JP2005213211A - Agent for inhibiting increase of blood glucose level - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an agent for inhibiting the increase of a blood glucose level, capable of readily and safely inhibiting the increase of the blood glucose level in the blood by daily administration. <P>SOLUTION: The agent for inhibiting the increase of the blood glucose level contains a component obtained by culturing a mycelium of basidiomycete such as a shelf fungus and a shiitake mushroom (hentinus edodes) by using a medium containing rice bran, a vegetable fiber-based raw material, preferably, a plant of true grasses, more preferably, at least one kind selected from bagasse, a stalk and phyllome of bamboo grass, and a stem of corn, and extracting the obtained cultured product as an active ingredient. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blood sugar level increase inhibitor comprising a component extracted from a culture obtained by culturing mycelium of basidiomycetes using a medium containing a plant fiber component.

  Diabetes, which is said to be a representative of lifestyle-related diseases, has been increasing year by year, and has been ranked first among chronic diseases, and has increased 50 times over the past 40 years. According to a survey conducted by the Ministry of Health, Labor and Welfare in 1997, there were 6.9 million patients and 6.8 million reserves.

  In today's Japan, you can get as many delicious foods as you can, and these foods are rich in fat, sugar, and low in fiber, and easily fall into an overeating condition when they are full. Cheap. As a result, the blood sugar level is rapidly increased and the pancreas is overused. At the same time, it is possible to live with little effort due to the development of the civilization, and it is naturally in a state of lack of exercise, which is the cause of diabetes.

  Diabetes means that glucose in the blood remains above a certain level. That is, it refers to a metabolic disease that causes chronic hyperglycemia due to insufficient secretion of insulin hormone from the pancreas or a decrease in action. Insufficiency of insulin is caused by a decrease in insulin secretion and also by a decrease in insulin sensitivity (insulin resistance) in muscle, liver, fat and the like. If hyperglycemia continues, serious complications will occur in the eyes, kidneys and nerves.

  Diabetes is also said to be a “silence disease”, and even if the blood glucose level is high, it is difficult to produce subjective symptoms immediately. Therefore, complications such as diabetic nephropathy, diabetic retinopathy, and neuropathy that become artificial dialysis when noticed. It is a disease that is often progressing. Once it develops, it is difficult to treat, so you must try to prevent it.

  The basis of diabetes prevention is diet and exercise, but restricting meals on a daily basis in an environment full of delicious foods can be a great stress. Also, it is not so easy to forcibly exercise in the daily lives of busy modern people who are busy with time.

  Therefore, attention has been paid to a method of making digestion absorption milder by inhibiting carbohydrate digestive enzymes, and α-glucosidase inhibitors are actually used as therapeutic agents for diabetic patients.

  In addition, a method for suppressing the diffusion of nutrients in the digestive tract and delaying digestion is also known, and certain types of dietary fiber have been put into practical use.

  On the other hand, basidiomycetous fruit bodies and mycelia, or extracts thereof, are known to have various physiologically active functions, and have been proposed as preventive / therapeutic agents for diabetes or inhibitors for increasing blood sugar levels. .

  For example, Patent Document 1 below discloses an anti-diabetic agent containing a water extract of the fruit body of a jellyfish.

  Patent Document 2 listed below discloses an antihyperglycemic agent containing a fruit body of Agaricus blazei and / or an extract of mycelium as an active ingredient.

  Furthermore, Patent Document 3 listed below discloses an antiglycemic inhibitor comprising as an active ingredient an extract obtained by subjecting a gold ear fruit body or mycelium to extraction treatment with water, a concentrated solution thereof, a dried product thereof or a dried pulverized product thereof. ing.

  Furthermore, the following Patent Document 4 discloses a substance having an improvement effect on type I and type II diabetes, which comprises a soluble substance obtained by hydrothermal treatment of a mycelium or fruit body of maitake as an active ingredient. ing.

