Patent Application
20050090527
The present invention provides methods for treating allergic, non-allergic pulmonary and nasal obstructive disease conditions by administration of histamine receptor antagonist combinations.
Allergic rhinitis, pulmonary inflammation and congestion are medical conditions which may be associated with other medical conditions including asthma, chronic obstructive pulmonary disease (COPD), seasonal allergic rhinitis and perennial allergic rhinitis. In general, these conditions are mediated, at least in part, by inflammation which may be controlled by antagonizing histamine receptors.
Allergic rhinitis, sometime referred to as “hay fever”, is a common illness affecting an estimated 20-40 million Americans, and resulting in 10 million lost days of school or work each year. Two types of allergic rhinitis include seasonal allergic rhinitis and perennial allergic rhinitis. Similarly, congestion, particularly sinus congestion is characterized by inflammation of the tissues in the sinus cavities. Common remedies for rhinitis are “antihistamine” H1 receptor antagonists such as chlorpheniramine maleate.
COPD, asthma and repeated episodes of pulmonary inflammation can lead to alveolar damage and fibrosis which can lead to impaired lung capacity and gas exchange. In general, exposure of the lungs to allergens may lead to mast cell mediated release of histamine and other substances which, in turn, begins a cascade of events leading to inflammation.
U.S. Pat. Nos. 5,217,986 and 5,352,707 to Pomponi et al. attribute an ability for treating conditions including rhinitis and airway congestion to certain compounds apparently having H3 receptor binding activity, but no H1 receptor antagonist activity. No clinical observation or other support is provided for this proposition.
International Patent Application Publication No. WO 02/56871 discloses, generally, the use of a combination of histamine H1 and H4 receptor antagonists for treating allergic disorders and diseases. The publication does not, however, exemplify any particular H1 or H4 receptor antagonists which may be useful for this purpose.
International Patent Application Publication No. WO 98/06394 discloses the use of a combination of histamine H1 and H3 receptor antagonists for treating upper airway allergic responses. The Application does not disclose use of a histamine H4 receptor antagonist.
Further, U.S. Pat. No. 5,869,479 discloses compositions for the treatment of the symptoms of allergic rhinitis using a combination of at least one histamine H1 receptor antagonist and at least one histamine H3 receptor antagonist. The patent does not mention use of an histamine H4 receptor antagonist.
Accordingly, there is a need in the art for an effective method by which to treat or prevent medical conditions such as allergic rhinitis, pulmonary inflammation and congestion by antagonizing histamine receptors such as H1, H3 and H4.
The present invention provides a method for treating or preventing an allergic or non-allergic condition characterized by airway inflammation (e.g., allergic rhinitis, congestion or pulmonary inflammation) in a subject (e.g., a human) comprising administering one or more histamine H3 receptor antagonists, one or more histamine H4 receptor antagonists and, optionally, one or more histamine H1 receptor antagonists to the subject. One or more of the antagonists may be combined with a pharmaceutically acceptable carrier in a pharmaceutical composition (e.g., pill, tablet, capsule). Furthermore, substances which antagonize multiple histamine receptors may be used in the present invention. For example, a subject can be administered one or more dual H3H4 antagonists and, optionally, one or more H1 antagonists.
Also provided are combinations comprising one or more substances which antagonize the histamine H3 receptor, in association with one or more substances which antagonize histamine H4 receptor and, optionally, in association with one or more substances which antagonize histamine H1 receptor as well as pharmaceutical compositions, which comprise a pharmaceutically acceptable carrier, thereof. Pharmaceutical compositions are preferably in the form of a pill, capsule or tablet. Preferred combinations comprise one or more H3 receptor antagonists, in association with one or more H4 receptor antagonists, or, alternatively, one or more dual H3/H4 receptor antagonists, in association with one or more H1 receptor antagonists. Another preferred combination comprises one or more dual H1/H3 antagonists in association with one or more H4 antagonists. Preferred antagonists are discussed, in detail, infra.
