阅读说明：本技术 醋炙五味子多糖提取物在制备治疗糖尿病的药物中的应用 (Application of vinegar-roasted schisandra polysaccharide extract in preparation of medicine for treating diabetes ) 是由 王敏 闫东 矫林彤 唐菊菊 于 2021-07-27 设计创作，主要内容包括：本发明涉及醋炙五味子多糖提取物及其制备方法,以及醋炙五味子多糖提取物在制备预防和/或治疗糖尿病的药物中的应用。所述醋炙五味子多糖提取物增强所述受试者的糖耐量,加速外源性葡萄糖的消耗,降低所述受试者的血糖浓度,提高所述受试者的血浆胰岛素水平,恢复所述受试者胰岛β细胞的正常细胞形态。(The invention relates to a polysaccharide extract of vinegar-roasted schisandra chinensis and a preparation method thereof, and application of the polysaccharide extract of vinegar-roasted schisandra chinensis in preparing a medicament for preventing and/or treating diabetes. The vinegar-roasted schisandra chinensis polysaccharide extract enhances the sugar tolerance of the subject, accelerates the consumption of exogenous glucose, reduces the blood sugar concentration of the subject, improves the plasma insulin level of the subject and restores the normal cell morphology of the islet beta cells of the subject.)

1. Use of a vinegar-roasted schisandra chinensis polysaccharide extract for the preparation of a medicament for the prevention and/or treatment of diabetes in a subject in need thereof.

2. The use as claimed in claim 1, wherein the polysaccharide content of the polysaccharide extract of schisandra fruit processed with vinegar is above 60 w/w%, preferably the polysaccharide content of schisandra fruit processed with vinegar is 60-80 w/w%.

3. Use according to claim 2, characterized in that the uronic acid content of the polysaccharide extract is between 8 w/w% and 15 w/w% and the glycoprotein content is between 20 w/w% and 40 w/w%, preferably the uronic acid content is between 9.21 w/w% and the glycoprotein content is 25.6 w/w%.

4. Use according to any one of claims 1 to 3, characterized in that the polysaccharide consists of xylose, arabinose, glucose, rhamnose, mannose, galactose, glucuronic acid and galacturonic acid.

5. Use according to claim 4, characterized in that the polysaccharide extract has a polysaccharide content of 63.6 w/w%, the polysaccharides comprising 2.67 w/w% xylose, 30.02 w/w% arabinose, 2.01 w/w% glucose, 6.56 w/w% rhamnose, 1.25 w/w% mannose, 22.51 w/w% galactose, 2.18 w/w% glucuronic acid and 16.44 w/w% galacturonic acid.

6. The use according to any one of claims 1 to 5, wherein the diabetes is type II diabetes.

7. The use according to claim 6, wherein said polysaccharide extract of schisandra fruit processed with vinegar enhances sugar tolerance of said subject, accelerates the consumption of exogenous glucose, lowers the blood glucose concentration of said subject, and/or said polysaccharide extract of schisandra fruit processed with vinegar raises the plasma insulin level of said subject, restoring the normal cell morphology of the islet beta cells of said subject.

8. The use according to claim 6, wherein the medicament further comprises other antidiabetic agents commonly used in clinic, preferably the other antidiabetic agents are DPP-4 inhibitors or SGLT-2 inhibitors, and the weight ratio of the polysaccharide extract of schisandra fruit processed with vinegar to the other antidiabetic agents is 5: 1-20: 1, preferably 10: 1.

9. the use as claimed in any one of claims 1 to 8, wherein the vinegar-roasted schisandra chinensis is prepared by the following steps:

(1) adding rice vinegar into fructus Schisandrae decoction pieces, stirring, and moistening at room temperature;

(2) steaming until vinegar is absorbed, removing the surface to dry;

preferred step (1): the mixing ratio of the schisandra chinensis decoction pieces to the rice vinegar is 5: 1, moistening for 1.5 hours; preferred step (2): the steaming time is 5 hours.