On the other hand, in Patent Document 5 below, a solid medium containing mycelium obtained by inoculating shiitake fungus on a solid medium based on bagasse and then growing the mycelium is unbundled, and this bundle is released. To the solid medium, water and one or more enzymes selected from cellulase, glucosidase or protease are added while keeping the solid medium at 30 to 50 ° C., and then heated to a temperature up to 95 ° C. An antioxidant containing a shiitake mycelium extract obtained by inactivation and sterilization is disclosed. The antioxidant is used for treatment of diseases involving oxidative cell damage, such as digestive system diseases, respiratory diseases, diabetic complications, skin diseases, cancer, and aging. Or it is described that it is used for prevention.
JP 2002-275087 A Japanese Patent Laid-Open No. 11-80014 JP-A-9-67268 JP-A-6-312936 JP 2003-12538 A

  From the viewpoint of diabetes prevention, it is better to take foods with a preventive effect on a daily basis, but in the case of dietary fiber, the effect is difficult to exert unless it is added before the taste or quality of the food itself is changed. there were.

  In addition, the conventional preventive / therapeutic agent for diabetes or the blood sugar level increase inhibitor described in Patent Documents 1 to 4 each include an ingredient extracted from the fruiting body and / or mycelium of basidiomycetes as an active ingredient, No attention has been paid to the components resulting from the medium raw material.

  Patent Document 5 describes that an ingredient extracted from a solid medium containing mycelia of Shiitake mushrooms is used as an antioxidant, and the antioxidant is used for the treatment and prevention of diabetic complications. However, there is no suggestion of a therapeutic effect on diabetes itself, an inhibitory action on an increase in blood glucose level, or the like.

  Accordingly, an object of the present invention is to provide a blood glucose level increase inhibitor that can easily and safely suppress an increase in blood glucose level by daily ingestion.

  As a result of various researches on basidiomycetes such as shiitake mushrooms over many years, the present inventors have found that substances in mycelium cultures of basidiomycetes have an action of suppressing an increase in blood glucose level. It came to complete.

  That is, the blood glucose level elevation inhibitor of the present invention is a component extracted from a culture obtained by culturing mycelium of basidiomycetes using a medium containing plant fiber raw material, And water-soluble lignin as a main component.

  In this invention, it is preferable that the said plant fiber raw material contains a scallop.

  The plant fiber material preferably contains at least one selected from bagasse, bear stems and corn stalks, and rice bran.

  Furthermore, it is preferable that the basidiomycete is mannen or shiitake mushroom.

  The inhibitor of blood sugar level elevation of the present invention includes cellulase, phenol oxidase, laccase, peroxidase, protease, etc. produced by mycelial cells of basidiomycetes during the culture period, such as cellulose, hemicellulose, lignin contained in plant tissues It consists of a substance in which a modified water-soluble lignin that has been modified by an enzyme and water-solubilized by a pentose-based proteoglycan produced by digestion, degradation, and condensation by an enzyme is combined. And this substance inhibits the production of glucose by inhibiting the α-glucosidase activity prepared from the intestinal tract of rats in a concentration-dependent manner, as shown in Examples described later. Furthermore, in an animal sugar tolerance test, administration of this drug before administration of sugar significantly suppresses an increase in blood glucose level.

  As described above, by ingesting the blood sugar level increase inhibitor of the present invention, it is expected to suppress an increase in blood sugar level (glucose concentration in the blood), prevent diabetes and suppress obesity. Moreover, the blood glucose level elevation inhibitor of the present invention is a product obtained from a natural product, and can be easily taken in daily life without worrying about the side effects seen in chemicals and the like.

  The basidiomycetes used in the present invention include edible mushrooms such as shiitake mushrooms, Japanese cypress mushrooms, mai mushrooms, enoki mushrooms, shimeji mushrooms, and yamabushi mushrooms, and various varieties such as medicinal mushrooms such as mannen mushrooms, bukuryo, kofukisarno mushrooms, and kawara mushrooms. Is mentioned. Among these, shiitake mushrooms and mannen mushrooms are particularly preferably used.

