Preliminary Study On The Function Of Hypoglycemic And Hypolipidemic Of Dendrobium Officinale Polysaccharides In Vivo And In Vitro

Dendrobium officinale Kimura et Migo belonging to Dendrobium,is a kind of perennial herb.Modern medical research shows that D.officinale has various efficacies: strengthen body immunity,clear heat and promote fluid,protect the environment of gastrointestinal tract,anti-tumor,alleviate hypertension,prevent diabetic and so on.This thesis extracts and purifies the crude polysaccharide in dendrobium officinale by adopting ultrasonic hot water extraction method,and also makes anti-hyperglycemic and hypolipidemic experiments in vitro and in vivo by using polysaccharide of D.officinale.The conclusions are as follows:The result of in vitro anti-hyperglycemic and hypolipidemic experiment indicates that polysaccharide in D.officinale has an inhibiting effect on ?-amylase,and when its concentration is 2mg/mL within 20 minutes of reaction,the inhibition ratio can reach to 33.24% with obvious enzyme inhibition effect.Extracorporeal hypolipidemic experiment result shows that polysaccharide in D.officinale possesses the ability of absorbing cholate and its capacity of absorbing pig bile salt presents dose-effect relationship.In the experiment,its maximum absorption rate of pig bile salt can reach to 11.17%,and its absorption capacity of sodium glycol-cholate tends to be stable when the concentration of polysaccharide is 1.5mg/mL,whose maximum absorption rate can reach to 21.52%.The result of in vivo experiment about the effect of polysaccharide in D.officinale on diabetic mice indicates: when the diabetic mice model is constructed by the method of three times of alloxan(100mg/kg)intraperitoneal injection with an interval of 1d each time,the success rate of modeling can reach to 86.67% which is higher than traditional modeling approach;the mice's apparent characteristics of activeness,mental status,weight,food-intake,and water-intake all have significant improvement after polysaccharide intragastric administration.In respect of anti-hyperglycemic: the polysaccharide in D.officinale is capable of repairing islet cells and stimulating insulin secretion.High and medium dosages of it have an extremely prominent effect on the increase of serum insulin of the diseased mice(P<0.01),in which the serum insulin level of high-dose group approaches to the level of normal-dose group;polysaccharide has a remarkable effect on lowering the fasting blood-glucose level of diseased mice.Among them,the fasting blood-glucose level of mice,in positive control group,high-dose group,and medium-dose group,decreases respectively to 44.29%,36.76% and 26.21%,which presents obvious dose-dependence;when compared with negative control group,the glycosylated serum protein(GSP)of the diseased mice,in both positive control group and polysaccharide medicated group,decreases obviously.Besides,polysaccharide in D.officinale can promote the synthesis of hepatic glycogen and significantly enhance the diabetic mice's endurance capacity to glucose.In respect of reducing blood lipids and antioxidants of organs: polysaccharide in D.officinale has the capability of lowering the hyperlipidemia of the diseased mice.Compared with negative control group,the content of TC and TG in serum of the diseased mice in high-dose group decreases respectively 29.89% and 57.14%,and HDL increases 38.15%.It indicates that polysaccharide in D.officinale is capable of balancing blood lipids,as well as regulating the blood glucose level by decreasing the content of TC and TG in blood and increasing the content of HDL.The interference of polysaccharide in D.officinale obviously relieves the organ injury of the diseased mice.Compared with negative control group,the improvement of the SOD activity of diseased mice's organ in high-dose group is the most prominent(P<0.01),with the result that the SOD activity of its liver,spleen and kidney respectively increases by 18.67%,21.4%,and 23.8%.Polysaccharide also has an obvious effect on decreasing MDA content of the organ,in which the decrease of spleen's MDA content is the most obvious.Moreover,polysaccharide in D.officinale can obviously improve the intestinal environment of the diseased mice,promote the multiplication of beneficial bacteria,as well as strengthen the immune function.