10. The use as claimed in any one of claims 1 to 9, wherein the vinegar-roasted crude schisandra chinensis polysaccharide is prepared by the following steps:

(1) reflux-extracting fructus Schisandrae with 95 v/v% ethanol, filtering with 4 layers of gauze, and mixing filtrates;

(2) air drying, reflux extracting with distilled water, filtering the water extractive solution with 16 layers of gauze, mixing filtrates, and centrifuging;

(3) filtering, concentrating, precipitating with 95 v/v% ethanol, and standing;

(4) suction filtering, recovering and storing the filtrate, and alternately washing filter residues with absolute ethyl alcohol and acetone;

(5) washing, dissolving with deionized water, and freeze drying to obtain vinegar processed fructus Schisandrae crude polysaccharide;

preferred step (1): extracting with ethanol under reflux for 2 times, each for 2 hr;

preferred step (2): refluxing with 30 times of water for 2 times, each time for 3 hours;

preferred step (3): concentrating the filtrate to 1/2, adding 4 times of ethanol, and precipitating with ethanol;

preferred step (4): and alternately washing for 2-3 times until the solution is colorless.

Technical Field

The invention belongs to the field of medicines, and particularly relates to vinegar-fried schisandra chinensis polysaccharide, a preparation method thereof and medical application thereof in treating diabetes.

Background

Schisandra chinensis is dried mature fruit of Schisandra chinensis Baill (Turcz.) Baill, a Magnoliaceae plant, mainly produced in northeast China, so it is known as Schisandra chinensis Baill. Kadsura longepedunculata is dried mature fruit of Schisandra chinensis Schisandra Sphenhera Rehd. Et Wils. Wu Wei Zi can astringe and induce astringency, tonify qi and promote the production of body fluid, tonify kidney and calm heart. Can be used for treating chronic cough, asthma, nocturnal emission, enuresis, frequent micturition, chronic diarrhea, spontaneous perspiration, night sweat, thirst due to body fluid consumption, short breath, weak pulse, internal heat, diabetes, palpitation, and insomnia. The vinegar-roasted Chinese magnoliavine fruit is another Chinese medicinal material of raw Chinese magnoliavine fruit which is vinegar-roasted, enters lung, heart and kidney channels, has the effects of astringing and arresting discharge, tonifying qi and promoting the production of body fluid, tonifying kidney and calming heart, is a famous Chinese medicament for treating diabetes in the traditional Chinese medicine, has enhanced astringency after vinegar roasting, is always used for treating diseases such as nocturnal emission, spermatorrhea, enuresis, frequent micturition, internal heat and thirst quenching and the like, and has a long medicinal history.

Diabetes mellitus (diabetes mellitus) is a group of metabolic disorders characterized by hyperglycemia due to defects in insulin secretion or impaired physiological actions, or both. Hyperglycemia existing in long-term diabetes causes chronic damage dysfunction of various tissues, particularly eyes, kidneys, hearts, blood vessels and nerves, and is clinically manifested as polydipsia, diuresis, polyphagia, emaciation, fatigue, weakness and obesity, typical 'more than one and less' symptoms appear when the hyperglycemia is serious, and obvious 'more than one and less' symptoms of ketosis or ketoacidosis occur. In addition, the diabetes has obvious genetic heterogeneity and family morbidity tendency, and at least more than 60 clinical genetic syndromes can be accompanied with the diabetes. Meanwhile, with the development of the current society and the change of life style of people, most people develop a diet habit which is not easy to exercise and has high sugar and high fat, and the obesity caused by excessive eating and reduced physical activity is the most main environmental factor of diabetes, so that individuals with the genetic susceptibility of diabetes easily suffer from diseases. Moreover, the diabetes patients have immune system abnormality, the autoimmune reaction is caused after certain viruses such as coxsackie virus, rubella virus, mumps virus and the like are infected, islet beta cells are damaged, the treatment of simply injecting insulin for reducing blood sugar is difficult to change the occurrence and the development of diabetes, a radical treatment method is not available at present, the diabetes patients can be controlled only by various treatment means, mainly comprising the education, the self-monitoring of blood sugar, the diet treatment, the exercise treatment and the drug treatment of the diabetes patients, and the effect is different from person to person during the treatment, so the research and development of the drugs for the diabetes are urgently needed in clinic.