Preferably, one or more histamine H3 receptor antagonists are selected from thioperamide, impromidine, burimamide, clobenpropit, impentamine, mifetidine, clozapine, S-sopromidine, R-sopromidine, ciproxifam, SKF-91486 (3-(imidazole-4-yl)-propylguanidine sulfate), GR-175737 (Clitherow, et al., (1996) Bioorg. Med. 6: 833-838), GT-2016 (Tedford, et al., (1995) J. Pharm. Exp. Ther 275(2): 596-604), GT-2331 (Tedford, et al., (1998) Eur. J. Pharmacol. 351(3): 307-11), GT-2394 (Yates, et al., (2000) Soc. Neurosci. Abstr. 26: 279.), JB98064 (Linney, et al., (2000) J. Med. Chem. 43: 2362-2370), UCL-1199 (Ganellin, et al., (1995) J. Med. Chem. 38(17): 3342-50), ABT331440 (PCT Publication No. WO 02/06223),
Preferably, one or more dual histamine H3 receptor/histamine H4 receptor antagonists are selected from
Preferably, one or more histamine H1 receptor antagonists are selected from astemizole, azatadine, azelastine, acrivastine, brompheniramine, cetirizine, chlorpheniramine, clemastine, cyclizine, carebastine, cyproheptadine, carbinoxamine, desloratadine, doxylamine, dimethindene, ebastine, epinastine, efletirizine, fexofenadine, hydroxyzine, ketotifen, loratadine, levocabastine, mizolastine, mequitazine, mianserin, noberastine, meclizine, norasternizole, picumast, pyrilamine, promethazine, terfenadine, tripelennamine, temelastine, trimeprazine, triprolidine and
More preferably, one or more histamine H1 receptor antagonists are selected from loratadine, desloratadine, cetirizine and fexofenadine.
The antagonists of the present invention may be administered to the subject by any mode, such as parenterally or non-parenterally. Furthermore, the antagonists may be administered in a single composition.
The present invention includes methods for administering one or more histamine receptor antagonists for the treatment or prevention of diseases and conditions which are mediated by the histamine receptors (e.g., allergic rhinitis, congestion and pulmonary inflammation, preferably associated with asthma, chronic obstructive pulmonary disease (COPD), seasonal allergic rhinitis and perennial allergic rhinitis). Any antagonist or combination of antagonists which antagonize the histamine H3 receptor, the histamine H4 receptor and, optionally, the histamine H1 receptor may be administered to a subject for the purposes of the present invention. The antagonists can antagonize one or more histamine receptors. For example, a subject can be administered a single substance which antagonizes both a histamine H3 receptor and a histamine H4 receptor (dual H3H4 antagonist) and optionally, an additional histamine H1 receptor antagonist.
The terms “H1” and “H1 receptor” both refer to a histamine H1 receptor. The terms “H3” and “H3 receptor” both refer to a histamine H3 receptor. The terms “H4” and “H4 receptor” both refer to a histamine H4 receptor.
The histamine H1 receptors, histamine H3 receptors and histamine H4 receptors of the invention may be from any organism, preferably a mammal (e.g., horse, dog, cat, rat, mouse, rabbit, horse, pig and guinea pig) and most preferably a human. Genbank Accession No. AY136743 discloses a typical human histamine receptor H1, Genbank Accession No. AB045369 discloses a typical human histamine receptor H3 and Genbank Accession No. NM021624 discloses a typical human histamine receptor H4. Moreover, U.S. Pat. No. 6,204,017 discloses a human histamine H4 receptor in SEQ ID NOs: 1 and 2 (SP9144).
The term “subject” includes any organism, preferably a mammal (e.g., horse, dog, cat, rat, mouse, rabbit, horse, pig and guinea pig) and most preferably a human.
The term “in association with” indicates that the components of the combinations of the invention can be formulated into a single composition for simultaneous delivery or formulated separately into two or more compositions (e.g., a kit). Furthermore, each component of a combination of the invention can be administered to a subject at a different time than when the other component is administered; for example, each administration may be given non-simultaneously at several intervals over a given period of time. Moreover, the separate components may be administered to a subject by the same or by a different route (e.g., orally, intranasally, intravenously).
Histamine H3 receptor antagonists include, without limitation: thioperamide, impromidine, burimamide, clobenpropit, impentamine, mifetidine, clozapine, S-sopromidine, R-sopromidine, ciproxifam, SKF-91486 (3-(imidazole-4-yl)-propylguanidine sulfate), GR-175737 (Clitherow, et al., (1996) Bioorg. Med. 6: 833-838), GT-2016 (Tedford, et al., (1995) J. Pharm. Exp. Ther 275(2): 596-604), GT-2331 (Tedford, et al., (1998) Eur. J. Pharmacol. 351(3): 307-11), GT-2394 (Yates, et al., (2000) Soc. Neurosci. Abstr. 26: 279.), JB98064 (Linney, et al., (2000) J. Med. Chem. 43: 2362-2370), UCL-1199 (Ganellin, et al., (1995) J. Med. Chem. 38(17): 3342-50) and ABT331440 (PCT Publication No. WO 02/06223;
Other exemplary histamine H3 receptor antagonists are set forth, below, in Table 1.
