with PBS and 0.05 mg/ml propidium iodide, diluted in cycling buffer (0.1% sodium citrate, 0.3% Nonidet P-40 and 0.02 mg/ml RNase) were added and they were incubated for 1 hour at 37° C. After this time they were analyzed by flow cytometry, comparing the fluorescence of propidium iodide against the amount of DNA. The percentage of apoptosis was measured on the sub-G1 region of each of the conditions.
The obtained results are shown, as can be seen in
Based on the results of Example 2, the inventors decided to investigate if the neuroprotective effect of NST0037 demonstrated in human cholinergic neurons was corroborated in a model of sporadic Alzheimer's disease in mice by means of the administration of kainate (KA).
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
Twenty-eight animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. Hematoxylin and eosin stain was used in 5 μm thick sections to analyze the cell architecture of the hippocampus.
As shown in
In summary, the pre-treatment with NST0037 (NST0037+KA+NST0037 group) completely protected against neuronal death caused by KA in the hippocampal CA1 and CA2 regions. Furthermore, the beginning of treatment with NST0037 after the inoculation of KA qualitatively reduced neuronal death and damage in this region. It was also demonstrated that the daily administration of NST0037 for 8 days was not neurotoxic for the mice.
The excitotoxicity caused by KA induces, a few days after its inoculation in mice, episode-type memory deterioration, affecting the temporal memory and causing a severe spatial memory deficit. As a result the inventors decided to investigate if the neuroprotective effect of NST0037 was accompanied by a protection of the memory which deteriorates due to the effect of an excitotoxic substance.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
Twenty-eight animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Three days after inoculation of KA, an object recognition test called integral memory test was performed on the animals.
These studies indicate that the treatment before and after (or only after) the damage with an excitotoxic substance with compound NST0037 has a protective effect on episodic (temporal and spatial) memory which degenerates after the administration of an excitotoxic substance.
It is known that the administration of an excitotoxic substance to animals induces, in some cases, death of the animal. As a result, the inventors decided to investigate if the neuroprotective effect of NST0037 was accompanied by a reduction of the mortality caused by an excitotoxic substance.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
Twenty-eight animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimen:
The deaths were recorded during the entire time the assay lasted, and the results are shown in
These studies indicate that the treatment before and after (or only after) of the damage with an excitotoxic substance with compound NST0037 has a protective effect against mortality caused by the administration of an excitotoxic substance.
It is known that the administration of an excitotoxic substance to animals induces, in some cases, epileptic seizures and convulsions in the animals. As a result, the inventors decided to investigate if the neuroprotective effect of NST0037 was accompanied by an antiepileptic effect caused by an excitotoxic substance.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
The animals were intraperitoneally inoculated with 25 mg/kg of kainate (KA) dissolved in PBS. Thirteen animals were pre-treated 24 and 0.5 hours before inoculation with KA by means of intraperitoneal injection with PBS (PBS+KA administration regimen) and 6 were pre-treated 24 and 0.5 hours before inoculation with KA by means of intraperitoneal injection with NST0037 at a dose of 50 mg/kg (NST0037+KA administration regimen). After the inoculation, the animals were individually housed in trays to monitor them. The maximum epilepsy level of the animals was recorded during the observation according to the Racine scale every ten minutes and for at least 120 minutes post-inoculation (m.p.i.).
Comparative studies of the epileptogenic phenomena between the treatment with PBS (PBS+KA) and with NST0037 (NST0037+KA) were subsequently conducted. Differences were observed in the percentage of animals that entered in status epilepticus, i.e., they showed tonic-clonic seizures, among the NST0037+KA group which was 33.3% (2 out of 6) compared to the PBS+KA treatment regimen group which was 76.9% (10 out of 13), which demonstrates that compound NST0037 is antiepileptic and anticonvulsant. Differences over time were also observed in which the first convulsions occurred (latency period), in which the latency of the NST0037+KA group (103.3±13.1 minutes) was greater than with the PBS+KA treatment regimen (74.6±8.6 minutes) as shown in
These studies indicate that treatment with compound NST0037 has an antiepileptic and anticonvulsant effect due to the administration of an excitotoxic substance.
Due to the nature of the compound, the degree of inhibition of the HMGR enzyme by compound NST0037 was determined since this enzyme is key in cellular cholesterol synthesis and in the physiological regulation of said synthesis. The effect of this compound was compared with that of two known statins, atorvastatin and simvastatin, compounds for which a potent inhibitory effect on HMGR has already been described. For the reaction, HMGR uses NADPH as a reducing agent and 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) as a substrate, producing mevalonic acid, CoASH and NADP+. The reduction of the absorbance at which NADPH (340 nm) is absorbed is a direct measurement of the catalytic activity of HMGR and serves to calculate the inhibition percentages of different compounds. In order to take the HMGR inhibition, the assay was performed on a 96-well plate, with a total reaction volume of 200 μl. The reaction buffer (50 mM KH2PO4, 1 M KCl, 2 mg/ml Bovine Serum Albumin [BSA] and 5 mM DTT, at pH=7.3) was prepared at the time the reaction was conducted and was maintained at 37° C. The following was included in the assays:
Five independent assays were conducted with NST0037, four independent assays with atorvastatin and six independent assays with simvastatin, the inhibition potency being determined in a range of concentrations which allowed defining the 50% inhibition constants (IC50) by means of spectrophotometric determination of the drop of NADPH at 37° C., and as is shown in
Based on the results of the previous point, the inventors decided to investigate if the inhibitory activity of HMGR enzyme by compound NST0037 corresponds with a variation of total cholesterol and of its fractions in an endogenous hyperlipidemia model in mice.
All the animals included for the experimental process were 46-week old males of the ApoB100 strain, which strain has a deficiency in removing cholesterol from the blood which causes an abnormally high increase of plasma cholesterol. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
In order to conduct the experiment on the fasting animals, blood was extracted by ocular puncture. The plasma was obtained from said blood, in which plasma total cholesterol levels and levels of its fractions were determined prior to administration of the substances under study. Immediately after that, the animals were intraperitoneally inoculated with 50 mg/kg of each of the test compounds. Four animals were treated with the vehicle and were considered the control group. A second group of five mice received 50 mg/Kg of simvastatin. Finally, a third group of five mice received 50 mg/Kg of NST0037. Twelve hours after the treatments, blood was again extracted from the fasting animals and the plasma was obtained from said blood.
The results shown in this section demonstrate that compound NST0037 shows an effect that is surprisingly similar to simvastatin, significantly reducing TC, LDL-c, VLDL-c and EC levels without changing HDL-c or FC levels.
