Preliminary Study On The Extraction Technology Of Cornus Seed Tannins And Its Hypoglycemic Effect

Belonging to Cornus of Comaceae,Cornus officinalis Sieb.et Zucc is an important plant for medicine as well as of popular herbal medicine in China,with a distribution mainly over the Zhejiang,Henan,Shaanxi and Anhui provinces.The pulp of Fructus corni contains a number of active principles such as iridoid glycoside,polysaccharide,saponin,tannin and so on.The modern pharmacological study indicated the pulp of Fructus corni had the functions of anti-oxidant,anti-inflammatory,hypoglycemic,anti-bacterial and anti-tumor.It was widely used clinical application as medicinal herbs,in the tradition of the ancient prescription,Fructus corni was regarded as uppermost medicinal herbs to treat the diabetes.Fructus corni stone was rich in tannin that was generally removed as impurities in the traditional processing.However,recent studies have shown that the tannin also had the functions of anti-oxidant,anti-inflammatory,hypoglycemic,anti-bacterial and anti-tumor.Consequently,this study will optimize the extraction process of tannins through the response surface method,compare the tannin content of Fructus comi from different areas.Meanwhile,the effects of tannin depressant a-glucosidase and the kinetics of depressant have been studied in the vitro experiment.Eventually,We based on feeding the mice with high-sucrose and high-fat diet and combined with induce by low doses of STZ strategy,a model was established to test the effects of Fructus corni stone tannins on streptozotocin multiple-induced type 2 diabetic mice fasting glucose(GLU),glucose tolerance(OGTT),glycerol three ester(TG),total cholesterol(TC),high density lipoprotein(HDL),low density lipoprotein(LDL)and malondialdehyde(MDA)and other aspects,this study will provide a theoretical basis for prevention and treatment diabetes,meanwhile,the research provide the technical basis for project approval,and it provide a standardization churned out and high value products for Fructus corni.The main contents of the research include the following aspects:1.Using response surface methodology to optimize the extraction process for Fructus comi stone tannins,The optimal extraction condition included ethanol concentration 42%,solid-liquid ratio 1:22,ultrasonic time 71 min,ultrasonic temperature 51 ℃,simulation predictions and experimental test results are basically consistent.2.Compared with the content of the tannins in Fructus corni from different areas:the tannin contents of Fructus comi stone in different province in order of Henan,Zhejiang,Shaanxi,the coefficient of variation of Henan Fructus corni stone tannins is small and good stability.3.The study of in vitro inhibition kinetics of Fructus corni stone tannins enzyme inhibitors:The hemi-inhibitory concentration of Fructus corni stone tannins and acarbose to a-glucosidase are 1076 mg/L and 1081.78 mg/L,which indicated Fructus corni stone tannins has better inhibition on a-glucosidase,inhibition kinetics research showed that Fructus corni stone tannins on the a-glucosidase inhibition was reversible non-competitive inhibition.4.The preliminary study on hypoglycemic with Fructus corni stone tannins:Fructus corni stone tannins had no significant effect on body weight in mice,delayed the increase of fasting blood glucose in mice,and high doses of Fructus corni stone tannins improved glucose tolerance in mice,which can prevent diabetes;High-dose Fructus corni stone tannins significantly reduced fasting blood glucose and improved glucose tolerance in diabetic mice after administered 20 days,meanwhile,the high-dose Fructus corni stone tannins significantly reduced TC,TG,LDL,MDA and increased HDL levels of diabetic mice,which indicated a dose-dependent relationship of Fructus corni stone tannins concentration and the effect of blood glucose in diabetic mice and other indicators,so the experiment indicated Fructus corni stone tannin has better hypoglycemic effect.