The traditional Chinese medicine has unique advantages in treating diabetes, has an action mechanism of not directly reducing the blood sugar content, but has the effects of increasing hepatic glycogen and inhibiting gluconeogenesis to generate the blood sugar reduction effect by influencing certain links of glucose metabolism after a receptor, and is verified by long-term clinical practice. In recent years, researches show that the schisandra chinensis polysaccharide has the effect of reducing blood sugar and has no toxic or side effect. According to the report of the prior art, CN107163157A discloses the application of schizandrin in the preparation of drugs or health products for resisting oxidation, improving memory, reducing blood sugar and/or resisting liver injury. Tao Xue et al (university of North China, Nature's edition), vol.20, No. 1, pp.43-46, 2019, 1 month) reported the protective effect of schisandra chinensis polysaccharides on the liver of type II diabetic rats. Duxingx et al (journal of Jilin university (medical edition), volume 46, No. 1, pages 50-55, 2020, 1 month) reported the effects of Schizandra chinensis polysaccharides on inflammatory factors in serum of type II diabetic rats and their mechanism of action.

However, the therapeutic action and action mechanism of polysaccharide extract of vinegar-roasted schisandra chinensis on type II diabetes mellitus are not researched at present.

Disclosure of Invention

The invention discovers the treatment effect and the action mechanism of the polysaccharide extract of the vinegar-roasted schisandra chinensis on the type II diabetes through corresponding pharmacological experiments and active ingredient research, and then the invention is completed.

The first aspect of the invention relates to a vinegar-fried schisandra chinensis polysaccharide extract.

The polysaccharide content in the vinegar-roasted schisandra chinensis polysaccharide extract is more than 60 w/w%, and preferably 60 w/w% to 80 w/w%.

The uronic acid content of the polysaccharide extract is 8 w/w% to 15 w/w%, and the glycoprotein content is 20 w/w% to 40 w/w%.

Preferably, the polysaccharide extract has a polysaccharide content of 63.6 w/w%, an uronic acid content of 9.21 w/w%, and a glycoprotein content of 25.6 w/w%.

In a specific embodiment, the polysaccharide consists of xylose, arabinose, glucose, rhamnose, mannose, galactose, glucuronic acid and galacturonic acid.

Preferably, the polysaccharide extract has a polysaccharide content of 63.6 w/w% and comprises a composition of 2.67 w/w% xylose, 30.02 w/w% arabinose, 2.01 w/w% glucose, 6.56 w/w% rhamnose, 1.25 w/w% mannose, 22.51 w/w% galactose, 2.18 w/w% glucuronic acid and 16.44 w/w% galacturonic acid.

The second aspect of the invention relates to a preparation method of a vinegar-roasted schisandra chinensis polysaccharide extract.

The vinegar-roasted schisandra chinensis is prepared by the following steps:

(1) adding rice vinegar into fructus Schisandrae decoction pieces, stirring, and moistening at room temperature;

(2) steaming until vinegar is absorbed, removing the surface to dry;

preferred step (1): the mixing ratio of the schisandra chinensis decoction pieces to the rice vinegar is 5: 1, moistening for 1.5 hours; preferred step (2): the steaming time is 5 hours.

The vinegar-fried schisandra chinensis crude polysaccharide is prepared by the following steps:

(1) reflux-extracting fructus Schisandrae with 95 v/v% ethanol, filtering with 4 layers of gauze, and mixing filtrates;

(2) air drying, reflux extracting with distilled water, filtering the water extractive solution with 16 layers of gauze, mixing filtrates, and centrifuging;

(3) filtering, concentrating, precipitating with 95 v/v% ethanol, and standing;

(4) suction filtering, recovering and storing the filtrate, and alternately washing filter residues with absolute ethyl alcohol and acetone;

(5) after washing, dissolving the mixture in deionized water, and then freezing and drying the mixture to prepare the vinegar-fried schisandra chinensis crude polysaccharide.

A preferred step (1); extracting with ethanol under reflux for 2 times, each for 2 hr;

preferred step (2): refluxing with 30 times of water for 2 times, each time for 3 hours;

preferred step (3): concentrating the filtrate to 1/2, adding 4 times of ethanol, and precipitating with ethanol;

preferred step (4): and alternately washing for 2-3 times until the solution is colorless.

The third aspect of the present invention relates to the use of a polysaccharide extract of schisandra chinensis processed with vinegar for the preparation of a medicament for the prevention and/or treatment of diabetes in a subject in need thereof.

The diabetes is type II diabetes.

The vinegar-roasted schisandra polysaccharide extract can enhance the glucose tolerance of the subjects, accelerate the consumption of exogenous glucose and reduce the blood glucose concentration of the subjects

The vinegar-roasted schisandra polysaccharide extract increases the plasma insulin level of the subject and restores the normal cell morphology of the islet beta cells of the subject.