Based on the results obtained in the experiment with ApoB100 animals, the inventors decided to investigate if compound NST0037 also showed a hypocholesterolemic effect in an induced acute hyperlipidemia model.
All the animals included for the experimental process were wild-type 6-week old male mice of the C57BL6 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
In order to conduct the experiment on the fasting animals, blood was extracted by ocular puncture. The plasma was obtained from said blood, in which plasma total cholesterol levels and levels of its fractions were determined prior to administration of the substances under study. Immediately after that, the animals were intraperitoneally inoculated with 500 mg/kg of Triton 1339, also known as Tyloxapol. After thirty minutes, the animals were intraperitoneally inoculated with 50 mg/kg of each of the test compounds. Seven animals were treated with the vehicle alone and were considered the control group. A second group of six mice received 50 mg/Kg of simvastatin. Finally, a third group of seven mice received 50 mg/Kg of NST0037. Twenty-four hours after the treatments, blood was again extracted from the fasting animals and the plasma was obtained from said blood.
The results shown in this section surprisingly demonstrate that compound NST0037 has a hypocholesterolemic effect identical to or greater than simvastatin, reducing TC and LDL-c levels in a statistically significant manner. These results confirm the hypocholesterolemic effect of NST0037 observed in the apoB100 mice model.
7.1. Analysis of the Survival Rate of Compound NST0037 in Comparison with Simvastatin
To evaluate the biosafety of compound NST0037, its toxicological effects on the zebrafish embryo model were analyzed by means of determining the safety parameters of the OECD C15 protocol.
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L), the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and were deposited in a Petri dish.
To assure exposure in the earliest stages of development, the eggs were quickly transferred (a minimum of 50 per condition) to another Petri dish with solutions of the compounds to be tested. Subsequently, only the fertilized eggs (10 per experimental condition) were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The embryos were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted in a total of 9 days post-fertilization, in which the treatment was renewed every day, thus conducting a semi-static assay. The treatments conducted followed the following regimen:
The mortality of the embryos-larvae was recorded for the entire duration of the assay, the results being shown in
7.2. Analysis of the Lethal Dose 50s Over Time of Compound NST0037 in Comparison with Simvastatin
Based on the results of the previous section, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the lethal dose 50s (LD50) over time.
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L) the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and deposited in a Petri dish.
To assure exposure in the earliest stages of development, the eggs were quickly transferred (a minimum of 50 per condition) to another Petri dish with solutions of the compounds to be tested. Subsequently, only the fertilized eggs (10 per experimental condition) were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The embryos were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted in a total of 9 days post-fertilization, in which the treatment was renewed every day, thus conducting a semi-static assay. The treatments conducted followed the following regimen:
For the duration of the study, the number of dead embryos/larvae was recorded at 24-hour intervals and the LD50 was calculated at each time point of the experiment, as shown in
7.3. Analysis of the Percentage of Healthy Larvae at the End of the Experiment of Compound NST0037 in Comparison with Simvastatin Over Time
Based on the results of the previous sections, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the percentage of healthy larvae at the end of the experiment.
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L) the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and deposited in a Petri dish.
To assure exposure in the earliest stages of development, the eggs were quickly transferred (a minimum of 50 per condition) to another Petri dish with solutions of the compounds to be tested. Subsequently, only the fertilized eggs (10 per experimental condition) were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The embryos were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted in a total of 9 days post-fertilization, in which the treatment was renewed every day, thus conducting a semi-static assay. The treatments conducted followed the following regimen:
The results at the end of the experiment allowed collecting the percentage of healthy larvae which reach the end of the experiment, defined as the number of live larvae and without symptoms of external physiopathological anomalies (morphological and/or behavioral), this being a parameter determining the biosafety of a substance under study and is complementary to the survival rates and to the LD50. As shown in
7.4. Analysis of the Percentage of Larvae with Malformations or Anomalous Appearance at the End of the Experiment of Compound NST0037 in Comparison with Simvastatin Over Time
Based on the results of the previous sections, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the percentage of larvae with malformations or anomalous appearance, collecting the number of larvae showing bodily and/or pigmentary anomalies, as well as the yolk sac reabsorption phase at suitable intervals (every 24 hours). The anomalies recorded in the study are described below:
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L) the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and deposited in a Petri dish.
To assure exposure in the earliest stages of development, the eggs were quickly transferred (a minimum of 50 per condition) to another Petri dish with solutions of the compounds to be tested. Subsequently, only the fertilized eggs (10 per experimental condition) were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The embryos were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted in a total of 9 days post-fertilization, in which the treatment was renewed every day, thus conducting a semi-static assay. The treatments conducted followed the following regimen:
The results indicate that the percentage of larvae with malformations or anomalous appearance is dependent on time and on the treatment, as shown in
These results indicate that compound NST0037 is safer than simvastatin, since the latter induces a significantly higher percentage of more severe toxicological problems.
7.5. Analysis of the Variation of the Cardiotoxicity of Compound NST0037 in Comparison with Simvastatin Dependent on the Dose
Based on the results of the previous sections, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the cardiotoxicity after the treatment with the different compounds and at various doses. The study of this parameter (cardiotoxicity) not only determines the cardiac rhythm of the animals but it furthermore allows observing heartbeat alterations (tachycardia, bradycardia, etc) or heart development anomalies (pericarditis, atrophy, hypertrophy, etc.).
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L) the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and deposited in a Petri dish.
To assure exposure in the earliest stages of development, the eggs were quickly transferred (a minimum of 50 per condition) to another Petri dish with solutions of the compounds to be tested. Subsequently, only the fertilized eggs (10 per experimental condition) were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The embryos were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted in a total of 9 days post-fertilization, in which the treatment was renewed every day, thus conducting a semi-static assay. The treatments conducted followed the following regimen:
The cardiac rhythm of the zebrafish embryos-larva was determined by means of visual analysis in stereomicroscopy, determining the heartbeat with the aid of a manual counter for a period of one minute. The different treatments varied the cardiac rhythm of the animals, as shown in
The fungicidal activity of NST0037 was analyzed by means of bioassay against Candida albicans. Solutions of the β-hydroxy acid form of NST0037, lovastatin, atorvastatin and simvastatin were prepared for this purpose. The assayed concentrations were the following: 2, 1.5, 1, 0.5, 0.25, 0.125, 0.06, 0.025 and 0.01 mM. Plates of MA medium (containing per liter: 20 g malt extract, 20 g glucose, 1 g mycopeptone and 10 g agar) previously inoculated with a culture of Candida albicans CECT (Spanish Type-Culture Collection) 1002 were prepared. With aid of a die (6 mm in diameter) various wells were prepared in which 40 μL of the previous solutions were deposited. The study was performed in triplicate and triplicates for each compound and concentration were included in each plate. The plates were kept at 4° C. for 1 hour and were subsequently incubated at 28° C. overnight. The presence of antifungal activity was determined by means of the formation of C. albicans growth inhibition halos.
