Patent Description:
Hyperglycemia is a condition wherein the glucose levels in the blood remain elevated. Chronic hyperglycemia, if left untreated can cause secondary complications that lead to the development of many diseases like diabetes, obesity, hyperlipoproteinemia, hyperlipidemia, cardiovascular complications, cancer, atherosclerosis, neurodegenerative disorders, allergy, inflammation, and osteoporosis. The increased glucose levels in blood increases the production of reactive oxygen/nitrogen species and pro-inflammatory cytokines thereby causing oxidative stress and inflammation. Elevated glucose levels further increase the non-enzymatic glycosylation of proteins and other biomolecules (glycation) leading to the production of Advanced glycation end products (AGEs) which are reported to be main cause for cellular aging. AGEs also exemplify the cellular inflammatory cascade leading to progressive deterioration and apoptosis.

The current drugs which are administered (e. g metformin) are effective in controlling the blood glucose levels. Continuous intake of these synthetic drugs causes many side effects which include hepatotoxicity and nephrotoxicity. Thus, a more safe and effective natural plant based molecule is warranted to manage blood glucose levels.

The treatment methods that are currently employed in the management of hyperglycemia include administering inhibitors against key enzymes that regulate carbohydrate breakdown and increasing glucose uptake. In this aspect, glucosidase inhibitors are of particular importance (<NPL>). α-glucosidase, is essential for the degradation of glycogen to glucose. It acts on complex carbohydrate molecules to yield monosaccharide units which are readily absorbed in the blood stream. Inhibiting α-glucosidase results in the reduction of glucose release into the blood stream thereby decreasing the hyperglycemic condition.

There are many plant based inhibitory molecules for α-glucosidase which are discussed in the following prior arts:.

However, a plant based molecule that effectively inhibits α-glucosidase and increases glucose uptake is required for effective management of hyperglycemia.

Nigella sativa is well known for its many therapeutic properties in the Ayruvedic, Siddha and Unani systems of medicine. The plant is reported to contain many active molecules like thymoquinone, thymohydroquinone, dithymoquinone, p-cymene, carvacrol, <NUM>-terpineol, t-anethol, sesquiterpene longifolene, α-pinene, thymol, α hederin and hederagenin (<NPL>), which are responsible for the beneficial effects of the plant. Some of the therapeutic effects of Nigellia sativa are listed in the following prior art documents:.

Most of the reported biological effects of Nigella sativa are either for the whole extract or specifically for thymoquinone. Reports on the biological effects of the thymohydroquinone with respect to the management of hyperglycemia are not available. Although thymohydroquinone is the reduced form of thymoquione it is different both structurally and functionally.

It is the principle object of the invention to disclose a method for the inhibiting the activity of α-Glucosidase using a composition comprising thymohydroquinone.

It is another object of the invention to disclose a method of increase the uptake of glucose by mammalian cells by administering a composition comprising thymohydroquinone.

It is yet another object of the invention to disclose thymohydroquinone for use in therapeutic management of hyperglycemia in mammals.

The present invention solves the above mentioned objectives and provides further related advantages.

This specification discloses compositions comprising thymohydroquinone. Specifically, the specification discloses compositions containing thymohydroquinone for inhibiting the activity of the enzyme α-Glucosidase. The specification also discloses the use of compositions containing thymohydroquinone for increasing the cellular uptake of glucose by mammalian cells. More specifically the specification discloses a method for therapeutic management of hyperglycemia in mammals using compositions containing thymohydroquinone. The antioxidant, anti-inflammatory and anti-glycation effects of thymohydroquinone are also disclosed herein.

Features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principle of the invention.

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

In a related embodiment, the composition comprises of <NUM>% - <NUM>% w/w thymoquinone, <NUM>% - <NUM>% w/w thymohydroquinone, <NUM>% - <NUM>% w/w fatty acids, <NUM>%-<NUM>% w/w α-hederin or hederagenin, <NUM>% - <NUM> % w/w stabilizing agent and <NUM>%-<NUM>% 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 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 <NUM>% - <NUM>% w/w thymoquinone, <NUM>% - <NUM>% w/w thymohydroquinone, <NUM>% - <NUM>% w/w fatty acids, <NUM>%-<NUM>% w/w α-hederin or hederagenin, <NUM>% - <NUM> % w/w stabilizing agent and <NUM>%-<NUM>% 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.

In another preferred embodiment, the invention discloses thymohydroquinone for use in the therapeutic management of hyperglycemia in a mammal to bring about a reduction in the levels of glucose in the blood. In a related embodiment, the management of hyperglycemia 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 mammal is a human. In another related embodiment, the thymohydroquinone is comprised by a composition formulated of thymohydroquinone and pharmaceutically/nutraceutically 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.

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

For glucosidase inhibition, α-glucosidase (Code G5003; Sigma-Aldrich, St. Louis, MO, USA) was dissolved in <NUM> potassium phosphate buffer, pH <NUM>, containing <NUM> containing <NUM>% Bovine Serum Albumin (Sigma-Aldrich) & <NUM>% sodium azide (Sigma-Aldrich) which was used as enzyme source. Paranitrophenyl- α-d-glucopyranoside (Sigma-Aldrich) was used as substrate. Thymoquinone, thymohydroquinone and composition containing tymohydroquinone were weighed prepared at concentration of <NUM>, <NUM>, <NUM> and <NUM>µg/ml and were made up with equal volumes of distilled water. <NUM>µl of said composition was incubated for <NUM> with 50µl enzyme source (<NUM> U/ml). After incubation, <NUM>µl of substrate (<NUM>) was added and further incubated for <NUM> at room temperature. Presubstrate and post-substrate addition, absorbance was measured at <NUM> 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 α-glucosidase inhibition. Acarbose was used as positive control with various concentrations. The inhibitory activities of varying concentrations of said composition were expressed as <NUM> 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<NUM> value (i.e., the concentration of said composition that results in <NUM>% inhibition of maximal activity) was determined.

