Diabetes mellitus is a group of metabolic disorders characterized by chronic high blood glucose condition [1,2]. Two main types of diabetes mellitus are Type 1 diabetes and Type 2 diabetes. In contrast, Type 1 diabetes affects approximately 5% of all patients diagnosed with diabetes. Type 1 diabetes accounts for up to 90% of diabetes in children and adolescents. Type 1 diabetes is a consequence of impaired insulin production due to a loss of pancreatic β cells. Type 1 diabetes is also known as insulin-dependent diabetes mellitus or juvenile diabetes. In contrast, Type 2 diabetes affects approximately 95% of all patients diagnosed with diabetes. Patients with Type 2 diabetes are mostly adults who experience insulin resistance, a condition in which cells of the body do not respond properly to insulin. Type 2 diabetes is commonly a consequence of overweight, smoking, and insufficient exercise. Type 2 diabetes is also known as non-insulin-dependent diabetes mellitus or adult-onset diabetes. Signs and symptoms of both types of diabetes mellitus include increased thirst, frequent urination, extreme hunger, fatigue, blurred vision, and frequent infections. Long-term complications of diabetes mellitus include cardiovascular disease, stroke, neuropathy, nephropathy, retinopathy, foot ulcer, and cognitive impairment. In 2018, approximately 10.5% of the US population, or 34.1 million people of all ages, had diabetes. The total cost for diabetes management in the US was estimated to be $327 billion in 2017.
Management of Type 1 diabetes requires insulin injection to lower blood glucose level [3]. In contrast, management of Type 2 diabetes involves weight management and glycemic control with lifestyle modifications and medications [4]. The first line of defense against Type 2 diabetes includes the maintenance of a healthy bodyweight via a healthy diet, regular physical exercise, and the cessation of smoking. In addition, anti-diabetes and anti-obesity medications can be prescribed. Anti-diabetes therapies using insulin, sulfonylurea and thiazolidinediones lower blood glucose level but lead to weight gain. Alternatively, anti-diabetes therapies using alpha-glucoside inhibitors, amylin mimetics, metformin, GLP-1R agonists, DPP-4 inhibitors and SGLT2 inhibitors are not associated with weight gain. Furthermore, a number of anti-obesity therapies are approved for weight management including orlistat, liraglutide, lorcaserin, phenteramine-topiramate ER, and naltrexone-bupropion XR. However, current anti-obesity and anti-diabetes therapies are frequently associated with adverse side effects, which limit their long-term usage for weight management and glycemic control [5].
In the management of diabetes, insulin therapy is positively correlated with glycemic control and weight gain. Weight gain in diabetic patients is associated with hyperlipidemia, hypertension, and deterioration of β-cell function. Thus, any insulin therapy or diabetic medication that can provide glycemic control without weight gain is highly desirable. Many approved anti-diabetic pharmaceutical agents are associated with adverse effects, which limit their long-term usage for diabetes care. Thus, there is an unmet need for formulations that can effectively manage diabetes without causing weight gain.
Herein, we describe a novel approach for rational combination of phytonutrients for diabetes management. Anti-diabetic phytonutrients, or natural compounds found in plants, are generally recognized as safe for long-term diabetes care. Phytonutrients in plants and mushrooms have anti-obesity and anti-diabetes effects by modulating physiological pathways that regulate appetite, metabolism, lipid absorption, insulin sensitivity, thermogenesis, and gut microbiota [6]. Consumption of phytonutrients is generally considered as a safe, widely available and inexpensive approach to manage obesity and diabetes. The disclosure herein identifies phytonutrients and combinations thereof that promote insulin sensitivity and have weight-loss potentials.
The present disclosure relates to novel compositions of phytonutrients and methods of treating diabetes by administering these compositions to subjects in need thereof. The compositions described herein are rationally designed compositions of phytonutrients that promote insulin sensitivity and have weight-loss potential.
The compositions include formulation of rationally combined phytonutrients for diabetes treatment and management. Using nanofluidic proteomics, phytonutrients were classified as insulin sensitizing or anti-adipogenic based on their ability to enhance insulin-stimulated Akt2 phosphorylation and glucose uptake or inhibit adipogenesis, respectively. In some embodiments, the formulation includes a synergistic amount of insulin-sensitizing phytonutrients cinnamaldehyde and curcumin.
The formulation of rationally combined phytonutrients exhibit unique properties of providing glycemic control without weight gain that are distinct from those of individual phytonutrients. The formulations of rationally combined phytonutrients disclosed herein may improve glucose tolerance, reduce HbAlc, prevent weight gain, reduce blood lipid level, and/or suppress liver steatosis.