The obtained results showed that compound NST0037 has a higher antifungal activity than the statins included in the assay. As shown in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The expression of the seladin-1/DHCR24 gene (NCBI Reference Sequence: NM—014762.3) was analyzed by means of real-time quantitative RT-PCR in comparison with memantine (a drug normally used to treat Alzheimer's disease). The SK-N-MC cells were treated for 24 hours in the absence (control) or presence of NST0037 or of memantine at 1, 4, 10 or 40 μM. The total RNA was extracted by means of the High Pure RNA Isolation kit (Roche) and the amount and quality of the RNA were analyzed by means of spectrophotometry (Infinite 200 with NanoQuant, Tecan) and viewing of the 18S and 28S bands by means of electrophoresis. The RT-PCR was performed by means of two steps, first, the mRNA was changed to cDNA using the RNA to cDNA kit (Applied Biosystem) and the gene expression was subsequently analyzed by means of TaqMan probes using the validated probes Hs00207388_m1 for seladin-1/DHCR24 and Hs99999901_s1 for 18S (used to normalize the results) in the 7500 Fast Real-Time PCR System equipment (Applied Biosystem). Two independent assays were performed in triplicate. The relative amount of the gene expression was determined by using the ΔΔCt method with the SDS v2.1.1 software (Applied Biosystem); the expression of 18S was used to normalize the measurement.
The obtained results, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 of cell death caused by the treatment with okadaic acid (OA) which inhibits the activity of protein phosphatase 1 (PP1) was analyzed. OA is one of the most used drugs for studying the phosphorylation mechanism of the tau protein, involved in the pathogenesis and progression of AD. The inhibition of PP1 causes cytoskeleton alterations and mitochondrial damage. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 22 hours, after which time the WST-1 reagent (Roche) was added. The Test WST-1 is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth, therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan which is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The inhibition caused by compound NST0037 of cell death caused by treatment with 3-Nitropropionic (3-NP) acid was analyzed. 3-NP is an irreversible inhibitor of the succinate dehydrogenase enzyme which in animal models causes oxidative stress and apoptotic cell death in the striatum, which mimics neurochemical and anatomical changes associated with Huntington's disease (HD). These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 22 hours, after which time the WST-1 reagent (Roche) was added. The Test WST-1 is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth, therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan which is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The induction of apoptosis on the cells in culture was performed by means of incubation with camptothecin (CPT), which triggers cell apoptosis activation. The apoptosis was determined by means of the measurement of the activation of effector caspases, caspase 3 or caspase 7, for which a kit for the fluorometric detection of active caspase 3/7 (Apo-ONE® Homogeneous Caspase-3/7, Promega) was used. The active caspase 3 or 7 of the cells cause the rupture of a substrate, which leads to fluorescence emission, which is read by means of a fluorometer. The effect of the pretreatment of compound NST0037 at 10 and 40 μM on the activation of caspase 3/7 caused by 50 μM of camptothecin (CPT) in the SK-N-MC cells was thus analyzed. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well, 3 wells of the plate were seeded for each condition of the assay. After 24 hours of cell incubation at 37° C. and 5% CO2, the pretreatment with NST0037 at 10 and 40 μM was performed.
After 24 hours, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CM with these treatments for 6 hours, after which the cell lysis buffer and the caspase substrate were added at the concentrations specified by the manufacturer; they were incubated at room temperature for 30 minutes and then frozen at −20° C. overnight. On the following day, fluorescence was measured (499/521 nm, Exci/Emi).
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), stably transfected with a construct carried by the APP gene (beta-amyloid precursor protein, Gene ID: 351) in isoform 695, which is the most frequent variant expressed in neurons, whereby overexpression of the APP protein is achieved. In all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum, the expression of APP is selected by means of adding the antibiotic hygromycin B at 0.16 mg/mL.
These cells, not exceeding 15 passages, were seeded on E-well plates treated for adherent cells with a cell concentration of 8×105 cells/well, 2 wells of the plate were seeded for each condition of the assay. After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 2 ml of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CO2) with these treatments for 48 hours, 500 μl of conditioned medium then being collected to perform the measurements. The cell remains were removed from the conditioned medium by means of centrifugation at 300×g and protease inhibitors (Mini EDTA-free, Roche) were then added. The two most frequent Aβ species, 1-40 and 1-42, were measured. For Aβ(1-42) it was necessary to concentrate the medium 5 times to perform the measurements, using the Amicon Ultra filtration system (Millipore). The amount of Aβ(1-40) and Aβ(1-42) of the conditioned medium was analyzed for each treatment by means of ELISA (Enzyme-linked immunosorbent assay), using the “beta amyloid 40 ELISA” and “beta amyloid 42 ELISA” kit (Biosource), following the recommendations of the manufacturer. The results were quantified by using an increasing concentration curve with synthetic peptides. The baseline values of secreted Aβ in these cells are 1340±141 pg/ml for Aβ(1-40) and 20±3 pg/mL for Aβ(1-42).
The results obtained for the treatments are shown in
From these results it is concluded that NST0037 reduces the secretion of Aβ in human neuroblastoma cells which overexpress APP. The production of Aβ has been related to cell death both in vitro and in vivo and is furthermore associated with the senile plaques present in patients with Alzheimer's disease.
The assay was performed on human neuroblastoma SK-N-MC cells in culture from the American Type Culture Collection (ATCC), in all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells were maintained in the following culture medium culture medium: Minimum Essential Medium Eagle (MEM) supplemented with 1 mM sodium pyruvate, 2 mM L-glutamine, 0.1 mM non-essential amino acids, 0.05 mg/ml gentamicin and 10% fetal bovine serum.
The effect of mevalonate on the protection caused by compound NST0037 against cell death caused by the treatment with xanthine/xanthine oxidase generating oxidative damage and cell death was analyzed. These cells, not exceeding 15 passages, were seeded on 96-well plates treated for adherent cells with a cell concentration of 5×104 cells/well; 3 wells of the plate were seeded for each condition of the assay.