Exemplary, dual H3/H4 receptor antagonists are shown, below, in Table 2.
Preferably, the dual H3/H4 receptor antagonist is selected from compounds comprising a formula selected from formulas 18, 19, 20, 20, 22, 23, 24, 26, 28, 31, 32, 33 and 35.
A H4 receptor antagonist can also be any one or more of those disclosed in Jablonowski et al., J. Med. Chem. 46:3957-3960 (2003), particularly compound 6, and/or compound 10e and/or compound 101 therein.
Numerous chemical substances are known to have histamine H1 receptor antagonist activity. Many useful compounds can be classified as ethanolamines, ethylenediamines, alkylamines, phenothiazines or piperidines. Representative H1 receptor antagonists include, without limitation: astemizole, cetirizine, azatadine, azelastine, acrivastine, brompheniramine, chlorpheniramine, clemastine, cyclizine, carebastine, cyproheptadine, carbinoxamine, desloratadine, doxylamine, dimethindene, ebastine, epinastine, efletirizine, fexofenadine, hydroxyzine, ketotifen, loratadine, levocabastine, mizolastine, mequitazine, mianserin, noberastine, meclizine, norasternizole, picumast, pyrilamine, promethazine, terfenadine, tripelennamine, temelastine, trimeprazine, triprolidine and the compound of formula 36:
Histamine H3 receptor antagonists which are part of the present invention are disclosed in several U.S. patents, applications and publications:
PCT Publication No. WO 02/72570 discloses compounds comprising the following structural formula:
PCT Publication No WO 02/32893 discloses compounds comprising the following structural formula:
U.S. Pat. No. 5,463,074 discloses compounds comprising the following structural formula:
U.S. Pat. No. 5,633,250 discloses compounds comprising the following structural formula:
U.S. Pat. No. 6,034,251 discloses compounds comprising the following structural formula:
U.S. Pat. No. 5,578,616 discloses compounds comprising the following structural formula:
U.S. Pat. No. 5,990,147 discloses compounds comprising the following structural formula:
U.S. Pat. No. 5,807,872 discloses compounds comprising the following structural formula:
Those skilled in the art will appreciate that the total number of substituents on each of the —(C)n— and —(C)p— groups is two, and that such substituents are independently selected from the group consisting of hydrogen, R3 and R4, such that there is a total of only one R3 and one R4 substituent in ring T.
The following PCT Publication discloses H3 antagonists and H1/H3 dual antagonists which may be used in the present invention: PCT Publication No. WO 02/24658 discloses compounds comprising the following formula:
PCT Publication No. WO 02/24659 discloses compounds comprising the following structural formula:
PCT Publication No. WO 02/44141 discloses compounds comprising the following structural formula:
PCT Publication No. WO 02/24657 discloses compounds comprising the following structural formula:
wherein
PCT Publication No. WO 02/72548 discloses compounds comprising the following structural formula:
According to one aspect of the invention, the invention features compounds of the following formula (Ib):
Wherein R1 is Ra, RaRb—, Ra—O—Rb—, or (Rc)(Rd)N—Rb—, where Ra is H, C1-10 alkyl, C3-8 alkenyl, C3-8 cycloalkyl, C2-5 heterocyclic radical, or phenyl; where Rb is C1-8 alkylene, C3-8 alkenylene, C3-8 cycloalkylene, bivalent C3-8 heterocyclic radical, or phenylene; and Rc and Rd are each independently H, C1-8 alkyl, C3-8 alkenyl, C3-8 cycloalkyl, or phenyl;
The present invention comprises compositions comprising an antagonist or a combination of antagonists which antagonize the H3 receptor (e.g., any of the H3 antagonists mentioned herein), the H4 receptor (e.g., any of the H4 antagonists mentioned herein), and, optionally, the H1 receptor (e.g., any of the H1 antagonists mentioned herein) and pharmaceutical compositions thereof.
The ability of any substance to bind to a histamine receptor can be evaluated by using the methods set forth herein (e.g., Examples) or by using the examples set forth in U.S. Pat. No. 6,204,017.
