| The incidence of diabetes mellitus is rapidly increasing in resent years,and most cases(90-95%)are type 2 diabetes mellitus(T2DM).The increasing interest has been attracted for development and utilization of antidiabetic plants due to their less side effects and no-drug-resistance,especially in developing countries.The western medicine is often accompanied with side effects,so more and more people pay attention to the high efficiency and low toxicity substances obtained from the natural medicine.Existing researches have showed that Fagopyri Dibotryis Rhizomam has a hypoglycemic effect,but the exact composition has not clear.Therefore,the object of this study is to clarify the effective components of Fagopyri Dibotryis Rhizomam for improving type 2 diabetes and the relative pharmacological effects.The contents of epicatechin,hyperoside and quercitrin in Fagopyri Dibotryis Rhizomam were determined by high performance liquid chromatography(HPLC)in this study.Access to different parts of the Fagopyri Dibotryis Rhizomam extract with system solvent gradient extraction method,Vitamin C as the positive control,the antioxidant activities of different polar parts of ethanol extract of Fagopyri Dibotryis Rhizomam were studied by DPPH,hydroxyl radical and ABTS radical scavenging experiment.With α-glucosidase and α-amylase as the drug target,Nitrophenyl-α-D-Glucopyranoside(PNPG)and starch as substrate,acarbose as positive control,by establishing α-glucosidase and amylase screen inhibitory model,the activity of extracts of Fagopyri Dibotryis Rhizomam was screened.A model of type 2 diabetes mellitus was established by one-time intraperitoneal injection of streptozotocin(STZ),the body weight and fasting blood glucose(FBG)of mice were determined by positive control of genistein and genistein.Serum levels of insulin(FINS),triglyceride(TG),cholesterol(TC),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),superoxide dismutase(SOD),malondialdehyde(MDA),catalase(CAT)and glutathione peroxidase(GSH-PX)were measured and the indexes of insulin resistance index(HOMA-IR)and insulin sensitivity index(ISI)were calculated.Fagopyri Dibotryis Rhizomam,and to elucidate the hypoglycemic effect of Fagopyri Dibotryis Rhizomam flavonoids and its related Pharmacological effects,and provide experimental basis for further development and utilization of flavonoids from Fagopyri Dibotryis Rhizomam in the field of improving diabetes mellitus.The main research results are as follows:1.HPLC method was used to measure the content of epicatechin in Fagopyri Dibotryis Rhizomam herbs at 0.80 mg/g,the content of hyperoside was 0.40 mg/g and the content of quercitrin was 0.89 mg/g.The establishment of the determination of indicators is superior to the existing pharmacopoeia determination method,can be used as Fagopyri Dibotryis Rhizomam content determination method.2.In the concentration range of 0-0.2 mg/m L,the ethyl acetate extraction site of the ethanol extract of Fagopyri Dibotryis Rhizomam had a strong scavenging effect on DPPH,hydroxyl radical and ABTS free radicals.3.At the same concentration of 25 mg/m L,the IC50 values of n-butanol extraction site,ethyl acetate extraction site and chloroform extraction site of α-glucosidase in ethanol extract of Fagopyri Dibotryis Rhizomam were lower than that of positive control acarbose,And the inhibition rate was greater than that of acarbose.The inhibition rate of α-amylase was higher than that of acarbose in the ethyl acetate extract.In the range of 0-50 mg/m L,the inhibitory effects of α-glucosidase and α-amylase were in a dose-dependent manner at different extraction sites of ethanol extract of Fagopyri Dibotryis Rhizomam.4.The high,medium and low dose of flavonoids extracted from Fagopyri Dibotryis Rhizomam(200 mg/kg and 100 mg/kg,50 mg/kg),can be in different degree,reduce the blood sugar,diabetic model mice caused by STZ present a dose dependent,to reduce the blood sugar diabetes mice including high dose group was obviously better than middle dose group and low dose group.5.The high,medium and low doses of flavonoids extracted from Fagopyri Dibotryis Rhizomam(200 mg/kg,100 mg/kg,50 mg/kg)can reduce insulin resistance and insulin resistance in mice at different levels,and increase insulin sensitivity index.6.The high and medium doses of flavonoids extracted from Fagopyri Dibotryis Rhizomam(100 mg/kg and 200 mg/kg)to the diabetic mice was reduced serum TG,TC,LDL-C,increase HDL-C,including the high dose(200 mg/kg),adjust the obvious effects of T2 DM lipid metabolism in mice.7.The high and medium doses of flavonoids extracted from Fagopyri Dibotryis Rhizomam(100 mg/kg and 200 mg/kg)can gradually increase the value of SOD,CAT and GSH-PX in the serum of diabetic mice,and gradually reduce the content of MDA in the serum of diabetic mice.Conclusion: Fagopyri Dibotryis Rhizomam contains epicatechin,hyperoside,quercitrin and other flavonoids.There are more flavonoids in the ethyl acetate extract of ethanol extract of Fagopyri Dibotryis Rhizomam,which showed a good pharmacological effect in the antioxidant test of scavenging free radicals and the inhibition of α-glucosidase and α-amylase in vitro.In the experiment of type 2 diabetic mice,Fagopyri Dibotryis Rhizomam flavonoids showed a better hypoglycemic effect,hypolipidemic effect and anti-oxidation effect.The mechanism of hypoglycemic effect was related to the scavenging of free radicals and the decrease of enzyme activity,on the other hand with the regulation of lipid metabolism and oxidative stress.The essential substance of hypoglycemic effect of Fagopyri Dibotryis Rhizomam is the chemical constituents of flavonoids.Chinese medicine hypoglycemic mechanism is complex,therefore this study laid a foundation of Fagopyri Dibotryis Rhizomam hypoglycemic mechanism research. |
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