The invention also provides a pharmaceutical composition for treating diabetes, which comprises the polysaccharide extract of the vinegar-roasted schisandra chinensis and a pharmaceutically acceptable carrier or excipient.

In one embodiment, the pharmaceutical composition is an oral dosage form.

In one embodiment, the pharmaceutical composition is a solid formulation or a liquid formulation.

In one embodiment, the pharmaceutical composition is a tablet, capsule, oral liquid, suspension, granule, powder, total, pill, or drop pill.

In one embodiment, the pharmaceutical composition further comprises other antidiabetic drugs commonly used clinically.

Preferably, the other antidiabetic agent is a DPP-4 inhibitor or SGLT-2 inhibitor.

The DPP-4 inhibitor is selected from one or more of sitagliptin, saxagliptin, vildagliptin, linagliptin and alogliptin. Preferably, the DPP-4 inhibitor is sitagliptin.

The SGLT-2 inhibitor is selected from one or more of dapagliflozin, engagliflozin, and canagliflozin. Preferably, the SGLT-2 inhibitor is engagliflozin.

Further preferably, the weight ratio of the vinegar-roasted schisandra polysaccharide extract to other antidiabetic drugs is 5: 1-20: 1, more preferably 10: 1.

drawings

FIG. 1 is a flow chart of extraction of polysaccharides from vinegar-roasted schisandra chinensis.

FIG. 2 is a standard curve for measuring the content of crude polysaccharide in vinegar-roasted schisandra fruit by a phenol-sulfuric acid method.

FIG. 3 is a standard curve for measuring uronic acid content in crude polysaccharide of vinegar-roasted fructus Schisandrae chinensis by sulfuric acid-carbazole method.

FIG. 4 is a standard curve for measuring protein content in crude polysaccharide of vinegar-roasted fructus Schisandrae chinensis by Coomassie Brilliant blue method.

FIG. 5 is a graph of monosaccharide composition of crude polysaccharide of vinegar-roasted fructus Schisandrae chinensis by gas-mass spectrometry.

FIG. 6 the effect of vinegar-roasted Schisandra chinensis polysaccharide (Svp) on the body weight of diabetic rats.^###p<0.001vs. normal control group; p<0.05 and x p<0.01vs. model set.

FIG. 7 the effect of vinegar-roasted Schisandra chinensis polysaccharide (Svp) on blood glucose levels in diabetic rats.^###p<0.001vs. normal control group; p<0.05 and x p<0.01vs. model set.

FIG. 8 the effect of vinegar-roasted Schisandra chinensis polysaccharide (Svp) on oral glucose tolerance in diabetic rats. Figure 8A effect of Svp on oral glucose tolerance in diabetic rats; figure 8B glucose tolerance experiment AUC results.^###p<0.001vs. normal control group; p<0.05 and x p<0.01vs. model set.

FIG. 9 Effect of Vinegar-roasted Schisandra chinensis polysaccharide (Svp) on plasma insulin levels in diabetic rats.^#p<0.001vs. normal control group; p<0.05 and x p<0.01vs. model set.

FIG. 10 the effect of vinegar-roasted Schisandra chinensis polysaccharide (Svp) on ultrastructure of islet beta cells in diabetic rats.

Advantageous effects

Pharmacological experiments show that compared with raw schisandra chinensis polysaccharide, the vinegar-roasted schisandra chinensis polysaccharide has a remarkably stronger blood sugar reducing effect and has no toxic or side effect. Can be used for preparing pharmaceutical compositions or formulas, treating complications caused by diabetes and hyperglycemia, has the advantage of simple preparation method, and is suitable for industrial production.

The invention also discovers that the combination of the vinegar-roasted schisandra chinensis polysaccharide prepared by the method and a clinically common DPP-4 inhibitor or SGLT-2 inhibitor can generate a synergistic hypoglycemic effect, and particularly the synergistic effect of the polysaccharide and the inhibitor is optimal under the condition of a specific weight ratio, so that the administration dosage of the polysaccharide and the inhibitor can be obviously reduced in application, and the related toxic and side effects are reduced.

Detailed Description

Example 1: preparation method of vinegar-roasted schisandra chinensis

Taking 5kg of schisandra chinensis decoction pieces, adding 1L of rice vinegar, uniformly stirring, and moistening for 1.5 hours at room temperature; steaming at normal pressure for 5 hr until vinegar is absorbed and the surface is purple black, and removing and drying.