After 24 hours of cell incubation at 37° C. and 5% CO2, the cell treatments were performed with 100 μl of total volume for the following conditions:
The cells were incubated (at 37° C. and 5% CM with the treatments for 22 hours, after which time the WST-1 reagent (Roche) was added. The Test WST-1 is based on the measurement of metabolic activity. Cell damage causes the loss of the ability of cells to obtain the energy necessary to maintain their metabolic functions and cell growth, therefore the metabolically active (live) cells reduce tetrazolium salt to formazan by means of the succinate-tetrazolium reductase system (of the mitochondrial respiratory chain). The formazan which is formed can be detected colorimetrically since it has an absorbance of 440 nm. The reading was taken in a plate reader at 440 nm 2 hours after adding the reagent.
The obtained results are shown, as can be seen in
Based on the neuroprotection results, the inventors decided to investigate if the neuroprotective effect of NST0037 in the hippocampus demonstrated in a model of sporadic Alzheimer's disease in mice by means of the administration of kainate (KA) was accompanied by the protection of another sign of neuronal damage such as neuritic dystrophy.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty-five animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of neuritic dystrophy in the hippocampus, bright field immunochemistry against microtubule associated protein type 2 (MAP2) was performed in 5 μm thick coronal sections.
As shown in
In summary, the treatment with NST0037, both before and after the inoculation of KA, protects against the neuritic dystrophy caused by the latter in the hippocampus.
Based on the neurodegeneration and neuritic dystrophy protection results, the inventors decided to investigate if the neuroprotective effect of NST0037 in the hippocampus demonstrated in a model of sporadic Alzheimer's disease in mice by means of the administration of kainate (KA) was accompanied by the protection from another sign of neuronal damage such as oxidative damage.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty-five animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of oxidative damage due to lipid peroxidation in the hippocampus, bright field immunochemistry against 4-hydroxynonenal (HNE) was performed in 5 μm thick coronal sections.
As shown in
In summary, the treatment with NST0037, both before and after the inoculation of KA, protects against the oxidative damage induced by the latter in the hippocampus.
Based on the previous results, the inventors decided to investigate if the neuroprotective effect of NST0037 in the hippocampus demonstrated in a model of sporadic Alzheimer's disease in mice by means of the administration of kainate (KA) was accompanied by the protection against death by apoptosis, a mechanism which is associated with the disease.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty-five animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of the presence of neurons in apoptosis in the hippocampus, the T.U.N.E.L. (TdT-mediated dUTP nick end labeling) fluorescence technique was performed in 5 μm thick coronal sections.
The PBS+KA+PBS administration regimen causes neuronal death by apoptosis in the hippocampus and especially in the CA1, CA3 (
In summary, the treatment with NST0037, both before and after the inoculation of KA, protects against the oxidative damage and against the apoptosis induced by the latter in hippocampal neurons.
Based on the previous results, the inventors decided to investigate if the antioxidant and antiapoptotic effect shown by NST0037 in the hippocampus demonstrated in a model of sporadic Alzheimer's disease in mice by means of the administration of kainate (KA) was accompanied by the reduction of reactive astrogliosis, which is another histopathological sign which is detected in the brain of patients with Alzheimer's disease.
All the animals included for the experimental process were 12-week old males of the FVB/NHan strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty-five animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. The analysis of reactive astrogliosis was performed by means of bright field immunochemistry against Glial fibrillary acidic protein (GFAP) in 5 μm thick coronal sections, which protein is present in astrocytes.
The PBS+KA+PBS administration regimen causes a significant increase of the activation and propagation of astrocytes in the neuropil of the hippocampus (
In summary, the treatment with NST0037, both before and after the inoculation of KA, protects against oxidative damage, against apoptosis and prevents the reactive astrogliosis induced by the latter in the hippocampal region.
Based on the neuroprotection results demonstrated by the compound NST0037 in a model of sporadic Alzheimer's disease in mice, the investigators decided to evaluate the neuroprotective capacity of the compound in a model of Parkinson's disease based on the death of dopaminergic neurons induced by a neurotoxic substance such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The systemic injection of MPTP in mice induces a massive death of the dopaminergic neurons of the substantia nigra, which reduces the concentration of dopamine in this region and in others such as the striatum that are highly linked to locomotor activity in humans. Due to these phenomena, this model has been widely used to study Parkinson's disease since it reproduces one of the central events in said disease such as motor deterioration. This example presents the results of the analysis of the effect of NST0037 against neurodegeneration and the symptoms induced by MPTP in an acute administration.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Forty animals were used in this assay and the treatments were conducted with a volume of 100 μl, according to the following regimens:
The deaths in the different treatment groups were recorded during the entire experimental procedure, with these data the corresponding survival curves presented in
The PBS+MPTP+PBS administration regimen causes a statistically significant increase (p<0.05) of the mortality in the mice. However, the treatment with NST0037 surprisingly promotes the survival of the animals after the acute administration of MPTP since no significant differences were observed between the NST0037+MPTP+NST0037 group and the PBS+PBS+PBS group (p>0.05).
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Forty animals were used in this assay and the treatments were conducted with a volume of 100 μl, according to the following regimens:
Before starting the treatments and once the treatment time of 7 days ended, the animals were subjected to a locomotor resistance test referred to as the Rotarod test for 2 minutes, recording the time the animals resisted walking over a cylinder which increased its speed from 4 to 40 r.p.m.
The PBS+MPTP+PBS administration regimen causes a statistically significant decrease of the motor resistance in the mice from their baseline state to 7 days after the acute administration of MPTP (p<0.05). However, the treatment with NST0037 surprisingly prevents the motor deterioration of the animals, maintaining the resistance of the mice at the level that they showed before the administration of MPTP (p>0.05), a pattern which is identical to that of the mice not injected with MPTP and treated with PBS (p>0.05).
In summary, the treatment with NST0037 protects against the loss of resistance induced by the acute administration of MPTP.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Forty animals were used in this assay and the treatments were conducted with a volume of 100 μl, according to the following regimens:
Before starting the treatments and once the treatment time of 7 days ended, the animals were subjected to a strength test in the so-called Grip-strength test, recording the strength of gripping a bar in grams exerted by the animals with the front paws in triplicate.
The PBS+MPTP+PBS administration regimen causes a statistically significant decrease of the strength exerted by the mice upon gripping with the front paws from their baseline state to 7 days after the acute administration of MPTP (p<0.05). Furthermore, the treatment with NST0037 prevents the loss of strength induced by MPTP and after 7 days of treatment the mice of the NST0037+MPTP+NST0037 group show strength levels identical to those before the administration of MPTP (p>0.05), a pattern which is very similar to that of mice not injected with MPTP and treated with PBS (p>0.05).
