JPH07228539A - Extrct from leaf lagerstroemia speciosa and antidiabetic agent - Google Patents

Abstract

PURPOSE:To obtain an antidiabetic agent, containing a specific fraction of an extract from a leaf of Lagerstroemia speciosa as an active ingredient and having remarkable hypoglycemic actions. CONSTITUTION:This extract from a leaf of Lagerstroemia speciosa is obtained by extracting a dried and pulverized leaf of the Lagerstroemia speciosa with hot water at 60-100 deg.C, preferably 95-IOOC, an organic solvent (e.g. methanol or ethanol) or a mixed solution of the organic solvent with hot water, then adsorbing the resultant crude extract on a styrene-divinylbenzene-based synthetic resin or a dextran-based synthetic resin, flowing distilled water therethrough, discharging the fraction unadsorbed on the resin and, on the other hand, eluting the ingredient adsorbed on the resin with an organic solvent. Thereby, the antidiabetic agent having more improved pharmacological effects than those of a crude extract is obtained by using the result extract from the adsorbed portion as an active ingredient. Remarkable hypoglycemic actions are recognized in the adsorbed fraction as compared with those of the unadsorbed fraction in tests using a mouse suffering from II type hereditary diabetes.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to banaba leaves (Lagerstroemia speciosa) from Southeast Asia, including the Philippines.
l.) and an antidiabetic agent.

[0002]

2. Description of the Related Art Banaba is a plant of the family Liliaceae that is distributed in tropical Asia, and is also known as Pleurotus cornucopia. In the Philippines, which is the place of origin for a long time, these leaves have been decocted and consumed. On the other hand, however, since Banaba leaves were produced in the tropics, they were heavily contaminated with various bacteria, and required a sufficient sterilization operation for normal drinking.

Therefore, conventionally, in order to extract this main component, first, banaba leaves were crushed and then heat-sterilized,
A method of brewing this directly or in tea bags and brewing for a long time as in the case of traditional Chinese medicine has been adopted. However, the extract once decocted is perishable and does not last as long as it is, so it is necessary to decoct the required amount every day, which is very troublesome and troublesome.

Although it has been generally known that the above-mentioned medicinal properties for drinking are effective, its antidiabetic active ingredient has not been confirmed, and it is difficult to industrially produce it as a highly pure antidiabetic agent. Met.

Therefore, the present inventor extracted banaba leaves with hot water, an organic solvent or a mixed solution of an organic solvent and hot water, concentrated the extract solution and dried it to obtain a dry powder. Proposed an industrially-produced Banaba leaf extract extract, and clinically confirmed the pharmacological effect of the Banaba leaf extract extract as an antidiabetic agent (Japanese Patent Laid-Open No. 5-310587).

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made by further researching the above-mentioned banaba leaf extract. The object of the present invention is to remove banaba leaf from hot water, an organic solvent, or an organic solvent. By further separating and purifying the extract obtained by extraction with a mixed solution of a solvent and hot water, a banaba leaf extract and an antidiabetic agent that have a higher antidiabetic effect and can be safely used are obtained. Especially.

[0007]

In the present invention, a crude extract obtained by extracting banaba leaves with hot water, an organic solvent or a mixed solution of an organic solvent and hot water is used as a styrene-divinylbenzene synthetic resin. Alternatively, by adsorbing onto a dextran-based synthetic resin and eluting the resin-adsorbed component with an organic solvent, a banaba leaf extract component having a higher antidiabetic effect was successfully separated and purified from the crude extract. In addition, we succeeded in obtaining an antidiabetic agent using the separated and purified Banaba leaf extract as an active ingredient.

The banaba leaf extract according to the present invention is obtained by extracting dried and crushed banaba leaves with hot water at a temperature of about 60 ° C to 100 ° C, preferably close to or above the boiling point, that is, 95 ° C to 100 ° C. Either extraction with a solvent such as methanol or ethanol, extraction with a mixed solution of an organic solvent and water, or extraction of the residue after the above hot water extraction with a mixed solution of an organic solvent or an organic solvent and water is performed. Obtainable. At this time, the amount of hot water, the organic solvent, or the mixed solution of the organic solvent and water is 1:10 to 1: 100, preferably about 1:25 with respect to the weight of the dried banaba leaf. .

