Compositions for the management of hyperglycemia and related conditions

Abstract

Disclosed is a method for therapeutic management of hyperglycemia in mammals using compositions containing thymohydroquinone. More specifically, the invention discloses compositions containing thymohydroquinone for inhibiting the activity of the enzyme -glucosidase and increasing the cellular uptake of glucose by mammalian cells. The anti-oxidant, anti-inflammatory and anti-glycation effects of thymohydroquinone are also disclosed herein.

Claims

1. A method of inhibiting glucosidase enzyme, said method comprising step of bringing into contact glucosidase enzyme with an effective dose of thymohydroquinone or a composition comprising thymohydroquinone standardized to contain about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% w/w a-hederin or hederagenin, 0.1%-4.0% w/w rosmarinic acid and 0.2%-2% w/w piperine, the bring about the effect of glucosidase enzyme inhibition.

2. A method of increasing glucose uptake by mammalian cells, said method comprising steps of bringing into contact mammalian cells with effective dose of thymohydroquinone or a composition comprising thymohydroquinone, standardized to contain about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% w/w a-hederin or hederagenin, 0.1%-4.0% w/w rosmarinic acid and 0.2%-2% w/w piperine, to increase glucose uptake by the cells.

3. A method for the therapeutic management of hyperglycemia and related conditions in mammals, said method comprising steps of administering effective dose of thymohydroquinone or a composition comprising thymohydroquinone, standardized to contain about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% w/w a-hederin or hederagenin, 0.1%-4.0% w/w rosmarinic acid and 0.2%-2% w/w piperine to bring about a reduction in the levels of glucose in the blood.

4. The method as in claim 3, wherein the management of hyperglycemia and related conditions is brought about by decreasing absorption of glucose by inhibiting glucosidase enzyme, increasing cellular uptake of glucose, reducing free radicals, reducing inflammation and decreasing glycation.

5. The method as in claim 3, wherein the hyperglycemia related conditions are present in disease states selected from the group comprising diabetes, obesity, hyperlipoproteiniemia, hyperlipidemia, cardiovascular complications, cancer, atherosclerosis, neurodegenerative diseases, allergy, inflammation, and osteoporosis.

6. The method as in claim 3, wherein the mammal is human.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1A and FIG. 1B shows the graphical representation -glucosidase inhibitory activity of thymoquinone (TQ), thymohydroquinone (THQ) and thymohydroquinone composition.

(2) FIG. 2A and FIG. 2B are graphical representations showing the percentage glucose uptake by adipocytes and mytocytes treated with thymoquinone (TQ), thymohydroquinone (THQ) and thymohydroquinone composition.

(3) FIGS. 3A, 3B, 3C, 3D and 3E show the representative histograms of glucose uptake by mammalian cells treated with Insulin (3A), thymoquinone (TQ) (3B), thymohydroquinone (THQ) (3C), and thymohydroquinone composition (3D), Un-treated cell serve as control group (3E).

(4) FIGS. 4A, 4B and 4C show the graphical representation of DPPH scavenging activity of thymoquinone (TQ) (4A), thymohydroquinone (THQ) (4B), and thymohydroquinone composition (4C).

(5) FIG. 5 shows the graphical representation of DPPH scavenging activity and glucosidase inhibition activity compositions with increasing percentages of thymohydroquinone. Increase in thymohydroquinone content directly correlated with increase in biological activity.

(6) FIG. 6 shows the graphical representation of DPPH scavenging activity and glucosidase inhibition activity compositions with increasing percentages of thymoquinone. Increase in thymoquinone content inversely correlated with increase in biological activity.

