Study On The Therapeutic Effect And Mechanism Of Gynura Divaricata Aqueous Extract On Diabetic Vascular Disease And Diabetic Foot

Objective:1.In this study,the toxicology test of Gynura divaricata Aqueous Extract was carried out to evaluate the drug safety.2.To investigate the effects of Gynura divaricata aqueous extract on oxidative stress and macroangiopathy in diabetes rat.3.To investigate the effects of Gynura divaricata aqueous extract on foot injury in diabetes foot（DF）model rats,and explore its possible mechanism,to provide theoretical basis for the development of preparation in hospital.Methods:1.The maximum tolerated dose of 120 g·kg^-11 body weight in one day was given orally to Kunming mice,the mice fasting for 4 hours after administration,observation continuous for 14 days the toxicity reaction of mice.The dose of 20,10,4g·kg^-1 was given orally to SD rats for 30 days,observation of chronic toxicity reaction of SD rats.2.The type 2 diabetes rat model(blood glucose≥16.7mmol·L^-1)was established by feeding a high fat and glucose fodder and intraperitoneally injecting low-dose streptozotocin（STZ）.50 diabetes model were randomly divided into model,metformin(0.2g·kg^-1),Gynura divaricata aqueous extract(16 g,8 g and 4 g·kg^-1)groups,and another the normal rats were control group.There were 10 rats in each group.The normal group was given ordinary diet,and other groups were given high fat and high glucose diet during the experiment.After 4 weeks the levels of blood glucose,blood lipid,insulin,MDA,T-SOD,and GSH-PX and the pathological changes of aorta were determined.3.A totol of 80 SD rats were included in the study.Among them,8 rats were randomly selscted as control group,while the other rats were established the diabetic model by the same method,and the diabetic foot model was established by ligating their lower extremity vascular and making foot surgery.The modle rats（n=40）were randomy divided into modle group,metformin group(0.2g·kg^-1),and Gynura divaricata aqueous extract groups(16 g、8 g and 4 g·kg^-1).The healing of ulcer were observed on day 1,4,7,14,21.After 28 days,the immunohistochemical method was used to observe the angiogenesis of the ischemic lower limb muscles.The content of ICAM-1,CRP,IL-6,IL-1β,TNF-α,ET-1 and TXA₂ were determined by ELISA,and NO and NOS content were determined by nitric acid reduction method.Real-time PCR and Western bolt were used to determine VEGF mRNA and protein expressions in ischemic lower limb muscles.Results:1.The shown,Observation of acute toxic reaction in mice by MTD,there was no obvious toxic reaction in the test mice except that the activity of each group decreased slightly on the day of administration of the drug,and there was no obvious toxic reaction in the liver function,kidney function,liver,kidney tissue examination.The 30 days feeding test in rats,there was no obvious toxic reaction.2.The diabetic and diabetic foot ulcer models were successfully established.Compared with the normal group,the blood glucose,blood lipid,ins and MDA levels in the model group increased significantly（P<0.01）,and the activity of T-SOD and GSH-Px decreased significantly（P<0.01）.Compared with the model group,the Gynura divaricata aqueous extract exhibited significant lower levels of blood glucose,blood lipids,insulin and MDA and higher activity of T-SOD and GSH-Px compared to the model group（P<0.05,P<0.01）.The aortic atherosclerosis were lighter than that in the model group.3.Compared with the normal group,the wound healing in the model group was delayed,while that the G.divaricata aqueous extract.Compared with the normal group,the microangiogenesis,serum NO and NOS levels,and VEGF mRNA and protein expression in the G.divaricata aqueous extract groups increased（P<0.05,P<0.01）.Compared with the normal group,ICAM-1,CRP,IL-6,IL-1β,TNF-α,ET-1and TXA2 levels in the model group significantly increased（P<0.01）,while those in the G.divaricata aqueous extraceat groups decreased（P<0.05,P<0.01）.Conclusion:1.Through the study,the Gynura divaricata aqueous extract non-toxic or low toxic.The 30 days feeding test has no obvious toxicity to rats.2.Gynura divaricata aqueous extract could proctect macroangiopathy and anti atherosclerosis in the diabetic model rats by ameliorating the disorder of glucose and lipid metabolism,improving anti-oxidative capability and reducing oxidative stress.3.Gynura divaricata aqueous extract could promote the foot wound healing of DF model rats,and its mechanism may be related to the inhibition of inflammation,regulating vascular endothelial function,increase the expression of VEGF,promote angiogenesis in ischemic tissue,and improve the blood supply of the lower extremity.