As the styrene-divinylbenzene synthetic resin in the present invention, DIAIO manufactured by Mitsubishi Kasei Co., Ltd.
N HP-10,20,30,40,50, Amberlite XAD-2,4 manufactured by Organo Co., or Duolite s series manufactured by Sumitomo Chemical Co., Ltd. , Sephadex LH-20 manufactured by Pharmacia can be used. Incidentally, the dextran-based synthetic resin, since the dextran chains constituting it form a three-dimensionally crosslinked polysaccharide-like stitch, the ratio of the number of carbon atoms to the hydroxyl group is relatively large, especially LH-20 In particular, since each glucose unit of the dextran chain has a hydroxypropyl group which is ether-bonded, it is particularly large. Therefore,
Dextran type synthetic resin gel, especially LH-20 is hydrophilic,
It has both lipophilic properties and can be considered to be similar to the styrene-divinylbenzene-based synthetic resin in terms of adsorptivity. However, at present, the styrene-divinylbenzene-based synthetic resin is superior from the economical point of view.

The antidiabetic agent of the present invention is a styrene-divinylbenzene-based synthetic resin or dextran-based resin obtained by extracting a crude extract obtained by extracting banaba leaves with hot water at about 60 ° C to 100 ° C or an organic solvent. Banaba leaf extract obtained by adsorbing to a synthetic resin and eluting the resin-adsorbed component with an organic solvent can be obtained as an active ingredient, and its antidiabetic effect could be confirmed by an animal test using diabetic mice. .

[0011]

【Example】

[Production method] Fresh leaves of Philippine Banaba are dried naturally or forcibly and adequately and then crushed with a crusher. 1 kg of well-mixed Banaba leaves is squeezed in about 50 liters of distilled water for about 30 minutes. Extracted at 100 ° C. The obtained extract was filtered, centrifuged, and then concentrated by an evaporator and dried by a method such as freeze-drying or spray-drying to obtain a crude extract (banaba leaf extract). At this time, the yield of the crude extract was about 10% (W / W) based on the dried banaba leaf (raw material).

Next, 2.5 liters of a styrene-divinylbenzene synthetic resin (product name: DIAION HP-20 manufactured by Mitsubishi Kasei Co., Ltd.) was filled in a glass column having a diameter of 10 cm and a length of 100 cm, and this filling was performed. After the agent was washed with methanol and further washed with distilled water, the crude extract (total amount) was dissolved in 1 liter of distilled water, and this was poured into a glass column. Then, about 6 times as much distilled water as the column volume was flowed to flow out the fraction not adsorbed on the styrene-divinylbenzene-based synthetic resin (hereinafter referred to as non-adsorbed fraction), while 10 times the equivalent of about 5 times
A fraction adsorbed on the styrene-divinylbenzene-based synthetic resin (hereinafter referred to as an adsorption fraction) was eluted by flowing 0% methanol. The non-adsorbed fraction and the adsorbed fraction thus obtained were concentrated and dried by a method such as freeze-drying or spray-drying to obtain a dry powder. The yields at this time were about 4.3% for the non-adsorbed fraction and about 2.7% for the adsorbed fraction based on the dried banaba leaf (raw material).

[Antidiabetic agent action test] Using a type II hereditary diabetic mouse, an antidiabetic action test of banaba leaf extract was tested as follows.

The adsorbed fraction and the non-adsorbed fraction obtained by the above-mentioned production method were used as test samples, and KKA ^y was used as an experimental animal.
T ^a J ^c1 mice (type II inherited diabetic mice) were used.

Type II hereditary diabetic mice (4 weeks old) were fed a basic diet (gasein 25.0% (W / W) (hereinafter% (W / W) omitted), salt mixture 3.5, vitamin mixture 1.0. , Vitamin C and vitamin K 0.2, choline chloride 0.2, corn oil 5.
After breeding for 1 week with 0, sugar 51.0, starch (α) 14.1), it was divided into 3 groups of 7 animals per group, and 1 group contained 5.0% (W / W) of the above basic diet. A diet to which a considerable amount of cellulose was added was used as a target group, and to the other group, a diet to which an adsorbed fraction equivalent to 2.0% (W / W) thereof was added to the above basic diet was administered ( Hereinafter, referred to as "adsorption fraction group"), to yet another group, a diet prepared by adding a non-adsorption fraction equivalent to 3.0% (W / W) to the above basic diet (hereinafter, "Non-adsorbed fraction group"), and each was bred for 6 weeks. The diet was orally administered.