In summary, the treatment with NST0037 protects against the loss of resistance and strength induced by the acute administration of MPTP.
Based on the previous results, the inventors wished to determine if the protection shown by compound NST0037 against the deterioration of the psychomotor state caused by MPTP would be accompanied by the neurodegeneration in brain regions involved in locomotor activity and related to Parkinson's disease such as the substantia nigra and the striatum.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Forty animals were used in this assay and the treatments were conducted with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of neurodegeneration in the substantia nigra and the striatum, fluorescent Fluoro Jade B (FJB) staining was performed in 5 μm thick sagittal sections.
The PBS+MPTP+PBS administration regimen causes a clear increase of the cells positive for FJB both in the substantia nigra and in the striatum with respect to the samples of the PBS+PBS+PBS group. In contrast, the samples of the NST0037+MPTP+NST0037 group had a number of cells in degeneration and positive for FJB significantly lower than those of the PBS+MPTP+PBS group.
In summary, the treatment with NST0037 protects against psychomotor deterioration and against neurodegeneration, induced by the acute administration of MPTP, in dopaminergic neurons of the substantia nigra, as well as of the nerve endings innerving the striatum.
Based on the previous results, the inventors wished to determine if the protection shown by compound NST0037 against the neurodegeneration caused by MPTP was accompanied by the protection of dopaminergic neurons in deteriorated brain regions in Parkinson's disease such as the substantia nigra and the striatum.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Forty animals were used in this assay and the treatments were conducted with a volume of 100 μl, according to the following regimens:
Once the treatment time of 7 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of the presence of dopaminergic neurons in the substantia nigra and the striatum, the immunohistochemistry against the tyrosine-hydroxylase (TH) protein was performed in 5 μm thick sagittal sections.
The PBS+MPTP+PBS administration regimen causes an evident decrease of the amount of dopaminergic neurons since a clear absence of TH labeling is observed in comparison with the PBS+PBS+PBS group, both in the neuronal bodies of the substantia nigra and in the nerve extensions in the striatum. In contrast, the samples of the NST0037+MPTP+NST0037 group had a larger number of TH-positive cells in the substantia nigra as well as a higher labeling intensity in the striatum than those of the PBS+MPTP+PBS group.
In summary, the treatment with NST0037 protects against the psychomotor deterioration of the mice, in addition to the neurodegeneration and the neuronal death induced by the acute administration of MPTP, in the substantia nigra and the striatum.
Due to the results obtained and presented in Example 16, the inventors decided to analyze the effect of NST0037 on clinical symptoms and on the neuropathology induced in the substantia nigra by the subchronic administration of MPTP in mice.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Seven days before starting the treatments and at 7, 14 and 21 days post-inoculation of MPTP, the animals were subjected to a locomotor resistance test referred to as the Rotarod test for 2 minutes, recording the time the animals resisted walking over a cylinder which increased its speed from 4 to 40 r.p.m.
The PBS+MPTP+PBS administration regimen causes a statistically significant decrease of the motor resistance in the mice from their baseline state starting from 14 days after the subchronic administration of MPTP (p<0.05). However, the treatment with NST0037 surprisingly prevents the motor deterioration of the animals, maintaining the resistance of the mice at the level that they showed before the administration of MPTP (p>0.05).
In summary, the treatment with NST0037 protects against the loss of resistance induced by the subchronic administration of MPTP.
Based on the previous results, the inventors wished to determine if the protection shown by compound NST0037 against the deterioration of the psychomotor state caused by MPTP was accompanied by neurodegeneration in one of the most important brain regions which is involved in Parkinson's disease such as the substantia nigra.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 21 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of the presence of dopaminergic neurons in the substantia nigra, the immunohistochemistry against the tyrosine-hydroxylase (TH) protein was performed in 5 μm thick sagittal sections.
The PBS+MPTP+PBS administration regimen causes an evident loss of dopaminergic neurons since a clear absence of TH labeling is observed in some substantia nigra regions. In contrast, the samples of the NST0037+MPTP+NST0037 group had a larger number of TH-positive cells in the same substantia nigra region.
In summary, the treatment with NST0037 protects against the psychomotor deterioration of the mice, in addition to the neuronal death induced in the substantia nigra by the subchronic administration of MPTP.
Based on the previous results, the inventors wished to determine if the neuroprotection shown by compound NST0037 against the neurodegeneration caused by MPTP in the substantia nigra was accompanied by the reduction of another histopathological sign of neuronal damage such as oxidative damage.
All the animals included for the experimental process were 12-week old males of the CD1 strain. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations during inoculations and handling.
Twenty animals were used in this assay and the treatments were all conducted by intraperitoneal (i.p.) route with a volume of 100 μl, according to the following regimens:
Once the treatment time of 21 days ended, the animals were sacrificed and the brains were dissected. The brain samples were processed and included in paraffin. For the analysis of lipid peroxidation in the neurons of the substantia nigra, bright field immunohistochemistry against 4-hydroxynonenal (HNE) was performed in 5 μm thick sagittal sections.
The PBS+MPTP+PBS administration regimen induces the presence of labeling against HNE in a number of neurons of the substantia nigra. In contrast, the samples of the NST0037+MPTP+NST0037 group have a modest number of isolated neurons with HNE-positive labeling in the substantia nigra.
In summary, the treatment with NST0037 protects against the psychomotor deterioration of the mice, in addition to neuronal death and oxidative damage due to lipid peroxidation induced in the substantia nigra by the subchronic administration of MPTP.
The object of the assay was to predict if compound NST0037, in comparison with simvastatin and atorvastatin, in the active forms thereof, was capable of crossing the blood-brain barrier (BBB), for which said barrier was mimicked in an in vitro system which allowed evaluating the compound without using cells. To that end, the assay referred to as PAMPA (Parallel Artificial Membrane Permeation Assay), which uses a sandwich system contemplating the passage of compounds by means of passive diffusion, was carried out. Verapamil, a compound with high permeability, was used as positive control, whereas theophylline, a compound which does not cross the BBB, was used as negative control.
To mimic the BBB, a commercial mixture of lipids derived from pig brain with a composition of phospholipids very similar to that which forms the barrier, and which is referred to as PBL (Porcine Polar Brain Lipid), was used. Verapamil, theophylline and atorvastatin were prepared at 10 mM in DMSO, whereas NST0037 and simvastatin were prepared in water and activated with 0.1 N NaOH at 4° C. for 12 hours.