Example 2: preparation method of vinegar-roasted schisandra chinensis crude polysaccharide extract

Taking 1kg of vinegar-fried schisandra chinensis decoction pieces prepared by the method of example 1, adding 500mL of 95 v/v% ethanol, and carrying out reflux extraction for 2 times, each time for 2 hours; filtering 4 layers of gauze, and combining filtrates; after being dried, the mixture is refluxed and extracted for 2 times by 30 times of distilled water, and each time lasts for 3 hours; filtering the water extract with 16 layers of gauze, combining the filtrates, and performing centrifugal filtration; filtering, concentrating to 1/2 of the original volume, adding 95 v/v% ethanol of 4 times of the volume, precipitating with ethanol, and standing for 10 hours; carrying out suction filtration, recovering and storing the filtrate, and alternately washing filter residues for 2-3 times by using absolute ethyl alcohol and acetone until the solution is colorless; after washing, dissolving the mixture in deionized water, and then freezing and drying the mixture to prepare the vinegar-fried schisandra chinensis crude polysaccharide.

Example 3: and (3) measuring the content of the vinegar-roasted schisandra chinensis crude polysaccharide by a phenol-sulfuric acid method.

The optimized conditions are as follows: glucose standard solutions with different concentrations are added with 6 w/v% phenol reagent and shaken up, and concentrated sulfuric acid is quickly dripped and shaken upMeasuring the absorbance value at 490nm, drawing a standard curve with the glucose content (μ g) as abscissa and the absorbance value as ordinate, and obtaining a regression equation: y is 0.0079x +0.1246 (R)²0.9979) (see fig. 2).

Measuring the absorbance value of the vinegar-roasted schisandra chinensis crude polysaccharide sample, carrying out parallel measurement for three times, calculating the content of glucose in the test solution from a regression equation, and calculating the polysaccharide content in the sample according to the following formula:

polysaccharide content (W/W%) ═ cxd/W × 100W/W%.

W is the mass (mg) of the vinegar-roasted schisandra chinensis crude polysaccharide, C is the glucose concentration (mg/mL) in the vinegar-roasted schisandra chinensis crude polysaccharide, and D is the dilution multiple of the vinegar-roasted schisandra chinensis crude polysaccharide.

As a result: the polysaccharide content in the vinegar-fried schisandra chinensis crude polysaccharide is measured to be 63.6 w/w% according to a standard curve.

Example 4: method for measuring content of uronic acid in vinegar-roasted schisandra chinensis crude polysaccharide by sulfuric acid-carbazole method

The optimized conditions are as follows: adding 6mL of sodium tetraborate/sulfuric acid solution into standard galacturonic acid solutions with different concentrations, uniformly mixing, heating in a water bath for 5 minutes, adding 100 mu L of 1.5mg/mL m-hydroxybiphenyl solution into an ice-water bath, measuring the absorbance value at 530nm, drawing a standard curve by taking the galacturonic acid concentration value (mu L/mL) as a horizontal coordinate and the absorbance value as a vertical coordinate, and obtaining a regression equation: y is 0.0029x +0.0105 (R)²0.9911) (see fig. 3).

As a result: the uronic acid content in the crude polysaccharide of vinegar-fried fructus Schisandrae chinensis was determined to be 9.21 w/w% according to the standard curve.

Example 5: determination of protein content in vinegar-roasted schisandra chinensis crude polysaccharide by using Massa Lianglan method

The optimized conditions are as follows: adding 5mL of Coomassie brilliant blue G-250 reagent into protein standard solutions with different concentrations, measuring absorbance value at 595nm, drawing a standard curve by taking the protein concentration value (mu G/mL) as an abscissa and the absorbance as an ordinate, and obtaining a regression equation of y being 0.0021x +0.0011 (R)²0.9997) (see fig. 4).

As a result: the protein content in the vinegar-fried crude schisandra chinensis polysaccharide is 25.6w/w percent according to a standard curve.

