JP2012131742A - Glp-1 secretion promoter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substance useful for GLP-1 secretion promotion, glucagon secretion depression, appetite depression, or prophylaxis and/or improvement or the like of a disease or a state such as postprandial hyperglycemia, diabetes and the like.SOLUTION: The GLP-1 secretion promoter contains Quillai or an extract thereof as an effective constituent. An glucagon secretion depressant contains the Quillai or the extract thereof as an effective constituent. An appetite depressant contains the Quillai or the extract thereof as an effective constituent. A medicine for the prophylaxis and/or improvement of the postprandial hyperglycemia contains the Quillai or the extract thereof as an effective constituent. A medicine for the prophylaxis and/or improvement of the diabetes contains the Quillai or the extract thereof as an effective constituent.

Description

  The present invention relates to a GLP-1 (glucagon-like peptide-1) secretion promoter.

  Glucagon-like peptide-1 (GLP-1) is a hormone produced from a gene and a precursor common to glucagon, which is an endocrine hormone. While glucagon is produced by α cells in the splenic islets, GLP-1 is produced by intestinal endocrine cells (L cells), and is produced from the precursor through processing different from that of glucagon. GLP-1 is a hormone with incretin (Intestine Secretion Insulin) action that plays an important role in glucose metabolism, and is secreted into the blood by ingestion of nutrients, acting on pancreatic β cells to promote insulin secretion. , Lower blood sugar levels. GLP-1 also acts on the pancreas to suppress glucagon secretion, thereby reducing glucose release from the liver and lowering blood glucose levels. Other actions of GLP-1 are known to promote pancreatic β-cell proliferation, suppress gastric excretion and gastric acid secretion, and suppress appetite and food intake (Non-patent Document 1). Therefore, enhancing the effect of GLP-1 is useful for improving lifestyle-related diseases such as obesity and diabetes. In recent years, development of diabetes treatment methods using GLP-1 replacement therapy and GLP-1 receptor (GLP-1R) agonists has also been promoted.

  GLP-1 is also known to have an effect on the central nervous system. GLP-1's appetite and feeding-suppressing effects are thought to be via GLP-1R present in the central nervous system (Non-patent Document 1). Moreover, while learning ability declines in a GLP-1R deficient mouse, memory learning ability improves in the mouse which overexpressed GLP-1R (nonpatent literature 2). In experiments in a culture system, GLP-1 has been observed to promote neurite outgrowth and to protect against apoptosis due to nerve injury (Non-patent Document 3). Therefore, GLP-1 is expected to be a useful substance for suppressing neurodegeneration and improving neurodegenerative diseases such as dementia and neuropathy associated with diabetes.

  GLP-1 is also considered useful for controlling blood glucose levels in diabetic patients. When GLP-1 suppresses pancreatic glucagon secretion, glucose release from the liver decreases and blood glucose decreases. It has been reported that this action does not antagonize glucagon secretion due to hypoglycemia and does not depend on insulin concentration. It has also been reported that administration of GLP-1 decreased the amount of insulin required to make blood glucose constant in both type 1 diabetic patients and type 2 diabetic patients. Furthermore, GLP-1 can exert an effect on blood glucose level control in the long term by acting on the central nervous system and suppressing appetite. Therefore, GLP-1 may improve the symptoms of patients with diabetes and insulin resistance through these actions. Exenatide and Liraglutide, which are actually GLP-1 analog preparations, have been used as antidiabetic drugs and have been reported to have an effect of improving insulin resistance (Non-patent Document 4).

  However, GLP-1 is usually very susceptible to degradation and has a very short half-life in vivo. Therefore, even if GLP-1 is administered from outside the body, it is very difficult to keep the blood concentration constant. Therefore, in order to increase the in vivo GLP-1 concentration over a long period of time, it is desirable to promote the secretion of endogenous GLP-1 rather than external administration.