In one aspect, the compositions disclosed herein may include any combination of phytonutrients cinnamaldehyde, curcumin, and berberine. For example, the combination of phytonutrients may be (1) cinnamaldehyde and curcumin; (2) cinnamaldehyde and berberine; (3) curcumin and berberine; or cinnamaldehyde, curcumin, and berberine. In a particular embodiment, the composition may include a synergistic amount of cinnamaldehyde and curcumin, and additionally include an effective amount of berberine.
In another aspect, the invention relates to methods of treating or managing diabetes comprising administering a therapeutically effective amount of the compositions disclosed herein. In some embodiments, diabetes is treated with minimal or no weight gain by the subject.
The compositions disclosed herein may further improve glucose tolerance, reduce HbAlc, prevent weight gain, reduce blood lipid level, and/or suppress liver steatosis.
Using nanofluidic proteomics, phytonutrients were screened and classified as either insulin sensitizing or anti-adipogenic. Phytonutrients cinnamaldehyde and curcumin were identified as insulin-sensitizing phytonutrients by their ability to promote pAkt2 (Thr450) phosphorylation, enhance insulin-stimulated pAkt2 (Ser473) phosphorylation, and increase glucose uptake in primary human preadipocytes. In addition, nine phytonutrients were identified, including berberine, as non-insulin sensitizing and anti-adipogenic phytonutrients. The combination of insulin-sensitizing and anti-adipogenic phytonutrients comprising cinnamaldehyde, curcumin, and berberine enhanced insulin-stimulated glucose uptake and inhibited adipogenesis in human primary preadipocytes. This combination was named the F2 formulation. In an animal model of diet-induced obesity and diabetes, the data shows that dietary supplementation with F2 formulation improved glucose tolerance, reduced HbAlc, prevented weight gain, reduced blood lipid level, and suppressed liver steatosis. Collectively, the proteomic method disclosed herein was used to identify insulin-sensitizing phytonutrients and a platform for the rational combinations of insulin-sensitizing and anti-diabetic phytonutrients. Furthermore, the therapeutic potential for the F2 formulation to provide glycemic control without weight gain for long-term diabetes care was demonstrated.
Insulin-Sensitizing Phytonutrients. The serine/threonine protein kinase B, also known as Akt, regulates many critical cellular processes including the canonical insulin-signaling cascade of IR/IRS/PI3K/Akt [7]. The Akt kinase family comprises three highly homologous isoforms of Akt1, Akt2 and Akt3, which exhibit distinctive functional specificity and tissue distribution [8]. Whereas Akt1 regulates cell growth, survival, and migration; Akt2 regulates glucose metabolism; and Akt3 regulates cell volume and ion homeostasis and neuronal development. Using a patented nanofluidic proteomics platform, phytonutrients were screened for their effects on the post-translational modifications of Akt2. Two phytonutrients were identified, cinnamaldehyde and curcumin, as insulin sensitizers. Both cinnamaldehyde and curcumin promoted Akt2 phosphorylation and glucose uptake in primary human preadipocytes. The experimental approaches are described below.
Mapping Akt Isoforms Using Capillary Isoelectric Focusing (cIEF) Immunoassays. cIEF immunoassays separate proteins in total cell extracts (TCEs) by their isoelectric points (pIs) in nano-capillaries. The positions of the proteins are stabilized via UV-irradiated crosslinking of proteins to the sidewalls of the capillaries. A primary antibody that recognizes a specific protein of interest is introduced to individual capillaries. Then a secondary antibody linked to horseradish peroxidase is introduced. Following the introduction of the chemiluminescent substrates, the distribution of the isoforms of a protein is detected and presented graphically as electropherograms of intensity versus isoelectric points. Phosphorylation and acetylation of a protein generally leads to shifts toward lower pI values. In contrast, glycosylation of a protein generally leads to a shift toward higher pI values.
Identification of Akt Isoforms on cIEF Electropherograms. Using primary antibodies specific to Akt1, Akt2, or Akt3, these Akt isoforms can be identified in individual nano-capillaries.