Other antagonists may be, for example, small molecules, nucleic acids (e.g., antisense oligonucleotides which bind to H1, H3 or H4 histamine receptor mRNA), peptides, or antibodies (and antigen-binding fragments thereof) which bind specifically to an H1, H3 or H4 receptor.
The present invention also includes a pharmaceutical composition comprising a histamine H3 receptor antagonist, a histamine H4 receptor antagonist and, optionally, a histamine H1 receptor antagonist along with a pharmaceutically acceptable carrier along with methods for administrating the compositions to treat allergic conditions. The pharmaceutical compositions may be prepared by any methods well known in the art of pharmacy; see, e.g., Gilman et al. (eds.) (1990), The Pharmacological Bases of Therapeutics, 8th Ed., Pergamon Press; and Remington's Pharmaceutical Sciences, supra, Easton, Pa.; Avis et al. (eds.) (1993) Pharmaceutical Dosage Forms: Parenteral Medications Dekker, New York; Lieberman et al. (eds.) (1990) Pharmaceutical Dosage Forms: Tablets Dekker, New York; and Lieberman et al. (eds.) (1990), Pharmaceutical Dosage Forms: Disperse Systems Dekker, New York.
Pharmaceutical compositions containing the antagonists can be prepared using conventional pharmaceutically acceptable excipients and additives and conventional techniques. Such pharmaceutically acceptable excipients and additives include non-toxic compatible fillers, binders, disintegrants, buffers, preservatives, anti-oxidants, lubricants, flavorings, thickeners, coloring agents, emulsifiers and the like. All routes of administration are contemplated including, but not limited to, parenteral (e.g., subcutaneous, intramuscular, intraperitoneal, intravenous), and non-parenteral (e.g., topical, ocular, transdermal, sublingual, inhalation, rectal, oral).
Unit forms of administration include oral forms such as tablets, capsules, powders, cachets, granules and solutions or suspensions, sublingual and buccal forms of administration, aerosols, implants, subcutaneous, intramuscular, intravenous, intranasal, intraocular, subcutaneous or rectal forms of administration.
When a solid composition is prepared in the form of tablets, e.g., a wetting agent such as sodium lauryl sulfate can be added to micronized or non-micronized antagonists and mixed with a pharmaceutical vehicle such as silica, gelatin starch, lactose, magnesium stearate, talc, gum arabic or the like. The tablets can be coated with sucrose, various polymers, or other appropriate substances. Tablets can be treated so as to have a prolonged or delayed activity and so as to release a predetermined amount of active principle continuously or at predetermined intervals, e.g., by using ionic resins and the like.
A preparation in the form of gelatin capsules may be obtained, e.g., by mixing the antagonists with a diluent, such as a glycol or a glycerol ester, and incorporating the resulting mixture into soft or hard gelatin capsules.
A preparation in the form of a syrup or elixir can contain the antagonists together, e.g., with a sweetener, methylparaben and propylparaben as antiseptics, flavoring agents and an appropriate color.
Water-dispersible powders or granules can contain the antagonists mixed, e.g., with dispersants, wetting agents or suspending agents, such as polyvinylpyrrolidone, as well as with sweeteners and/or other flavoring agents.
Rectal administration may be provided by using suppositories which may be prepared, e.g., with binders melting at the rectal temperature, for example cocoa butter or polyethylene glycols.
Parenteral, intranasal or intraocular administration may be provided by using, e.g., aqueous suspensions, isotonic saline solutions or sterile and injectable solutions containing pharmacologically compatible dispersants and/or solubilizers, for example, propylene glycol or polyethylene glycol.
Thus, to prepare an aqueous solution for intravenous injection, it is possible to use a co-solvent, e.g., an alcohol such as ethanol or a glycol such as polyethylene glycol or propylene glycol, and a hydrophilic surfactant such as Tween® 80. An oily, intramuscular injectable solution can be prepared, e.g., by solubilizing the antagonists with a triglyceride or a glycerol ester.
Topical administration can be provided by using, e.g., creams, ointments or gels.
Transdermal administration can be provided by using patches in the form of a multilaminate, or with a reservoir, containing the antagonists and an appropriate solvent.
Administration by inhalation can be provided by using, e.g., an aerosol containing sorbitan trioleate or oleic acid, for example, together with trichlorofluoromethane, dichlorofluoromethane, dichlorotetrafluoroethane or any other biologically compatible propellant gas; it is also possible to use a system containing the antagonists, by themselves or associated with an excipient, in powder form.