  As a substance that promotes the secretion of GLP-1 from studies in a culture system, palmitic acid, oleic acid, meat hydrolyzate (MH), gastrin releasing peptide (GRP), carbachol, forskolin, ionomycin, phorbol myristate acetate (PMA), essential amino acids (EAA), leucine, isoleucine, skim milk, casein, leptin, and muscarinic receptors M1 and M2 have been reported so far (Non-Patent Documents 5 to 9).

Quillaja Saponaria Mol. Is a plant of the Rosaceae family, and its extract contains Quillaja saponin (a triterpene-based glycoside with quinaya acid as aglycone), and as a food additive derived from natural products, It is widely used as an emulsifier and a foaming agent for beverages and cosmetics.

  The functions of Quillaja extract include enhancement of lowering action of blood cholesterol and blood triglyceride (Patent Document 1), pancreatic lipase inhibition, obesity prevention, hyperlipidemia prevention or treatment, fatty liver prevention or treatment (Patent Document 2) Inhibition of keratinase activity (Patent Document 3), inhibition of methionase activity (Patent Document 4), antibacterial action against Helicobacter pylori, urease activity inhibition action and suppression of adhesion to gastric mucosal epithelial cells, prevention and treatment of gastritis and gastroduodenal ulcer (Patent Document 5), Alcohol Absorption Suppression (Patent Document 6), Antioxidation (Patent Document 7), Antibody Production Capacity Improvement (Non-Patent Documents 10 and 11), Intestinal Methane Gas Reduction in Dairy Cows (Non-Patent Document 12), Blood Low cholesterol (Non-patent Documents 13 and 14), HDL increase, leukocyte DNA damage reduction, blood malondialdehyde / protein carbonylation reduction, O increases (Non-Patent Document 15) are known.

  In addition, there is no report on the effect of Kiraya or its extract on GLP-1.

JP 2007-82403 A JP 2006-182722 A Japanese Patent Laid-Open No. 2004-18508 Japanese Patent Laid-Open No. 2003-160459 Japanese Unexamined Patent Publication No. Hei 8-19872 Japanese Patent Laid-Open No. 4-145028 JP 62-243681 A

Eur J Pharmacol, 2002, 440 (2-3): 269-279 Nat Med, 2003, 9: 1173-1179 J Pharmacol Exp Ther, 2002, 302 (3): 881-888 History of Medicine, 2009, 231 (7): 755-758 Endocrinology, 2001, 142 (10): 4522-4528 Journal of Endocrinology, 2006, 191,159-170 Nutrition, 2009, 25 (3): 340-349 Endocrinology, 2003, 144 (7): 3244-3250 Diabetes, 2006, 52 (2): 252-259 Can. J. microbiol. 1986, 32, 414-420 Immunobiol. 1987, 174, 347-359 J Dairy Sci. 2009, 92 (6): 2809-2821 Nutr Res. 2009, 29 (5): 350-354. Arch Pharm Res. 2003, 26 (12): 1042-1046. J Diabetes Complications. 2008, 22 (5): 348-356

  The present invention relates to the provision of a substance that promotes secretion of GLP-1, and the prevention and / or improvement of diseases or conditions such as promotion of GLP-1 secretion, suppression of glucagon secretion, suppression of appetite, hyperglycemia, diabetes, etc. Relates to the use of the substance.

  When the present inventors examined the material which can accelerate | stimulate the secretion of GLP-1, it discovered that a quilla extract could promote the secretion of GLP-1.

That is, the present invention provides the following.
(1) A GLP-1 secretion promoter containing Kiraya or an extract thereof as an active ingredient.
(2) The GLP-1 secretion promoter according to (1), wherein the extract is a water extract or an aqueous ethanol extract.
(3) A glucagon secretion inhibitor containing Kiraya or an extract thereof as an active ingredient.
(4) The glucagon secretion inhibitor according to (3), wherein the extract is a water extract or an aqueous ethanol extract.
(5) An appetite suppressant containing Kiraya or an extract thereof as an active ingredient.
(6) The appetite suppressant according to (5), wherein the extract is a water extract or an aqueous ethanol extract.
(7) An agent for preventing and / or improving postprandial hyperglycemia comprising Kiraya or an extract thereof as an active ingredient.
(8) The postprandial hyperglycemia prevention and / or ameliorating agent according to (7), wherein the extract is a water extract or an aqueous ethanol extract.
(9) Diabetes preventive and / or ameliorating agent comprising Kiraya or an extract thereof as an active ingredient.
(10) The diabetes preventive and / or ameliorating agent according to (9), wherein the extract is a water extract or an aqueous ethanol extract.