Insulin Promotes Akt Phosphorylation. Following the treatment of human primary preadipocytes with 100 nM insulin for 30 minutes, cIEF electropherograms of Akt isoforms and phosphorylated isoforms were examined and compared to those without insulin treatment. Surprisingly, the cIEF electropherograms of Akt1 isoform were nearly identical before and after insulin treatment (
Cinnamaldehyde Selectively Promotes pAkt (Thr450) Phosphorylation. Following a screen of over 50 phytonutrients, cinnamaldehyde, was identified as an insulin sensitizer. Cinnamaldehyde is a principal constituent of cinnamon bark essential oil. Cinnamaldehyde gives cinnamon its flavor and aroma. Treatment of human primary preadipocytes with cinnamaldehyde had no observable effect on the electropherogram of Akt1 or Akt3 isoforms (
Cinnamaldehyde Promotes Insulin-Stimulated pAkt2 (Ser473) Phosphorylation. Treatment of human primary preadipocytes with insulin together with cinnamaldehyde had no observable effect on the phosphorylation of Akt1 (
In addition to cinnamaldehyde, curcumin was identified as another insulin sensitizer (Table 1). Curcumin is a principal curcuminoid of turmeric. Like cinnamaldehyde, treatment of human primary preadipocytes with curcumin also induced a new peak at pI 5.41 on the Akt2 electropherogram (
Cinnamaldehyde and Curcumin Synergize to Promote Insulin-Stimulated pAkt2 (Ser473) Phosphorylation.
Similar to cinnamaldehyde, curcumin also promoted insulin-stimulated pAkt2 (Ser473) phosphorylation (
The synergy between curcumin and cinnamaldehyde to promote insulin-stimulated pAkt2 (Ser473) phosphorylation was further observed with glucose uptake by preadipocytes. The glucose uptake assay used 2-NBDG, a fluorescently-labeled deoxyglucose analog, as a probe for the detection of glucose taken up by human primary preadipocytes. Flow cytometry was used to detect 2-NBDG uptake in single preadipocytes. Insulin treatment together with either cinnamaldehyde or curcumin individually increased glucose uptake by preadipocytes by approximately 1.6 and 1.7 folds, respectively, compared to insulin treatment alone (
Nine anti-adipogenic and non-insulin sensitizing phytonutrients using human primary preadipocytes were identified (Table 2). The anti-adipogenecity of these phytonutrients was recognized. In addition, these phytonutrients also met the following selection criteria: (1) had no effect on pAkt (Thr450) phosphorylation; (2) did not interfere with the effects of cinnamaldehyde or curcumin on pAkt (Thr450) phosphorylation; (3) did not interfere with the effects of insulin-stimulated phosphorylation of pAkt2 (Ser473) or glucose uptake; and (4) did not interfere with the synergy between cinnamaldehyde, curcumin, and insulin on the promotion of pAkt2 (Ser473) phosphorylation or glucose uptake.
The combination of cinnamaldehyde, curcumin, and berberine, also known as F2 formulation, was capable of enhancing insulin sensitivity while inhibiting fat cell differentiation. Berberine, a strong inhibitor of adipogenesis, did not interfere with the insulin sensitizing capability of cinnamaldehyde or curcumin (
The therapeutic effects of F2 for obesity prevention were evaluated using a DIO mouse model (
At 16th week, glucose tolerance tests were performed for all mice after 16 hours of overnight fasting (
At 17th week, blood and tissue samples were terminally collected from all mice and measured for triglyceride, total cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol. The average triglyceride levels were 85 mg/dL, 128 mg/dL, and 94 mg/dL for mice fed with a lean diet, a high-fat diet, and a high-fat diet supplemented with F2, respectively (
Terminally collected liver and visceral adipose tissues were sent to IHC World (Woodstock, Md.) for hematoxylin & eosin (H&E) histology preparation. H&E histology revealed an average diameter of lipid droplets of visceral adipocytes that was 2 times higher for mice fed with a high-fat diet compared to those fed with a lean diet (