At the time of the assay, 1.5 mL of the compounds to be evaluated and of the controls were prepared, in all cases at 100 μM from the stocks in a phosphate buffer at pH 7.4 which contained monobasic sodium phosphate (0.41 M) and dibasic potassium phosphate (0.287 M). To that end, a 1/100 dilution of the compounds was carried out, equaling the content of DMSO at 1% in all cases.
In a 96-well filter plate, with a PVDF membrane, with a 45 μm pore size (MAIPN4550, Millipore), 5 μL of PBL at 20 μg/mL were added. After two minutes, 300 μL of the phosphate buffer used to dilute the compounds were added. This plate was considered the acceptor plate and was placed in the upper part of the sandwich. On another 96-well plate which was perfectly assembled with the previous one (MATRNP550 from Millipore), 300 μL of the compounds at 100 μM were added in triplicate. Furthermore, a blank which only included 1% DMSO in the phosphate buffer used was included. This plate was referred to as donor plate. The acceptor plate was carefully placed on the donor plate, forming the sandwich system. The compounds object of study diffused from the wells of the donor plate to the corresponding wells of the acceptor plate during the 18 hours in which was the system remained intact. The remaining compound prepared was preserved in the same conditions of humidity, temperature and darkness as the sandwich system formed by the plates. After this time, 100 μL of the wells of the donor plates and of the acceptor plates were transferred to a special 96-well plate for UV reading. Furthermore, 100 μL, in triplicate, of the compounds prepared to perform the assay were transferred and preserved in the same manner as the plates (baseline wells). The UV plate was introduced in a spectrophotometer in which a scan was carried out in UV from 230 to 498 nm, with readings every 4 nm. Based on the spectrophotometer data, the percentage of barrier passage as well as the effective permeability (Pe) were calculated. The following formula was applied to calculate Pe:
The theoretical calculation of lipophilicity of a compound can be obtained by calculating the logarithm of the octanol/water partition coefficient, which is given by cLogP. cLogP was theoretically calculated by means of the CLOGP program (OSIRIS Property Explorer), entering the chemical structures into the software. The n for each compound is indicated in the table together with the numerical results of the mean±SD of the values obtained in the assay.
As can be observed in Table I and in
The object of the assay was to determine to what extent compound NST0037, in comparison with simvastatin, was capable of modifying the total cholesterol levels in cell lines of neuronal and hepatic origin. To carry out this assay, the compounds were activated with NaOH until the lactone form was completely opened.
Both the Hep G2 (human hepatocarcinoma) line and the SK-N-MC (human neuroblastoma) line were obtained from the American Type Culture Collection (ATCC no. HB-8065 and HTB-10 respectively). In all cases strict rules of sterility were followed and the manipulation was performed in class II biological safety cabinets following European standard EN 12469. The cells maintained in passage were seeded in 96-well plates in MEM supplemented with 10% FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, 0.1 mM non-essential amino acids and 0.05 mg/mL gentamicin. In the case of HepG2, 4×104 cells/well were seeded and in the case of SK-N-MC 5×104 cells/well were seeded. After 24 hours had elapsed from the seeding, the cells were deprived of FBS for 8 hours. The cells were then incubated with the treatments at various concentrations for 20 hours. After the incubation period, the cells were washed with PBS and lysed with a phosphate buffer with 0.5% Triton X-100. The lysis was completed by means of a double freezing-thawing.
The total cholesterol was quantified by means of enzymatic and fluorometric techniques. 25 μL of each lysate were transferred to a 96-well plate together with a standard cholesterol curve starting from 10 μg/mL to 0.08 μg/mL. 75 μL of the reactive mixture prepared based on 0.05 M MES (pH 6.5) containing cholesterol oxidase (0.5 U/mL), cholesterol esterase (0.8 U/mL), horseradish peroxidase (4 U/mL) and ampliflu red (20 μg/mL) were added on the samples and incubation was performed for 15 minutes at 37° C. The fluorescence intensity was determined at 530 nm of excitation and 580 nm of emission by means of a fluorometer. The results were normalized by protein, which was determined by means of the BCA technique.
Based on the results previously presented on the hypocholesterolemic character of compound NST0037, the investigators decided to evaluate the effect of the oral administration over time of NST0037 in the same familial endogenous hyperlipidemia model (apoB100 mice) which was used in Example 5.2. The objective of this new study was to analyze if prolonged oral administration is effective for reducing cholesterol levels over time.
All the animals included for the experimental process were 12-week old female mice. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
The mice were divided into three groups: control group (n=8); simvastatin group (n=8); NST0037 group (n=8). After a conditioning to the diet, 50 mg/kg of simvastatin or NST0037 (in the lactone forms thereof) were orally administered to the mice at the same time (15.00 to 18.00 h) for 28 consecutive days, using in both cases 0.25% carboxy methylcellulose in water as a vehicle. The control group received this same vehicle. Before starting the treatments and at 7, 21 and 28 days of starting them, retro-orbital blood extractions after fasting for 16 hours were carried out. The plasma was obtained from said blood, in which the total cholesterol (TC), free cholesterol (FC), cholesterol (EC), HDL-c, LDL-c, VLDL-c and apoB100 levels were evaluated by enzymatic and spectrophotometric techniques. In order to check if the effect at the lipid level involved an alteration of the oxidative stress, the redox state in the plasmas obtained was furthermore evaluated by means of the TEAC (Trolox Antioxidant Capacity Assay) technique. This technique determines the antioxidant capacity in vitro, giving an idea of the redox state of the sample analyzed by means of the absorbance capacity by electron transfer. The different components of the reaction, myoglobin, ABTS (2,2-azino-bis-(3-ethylbenzthiazoline-sulfonic acid), hydrogen peroxide and H2O2 were added to the plasmas diluted 1/10 in PBS (10 μL) in a 96-well plate. After 3 minutes of incubation, the absorbance was measured at 405 nm (with a reference of 600 nm).
In summary, the treatment with NST0037 for 28 days by means of the oral administration to mice with congenital hyperlipidemia causes a reduction of total cholesterol, esterified cholesterol, free cholesterol levels, of all the lipoprotein fractions associated with cholesterol, of the ApoB levels and of the redox state of the animals.
Based on the results previously presented on the hypocholesterolemic character of compound NST0037, the investigators decided to evaluate the effect of the oral administration for 3 months of NST0037 in the same familial endogenous hyperlipidemia model (apoB100 mice).