  The GLP-1 secretion promoter of the present invention promotes excellent GLP-1 secretion, suppresses glucagon secretion, suppresses appetite, or treats diseases such as postprandial hyperglycemia, diabetes, insulin resistance, and neuropathy. Useful for prevention and / or improvement.

GLP-1 secretion promoting action in NCI-H716 cells by Quillaja extract. **: p <0.01, ***: p <0.001. GLP-1 secretion promoting effect in mice by Quillaja extract. *: P <0.05. Antihyperglycemic effect of Kiraya extract. ***: p <0.001.

  As used herein, “GLP-1 secretion promotion” means promoting GLP-1 secretion in vivo caused by ingesting a meal, particularly a meal rich in carbohydrates or lipids. Alternatively, “promoting GLP-1 secretion” refers to enhancing the increase in blood GLP-1 concentration accompanying GLP-1 secretion in vivo, mainly occurring after meals, or maintaining the increased GLP-1 concentration, Suppressing a decrease in the increased GLP-1 concentration.

  In the present specification, “non-therapeutic” is a concept that does not include a medical act, that is, a treatment act on the human body by therapy.

  As used herein, “improvement” refers to improvement of a disease, symptom or condition, prevention or delay of worsening of the disease, symptom or condition, or reversal, prevention or delay of progression of a disease or symptom.

  As used herein, “prevention” refers to preventing or delaying the onset of a disease or symptom in an individual, or reducing the risk of developing an individual's disease or symptom.

In this specification, “ Killaya ” refers to Quillaja Saponaria Mol., And “ Killaya extract” means an extract obtained from Quillaja. The extract can be any part of Kiraya, such as whole grass, leaves, stems, buds, flowers, buds, wood parts, bark, lichens, roots, rhizomes, corms, corms, tubers, seeds, fruits, mycorrhiza or resin Etc., or a combination thereof, but an extract from the bark is preferred. The part may be subjected to the extraction step as it is, or may be subjected to the extraction step after being pulverized, cut or dried.

  As the above extract, commercially available ones may be used, or various solvent extracts obtained by a conventional method, or diluted solutions thereof, concentrated solutions thereof, dried powders thereof, pastes or activated carbon treatments thereof. There may be. As an example, the kiraya extract in the present invention is extracted with kiraya extracted at room temperature (for example, 4 to 50 ° C.) or under heating (room temperature to solvent boiling point) or using an extraction device such as a Soxhlet extractor. Can be obtained.

  As the solvent for extraction, either a polar solvent or a nonpolar solvent can be used. Specific examples of the solvent include water; alcohols such as methanol, ethanol, propanol and butanol; polyhydric alcohols such as propylene glycol and butylene glycol; ketones such as acetone and methyl ethyl ketone; methyl acetate and ethyl acetate Esters; linear and cyclic ethers such as tetrahydrofuran and diethyl ether; polyethers such as polyethylene glycol; hydrocarbons such as squalane, hexane, cyclohexane and petroleum ether; aromatic hydrocarbons such as toluene; dichloromethane and chloroform And halogenated hydrocarbons such as dichloroethane; and supercritical carbon dioxide; pyridines; organic solvents such as oils and fats, other oils such as wax; and mixtures thereof. Preferable examples include water, alcohols and aqueous solutions thereof, and ethanol is preferable as the alcohols. More preferred solvents are water and an aqueous ethanol solution.