The antagonists can also be formulated as microcapsules or microspheres, e.g., liposomes, optionally with one or more carriers or additives.
Implants are among the prolonged release forms which can be used in the case of chronic treatments. They can be prepared in the form of an oily suspension or in the form of a suspension of microspheres in an isotonic medium.
The daily dose of a antagonists can be determined by a clinician and is generally dependent on the potency of the compound administered, the age, weight, condition and response of the subject.
Methods of the present invention may include administration of the antagonists along with, for example, known antihistamine, decongestant or anti-allergy agents. The administration and dosage of such agents is typically as according to the schedule listed in the product information sheet of the approved agents, in the Physicians' Desk Reference 2003 (Physicians' Desk Reference, 57th Ed); Medical Economics Company; ISBN: 1563634457; 57th edition (November 2002), as well as therapeutic protocols well known in the art. For example, histamine antagonists of the present invention can be administered to a patient at a “therapeutically effective dosage”. A therapeutically effective dosage is any dosage which is sufficient to alleviate or prevent the symptoms or physiological effects of allergic or non-allergic airway obstruction including, but not limited to, allergic rhinitis, congestion (e.g., sinus congestion), pulmonary inflammation, acute respiratory distress syndrome, asthma, bronchitis, chronic obstructive pulmonary disease, pulmonary fibrosis, emphysema, respiratory infections and sinus infections to any degree. In one embodiment of the invention, a histamine receptor antagonist of the present invention is administered to a patient or subject in need of such treatment (e.g., a patient or subject suffering from or susceptible to any of the indications mentioned herein) at a dosage of about 5 to about 2000 mg per day or about 50 mg per day to about 1900 mg/day or about 100 mg per day to about 1800 mg/day or about 300 mg per day to about 1600 mg/day or about 500 mg per day to about 1200 mg/day or about 750 mg per day to about 1000 mg/day or about 5 mg per day to about 500 mg per day or about 500 mg per day to about 1000 mg per day or about 1000 mg per day to about 2000 mg per day.
Typical agents which may be included along with the histamine receptor antagonists include glucocorticoids (e.g., mometasone, fluticasone, budesonide), Non-steroidal anti-inflammatory drugs (NSAIDs) (e.g., COX2 inhibitors (e.g, rofecoxib, celecoxib) ibuprofen, naproxen), leukotriene receptor antagonists (e.g., montelukast sodium), M3 antagonists (e.g., ipratropium, tiotropium) and antibiotics (e.g., penicillin, amoxicillin, ampicillin, methicillin).
The histamine receptor antagonists of the invention along with any additional agents (discussed above) may be formulated together into a single composition or into two or more separate compositions for simultaneous consumption. Alternatively, for example, an H1 antagonists may be administered to a subject at a different time than when the H3 and H4 antagonists are administered; for example, each administration may be given non-simultaneously at several intervals over a given period of time.
The compositions of the present invention can be used to treat or prevent medical conditions characterized by allergic or non-allergic airway obstruction including, but not limited to, allergic rhinitis, congestion (e.g., sinus congestion), pulmonary inflammation, acute respiratory distress syndrome, asthma, bronchitis, chronic obstructive pulmonary disease, pulmonary fibrosis, emphysema, respiratory infections and sinus infections.
Clinical symptoms of seasonal allergic rhinitis typically include nasal itching and irritation, sneezing and watery rhinorrhea, frequently accompanied by nasal congestion. The perennial allergic rhinitis clinical symptoms are similar, except that nasal blockage may be more pronounced. Either type of allergic rhinitis may also cause other symptoms such as itching of the throat and/or eyes, epiphora and edema around the eyes. These symptoms may vary in intensity from the nuisance level to debilitating. Other types of rhinitis present similar symptoms. In addition to other processes, allergic rhinitis involves the release of histamine (e.g., from mast cells) which is a mediator in immediate hypersensitivity reactions.
Congestion, particularly sinus congestion, involves blockage of one or more of the four pairs of sinus passageways in the skull. The blockage may result from inflammation and swelling of the nasal tissues or from secretion of mucus. It may be acute or chronic. Acute sinus congestion is most often caused by the common cold. Chronic sinus congestion may result from environmental irritants such as tobacco smoke, food allergens, inhaled allergens, or foreign bodies in the nose. Sinus congestion leads to impaired flow of fluids in the sinuses, which predisposes individuals to bacterial infections that can cause sinusitis.