Example 6: method for measuring monosaccharide composition of vinegar-roasted schisandra chinensis crude polysaccharide by gas-phase mass spectrometry

(1) TEA is adopted to hydrolyze polysaccharide at the temperature of 110 ℃, the hydrolysis time is 4 hours, and methanol is brought to dryness;

(2) ammonia and NaBH₄Reducing polysaccharide, and drying with hydrochloric acid methanol;

(3) adding hexamethyldisilazane and trimethylchlorosilane into the mixture after reduction, and placing the mixture in a water bath kettle at the temperature of 70 ℃ for a silicon etherification reaction for 12 hours;

(4) gas quality analysis of organic filter membrane by chloroform and distilled water extraction result

As a result: it was determined that the vinegar-roasted crude polysaccharide of Schisandra chinensis consisted of xylose, arabinose, glucose, rhamnose, mannose, galactose, glucuronic acid and galacturonic acid (see FIG. 5).

Example 7: changes of polysaccharide content and monosaccharide composition of raw and vinegar-processed fructus Schisandrae chinensis

Schisandra chinensis polysaccharides were prepared according to the method of example 2.

According to the glucose standard curve Y ═ 0.0079X +0.1246 (R)²0.9979) was well-lined, and the polysaccharide content of raw and vinegar-roasted schisandra chinensis was calculated from this, and the results are shown in table 1. As can be seen from Table 1, the content of polysaccharides in the raw fructus Schisandrae chinensis is the highest, reaching 69.76 w/w%, and the content of polysaccharides is reduced after vinegar roasting.

Table 1: determination of polysaccharide content and monosaccharide composition of raw and vinegar-roasted schisandra chinensis

Example 8: effect study of vinegar-roasted schisandra chinensis on rats with type II diabetes (T2DM) induced by high-fat diet combined with Streptozotocin (STZ)

1. Effect of Vinegar-roasted Schisandra chinensis polysaccharide (Svp) on rat body weight

The weight change of the rats in the experimental process is shown in fig. 6, and after the modeling of the rats is successful, the weight of the rats in the diabetes model group is reduced sharply compared with that of the control group (p < 0.001). After 4 weeks of administration to rats, the body weight of rats of the Svp-L (50mg/kg, the same amount in the following experiment), Svp-H (100mg/kg, the same amount in the following experiment) and Met groups was increased, and the body weight of rats of the Svp-H group was increased by 32.3% (p <0.01) as compared with that of the model group. The dosage of the raw schisandra chinensis polysaccharide is 100mg/kg, and the following experiment dosage is the same.

2. Influence of vinegar-fried schisandra chinensis polysaccharide (Svp) on blood glucose value of diabetic rats

Hyperglycemia was one of the major features of diabetes, and as shown in fig. 7, the blood glucose levels of diabetic rats were significantly elevated (p <0.001) compared to the control group after STZ was injected into the tail vein of the rats. After 4 weeks of Svp-L, Svp-H treatment, the blood glucose levels in rats were reduced by 32.3% and 38.6%, respectively, compared to the model group (p < 0.05). Therefore, the Svp has a good recovery effect on the weight and the blood sugar of the STZ-induced type II diabetic rat.

3. Influence of Vinegar-roasted Schisandra chinensis polysaccharide (Svp) on oral glucose tolerance of diabetic rats

As shown in FIG. 8A, after the gavage of glucose for 0.5H, the blood glucose value of the diabetic rats is significantly increased and reaches a peak value about 1.0H, compared with the model group, the blood glucose concentration increase amplitude of the rats in each administration group is reduced, wherein the blood glucose peak value of the rats in the Svp-H administration group is reduced and is significantly advanced. Meanwhile, the area under the blood glucose curve (AUC ═ 0H +0.5H) × 0.25+ (0.50H +1H) × 0.25+ (1H +2H) × 0.25+ (2H +4H) × 0.25) of the rats treated with Svp-H was significantly reduced (p <0.05, fig. 8B) compared to the model group. Therefore, the Svp effectively enhances the glucose tolerance of the diabetic rat, accelerates the consumption of exogenous glucose and reduces the blood glucose concentration.

4. Effect of Vinegar-roasted Schisandra chinensis polysaccharide (Svp) on plasma insulin levels in diabetic rats

Insulin is the only hypoglycemic hormone secreted by the islet beta cells in the body, and insulin resistance is the main cause of type II diabetes. As shown in FIG. 9, plasma insulin levels were significantly decreased in diabetic rats (p <0.001), significantly increased in both Svp-L and metformin hydrochloride-treated rats (p <0.05), and significantly increased in Svp-H-treated rats (p <0.001), as compared to the blank group.