DESCRIPTION OF THE MOST PREFERRED EMBODIMENTS

(7) In a most preferred embodiment, the invention discloses a method of inhibiting glucosidase enzyme, said method comprising steps of:

(8) i) Bringing into contact glucosidase enzyme with a paranitrophenyl--d-glucopyranoside substrate;

(9) ii) Incubating with an effective doses of thymohydroquinone or a composition comprising thymohydroquinone under optimal conditions;

(10) iii) Reading the change in absorbance using spectrophotometric and fluorimetric methods

(11) iv) Comparing the absorbance with a control blank and determining the percentage enzyme inhibition (IC.sub.50) by thymohydroquinone or a composition comprising thymohydroquinone using the formula:
% Inhibition=[(absorbance of controlabsorbance of inhibitor)/absorbance of control]100

(12) In a related embodiment, the composition comprises of about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% w/w -hederin or hederagenin, 0.1%-4.0% w/w stabilizing agent and 0.2%-2% w/w bioavailability enhancer. In another related embodiment, the stabilizing agent is selected from the group comprising rosmarinic acid, butylated hydroxyanisole, butylated hydroxytoluene, sodium metabisulfite, propyl gallate, cysteine, ascorbic acid and tocopherols. In yet another related embodiment the bioavailability enhancer is selected from the group comprising piperine, quercetin, garlic extract, ginger extract, and naringin.

(13) In another most preferred embodiment, the invention discloses a method of increasing glucose uptake by mammalian cells, said method comprising steps of bringing into contact mammalian cells with effective dose of thymohydroquinone or a composition comprising thymohydroquinone, to increase glucose uptake by the cells. In a related embodiment, the composition comprises of about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% w/w -hederin or hederagenin, 0.1%-4.0% w/w stabilizing agent and 0.2%-2% w/w bioavailability enhancer. In another related embodiment, the stabilizing agent is selected from the group comprising rosmarinic acid, butylated hydroxyanisole, butylated hydroxytoluene, sodium metabisulfite, propyl gallate, cysteine, ascorbic acid and tocopherols. In yet another related embodiment the bioavailability enhancer is selected from the group comprising piperine, quercetin, garlic extract, ginger extract, and naringin. In another related embodiment, the mammalian cells are human cells.

(14) In another preferred embodiment, the invention discloses a method for the therapeutic management of hyperglycemia and related conditions in mammals, said method comprising steps of administering effective dose of thymohydroquinone or a composition comprising thymohydroquinone, to bring about a reduction in the levels of glucose in the blood. In a related embodiment, the management of hyperglycemia and related conditions is brought about by decreasing absorption of glucose by inhibiting glucosidase enzyme, increasing cellular uptake of glucose, reducing free radicals, reducing inflammation and decreasing glycation. In another related embodiment, the hyperglycemia related conditions are present in disease states selected from the group comprising diabetes, obesity, hyperlipoproteinimia, hyperlipidemia, cardiovascular complications, cancer, atherosclerosis, neurodegenerative diseases, allergy, inflammation, and osteoporosis. In a related embodiment, the composition comprises of about 0.1%-5% w/w thymoquinone, about 0.01%-10% w/w thymohydroquinone, about 20%-95% w/w fatty acids, about 0.001%-3% -hederin or hederagenin, 0.1%-4.0% w/w stabilizing agent and 0.2%-2% w/w bioavailability enhancer. In another related embodiment, the stabilizing agent is selected from the group comprising rosmarinic acid, butylated hydroxyanisole, butylated hydroxytoluene, sodium metabisulfite, propyl gallate, cysteine, ascorbic acid and tocopherols. In yet another related embodiment the bioavailability enhancer is selected from the group of piperine, quercetin, garlic extract, ginger extract, and naringin. In another related embodiment, the mammalian cells are human cells. In another related embodiment, the composition is formulated with pharmaceutically/inutraceutically acceptable excipients, adjuvants, diluents or carriers and administered orally in the form of tablets, capsules, soft gels, syrups, gummies, powders, suspensions, emulsions, chewables, candies or eatables.

(15) The aforesaid most preferred embodiments incorporating the technical features and technical effects of instant invention, are explained through illustrative examples herein under.