Pulmonary inflammation is a condition which is often characterized by wheezing and shortness of breath. When the lungs are exposed to allergens (e.g., particulate matter, automobile exhaust or pollen) and pathogens (e.g., Pseudomonas aeruginosa) pulmonary inflammation often occurs.
Adult (acute) respiratory distress syndrome (ARDS) is a condition characterized by pulmonary inflammation. In general, ARDS results in the rapid onset of progressive malfunction of the lungs, especially with regard to the ability to take in oxygen, usually associated with the malfunction of other organs. The condition is associated with extensive pulmonary inflammation and small blood vessel injury in all affected organs.
The fundamental pathophysiologic entity resulting in the clinical disease of asthma is airway inflammation. Histological findings in the asthmatic airway may include bronchial occlusion with mucous and cellular debris, denudation of the epithelial layer, edema and inflammatory infiltrate in the submucosa, mucous gland hypertrophy, and bronchial smooth muscle hypertrophy.
The methods and compositions of the present invention may also be used to treat chronic bronchitis, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, emphysema and sinus and respiratory infections.
The present invention also provides kits comprising the components of the combinations of the invention in kit form. A kit of the present invention includes one or more components including, but not limited to, one or more histamine H3 antagonists, for example, as discussed herein, in association with one or more histamine H4 receptor antagonists, for example, as discussed herein and, optionally, in association with one or more histamine H1 receptor, for example, as discussed herein. The antagonists can be formulated as a pure composition or in combination with a pharmaceutically acceptable carrier, in a pharmaceutical composition.
In one embodiment, a kit includes one or more histamine H3 antagonists, or a pharmaceutical composition thereof, in one container (e.g., in a sterile glass or plastic vial), one or more histamine H4 antagonists, or a pharmaceutical composition thereof, in another container (e.g., in a sterile glass or plastic vial) and, optionally, one or more histamine H1 antagonists, or a pharmaceutical composition thereof, in another container (e.g., in a sterile glass or plastic vial).
In another embodiment of the invention, the kit comprises a combination of the invention, including one or more histamine H3 antagonists along with one or more histamine H4 antagonists and, optionally, one or more histamine H1 antagonists formulated together, optionally, along with a pharmaceutically acceptable carrier, in a pharmaceutical composition, in a single, common container.
If the kit includes a pharmaceutical composition for parenteral administration to a subject, the kit can include a device for performing such administration. For example, the kit can include one or more hypodermic needles or other injection devices.
The kit can include a package insert including information concerning the pharmaceutical compositions and dosage forms in the kit. Generally, such information aids patients and physicians in using the enclosed pharmaceutical compositions and dosage forms effectively and safely. For example, the following information regarding a combination of the invention may be supplied in the insert: pharmacokinetics, pharmacodynamics, clinical studies, efficacy parameters, indications and usage, contraindications, warnings, precautions, adverse reactions, overdosage, proper dosage and administration, how supplied, proper storage conditions, references, manufacturer/distributor information and patent information.
The following examples are provided to further describe the present invention and should not be construed to limit the scope of the present invention.
The following examples make reference to standard methods known to those skilled in the art which may be performed, as described, e.g., in Maniatis, et al., Molecular Cloning: A Laboratory Manual, 1982, Cold Spring Harbor Laboratory, Cold Spring Harbor Press; Sambrook, et al., Molecular Cloning: A Laboratory Manual, (2d ed.), Vols 1-3, 1989, Cold Spring Harbor Press, NY; Ausubel, et al., Biology, Greene Publishing Associates, Brooklyn, N.Y.; or Ausubel, et al., (1987 and Supplements), Current Protocols in Molecular Biology, Greene/Wiley, New York; Innis, et al., (eds.) PCR Protocols: A Guide to Methods and Applications, 1990, Academic Press, N.Y.
In this example, the ability of several compounds to compete against radiolabeled histamine for binding to membrane-bound human histamine H4 receptor is evaluated. The histamine H4 receptor used in this assay is SP9144 which is set forth in SEQ ID NOs: 1 and 2 of U.S. Pat. No. 6,204,017.
