Protective Effects Of Radix Astragali On Diabetic Rats And ECV-304 Exposed To High Glucose

Diabetes mellitus is one of the main chronic diseases which can produce severe adverse effects on people's health. Chinese traditional medicine has great advantages and potential for treating chronic disease like diabetes mellitus. Radix Astragali (RA), as a commonly used Chinese medicine, can be applied to clinical treatments of various diseases. The present study is to explore the effects of Radix Astragali on ECV-304 cells and diabetic rats.Objective To explore the protective effects of RA on Streptozocin- induced diabetic rats and ECV-304 cells exposed to high level of glucose.MethodsIn vitro experiments: ECV-304 cells were used in vitro experiments. 1) ECV-304 cells were exposed to different concentrations of glucose in the culture medium, and mannitol group was set up as osmotic pressure control. The intracellular calcium concentration and mitochondrial membrane potential were measured by flow cytometry after the cells exposed to different treatment for 24 hours. 2) The cells were classified into control group, high glucose group, low RA group, high RA group and mannitol group. After cells exposed to different treatment for 24 hours, the intracellular calcium concentration, the mitochondrial membrane potential, the activities of superoxide dismutase (SOD), the ability of anti-superoxide anion, the suppression ability of hydroxyl radical and contents of malondialdehyde (MDA) were measured, the morphological changes of cells were observed by electron microscope. 3) The cells were divided into control group, high glucose group, RA group and RA pretreatment group (ECV-304 cells were pretreated 24 h with RA). After the cells exposed to different treatment for 24 hours, the intracellular calcium concentration, the mitochondrial membrane potential and membrane fluidity were measured.In vivo experiments: The diabetic rat models were established by using streptozocin. The rats were classified into control group, diabetes group, RA group. Diabetic rats in RA group were given RA 3.3 ml per kilogram body weight by intraperitoneal injection daily for consecutive 14 days. The level of Triglyceride, insulin, LDL-C, HDL-C and other serum indicators, and muscle glycogen contents in skeletal muscle were determined.ResultsIn vitro experiments: 1) High level of glucose was able to increase intracellular calcium concentration and decrease mitochondrial membrane potential in ECV-304; RA could significantly reverse the damages produced by high level of glucose, that is, reduce the intracellular calcium concentration, and increase the mitochondrial membrane potential. RA pretreatment could strengthen the protective effects of RA. 2) The activities of SOD, the ability of anti-superoxide anion, and the suppression ability of hydroxyl radical were significantly decreased when ECV-304 cells were exposed to high level of glucose, while the content of MDA was significantly increased. RA induced an increase in the activities of SOD, the ability of anti-superoxide anion, and the suppression ability of hydroxyl radical, and decrease in the content of MDA. 3) RA can protect ECV-304, which were exposed to high level of glucose. It increased the number of mitochondria with clear mitochondrial cristae. 4) RA can protect the cell membrane fluidity of ECV-304 exposed to high level of glucose. The protective effects of RA was strengthened when the cells was pretreated by RA.In vivo experiments: RA was able to decrease the level of TG and increase the level of insulin in diabetic rats injected with RA, and increase the synthesis of muscle glycogen.Conclusion 1) Radix Astragali was able to produce protective effects on ECV-304 cells through maintaining the normal functions of the cells and antioxidization. 2) Radix Astragali was able to protect the diabetic rats through involving in the regulation of lipid metabolism and increasing the insulin level.