  In the present invention, mycelia of these basidiomycetes are cultured, and active ingredients are extracted from the culture. In this case, either a solid medium or a liquid medium can be used as the medium, but a medium containing a plant fiber component, preferably a medium prepared from a plant containing lignin is used. As the lignin-containing plant, a plant family such as bagasse (squeezed sugar cane), corn stover, wheat bran, rice bran, rice straw, and straw are preferably used. In addition, bears, bamboo, etc. can be used. Moreover, you may add and mix yeast extract, dry yeast, chlorella, spirulina, corn meal, etc. as another nutrient component as needed.

  The mycelium of basidiomycetes is cultured by inoculating a mycelium that has been germinated and grown from spores into a medium mainly composed of the above-mentioned plants. In the case of a solid medium, the water content is adjusted to 60 to 80% by mass, sterilized by high-pressure steam according to a conventional method, then inoculated with mycelia, for example, 3 to 3 in a culture room conditioned at 18 to 25 ° C. Incubate for 6 months. The medium in which the mycelium has spread is preferably transferred to a temperature treatment chamber and subjected to a temperature change treatment. In the temperature change treatment, for example, the mixture is first heated at 30 to 34 ° C. for 24 to 48 hours, and then transferred to a low temperature chamber and treated for 3 to 5 days. After that, when it is moved to a culture room, the generation of fruiting bodies starts. At this point, the culture is terminated and the culture is crushed with a crusher.

  On the other hand, in the case of a liquid medium, the plant raw material is finely crushed, and if necessary, other nutrients such as rice bran are added and the medium is prepared so that the raw material becomes 5 to 20% by mass, and then aeration stirring culture or By shaking culture, culture is preferably performed at a temperature of 20 to 28 ° C. for about 2 weeks to 2 months. The culture is terminated when the pH of the medium is lowered to 3.0 to 3.5 and the mycelium is prevalent in the medium.

After completion of the culture, the mycelium is self-digested using an enzyme present in the mycelium and the culture is extracted. As a preferable method, in the case of a solid medium, the cultured culture is crushed, a small amount of water is added as necessary, and the mycelium is subjected to an enzymatic reaction for 3 to 6 hours at 30 to 60 ° C. to self digest Let Next, the crushed material is infiltrated with hot water or hot water of 50 ° C. or higher to extract active ingredients. The extraction can also be carried out under a high pressure such as 120 ° C. under a vapor pressure of 1.2 kg / cm ² , for example. The extract suspension thus obtained is preferably filtered or centrifuged, and the filtrate or supernatant is collected to obtain the mycelium metabolite and the active ingredient contained in the mycelium cells.

On the other hand, in the case of liquid culture, the whole culture is treated at 30 to 60 ° C. for 3 to 6 hours to self-digest mycelium to obtain a liquid suspension culture. Then, if necessary, a small amount of water is added, and the mixture is heated at 50 ° C. or higher, sometimes under high pressure conditions (for example, under a vapor pressure of 1.2 kg / cm ² ) to obtain an extract. The extract is filtered or centrifuged as necessary, and the filtrate or supernatant is collected to obtain the active ingredient.

  The blood sugar level elevation inhibitor of the present invention can be produced as it is by concentrating the extract obtained by the above method as it is or by concentrating the extract on freeze drying or spray drying. It can also be pulverized. As shown in the examples described later, the powder obtained from this extract was mainly composed of saccharides, proteins, and water-soluble lignin, and was confirmed to have an effect of suppressing an increase in blood glucose level.