When an aqueous ethanol solution is used as a solvent for extraction, the mixing ratio (volume ratio) of alcohols and water is preferably 0.001 to 100: 99.999-0, and 5 to 95:95 to 5 is more preferable, 20 to 80:80 to 20 is more preferable, 30 to 70:70 to 30 is still more preferable, and 40 to 60:60 to 40 is still more preferable. In the case of an ethanol aqueous solution, the ethanol concentration is preferably 40 to 60% by volume.
As a usage-amount of a solvent, 1-100 mL is preferable with respect to 1 g of kiraya (dry mass conversion), As extraction time, 1 minute-100 days are preferable, and 1 minute-10 days are more preferable. The extraction temperature at this time is 0 ° C. to the boiling point of the solvent, more preferably 20 to 100 ° C., further preferably 50 to 100 ° C., and still more preferably 70 to 80 ° C.

Specific examples of the extraction means for obtaining the kiraya extract include solid-liquid extraction, liquid-liquid extraction, immersion, decoction, leaching, reflux extraction, ultrasonic extraction, microwave extraction, and stirring. For example, as a suitable example of immersion, immersion at 10 to 50 ° C. for 1 hour to 14 days can be mentioned. Moreover, when shortening extraction time, solid-liquid extraction with stirring is desirable. An example of suitable conditions for this solid-liquid extraction is stirring at 100 to 400 rpm under 10 to 100 ° C. (preferably 70 to 80 ° C.) for 1 to 30 minutes.
In order to prevent the oxidation of the extract, a means for extracting under a so-called non-oxidizing atmosphere while removing dissolved oxygen by bubbling degassing or inert gas such as nitrogen gas may be used in combination.

As shown in the Examples described later, Kiraya extract has an effect of significantly promoting GLP-1 secretion from gastrointestinal cells. Moreover, as shown in the Example below, Kiraya extract has an action of significantly suppressing an increase in postprandial blood glucose. Therefore, Kiraya or an extract thereof is useful as a GLP-1 secretion promoter, and controls various states related to GLP-1 secretion, such as glucagon secretion suppression, appetite suppression, postprandial hyperglycemia, diabetes, etc. It is useful for preventing and / or improving diseases, and for preventing and / or improving diseases such as insulin resistance and neurological diseases.
That is, Kiraya or an extract thereof can be used to promote GLP-1 secretion, suppress glucagon secretion, suppress appetite, or prevent and / or improve diseases such as postprandial hyperglycemia and diabetes. it can. The use can be in humans or non-human animals, or specimens derived therefrom, and can be therapeutic or non-therapeutic.

Therefore, the present invention provides a GLP-1 secretion promoter containing Kiraya or an extract thereof as an active ingredient.
The present invention also provides a glucagon secretion inhibitor containing Kiraya or an extract thereof as an active ingredient.
The present invention also provides an appetite suppressant containing Kiraya or an extract thereof as an active ingredient.
Furthermore, this invention provides the postprandial hyperglycemia prevention and / or improvement agent which contains kiraya or its extract as an active ingredient.
Furthermore, the present invention provides an agent for preventing and / or improving diabetes containing Kiraya or an extract thereof as an active ingredient.
The agent of the present invention may consist essentially of kiraya or an extract thereof.

  Kiraya or an extract thereof is a composition, medicament, pharmaceutical for preventing GLP-1 secretion, suppressing glucagon secretion, suppressing appetite, or preventing and / or improving diseases such as postprandial hyperglycemia and diabetes It can be blended as a raw material in a quasi-drug, food and drink or its raw material, or feed or its raw material, and can be used for its production.

  The composition, medicine, quasi-drug, food / beverage product, feed, or food / beverage product or feed material may be produced or used for human or non-human animals. Kiraya or an extract thereof is blended as a raw material of the composition, medicine, quasi-drug, food / beverage product, feed, or food / beverage product or feed, for promoting GLP-1 secretion, for suppressing glucagon secretion, It may be an active ingredient for appetite suppression or for prevention and / or improvement of diseases such as postprandial hyperglycemia and diabetes.