Using nanofluidic proteomics, phytonutrients were classified as insulin sensitizing or anti-adipogenic based on their ability to enhance insulin-stimulated Akt2 phosphorylation and glucose uptake or inhibit adipogenesis, respectively. In one aspect, insulin sensitizing phytonutrients (Table 1) were identified by their unique ability to induce the formation of a new peak at pI 5.41 on the Akt2 cIEF electropherogram, which was attributed to increased pAkt2 (Thr450) phosphorylation. In general, phosphorylation of pAkt2 (Thr450) primes Akt2 for insulin-stimulated phosphorylation at pAkt2 (Thr308) and pAkt2 (Ser473), which fully activates Akt2 [10]. Insulin-sensitizing phytonutrients cinnamaldehyde and curcumin synergized to increase the peak intensity at pI 5.41 on Akt2 cIEF electropherogram, which indicates increased pAkt2 (Thr450) phosphorylation. In addition, cinnamaldehyde and curcumin synergized to enhance insulin-stimulated phosphorylation at pAkt2 (Ser473) by nearly 7 folds and glucose uptake by 2.3 folds compared to insulin alone. In another aspect, anti-adipogenic phytonutrients are non-insulin sensitizing and strong suppressors of adipogenesis (Table 2). Anti-adipogenic phytonutrients did not interfere with insulin signaling or the activities of insulin-sensitizing phytonutrients. In human primary preadipocytes, a combination of insulin-sensitizing and anti-adipogenic phytonutrients comprising cinnamaldehyde, curcumin, and berberine was capable of enhancing glucose uptake while inhibiting adipogenesis. The combination of cinnamaldehyde, curcumin, and berberine was named F2 formulation. In an animal model of diet-induced obesity and diabetes, dietary supplementation with F2 formulation improved glucose tolerance, reduced HbAlc, prevented weight gain, reduced blood lipid level, and suppressed liver steatosis. In summary, a proteomic method was used to identify insulin-sensitizing phytonutrients and a platform for the rational combinations of insulin-sensitizing and anti-diabetic phytonutrients. Furthermore, the therapeutic potential for the F2 formulation to provide glycemic control without weight gain for long-term diabetes care was demonstrated.
Human Primary Preadipocytes. Primary human preadipocytes were isolated from omental adipose tissues overweight and diabetic donors who were undergoing elective surgery using a previously published protocol [11]. Primary human preadipocytes were maintained in growth media comprising Minimum Essential Medium a supplemented with 10% fetal bovine serum, 100 units/ml penicillin, and 100 μg/ml streptomycin.
Screening for Insulin-Sensitizing Phytonutrients. Primary human preadipocytes were treated for 30 minutes with 100 nM insulin (Humulin R, Eli Lilly, Indianapolis, Ind.), individual phytonutrients (Table 1 & Table 2), or combinations of insulin and phytonutrients. Total cell extracts (TCE) were collected and subjected to nanofluidic proteomic analysis including capillary isoelectric focusing (cIEF) immunoassays and capillary Western (CW) immunoassays.
Preparation of Total Cell Extracts. Approximately one million cells were incubated on ice for 10 minutes with 60 μl of lysis buffer (cat. no. 040-764, ProteinSimple, Santa Clara, Calif., USA), sonicated 4 times for 5 seconds each, mixed by rotation for 2 hours at 4° C., and centrifuged at 12,000 rpm in an Eppendorf 5430R microfuge for 20 minutes at 4° C. The supernatant was collected as the cell lysate. The total protein concentration in the cell lysate was determined with a Bradford protein assay and adjusted to a final concentration of 0.3 μg/μl with separation gradients (cat. no. Premix G2, pH 5-8, ProteinSimple, Santa Clara, Calif.) for charge-based cIEF immunoassays or to 0.4 μg/μl with denaturing buffers (cat. no. PS-ST01EZ or PS-ST03EZ, ProteinSimple) for size-based Western immunoassays.
Capillary Isoelectric Focusing Immunoassays. Cell lysates in separation gradients were loaded into 384-well assay plates (cat. no. 040-663, ProteinSimple) preloaded with primary and secondary antibodies and chemiluminescent substrates. Charge-based protein separation and detection in individual capillaries were performed using the default protocols of the NanoPro 1000 system (ProteinSimple). Hsp70 was used as the loading control. All cIEF immunoassays were performed in triplicate for each protein, and duplicate experiments were performed for each treatment condition, producing six repeated measurements per protein.
Capillary Western Immunoassays. Cell lysates in denaturing buffers were denatured at 95° C. for 5 minutes, and then transferred to assay plates (cat. no. SM-W004 or SM-W008, ProteinSimple) preloaded with blocking reagents, wash buffer, primary and secondary antibodies, and chemiluminescent substrates. Sized-based protein separation and detection in capillaries were performed using the default protocols of the Jess system (ProteinSimple). β-Actin was used as loading controls. All capillary Western immunoassays were performed in triplicate for each protein, and duplicate experiments were performed for each treatment condition, producing six repeated measurements per protein.