Membrane preparation. Forty-eight hours after transfection with plasmid containing the sequence for SP9144, HEK293 cells were harvested from T150 flasks by incubating 5 minutes in 5 ml of 5 mM EDTA/Hanks' balanced salt solution followed by repeated pipeting. They were centrifuged 5 minutes at 1000×g. The EDTA/PBS was decanted and an equal volume of ice-cold 50 mM Tris-HCl, pH 7.5, was added and cells were broken up with a Polytron (PT10 tip, setting 5, 30 seconds). Nuclei and unbroken cells were sedimented at 1000×g for 10 minutes and then the supernatant was centrifuged at 50,000×g for 10 minutes. The supernatant was decanted, the pellet was resuspended by Polytron, a sample was taken for protein assay (bicinchoninic acid, Pierce; Rockford, Ill.), and the tissue was again centrifuged at 50,000×g. Pellets were stored frozen at −20° C.
Binding assay. For saturation binding, four concentrations of [3H]-histamine (15 Ci/mmol, Dupont NEN; Boston, Mass.) were incubated without and with 10−5 M histamine in triplicate with 50 μg of membrane protein in a total volume of 200 μl of 50 mM Tris-HCl, pH 7.5, for 30 minutes at 30° C. Samples were filtered on GF/B filters and washed thrice with 2 ml of cold Tris buffer. Filters were dried in a microwave oven, impregnated with Meltilex wax scintillant, and counted at 45% efficiency.
Competition binding assays. Five concentrations of compounds were incubated in triplicate with 18 nM [3H]-histamine and 70 μg of membrane protein under conditions as described above.
Curves were fit to the data with Prism (GraphPad Software) nonlinear least-squares curve-fitting program and Ki values were derived from IC50 values according to Cheng and Prusoff (Cheng, et al., (1973) Biochem. Pharm. 22:3099-3108). The data generated in these experiments is shown, below, in Table 3.
1Standard error of the mean
The methods set forth in this example may be adapted to evaluate the ability of other substances to antagonize histamine H4 receptors.
Methods by which compounds can be evaluated to determine activity at histamine H3 receptors include the guinea pig brain membrane assay and the guinea pig neurogenic ileum contraction assay, both of which are described in U.S. Pat. No. 5,352,707. Another useful assay utilizes rat brain membranes and is described by West, et al., (1990) Molecular Pharmacology 38: 610-613.
A particularly useful screening assay measures binding to sites in guinea pig brain membranes. This test is described in detail by Korte, et al., (1990) Biochem. Biophys. Res. Comm. 168: 979-986, and quantifies the inhibition of radiolabeled Nα-methylhistamine binding to tissues by candidate compounds.
Affinity values (Ki) may be determined using the following formula: Ki=IC50/(1+(concentration of ligand/affinity (KD) of radioligand)) The method of Korte, et al (supra) was used to analyze thioperamide and clobenpropit. The results are set forth below in Table 4 (see also WO 98/06394):
In the present example, the affinities of several compounds for the H1, H3 and H4 receptors was determined by a membrane binding assay.
Materials. Rat and guinea-pig brains were obtained frozen from Rockland Immunochemicals (Gilbertsville, Pa.). Cell lines expressing recombinant human receptors were generated by using standard transfection techniques. The following radioligands were obtained from Dupont NEN (Boston, Mass.): [3H]-pyrilamine, 23 Ci/mmol, for H1 binding; [3H]-N′-methylhistamine, 82 Ci/mmol, for H3 binding and [3H]-histamine, 20 Ci/mmol, for H4 binding.
Methods. Recombinant cell lines (i.e., human H1-CHO cells, human H3-HEK293 and human H4-HEK293 cells) were cultured in Dulbecco's modified Eagle's medium/10% fetal bovine serum supplemented with 2 mM glutamine, penicillin (100 U/ml), and streptomycin (100 μg/ml) in a humidified 5% CO2 atmosphere at 37° C. Selection was maintained with 0.5 mg geneticin/ml. Cells were harvested for membrane preparation by aspirating media, replacing it with Hanks' balanced salt solution/5 mM EDTA, and incubating flasks for 10 minutes at 37° C. Cells were pelleted by centrifugation at 1000×g for ten minutes at 4° C.
Membrane preparation. Membranes were prepared by disrupting cells or tissue in at least ten volumes of ice-cold 50 mM Tris-HCl, pH 7.5 at 25° C., with a Polytron. homogenates were centrifuged ten minutes at 1000×g and the supernatants were then centrifuged for ten minutes at 50,000×g. Pellets from this centrifugation step were resuspended with a Polytron, a sample was taken for protein determination (BCA; Pierce; Rockford, Ill.), and the resuspension was again centrifuged at 50,000×g. Brain membranes were stored as pellets, cell membranes as suspensions of 1 mg protein/ml Tris buffer at −20° C.