  The medicine or quasi-drug contains Kiraya or an extract thereof as an active ingredient. The pharmaceutical or quasi drug can be administered in any dosage form. The dosage form may be oral or parenteral. For example, oral dosage forms include solid dosage forms such as tablets, coated tablets, granules, powders, capsules, and liquid dosage forms such as elixirol, syrups and suspensions, and parenteral dosage forms. Examples thereof include injection, infusion, transdermal, transmucosal, nasal, enteral, inhalation, suppository, bolus, and patch.

  The said medicine and quasi-drug may contain kiraya or an extract thereof alone or in combination with a pharmaceutically acceptable carrier. Examples of such carriers include excipients, coating agents, binders, extenders, disintegrants, surfactants, lubricants, diluents, dispersants, buffers, osmotic pressure adjusting agents, pH adjusting agents, Examples include emulsifiers, preservatives, stabilizers, antioxidants, colorants, ultraviolet absorbers, humectants, thickeners, activity enhancers, anti-inflammatory agents, bactericides, taste-masking agents, and flavoring agents. Moreover, the said pharmaceutical and quasi-drug may contain another active ingredient and a pharmacological component, as long as the GLP-1 secretion promotion effect of Kiraya or its extract is not lost.

  The said pharmaceutical or quasi-drug can be manufactured by a conventional method from Kiraya or its extract, or as needed, combining the said carrier and / or another active ingredient and pharmacological ingredient. The content of Kiraya or the extract thereof in the medicine or quasi-drug (in terms of dry matter of the extract) is usually 0.0001 to 20% by mass, preferably 0.001 to 10% by mass, It is more preferable to set it as 0.01-5 mass%.

  The food and drink and feed have functions such as GLP-1 secretion promotion, glucagon secretion suppression, appetite suppression, postprandial hyperglycemia, and prevention and / or improvement of diseases such as diabetes, and the function is displayed as necessary. Food, functional food, food for the sick, food for specified health use, pet food, and the like.

  The kind of said food / beverage products is not specifically limited. Examples of the beverage include all beverages such as fruit juice beverages, carbonated beverages, tea beverages, coffee beverages, milk beverages, alcoholic beverages, and soft drinks. The form of the food may be any form such as solid, semi-solid, liquid, etc., and may be tablet form, pill form, tablet, capsule form, liquid form, syrup form, powder form, granule form, etc. Also good. For example, as food, breads, noodles, pasta, jelly-like foods, various snacks, cakes, confectionery, ice creams, soups, dairy products, frozen foods, instant foods, other processed foods, seasonings, And supplements. The kind of the feed is not particularly limited and may be a feed for any animal, and the form thereof may be any form as in the case of the food.

  The above-mentioned food or drink or feed, or their raw materials may contain kiraya or its extract alone, or other foods, solvents, softeners, oils, emulsifiers, preservatives, aromatics, stabilizers Further, additives such as a colorant, an antioxidant, a moisturizing agent, and a thickener may be contained in combination. The content of Kiraya or the extract thereof in the food or drink or feed is usually 0.0001 to 10% by mass, preferably 0.0001 to 5% by mass, 0 More preferably, the content is 0.001 to 1% by mass.

  Kiraya or an extract thereof is a subject that needs them to promote GLP-1 secretion, to suppress glucagon secretion, to suppress appetite, or to prevent and / or ameliorate diseases such as postprandial hyperglycemia and diabetes Is administered in an effective amount. Alternatively, Kiraya or an extract thereof requires them to promote GLP-1 secretion, to suppress glucagon secretion, to suppress appetite, or to prevent and / or ameliorate diseases such as postprandial hyperglycemia and diabetes. Ingested in an effective amount by the subject.

  Examples of subjects to be administered or ingested include animals suffering from diseases or conditions such as postprandial hyperglycemia and diabetes, animals suspected to be high risk animals thereof, and the like. Alternatively, the subject to be administered or ingested can be an animal that requires GLP-1 secretion promotion, glucagon secretion suppression, or appetite suppression. The animal is preferably a human or non-human mammal, more preferably a human.