The extract thus obtained was a substance mainly composed of carbohydrates, but was confirmed to have the following physicochemical properties.
(I) Molecular weight: 20,000-1 million (ii) Chemical composition Carbohydrate: 30-50%
Protein: 8-15%
Water-soluble lignin: 20-40%

In addition, the result of having tested safety | security about the said culture extract (powder) obtained using shiitake mushroom is as follows.
(A) Acute toxicity (LD50mg / kg)
(I) Oral administration for 7 days Mouse Male: 19600 Female: 17700
Rat Male: 16400 Female: 15600
(Ii) Intraperitoneal mouse Male: 5500 Female: 4920
Rat Male: 2490 Female: 2270
(B) Subacute toxicity (mg / kg), maximum no-effect mouse Male: 6740 Female 9100
Rat Male: 3840 Female 7910

  Moreover, the effective dosage of the blood sugar level elevation inhibitor of the present invention is 1 to 10 g per day for an adult when taken orally. If the dose is smaller than this, the effect of suppressing an increase in blood glucose level in vivo cannot be sufficiently obtained, and if the dose is larger than this, loose stool or abdominal bloating may occur. However, there is no problem in safety even if the dose is larger than the above.

  The blood sugar level elevation inhibitor of the present invention can be commercialized as powders, granules, tablets, and capsules by conventional methods. Moreover, an extract can be added and commercialized as a liquid or jelly-like beverage. Furthermore, the blood sugar level increase inhibitor of the present invention can be added to various foods and drinks to produce a food or drink that can be expected to have an effect of suppressing blood sugar level rise.

Example 1
(1) Solid culture of Mannentake fungus 90% bagasse and 10% defatted rice bran were mixed to prepare a solid medium by adjusting the water content to 70%, followed by autoclaving as usual. This was inoculated with mycelia mushrooms and cultured for 3 months in a culture chamber adjusted to 25 ° C. After the mycelium had spread in the medium, it was transferred to a temperature treatment chamber and heated at 35 ° C for 24 hours, and then 10 ° C. Treated in a cold room at 3 ° C for 3 days. Then, after culture | cultivating for 3 days in a culture room, the culture medium was crushed with the crusher to the magnitude | size about the thumb. The crushed medium was treated at 40 ° C. for 6 hours to promote autolysis, then packed in an extraction tank and extracted for 16 hours while circulating 60 ° C. warm water. The obtained extract was filtered through a cartridge filter, further sterilized by filtration through a membrane filter, concentrated, and freeze-dried to obtain a brown powder. Hereinafter, this powder is referred to as “present powder”.

  As a result of analyzing the components of this powder, it was as follows.

Carbohydrate: 40% (phenol sulfate method)
Protein: 12% (semi-micro Kjeldahl method)
Water-soluble lignin: 30% (acetyl bromide method)
Inorganic: 13% (direct ashing method)

(2) Blood sugar level increase inhibitory activity When this powder was used, the inhibitory activity of α-glucosidase was measured. α-Glucosidase is also called maltase and is an enzyme that hydrolyzes α-glucoside bonds. Glucose is produced by acting on maltose (a product in which two molecules of glucose are combined), amylose and the like, which are constituents of starch.

(I) Preparation of enzyme solution As the maltase, a commercially available enzyme preparation (Sigma: I1630) was used. A 9-fold amount of 56 mM maleate buffer (pH 6.0) was added to the enzyme powder, homogenized with a glass homogenizer in ice, and centrifuged (4 ° C., 3000 rpm, 10 min) to obtain an enzyme solution. The inactivated enzyme preparation used was the above enzyme solution heated at 100 ° C. for 20 minutes.

(Ii) Method for measuring enzyme inhibitory activity In 20 μL of 2% maltose solution (substrate), this powder (0.15 mg / ml to 300 mg / ml) prepared in various concentrations and 56 mM maleate buffer (pH 6.0), etc. After the addition, the mixture was incubated at 37 ° C. for 5 minutes, 20 μL of the enzyme solution was added, and the mixture was incubated at 37 ° C. for 30 minutes. After the reaction, the reaction was stopped by heating in boiling water for 10 minutes to deactivate the enzyme. After stopping the reaction, the mixture was centrifuged (3000 rpm, 10 min), and the amount of glucose in the supernatant was measured using “Glucose CII-Test Wako” (trade name, manufactured by Wako Pure Chemical Industries, Ltd.). Maltose and this powder were dissolved in the maleate buffer. For each sample, a buffer solution was added as a control, and an inactivated enzyme solution was used as a blank. The inhibitory activity (%) was calculated from the amount of glucose produced by the solution with or without the addition of the present powder, with the amount of control produced glucose being 100%. All results are shown with the blanks subtracted.