EXAMPLE 1: INHIBITION OF GLUCOSIDASE

(16) For glucosidase inhibition, -glucosidase (Code G5003; Sigma-Aldrich, St. Louis, Mo., USA) was dissolved in 67 mM potassium phosphate buffer, pH 6.8, containing 8 containing 0.2% Bovine Serum Albumin (Sigma-Aldrich) & 0.02% sodium azide (Sigma-Aldrich) which was used as enzyme source. Paranitrophenyl--d-glucopyranoside (Sigma-Aldrich) was used as substrate. Thymoquinone, thymohydroquinone and composition containing thymohydroquinone were weighed prepared at concentration of 63, 125, 250 and 500 g/ml and were made up with equal volumes of distilled water. 50 l of said composition was incubated for 5 min with 50 l enzyme source (0.15 U/ml). After incubation, 50 l of substrate (1.25 mM) was added and further incubated for 20 min at room temperature. Presubstrate and post-substrate addition, absorbance was measured at 405 nm on a microplate reader (BMG FLUOstar OPTIMA Microplate Reader). The increase in absorbance on substrate addition was obtained. Each test was performed three times and the mean absorption was used to calculate percentage -glucosidase inhibition. Acarbose was used as positive control with various concentrations. The inhibitory activities of varying concentrations of said composition were expressed as 100 minus the absorbance difference (%) of the said composition relative to the absorbance change of the negative control (i.e., water used as the test solution). The measurements were performed in triplicate, and the IC.sub.50 value (i.e., the concentration of said composition that results in 50% inhibition of maximal activity) was determined.

(17) Thymohydroquinone (IC.sub.50 71.9 g/ml) and the composition comprising thymohydroquinone (IC.sub.50 150.9 g/ml) exhibited effective inhibition of a glucosidase when compared to thymoquinone (IC.sub.50407.6 g/ml) (FIG. 1A and FIG. 1B).

EXAMPLE 2: INCREASE IN GLUCOSE UPTAKE

(18) The skeletal muscle cell line C2C12 myoblasts (procured from ATCC) were maintained in DMEM supplemented with 10% Fetal Bovine Serum at 37 C. with 5% CO.sub.2. Twenty thousand cells per well were seeded in a 24 well plate. When the cells reached 80-90% confluence, differentiation was induced by replacing the growth medium with DMEM containing 1% horse serum. Experiments were performed in completely differentiated C2C12 myotubes after 4-5 days in differentiation medium. Cells were then treated with 0.5% BSA in low glucose media for 16 hours and washed with cold Krebs-Ringer phosphate buffer without glucose. Cells were then treated with different non cytotoxic concentrations of samples in low glucose DMEM media with or without insulin at a concentration of 0.1 M for 30 minutes at 37 C. Cells were then washed with cold PBS and stained with 5 M of a fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG) for 15 minutes in dark followed by flow cytometric detection of fluorescence produced by the cells.

(19) Thymohydroquinone and the composition comprising thymohydroquinone showed enhanced glucose uptake in Adipocytes and Muscle cells when compared to thymoquinone (FIG. 2A and FIG. 2B).

EXAMPLE 3: ANTI-OXIDANT ACTIVITY OF THYMOHYDROQUINONE

(20) The antioxidant property of thymohydroquinone was assessed by DPPH scavenging activity.

(21) Chronic increase of sugar levels in the blood leads to the formation of reactive oxygen species. Reactive oxygen species (ROS) including superoxide, hydroxyl, peroxyl, and alkoxy radicals are scavenged by the cellular anti oxidants and remain in equilibrium. These ROS induced damage causes skin irritation, inflammation, ageing, cancer and many other diseases. ,-diphenyl--picrylhydrazyl (DPPH) free radical scavenging method is one of the first approach for evaluating the antioxidant potential of a compound.

(22) Procedure

(23) DPPH is a stable free radical in a methanolic solution with an absorbance at 520 nm. If the free radicals are scavenged by an anti oxidant molecule, the resulting solution appears yellow. The hydrogen atoms or electrons donation ability of the extracellular metabolite was measured by the bleaching of purple coloured DPPH methanol solution.