  Preferred dosages and intakes may vary according to the subject's species, weight, sex, age, condition or other factors. The dose, route, interval, and amount and interval of intake can be determined appropriately by those skilled in the art. For example, in the case of oral administration or ingestion to humans, the administration or intake is preferably 20 μg to 2000 mg / day, and 200 μg to 1000 mg / day per adult, as a kiraya extract (in terms of dried extract). Is more preferable, 2 mg to 500 mg / day is more preferable, and 20 mg to 200 mg / day is still more preferable. Oral administration or ingestion is preferably performed at the time of each meal or before each meal, more preferably 4 hours to 5 minutes before each meal.

  Alternatively, the subject to be administered or ingested can be an animal-derived tissue, organ, cell, or fraction thereof. The tissue, organ, cell, or fraction thereof is preferably a naturally derived or biologically or biotechnologically modified tissue, organ, cell, or their ability to secrete GLP-1. It is a fraction.

  EXAMPLES Hereinafter, an Example is shown and this invention is demonstrated more concretely.

Example 1 GLP-1 Secretion Promoting Activity in Cells by Quillaja Extract 50 ml of Quillaja saponaria MOLINA bark extract preparation (Quillajanin S-100, containing 25% by weight of Quillaja extract, Maruzen Pharmaceutical Co., Ltd.) The extract was diluted with 1% ethanol water to a concentration of 1% (w / v) to obtain a test sample. As a control, 50% ethanol water was used.
NCI-H716 cells (human colon-derived cells; purchased from ATCC) were cultured at 37 ° C. in the presence of 5% CO ₂ . As the culture solution, RPMI1640 (containing 10% fetal calf serum, high glucose; Invitrogen) was used. Cells were seeded in a 24-well plate coated with Matrigel (100 μL / well; BD) at 1 × 10 ⁶ cells / well (N = 4), and DMEM (containing 10% fetal calf serum, high glucose; Invitrogen) Incubated in medium. Three days later, the medium was replaced with KRB (Krebs-Ringer bicarbonate, Sigma) buffer / 0.2% BSA containing the test sample, and after culturing for 2 hours, the medium was recovered. The medium was collected in a microcentrifuge tube to which diprotin-A (DPP4 inhibitor, Sigma) and PMSF (Phenylmethylsulfonyl fluoride, serine protease inhibitor, Sigma) were added, and after floating cells were removed, until GLP-1 quantification Stored at -80 ° C. GLP-1 in the medium was quantified by ELISA using GLUCAGON-LIKE PEPTIDE-1 (ACTIVE) ELISA KIT (LINCO Research).
The results are shown in FIG. Quillaja extract significantly promoted cellular GLP-1 secretion at concentrations of 0.001% and above.

Example 2 GLP-1 secretion-promoting action in mice by Quillaja extract Quillaja saponaria MOLINA bark extract preparation (Quillajanin S-100, containing 25% by weight of Quillaja extract, Maruzen Pharmaceutical Co., Ltd.) was frozen. Dry powder was obtained by drying. This was dissolved in a 5% glucose solution to a concentration of 1% (w / v) to obtain a test sample. As a control, a 5% glucose solution was used.
Mice (C57BL / 6J male, 12 weeks old) were 9 per group, and the 5% glucose + 1% kiraya extract solution prepared above was orally administered with a sonde (kiraya group). A 5% glucose solution was administered to the control group. Ten minutes after administration, the abdomen was opened under deep anesthesia, and blood was collected from the portal vein. The blood was immediately collected in a micro blood collection tube (with EDTA) to which DPPIV inhibitor (Millipore) and aprotinin (Wako Pure Chemical Industries) were added, and centrifuged within 30 minutes after blood collection to obtain plasma. Plasma was immediately frozen in liquid nitrogen and stored at −80 ° C. until GLP-1 quantification. Plasma GLP-1 was quantified with the YK160 GLP-1 EIA kit (Yanaihara Institute).
The results are shown in FIG. GLP-1 secretion was enhanced in mice ingested with Quillaja extract.