All the animals included for the experimental process were 6-month old female mice. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
The animals were divided into three groups: control group (n=8); simvastatin group (n=6); NST0037 group (n=8). After a conditioning to the diet, 50 mg/kg of NST0021 or NST0037 were orally administered to the mice for 3 months, three times a week, using in both cases 0.25% carboxy methylcellulose in physiological saline as a vehicle. The control group received this same vehicle. Before starting the treatments and at one, two and three months of starting them, retro-orbital blood extractions after fasting for 16 hours were carried out. The plasma was obtained from said blood, in which the total cholesterol (TC), free cholesterol (FC), cholesterol (EC), HDL-c, LDL-c, VLDL-c levels were evaluated by enzymatic and spectrophotometric techniques.
In summary, the treatment with NST0037 for 3 months by means of oral administration to mice with congenital hyperlipidemia causes a reduction of total cholesterol, esterified cholesterol, free cholesterol levels, as well as a reduction of the LDL-c levels and an increase of HDL-c, which demonstrates its cardioprotective power.
Based on the results previously presented on the hypocholesterolemic character of compound NST0037 in mice, the investigators decided to evaluate the effect of the oral administration for 7 days of NST0037 in an endogenous hyperlipidemia model in genetically obese Zucker rats with abnormally high lipid levels.
All the animals included for the experimental process were 11 week-old male Zucker rats. The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The animals had their respective quarantine period and were treated with maximum precaution to minimize possible contaminations for inoculations and handling.
The animals were divided into three groups: control group (n=7); simvastatin group (n=7); NST0037 group (n=7). After a conditioning to the diet, 30 mg/kg of NST0021 or NST0037 were orally administered to the mice at the same time (15.00 to 18.00 h) for 7 consecutive days, using in both cases 0.5% carboxy methylcellulose in water as a vehicle. The control group received this same vehicle. Before starting the treatments and at 7 days therefrom, blood was extracted by lingual puncture under anesthesia after fasting for 16 hours. The plasma was obtained from said blood, in which the total cholesterol, HDL-c, LDL-c, VLDL-c, and triglyceride (TG) levels were evaluated by enzymatic and spectrophotometric techniques. In order to check if the effect at the lipid level involved an alteration of the oxidative stress, the redox state in the plasmas obtained was furthermore evaluated by means of the TEAC (Trolox Antioxidant Capacity Assay) technique. This technique determines the antioxidant capacity in vitro, giving an idea of the redox state of the sample analyzed by means of the absorbance capacity by electron transfer. The different components of the reaction, myoglobin, ABTS (2,2-azino-bis-(3-ethylbenzthiazoline-sulfonic acid) and hydrogen peroxide were added to the plasmas diluted 1/10 in PBS (10 μL) in a 96-well plate. After 3 minutes of incubation, the absorbance was measured at 405 nm (with a reference of 600 nm).
In summary, the treatment with NST0037 for 7 days by means of oral administration to genetically obese Zucker rats with endogenous hyperlipidemia caused a reduction of the LDL-c levels, of triglycerides, and of the redox state, which demonstrates its cardioprotective power.
Based on the results presented in Example 9 on the induction of the seladin-1/DHCR24 gene in human neuronal lines, the investigators decided to analyze if NST0037 modulated said gene in brains of mice treated with this compound.
In order to carry out this study, 3-month old male C57BL6 mice (n=3/group) were orally treated with 50 mg/kg of simvastatin or NST0037. A control group received only the vehicle, which consisted of 0.25% carboxy methylcellulose in physiological saline. 4 hours after the oral administrations, the animals were sacrificed under gas anesthesia with isoflurane and the brains, previously perfused with PBS, were removed and immediately afterwards frozen in liquid nitrogen. Subsequently, the total RNA of the brain was extracted by means of the High Pure RNA Isolation kit (Roche) and the amount and quality of the RNA were analyzed by means of spectrophotometry (Infinite 200 with NanoQuant, Tecan) and viewing of the 18S and 28S bands by means of electrophoresis. The RT-PCR was performed by means of two steps, first, the mRNA was changed to cDNA using the RNA to cDNA kit (Applied Biosystem) and the gene expression was subsequently analyzed by means of TagMan probes using the validated probes Mn00519071_m1 for seladin-1/DHCR24 and Hs99999901_s1 for 18S (used to normalize the results) in the 7500 Fast Real-Time PCR System equipment (Applied Biosystem). The relative amount of the gene expression was determined by using the ΔΔCt method with the SDS v2.1.1 software (Applied Biosystem); the expression of 18S was used to normalize the measurement.
In summary, the oral treatment with NST0037 in wild-type mice causes an increase of the seladin-1/DHCR24 neuroprotective gene, which furthermore confirms that the compound crosses the blood-brain barrier.
24.1. Analysis of the Survival Rate of Compound NST0037 in Comparison with Simvastatin in Zebrafish Larvae. Acute Toxicity Assay.
To evaluate the biosafety of compound NST0037, its toxicological effects on the zebrafish larvae model were analyzed by means of determining the safety parameters of the OECD C15 protocol.
The fertilized eggs were obtained by natural mating of the zebrafish (Danio rerio, AB strain). A total of 8-10 pairs were used for each cross and a total of 200-250 eggs were generated on average per pair. The eggs were collected immediately after spawning and were washed with dilution water (CaCl2.2H2O2 0.29 g/L, MgSO4.7H2O2 0.12 g/L, NaHCO3 0.065 g/L, KCl 0.006 g/L), the pH being adjusted to 7.8±0.2, in accordance with EC Regulation 440/2008, method C.1, and were deposited in a Petri dish.
The embryos were developed normally until 96 hours post-fertilization in their growth medium. At said time, the larvae were transferred from the Petri dishes to the exposure chambers (M24 microtiter plates) by means of pipettes and exposed to the substances to be tested (NST0037 or simvastatin) with dilution water (controls) or with different concentrations of the treatments. The larvae were incubated without additional aeration, at the suitable temperature (25±1° C.) and under a regimen of 12 hours light/12 hours darkness. Each experiment was performed in triplicate.
The studies were conducted for 24 hours of treatment, thus performing an acute toxicity assay. The treatments conducted followed the following regimen:
After the time of exposure of the substances under study, the record of the mortality of the larvae was determined. Table II shows the analysis of the survival rate of compound NST0037 in comparison with simvastatin in zebrafish larvae. The table shows the number of larvae used for the experiments, the dose in mg/Kg (of weight of the animal), the treatment time and the number of dead larvae with respect to the total.
aEmbryo water
The results of the study showed that both compounds had a similar toxicological profile in terms of the parameter of induction of mortality of zebrafish larvae, no death being observed at any of the doses used.
24.2. Analysis of the Percentage of Healthy Larvae after the Exposure of Compound NST0037 in Comparison with Simvastatin in Larvae. Acute Toxicity Assay.