Glucose Uptake Assays. Primary human preadipocytes grown to 70% confluence in growth media, washed with phosphate buffered saline, and replaced with glucose-free DMEM media. Following 2 hours of incubation in glucose-free DMEM media, preadipocytes were treated with 100 μg/ml of 2-NDBG fluorescent glucose analog and insulin (100 nM) or phytonutrients (EC50) for 30 minutes. Preadipocytes were collected and analyzed using the Acuri C6 flow cytometer (BD Biosciences, San Jose, Calif.) and the 485 nm excitation and 535 nm emission filters.
Adipogenesis Assays. Primary human preadipocytes were grown to confluence in growth media. At 2 days post-confluence, growth media were aspirated off the culture dishes and complete differentiation media were added. Complete differentiation media comprise DMEM/F22 with 18.5 mM glucose, HEPES (15 mM), NaHCO3 (25 mM), 100 units/ml penicillin, 100 μg/ml streptomycin, d-biotin (33 μM), pantothenate (17 μM), dexamethasone (100 nM), insulin (100 nM), rosiglitazone (1 μM), IBMX (0.5 mM), triiodothyronine (T3, 2 nM), and transferrin (10 μg/ml). On day three post-differentiation, complete differentiation media were replenished. On day seventh post-differentiation, complete differentiation media were replaced with maintenance media. Maintenance media comprise DMEM/F22, 100 units/ml penicillin, 100 μg/ml streptomycin, HEPES (15 mM), NaHCO3 (25 mM), d-biotin, pantothenate, insulin (10 nM), and dexamethasone (10 nM). Maintenance media were replenished on days tenth post-differentiation. Complete differentiation of preadipocytes into adipocytes were achieved on day fourteenth post-differentiation. To screen for anti-adipogenic phytonutrients, individual phytonutrients were mixed in complete differentiation media from day 0 to day 6th post-differentiation. Phytonutrients were removed together with complete differentiation media on day 7th post-differentiation following the replacement with maintenance media. Anti-adipogenic phytonutrients were identified based on their ability to: (1) suppress the expression of adipogenic biomarkers using proteomic assays of total cell extracts collected on day 6th post-differentiation, and (2) suppress intracellular lipid droplet accumulation using Oil Red O staining assays on day 14th post-differentiation.
Antibodies. The antibodies used are listed in Table 3.
F2 Formulation. F2 formulation is a combination of three phytonutrients cinnamaldehyde, curcumin, and berberine. For tissue cultures, F2 formulation is the combination of cinnamaldehyde, curcumin, and berberine at the final concentrations of 8 μM, 4 μM, and 2 μM, respectively. For animal studies, F2 formulation is the combination of cinnamaldehyde, curcumin, and berberine at 1:1:1 weight ratio. F2 is supplemented to the diet at 0.1% by weight, leading to an approximately daily dose of 200 mg/kg for mice, or approximately 16 mg/kg of human equivalent dose.
DIO Animal Model. C57BL/6J mice (male, —10 weeks old, Jackson Lab, Bar Harbor, Me.) were divided into three groups: a group of 40 mice fed with a lean diet, a group of 40 mice fed with a high-fat diet, and a group comprising mice fed with a high-fat diet supplemented with F2 formulation. The lean diet (cat. no. TD7001, Teklad Diets, Madison, Wis.) comprised protein (25.2% by weight), carbohydrate (39.5% by weight), fat (4.4% by weight), and others (30.9% by weight, ash, fibers, others). The lean diet has 3 kcal/g, with 34% of kcal from protein, 53% of kcal from carbohydrate, and 13% of kcal from fat. The high-fat diet (cat. no. TD88137, Teklad Diets) comprised protein (17.3% by weight), carbohydrate (48.5% by weight), fat (21.2% by weight), and others (13% by weight, ash, fibers, others). The high fat diet has 4.5 g/kcal, with 15.2% of kcal from protein, 42.7% of kcal from carbohydrate, and 42% of kcal from fat. Mice groups were placed on their respective diets in the form of ground pellets for 17 weeks. Glucose tolerance tests using standard protocols were performed at 16th week. Terminal tissue and blood samples collection were performed at 17th week. Collected liver and visceral adipose tissues were sent to IHC WORLD (Woodstock, Md.) for histopathology analysis. Collected blood samples were analyzed for HbAlc, triglyceride, cholesterol, HDL, and LDL using commercially available assay kits (Table 4). All animal studies were performed in conformity with the Public Health Service Policy on Humane Care and Use of Laboratory Animals and with the approval of the Animal Care and Use Committee at Roseman University of Health Sciences.
This application claims the benefit of U.S. Provisional Patent Application 63/187,330, filed May 11, 2021.
Number | Date | Country | |
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63187330 | May 2021 | US |