The body weight, feed intake and water intake of the mice before and during the rearing were measured, and the results are shown in Table 1. Further, tail vein blood of the mouse was collected every week to quantify the blood glucose level, and the results are shown in Table 2 and FIG. The results were statistically processed by Student-t test.

[0017]

[Table 1]

[0018]

[Table 2]

From Table 1, there was no significant difference in weight gain and feed intake between the groups, but in regard to blood glucose level, from Table 2 and FIG. A clear significant difference could be seen between the groups. In addition, it was also confirmed that this blood glucose elevation inhibitory effect became more prominent over the course of the week.

Therefore, the adsorbed fraction suppresses the increase in blood glucose.
It can be confirmed that it is significantly superior to the action of the non-adsorbed fraction, and from this, if the above-mentioned adsorbed fraction is extracted from the banaba leaf crude extract, it is possible to separate and purify components having a higher antidiabetic effect. It became clear that Also,
It was also found that when a diet containing an adsorbed fraction is administered from the time when the onset of diabetes is observed, a sufficient blood glucose elevation suppressing effect can be obtained.

[Effective amount] As shown in Table 1, the amount of feed consumed by 7 mice (adsorption fraction group) per week was 29.5 g.
Is. From this, one mouse is about 0.012 per day
It is sufficient to ingest the adsorbed fraction of g, and since the average weight of the mouse is about 22 g, it is sufficient for the mouse to ingest the adsorbed fraction of about 0.55 g per 1 kg of body weight per day. It is possible to obtain various antidiabetic action effects. However, since human sensitivity is higher than that of mice, when the adsorbed fraction is administered to humans, a dose of 1/10 to 1/100 of the dose for mice is sufficient. It is estimated to be.

[Toxicity test] To a type II hereditary diabetic mouse, a diet prepared by adding a crude extract obtained in the same manner as in the above production method to the above basic diet in an amount equivalent to 5% (W / W) of the basic diet was used. When observed orally for 6 consecutive weeks, no side effects were observed in the mice during and after the administration.

[0023]

According to the present invention, a crude extract obtained by extracting banaba leaves with hot water, an organic solvent, or a mixed solution of an organic solvent and hot water is further added to a styrene-divinylbenzene synthetic resin or dextran. By adsorbing the resin-adsorbed component on the system synthetic resin and eluting the resin-adsorbed component with an organic solvent, a component having a more excellent antidiabetic effect can be separated and purified from the crude banaba leaf extract component. As a result, we succeeded in obtaining an antidiabetic agent having a more excellent pharmacological effect.

The antidiabetic agent of the present invention can exert a sufficient pharmacological effect when it is administered at least when the symptoms of diabetes are observed. Regarding its safety,
It can be confirmed by the toxicity test described above, although it is clear from the fact that teas from which banaba is brewed for a long time have been always consumed in the Philippines and the like.

The banaba leaf extract of the present invention is sterilized by autoclaving and frozen, for example, freeze-dried to obtain a banaba leaf extract powder extract, which is diluted to an appropriate concentration for drinking,
It can be made into canned drinks and bottled drinks to be cheaply drinkable, or it can be molded into tablets, capsules, granules or the like to prepare pharmaceuticals or semi-pharmaceuticals. Further, it can be mixed with other crude drugs or juices to prepare a special nutrition food or a special nutrition drink. At this time,
After adjusting the concentration of the Banaba leaf extract and packing it in a container, it is retort sterilized, or the pH of this extract is adjusted to less than 4.6 and the center temperature is heated at about 85 ° C for 10 minutes, etc. If sterilized by the method described above, it can be provided after being sterilized under the conditions specified by the Food Sanitation Law.

[Brief description of drawings]

FIG. 1 is a graph showing the blood sugar effect of the Banaba leaf extract according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kawasaki 21 Goddess Sagara-cho, Haibara-gun, Shizuoka Prefecture Itoen Central Research Institute (72) Inventor Hisao Nao Takeuchi 2787-34 Otani, Shizuoka-shi

Claims (2)

[Claims] 1. A styrene-divinylbenzene-based synthetic resin comprising a crude extract obtained by extracting banaba leaves with hot water at about 60 ° C. to 100 ° C., an organic solvent, or a mixed solution of an organic solvent and hot water. Alternatively, a banaba leaf extract obtained by adsorbing it on a dextran-based synthetic resin and eluting the resin-adsorbing component with an organic solvent. 2. An antidiabetic agent comprising the resin adsorbing component according to claim 1 as an active ingredient.