Binding assays. Membrane (300 μg of brain membrane protein, 5-10 μg of recombinant cell membrane) was incubated with radioligand at a concentration near its KD value without or with inhibitor compounds in a total volume of 200 μl Tris buffer. Nonspecific binding was determined in the presence of 10−6 M chlorpheniramine for H1 binding, 10−6 M clobenpropit for H3 binding, or 10−5 M thioperamide for H4 binding. Assay mixtures were incubated for 30 minutes at 30° C. in polypropylene, 96-well, deep-well plates then filtered through 0.3% polyethylenimine-soaked GF/B filters. These were washed three times with 1.2 ml of Tris buffer, dried in a microwave oven, impregnated with Meltilex wax scintillant and counted at 40% efficiency in a Betaplate scintillation counter (Wallac). IC50 values were determined by interpolation or by nonlinear, least-squares, curve-fitting with the Prism program (GraphPad Software). Ki values were determined in the manner of Cheng and Prusoff (Cheng, et al., (1973) Biochem. Pharm. 22:3099-3108).
The data generated in these experiments are shown, below, in Table 5.
The methods in the foregoing examples can easily be adapted to determine whether any other substance binds to a histamine H1, H3 or H4 receptor.
The following example demonstrates the ability of a compound comprising formula 19 (i.e.,
) to reduce the lipopolysaccharide (LPS)-induced inflammatory response in rat airways.
Male Sprague-Dawley rats (250-300 g) were anesthetized by inhalation of isoflurane (flow rate 1 ml/min; supplemented with O2). Using a Penn-Centry microspray needle, 0.1 ml of a 100-μg/ml LPS solution in saline was injected into the trachea. Animals not challenged with the LPS solution received 0.1 ml of saline. Animals were placed on a heat pad until they recovered from anesthesia. Afterward, they were returned to their cages and allowed food and water ad libitum. All animals survived these manipulations and no additional interventions were required to ensure their survival. Animals fasted overnight were orally dosed with either the standard PD4 inhibitor and positive-control, SB207499 (c4-cyano-4-(3-cyclopentyloxy-4-methoxy-phenyl)-r-1-cyclohexanecarboxylic acid; Barnette, et al., (1998) J. Pharm. Exp. Ther. 284: 420-426), the compound of formula 17 or vehicle as a negative-control (0.4% methylcellulose) five hours before the LPS challenge.
At appropriate time points after intratracheal challenge with LPS, animals were surgically prepared with a tracheal cannula. Surgery was performed under anesthesia. The airways were flushed with 2×2 ml of 0.9% saline and the two washings pooled. Lavage fluid was centrifuged (350 g, 4° C., 7 minutes), supernatant aspirated, erythrocytes lysed, and pellet washed in phosphate-buffered saline containing 10% heat-inactivated fetal calf serum and 10 μg/ml DNase I. The cell suspension was centrifuged, supernatant aspirated, and pellet resuspended in the same buffer. Total cell counts were performed using a Nebauer hemacytometer. Differential cell counts were conducted on Cytospin-prepared slides stained with Fisher's Leukostat stain. At least 200 cells were assessed per slide and standard morphological criteria were used to define neutrophilic cells.
The total number of cells and the number of neutrophils in the broncheoalveolar lavage (BAL) recovered from rats treated with the compound of formula 17, SB207499 or a blank were counted and compared. Fewer cells (i.e., neutrophils or total cells) were counted in the BAL of LPS-challenged rats treated with the compound of formula 17 or with SB207499 than that of rats treated with a blank. The formula 17-dependent and SB207499-dependent inhibition of cellular influx into the BAL indicates that these compounds inhibit the pulmonary inflammation response induced by LPS. The cells identified in the BAL were primarily neutrophils indicating that the inflammatory response induced by LPS was primarily a neutrophilic inflammatory response. The data from these experiments is set forth below in Tables 6 and 7.
The experiments set forth in this example could easily be adapted to test the ability of any other compound or combination of compounds to inhibit pulmonary inflammation.
The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims.
Patents, patent applications, publications, product descriptions, and protocols are cited throughout this application, the disclosures of which are incorporated herein by reference in their entireties for all purposes.
This application claims the benefit of U.S. Provisional Patent Application No. 60/443,207, filed Jan. 28, 2003, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60443207 | Jan 2003 | US |