(24) Thymoquinone, Thymohydroquinone and the composition comprising thymohydroquinone were prepared in varying concentrations. For the DPPH radical scavenging assay, 20 L of test material was mixed with 180 L of DPPH in methanol in a 96 well plate following the method as described earlier (Clarke et al., 2013). The plate was kept in the dark for 15 min, after which the absorbance of the solution was measured at 540 nm using a microplate reader (TECAN Ltd, Mnnedorf, Switzerland). Blanks (DMSO, methanol) and standard (Trolox solution in DMSO) were recorded simultaneously. The extracts were screened with variable concentrations to establish the inhibition concentration (IC.sub.50, the concentration reducing DPPH absorbance by 50%).

(25) The free radical scavenging activity was calculated as follows,

(26) $\%\mathrm{scavenging}\mathrm{activity}=\frac{\left(B-C\right)-\left(S-C\right)}{\left(B-C\right)}100$

(27) Where, B=Absorbance of reference solution (OD of DPPH) C=Absorbance of reference solution, blank (OD of Methanol only) S=Absorbance of test solution C=Absorbance of test solution blank

(28) Thymohydroquinone is a potent anti oxidant with an IC.sub.50 of 1.78 g/ml (FIG. 4B). The composition comprising thymohydroquinone also exhibited excellent antioxidant potential with an IC.sub.50 of 540.1 g/ml (FIG. 4C), which is much effective that thymoquinone (FIG. 4A).

EXAMPLE 4: ANTI-INFLAMMATORY ACTIVITY OF THYMOHYDROQUINONE

(29) Chronic hyperglycemia increases cellular inflammation by increasing the production of pro-inflammatory cytokines like TNT-. Thymoquinone, thymohydroquinone and a composition comprising thymohydroquinone were tested for their anti-inflammatory activity by assessing their TNF- inhibitory activity.

(30) Cells: THP1-human monocytes purchased from American Type Culture Collection (ATCC, Manassas, Va.) and maintained as a monolayer culture in Rosewell park memorial institute Medium (RMPI Life technologies, CA, USA.) supplemented with 10% (v/v) heat-inactivated foetal bovine serum (FBS; GIBCO/Invitrogen, Carlsbad, Calif.), 100 units/mL penicillin and 100 g/mL streptomycin (Life technologies) at 37 C. in a humidified 5% CO2 incubator.

(31) Reagents and buffers: Lipopolysaccharide (LPS, Sigma chemicals, USA), Phosphate buffered saline, RPMI, FBS

(32) ELISA kit: Human TNF ELISA kit, Krishgen Biosciences, USA

(33) Procedure

(34) Anti inflammatory activity was examined using human monocyte/macrophage cell line THP-Monocytes respond to lipopolysaccharides (LPS) by secreting proinflammatory cytokines. Tumour necrosis factor (TNF-) is one of the principle cytokine which triggers a cascade of inflammatory reactions. The concentration of TNF- was measured using an Enzyme linked Immunosorbent assay (ELISA). Reduction in TNF- concentration indicates an anti inflammatory activity of the compound.

(35) 1105 THP-1 cells were stimulated with 100 ng with lipopolysacharide (LPS, 0.1 g/mL) to induce TNF- secretion. Cells were pre treated with different concentrations of test materials (Thymoquinone, thymohydroquinone and a composition comprising thymohydroquinone) before LPS treatment. The cell supernatants were collected 24 hour after treatment and secreted TNF- as estimated by cytokine ELISA as described by the manufacturer. Unstimulated cells were used as negative control. The limit of detection was <1 pg/mL.

(36) Results

(37) The results indicated the thymohydroquinone inhibited TNF- (Table 1), indicating significant anti inflammatory activity without affecting the cell viability.

(38) TABLE-US-00001 TABLE 1 Anti-inflammatory activity of thymohydroquinone Concentration (g/mL) % Inhibition Thymoquinone 0.13 35 0.06 31 0.03 22 Thymohydroquinone 0.13 11.9 0.06 4.5 0.03 2.5 Thymohydroquinone 25 26.2 composition 12.5 19.8 6.25 14.9