Based on the previous results, the inventors wished to determine if the absence of mortality recorded by the compound NST0037 was associated with a percentage of healthy larvae equal to or less than that of the treatment with simvastatin. The percentage of healthy larvae was defined as the number of live larvae without symptoms of external physiopathological anomalies (morphological and/or behavioral), the latter being a parameter determining the biosafety of a substance under study and is complementary to the survival rates and to LD50. As shown in
24.3. Analysis of the Percentage of Larvae with Anomalous Appearance (Symptomatology) after the Exposure of Compound NST0037 in Comparison with Simvastatin in Larvae. Acute Toxicity Assay.
Based on the results of the previous sections, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the percentage of larvae with malformations or anomalous appearance, collecting the percentage of larvae showing bodily and/or pigmentary anomalies. The anomalies recorded in the study are described below:
The results indicate that the percentage of larvae with malformations or anomalous appearance is very similar between both compounds, nevertheless, and as shown in
In summary, the treatment with NST0037 in zebrafish larvae in a wide range of concentrations does not cause any mortality, in addition to presenting a higher percentage of healthy larvae and a smaller number of larvae with malformations or anomalous appearance than simvastatin.
25.1. Study of the Variation of the Weight of Adult Zebrafish in a Single-Dose Toxicity Assay (24 Hours) by the Exposure in Water of Compound NST0037 in Comparison with Simvastatin
Based on the results of previous examples, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the variation of the weight of adult zebrafish, by means of a single-dose assay included in the European Medicines Agency (EMEA). This study of the EMEA is about the quality and the amount of the toxic phenomenon caused by the single administration of a substance or combination of substances, in relation to time. These studies report on information of the possible effects of overdoses occurring in humans and can be useful for designing toxicity studies in which repeated doses of administration of the treatment are required.
The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The assay developed has the following study parameters:
In this case, the weight of the animals of the different study groups at three established times: before starting the treatments (0 dpt), at day 7 post-treatment and at day 14 post-treatment, was used as a toxicity parameter.
25.2. Histopathological Study in Adult Zebrafish after a Single-Dose Toxicity Assay (24 Hours) by the Exposure in Water of Compound NST0037 in Comparison with Simvastatin
Based on the results of the previous studies, the inventors decided to investigate if there were differences in the histopathological study of the different treatment groups by means of staining the samples with hematoxylin-eosin, which allows distinguishing pathological marks in the organs or tissues of the animals under study. To that end, the fish were sacrificed at 14 days post-treatment (previously anesthetized) and the samples (whole fish) were included in paraffin. The hematoxylin-eosin staining was subsequently performed in order to conduct the histopathological studies, obtaining a minimum of 6 longitudinal sections per animal, for the purpose of collecting different study areas of the same organ. The following organs were studied: brain, kidney, pancreas, intestine, eye, gills, ovary, testicle, muscle and liver.
In summary, the treatment with NST0037 in adult zebrafish did not modify the weight thereof during a 14-day experiment, whereas with simvastatin a significant reduction of the weight of the animals was detected. Furthermore, simvastatin caused greater histopathological effects than NST0037, demonstrating that the latter compound is safer.
26.1. Lethality Study by the Constant Exposure in Water (4 Days) of NST0037 in Comparison with Simvastatin in Adult Zebrafish.
Based on the results of previous examples, the inventors decided to investigate if the higher biosafety of compound NST0037 in comparison with simvastatin was corroborated by means of the analysis of the lethality by the constant exposure in water for 4 days according to the acute toxicity test for fish of the OECD (Draft Revised Guideline 203). The object of this assay is to determine the acute lethal toxicity of a substance on freshwater fish. Acute toxicity is the distinguishable adverse effect induced in an organism as a result of the exposure to a given substance for a short time period (days). In the present assay, acute toxicity is expressed as mean lethal dose (LD50), i.e., the dose which in water causes the death of 50% of the fish of a batch subjected to assay for a continuous exposure period.
The experiments were conducted strictly following the Guidance on the Operation of Animals (Scientific Procedures, Act. 1986). The assay developed has the following study parameters:
The deaths of the animals under study during the entire time of the assay were recorded as a toxicity parameter.
Table III shows the analysis of the survival rate of compound NST0037 in comparison with simvastatin in adult zebrafish treated for 4 days with the compounds in water. The table shows the number of animals used for the experiments, the dose in mg/Kg (of weight of the animal), the treatment time and the number of dead animals with respect to the total.
aSystem water.
As shown in Table III, the mortality caused by both compounds in this acute toxicity assay surprisingly demonstrate that simvastatin was significantly more toxic than compound NST0037 (χ2, p-value<0.001), since at day 4 post-treatment, 14% ( 1/7) of the animals treated with NST0037 died, the percentage of mortality observed for the group of treatment with simvastatin being 86% ( 6/7). According to what is observed in this study, the LD50 of compound NST0037 was greater than 100 mg/Kg after 4 days of continuous treatment with the compound. Simvastatin had an LD50 of 60.55 mg/Kg after 4 dpt; it was again surprisingly more toxic than compound NST0037, since simvastatin reached the LD50 with fewer doses than NST0037 and in the same time.
26.2. Histopathological Study in Adult Zebrafish after the Lethality Assay by the Constant Exposure in Water (4 Days) of NST0037 in Comparison with Simvastatin in Adult Zebrafish
Based on the results of the previous studies, the inventors decided to investigate if there were differences in the histopathological study of the different treatment groups by means of staining the samples with hematoxylin-eosin, which allows distinguishing pathological marks in the organs or tissues of the animals under study. To that end, the fish that survived the treatment were sacrificed at 4 days post-treatment (previously anesthetized) and the samples (whole fish) were included in paraffin. The hematoxylin-eosin staining was subsequently performed in order to conduct the histopathological studies, obtaining a minimum of 6 longitudinal sections per animal, for the purpose of collecting different study areas of the same organ. The following organs were studied: brain, kidney, pancreas, intestine, eye, gills, ovary, testicle, muscle and liver.
In summary, the treatment with NST0037 in adult zebrafish for 4 days at 100 mg/Kg presented a residual mortality, which was extended in the same conditions with simvastatin. Furthermore, the histopathological damage found was restricted to the ovaries of the animals and were detected at the doses of 32 and 100 mg/Kg for simvastatin, whereas with NST0037 the ovarian damage was only detected at the highest dose, which demonstrates that the latter compound is safer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 09382051.2 | Apr 2009 | EP | regional |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13264167 | Dec 2011 | US |
| Child | 14314807 | US |