Thymohydroquinone (IC<NUM> <NUM>µg/ml) and the composition comprising thymohydroquinone (IC<NUM> <NUM>µg/ml) exhibited effective inhibition of α glucosidase when compared to thymoquinone (IC<NUM> <NUM>µg/ml) (<FIG>).

The skeletal muscle cell line C2C12 myoblasts (procured from ATCC) were maintained in DMEM supplemented with <NUM>% Fetal Bovine Serum at <NUM> with <NUM>% CO<NUM>. Twenty thousand cells per well were seeded in a <NUM> well plate. When the cells reached <NUM>-<NUM>% confluence, differentiation was induced by replacing the growth medium with DMEM containing <NUM>% horse serum. Experiments were performed in completely differentiated C2C12 myotubes after <NUM>-<NUM> days in differentiation medium. Cells were then treated with <NUM>% BSA in low glucose media for <NUM> 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 <NUM> for <NUM> minutes at <NUM>. Cells were then washed with cold PBS and stained with <NUM> of a fluorescent D-glucose analog <NUM>-[N-(<NUM>-nitrobenz-<NUM>-oxa-<NUM>,<NUM>-diazol-<NUM>-yl) amino]-<NUM>-deoxy-D-glucose (<NUM>-NBDG) for <NUM> minutes in dark followed by flow cytometric detection of fluorescence produced by the cells.

Thymohydroquinone and the composition comprising thymohydroquinone showed enhanced glucose uptake in Adipocytes and Muscle cells when compared to thymoquinone (<FIG>).

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

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. α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method is one of the first approach for evaluating the antioxidant potential of a compound.

DPPH is a stable free radical in a methanolic solution with an absorbance at <NUM>. 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.

Thymoquinone, Thymohydroquinone and the composition comprising thymohydroquione were prepared in varying concentrations. For the DPPH radical scavenging assay, <NUM>µL of test material was mixed with <NUM>µL of DPPH in methanol in a <NUM> well plate following the method as described earlier (Clarke et al. The plate was kept in the dark for <NUM>, after which the absorbance of the solution was measured at <NUM> using a microplate reader (TECAN Ltd, Männedorf, 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<NUM>, the concentration reducing DPPH absorbance by <NUM>%).

The free radical scavenging activity was calculated as follows, <MAT> Where,.

Thymohydroquinone is a potent anti oxidant with an IC<NUM> of <NUM>µg/ml (<FIG>). The composition comprising thymohydroquinone also exhibited excellent antioxidant potential with an IC<NUM> of <NUM>µg/ml (<FIG>), which is much effective that thymoquinone (<FIG>).

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

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-α) is one of the principle cytokine which triggers a cascade of inflammatory reactions. The concentration of TNF-α was measured using an Enzyme linked Immunosorbent assay (ELISA). Reduction in TNF-α concentration indicates an anti inflammatory activity of the compound.

1X105 THP-<NUM> cells were stimulated with 100ng with lipopolysacharide (LPS, <NUM>. 1µg/mL) to induce TNF-α 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 <NUM> hour after treatment and secreted TNF-α as estimated by cytokine ELISA as described by the manufacturer. Unstimulated cells were used as negative control. The limit of detection was <1pg/mL.

The results indicated the thymohydroquinone inhibited TNF-α (Table <NUM>), indicating significant anti inflammatory activity without affecting the cell viability.

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 Nε -(carboxymethyl)-lysine (CML), pyrraline, pentosidine, are known to be associated with degenerative disorders, including aging, diabetes, atherosclerosis Alzheimer's disease, and renal failure.

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.

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

Ribose - BSA method: 10µl of various concentrations of samples were added to 40µl of BSA (bovine serum albumin, <NUM>/ml stock) and <NUM>µl of D-Ribose (<NUM>/ml stock) was added per well of black <NUM>-well microplate and incubated for <NUM> at <NUM>. BSA was taken as the control. The AGEs (advanced glycation end product) formed were detected by the fluorescence at Ex/Em at <NUM>/<NUM> for vesperlysine and Ex/Em at <NUM>/<NUM> for pentosidine AGE.

The inhibition of the AGEs vesperlysine and Pentosidine by thymoquinone and thymohydroquinone is tabulated in table <NUM>.

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

The biological effects of compositions with increasing percentage of thymohydrquinone was also evaluated. Table <NUM> provides the list the compositions with increase in thymohydroquinone content.

Claim 1:
A method of inhibiting glucosidase enzyme, said method comprising steps of:
i) Bringing into contact glucosidase enzyme with a paranitrophenyl- α-d-glucopyranoside substrate;
ii) Incubating with an effective dose of thymohydroquinone or a composition comprising thymohydroquinone under optimal conditions;
iii) Reading the change in absorbance using spectrophotometric and fluorimetric methods;
iv) Comparing the absorbance with a control blank and determining the percentage enzyme inhibition (IC<NUM>) by thymohydroquinone or a composition comprising thymohydroquinone using the formula: <MAT>
wherein the method does not comprise a treatment of the human or animal body by therapy or a diagnostic method practised on the human or animal body.