(Iii) Measurement Results of Enzyme Inhibitory Activity FIG. 1 is a chart in which the relationship between the concentration of this powder and maltase inhibitory activity is measured. As shown in the figure, this powder inhibited maltase activity in a dose-dependent manner at a concentration of 10 mg / ml to 100 mg / ml. 100 mg / ml inhibited 65% of the activity when the control was 100.

  FIG. 2 is a chart showing the results of measuring the amount of glucose produced over time with the concentration of the present powder being 50 mg / ml, which is the concentration when maltase is inhibited by 50% in FIG. In this case, the inhibitory activity was observed after 15 minutes as compared with the control group, and the inhibitory activity was continuously observed until 2 hours later. It was confirmed that this powder continuously inhibited the production of glucose.

(Iv) Blood glucose level increase inhibitory effect in animals Next, the blood glucose level increase inhibitory effect of the present powder in animals was examined. That is, 1 g / kg of this powder was orally administered to 7-week-old male ICR mice. After 30 minutes, 2 g / kg of maltose was loaded, and blood glucose level was measured every 30 minutes. The result is shown in FIG.

  As shown in FIG. 3, in the mice administered with this powder, the increase in blood glucose level at 30 minutes and 60 minutes after maltose load was significantly suppressed as compared with the control group (distilled water). In this test, the area under the blood glucose curve in the powder administration group decreased by about 20% compared to the control group. Further, in this case, no increase in blood glucose level was observed in the administration without maltose load, and thus it was confirmed that this powder acts only in the presence of sugar and has no influence on the living body.

(3) Purification of active ingredient The refinement | purification fraction of the maltase inhibitory active ingredient of this powder was tried. That is, this powder is dissolved in water, ethanol is added so that the ethanol concentration becomes 80%, the produced precipitate is recovered and freeze-dried, and the resulting powder is dissolved in water, using Sephadex G-200. Column gel filtration was performed. Elution was carried out with water, and the void fraction was collected using the absorbance at 280 nm as an index to collect MP-1, and subsequently the eluted fraction was collected as MP-2. After concentration under reduced pressure, dialyzed with water and freeze-dried (Fig. 4).

  Subsequently, the inhibitory activity of maltase was observed in vitro for MP-1 and MP-2. As a result, MP-1 showed no inhibitory activity of maltase at any concentration of 25, 50 and 100 mg / ml. On the other hand, as shown in FIG. 5, MP-2 was found to have an inhibitory activity of 11% at 50 mg / ml and 60% at 100 mg / ml, and the main active ingredient of this powder was present on the low molecular weight side. MP-2 was sugar 45%, protein 25%, and water-soluble lignin 25%.

Example 2
Shiitake mushrooms were inoculated into the same medium as in Example 1 for solid culture, and the same treatment as in Example 1 was performed to obtain an extract. The components of the freeze-dried product of this extract were as follows.

Carbohydrate: 35%
Protein: 11%
Water-soluble lignin: 35%
Inorganic: 12%

  As a result of measuring the in vitro maltase inhibitory activity of this extract, as shown in FIG. 6, this substance has an inhibitory activity of 65% at 25 mg / ml, 75% at 50 mg / ml, and 100% at 100 mg / ml. Indicated.

Example 3
The leaves and stems of kumamushi were washed well, dried and crushed, a rice bran was mixed at a weight ratio of 20% to prepare a solid medium, and shiitake mycelium was cultured thereon, and an extract was obtained in the same manner as in Example 1. . This extract obtained maltase inhibitory activity in vitro as in Example 1.