EXAMPLE 5: ANTI-GLYCATION ACTIVITY OF THYMOHYDROQUINONE

(39) Advanced glycation end products (AGEs) are generated by the non enzymatic adduct formation between amino groups of proteins (predominantly lysine and arginine) and carbonyl groups of reducing sugar, also known as Maillard reaction. In the early stages, reducing sugars react with free amino groups to form an unstable aldimine compound which undergoes molecular rearrangement to form a stable early glycation product known as Amadori product. In the later stages, glycation process through oxidation, dehydration and cyclization reactions forms the advanced glycation end products also known as AGE. Various structures of AGEs such as N(carboxymethyl)-lysine (CML), pyrraline, pentosidine, are known to be associated with degenerative disorders, including aging, diabetes, atherosclerosis Alzheimer's disease, and renal failure

(40) Pentosidines are known to accumulate in diabetes patients and Vesperlysines are found in cataractogenesis and diabetic retinopathy. Agents that can prevent glycation can effectively used to counter the secondary complications associated with hyperglycemia. Thymoquinone and thymohydroquinone were tested for their anti-glycation effects.

(41) AGEs can be fluorescent as well as non fluorescent in nature. Typically the vesperlysine type of AGE have an excitation at 370-nm and emission at 440 nm, while pentosidine like AGE have an excitation at 335 nm and emission at 385 nm. The principle is based on the fact that ribose sugar and bovine serum albumin are mixed in specific ratio and incubated for 24 hours. Vesperlysine like AGE formed by the reaction was e estimated by the increase in fluorescence detected, at Ex/Em at 390/460 nm and pentosidines were detected at Ex/Em at 320/405 nm

(42) Materials

(43) Ribose, Bovine Serum Albumin, 96 Well Black Microtitre Plates

(44) RiboseBSA method: 10 l of various concentrations of samples were added to 40 l of BSA (bovine serum albumin, 25 mg/ml stock) and 50 l of D-Ribose (150 mg/ml stock) was added per well of black 96-well microplate and incubated for 24 h at 37 C. BSA was taken as the control. The AGEs (advanced glycation end product) formed were detected by the fluorescence at Ex/Em at 390/460 nm for vesperlysine and Ex/Em at 320/405 nm for pentosidine AGE.

(45) Results

(46) The inhibition of the AGEs vesperlysine and Pentosidine by thymoquinone and thymohydroquinone is tabulated in table 2.

(47) TABLE-US-00002 TABLE 2 Percentage inhibition of AGEs by thymohydroquinone % inhibition of vesperlysine % Inhibition of pentosidine Concentration Ex/Em at 390/460 nm Ex/Em at 320/405 nm (g/mL) TQ THQ TQ THQ 250 56.69 60.42 61.80 89.31 125 44.54 52.28 44.57 68.33 62.5 40.81 43.83 0.06 49.55 31.25 38.55 34.06 23.59 28.73 15.63 0 23.03 0 5.39 IC.sub.50 157.80 108.30 142.70 65.89

(48) The results indicated that thymohydroquinone is biologically more potent molecule and exhibits enhanced biological activity when compared to thymoquinone.

(49) The biological effects of compositions with increasing percentage of thymohydroquinone was also evaluated. Table 3 provides the list the compositions with increase in thymohydroquinone content.

(50) TABLE-US-00003 TABLE 3 Compositions containing thymohydroquinone Composition % TQ % THQ 1 0.643 0.029 2 0.620 0.093 3 0.558 0.120 4 0.450 0.250

(51) Increase in thymohydroquinone content in the compositions correlated with higher DPPH scavenging and glucosidase inhibition (FIG. 5) when compared to thymoquinone, which did not show correlation with biological activity (FIG. 6). Thus, thymohydroquinone can be effectively incorporated into formulations for the effective management of various diseases and disorders including, but not limited to, hyperglycemia, diabetes, obesity, hyperlipoproteiniemia, hyperlipidemia, cardiovascular complications, cancer, atherosclerosis, neurodegenerative diseases, allergy, inflammation, and osteoporosis.

(52) Other modifications and variations to the invention will be apparent to those skilled in the art from the foregoing disclosure and teachings. Thus, while only certain embodiments of the invention have been specifically described herein, it will be apparent that numerous modifications may be made thereto without departing from the spirit and scope of the invention and is to be interpreted only in conjunction with the appended claims.