5. Ultramicro structure of vinegar-roasted schisandra chinensis polysaccharide (Svp) on diabetic rat islet beta cells

The transmission electron microscope of the islet beta cells of each group of rats is shown in FIG. 10. The islet beta cell nucleus of the normal control group rat is oval or round, a large number of secretory granules with different sizes are arranged in cytoplasm, compact cores with different sizes are arranged in the granules, and a wider clear gap is arranged between the cores and a limiting membrane. The diabetes model rat islet beta cell nucleus is solidified and condensed, the nuclear membrane is sunken, the number of secreted particles is reduced, the hollow halo is widened, the nuclear core is reduced, and some limiting membranes are broken and fused with each other. The Svp-H group is similar to the Met group, the number of beta cell secretory granules is increased compared with that of a diabetes model group, the Svp-H group is stronger than that of the Met group, and the hollow halo between the core of the secretory granules and a limiting membrane is clear. There is a tendency for increased secretory granules with increasing Svp dose.

From the above experimental results, in the above experiments, the therapeutic effect of the raw schisandra chinensis polysaccharide on each detection index is not equal to that of vinegar-roasted schisandra chinensis polysaccharide sampled in the experiment at two dosage levels. The vinegar-roasted schisandra polysaccharide extract has no toxic or side effect on rats, can obviously reduce the blood sugar value of rats with type II diabetes, obviously increase the oral glucose tolerance of rats with type II diabetes, obviously improve the plasma insulin level of rats with type II diabetes, recover the normal form of islet beta cells, and has exact treatment effect on type II diabetes.

And, although the polysaccharide content of the vinegar-roasted schisandra chinensis polysaccharide extract is lower than that of the schisandra chinensis polysaccharide extract, the vinegar-roasted schisandra chinensis polysaccharide extract has a better treatment effect on type II diabetes than the schisandra chinensis polysaccharide extract with the same dose (100mg/kg), and the two have a significant difference (p < 0.05). Therefore, the structure and/or composition of the polysaccharide in the schisandra chinensis is changed in the vinegar roasting process, the bioactivity of the vinegar roasted schisandra chinensis polysaccharide is further improved, and the vinegar roasted schisandra chinensis polysaccharide has a better treatment effect on diabetes mellitus and belongs to an unexpected technical effect.

6. Synergistic effect of vinegar-roasted schisandra chinensis polysaccharide (Svp) and other antidiabetic drugs in combination

In a rat model of type II diabetes (T2DM) induced by high-fat diet combined with Streptozotocin (STZ), the influence of vinegar-roasted schisandra chinensis polysaccharide (Svp) on the blood glucose value of a diabetic rat is examined in part 2 experiment, and the synergistic effect of the Svp and other antidiabetic drugs is also researched.

The synergy index is judged by adopting a gold positive mean q value method, and the q value is obtained by the following formula: q ═ P_A+B/(P_A+P_B-P_A×P_B). In the formula P_A、P_BAnd P_A+BRespectively the treatment rates of the A medicine group, the B medicine group and the combination of the two medicines. q is less than 1, which indicates that the two medicines generate antagonism after being used together; q is more than 1, which indicates that the two drugs produce synergistic effect after being combined together, and q is 1, which indicates that the two drugs produce additive effect after being combined together.

In this experiment, the% decrease in blood glucose was used as an index for calculating the q value. The% blood glucose reduction was calculated using the mean blood glucose results for each group of animals after 4 weeks of treatment with each test drug shown in table 2, using the following formula: blood glucose reduction (%) (mean blood glucose in model group animals-mean blood glucose in test drug group animals)/mean blood glucose in model group animals × 100.

Specific results are shown in table 2 below.

Table 2: synergistic effect of raw and vinegar-roasted schisandra chinensis polysaccharide and other antidiabetic drugs

As can be seen from the results in Table 2, there is no synergistic effect of raw Schizandra chinensis polysaccharide in combination with sitagliptin or engagliflozin in reducing blood sugar. The combination of the low-dose and high-dose schisandra chinensis polysaccharide and sitagliptin or engagliflozin shows synergistic effect, and the synergistic effect of the combination of the high-dose schisandra chinensis polysaccharide and sitagliptin or engagliflozin in a specific dosage ratio is optimal.

The foregoing describes preferred embodiments of the present invention, but is not intended to limit the invention thereto. Modifications and variations of the embodiments disclosed herein may be made by those skilled in the art without departing from the scope and spirit of the invention.