Example 3 Suppressive effect on blood glucose increase by Quillaja extract Quillaja saponaria MOLINA bark extract preparation (Quillajanin S-100, containing 25% by weight of Quillaja extract, Maruzen Pharmaceutical Co., Ltd.) It was. This was dissolved in a 5% glucose solution to a concentration of 1% (w / v) to obtain a test sample. As a control, a 5% glucose solution was used.
Mice (C57BL / 6J male, 12 weeks old) were assigned to 9 mice per group, and the 5% glucose + 1% kiraya extract solution prepared above was orally administered with a sonde (kiraya group). A 5% glucose solution was administered to the control group. Ten minutes after the administration, blood was collected from the orbital venous plexus, and the blood glucose level was measured using Accu Check (Roche Diagnostics).
The results are shown in FIG. In the mice ingesting the Kiraya extract, the increase in blood glucose 10 minutes after administration of glucose was suppressed.

Example 1 GLP-1 Secretion Promoting Activity in Cells by Quillaja Extract 50 ml of Quillaja saponaria MOLINA bark extract preparation (Quillajanin S-100, containing 25% by weight of Quillaja extract, Maruzen Pharmaceutical Co., Ltd.) The extract was diluted with 1% ethanol water to a concentration of 1% (w / v) to obtain a test sample. As a control, 50% ethanol water was used.
NCI-H716 cells (human colon-derived cells; purchased from ATCC , developed by Dr. Herbert K. Oie et al. And supplied by agencies of the United States Public Health Service ) were cultured in the presence of 37 ° C., 5% CO ₂ . As the culture solution, RPMI1640 (containing 10% fetal calf serum, high glucose; Invitrogen) was used. Cells were seeded in a 24-well plate coated with Matrigel (100 μL / well; BD) at 1 × 10 ⁶ cells / well (N = 4), and DMEM (containing 10% fetal calf serum, high glucose; Invitrogen) Incubated in medium. Three days later, the medium was replaced with KRB (Krebs-Ringer bicarbonate, Sigma) buffer / 0.2% BSA containing the test sample, and after culturing for 2 hours, the medium was recovered. The medium was collected in a microcentrifuge tube to which diprotin-A (DPP4 inhibitor, Sigma) and PMSF (Phenylmethylsulfonyl fluoride, serine protease inhibitor, Sigma) were added, and after floating cells were removed, until GLP-1 quantification Stored at -80 ° C. GLP-1 in the medium was quantified by ELISA using GLUCAGON-LIKE PEPTIDE-1 (ACTIVE) ELISA KIT (LINCO Research).
The results are shown in FIG. Quillaja extract significantly promoted cellular GLP-1 secretion at concentrations of 0.001% and above.

Claims (10)

  A GLP-1 secretion promoter containing Kiraya or an extract thereof as an active ingredient.   The GLP-1 secretion promoter according to claim 1, wherein the extract is a water extract or an aqueous ethanol extract.   A glucagon secretion inhibitor containing Kiraya or an extract thereof as an active ingredient.   The glucagon secretion inhibitor of Claim 3 whose extract is a water extract or ethanol aqueous solution extract.   An appetite suppressant containing Kiraya or an extract thereof as an active ingredient.   The appetite suppressant according to claim 5, wherein the extract is a water extract or an aqueous ethanol extract.   An agent for preventing and / or improving postprandial hyperglycemia comprising Kiraya or an extract thereof as an active ingredient.   The postprandial hyperglycemia prevention and / or amelioration agent according to claim 7, wherein the extract is a water extract or an aqueous ethanol extract.   An agent for preventing and / or improving diabetes comprising Kiraya or an extract thereof as an active ingredient.   The diabetes preventive and / or ameliorating agent according to claim 9, wherein the extract is a water extract or an aqueous ethanol extract.

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