Example 4
Corn stalks are washed with water, dried and crushed, and rice bran is 20% by weight, adjusted to 70% moisture, a solid medium is prepared, and mycelia of mannentake are cultured and extracted in the same manner as in Example 1. The resulting solution inhibited maltase activity as in Example 1.

Example 5
A liquid culture medium prepared by adding 100 g of bagasse finely crushed with a mixer in a ratio of 1 g of water, 20 g of rice bran, and 5 g of yeast extract was autoclaved as usual, and inoculated with shiitake mycelia. After aeration (aeration rate: 5 L / min) and stirring (50 rpm) at 23 ° C. for 2 weeks, the culture was heated at 40 ° C. for 3 hours to allow the mycelial enzyme to self-digest. Thereafter, the mixture was sterilized by heating at 80 ° C. for 1 hour to extract metabolites. The extract was centrifuged at 3000 rpm for 30 minutes to remove the precipitate, and further centrifuged at 10,000 rpm to obtain a brown liquid. This extract was freeze-dried and had the following composition.

Carbohydrate: 38%
Water-soluble lignin: 35%
Protein: 16%
Other: 11%

  This product inhibited maltase in vitro as in Example 2.

Example 6
Example of a 55 year old man:
I have been diabetic since I was 30 years old and took urea drugs in the morning and evening, calculated calories every day for 10 years, and measured blood glucose levels with a blood glucose checker. Two weeks after drinking 3 g of the powder obtained in Example 1 per day, the fasting blood glucose level of 110 to 140 for 10 years or more dropped to 70 to 80.

Example 7
Example of a 65 year old woman:
Hospitalized for diabetes in Fukuoka Prefecture K Hospital. The fasting blood glucose level at admission was 263 mg / dl, and the blood glucose level at 2 hours after meals was 465 mg / dl. 2g / day of the dried extract obtained in Example 2 with only diet that dislikes insulin. In two months, hunger decreased to 139 and 2 hours after meal to 194. He went back to hospital and continued to take the medicine. During this time, no side effects such as phytotoxicity were observed.

  The blood sugar level increase inhibitor of the present invention is intended to prevent and treat diabetes by suppressing an increase in blood sugar level by being taken daily by diabetic patients or people who may have diabetes. It can be used as pharmaceuticals and health foods.

It is a graph which shows the result of having measured the relationship between the density | concentration of the powder obtained in Example 1, and maltase inhibitory activity. It is a graph which shows the result of having measured the production | generation amount of glucose over time by making the density | concentration of the powder obtained in Example 1 into 50 mg / ml. It is a graph which shows the result of having orally administered to the mouse | mouth the powder obtained in Example 1, loading a predetermined amount of maltose 30 minutes later, and measuring a blood glucose level every 30 minutes. It is a graph which shows the result of having melt | dissolved the powder obtained in Example 1 in water, and performing column gel filtration using Sephadex G-200. It is a graph which shows the result of having observed the inhibitory activity of maltase in vitro about the fraction of MP-2 obtained by the said column gel filtration. It is a graph which shows the result of having measured the relationship between the density | concentration of the extract obtained in Example 2, and maltase inhibitory activity.

Claims (4)

  It is a component extracted from a culture obtained by culturing mycelia of basidiomycetes using a medium containing plant fiber raw material, and contains saccharides, proteins, and water-soluble lignin as main components. A blood glucose level increase inhibitor characterized by the above.   The blood sugar level increase inhibitor according to claim 1, wherein the plant fiber raw material contains a succulent plant.   The blood sugar level increase inhibitor according to claim 2, wherein the plant fiber raw material contains at least one selected from bagasse, bear leaves, and corn stalks, and rice bran.   The blood sugar level increase inhibitor according to any one of claims 1 to 3, wherein the basidiomycete is mannen or shiitake mushroom.

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