ABSTRACT
Objective Fluctuation of glucose levels is more likely to cause oxidative stress which contributes to the development of insulin resistance through activating c-Jun N-terminal kinase (JNK).Such antio xidants as vitamin C or vitamin E do not appear very helpful.Radix Astragali (RA) is an herbal medicine with antioxidative ability.The study was to explore whether RA would lower the risk of insulin resistance in diabetic rats.Methods Diabetic rats received RA,insulin or both RA and insulin after diabetes were induced in male Wistar rats.Serum levels of interleukin 6 (IL-6) and tumor necrosis factor α (TNFα),advanced glycation endproducts(AGEs) levels in kidney,the expression of insulin receptor (IR),insulin receptor substrate 1 (IRS-1),p38 mitogen-activated protein kinase (MAPK),p-p38 MAPK,p-JNK,p-IRS-1 Ser307,and p-IRS-1 Tyr612 in skeletal muscles were determined.Results Compared to diabetic rats treated with insulin,the diabetic rats treated with both insulin and RA demonstrated significantly lower levels of IL-6,TNF-α and AGEs (P ＜ 0.05),significantly lower activation of p-p38 MAPK and JNK (P ＜0.05),significantly higher expressions of IRS-1 (P ＜0.05),p-IRS-1 Tyr612,and significantly lower expression of p-IRS-1 Ser307 (P ＜ 0.05).Conclusions RA can lower the risk of insulin resistance through fighting oxidative stress in diabetic rats.
ABSTRACT
Objective To investigate the mechanisms of Chinese traditional medicine mixture protection of vascular endothelial cell from apoptosis in cerebral ischemia-reperfusion injury. Methods Healthy, clean SD rats were randomly divided into 4 groups: Sham opera-tion group (SOG), cerebral ischemia reperfusion injury group (IRG), cerebral ischemia preconditioning group (IPG) and Chinese tradi-tional medicine mixture preconditioning group (CPG). Furthermore, IRG, IPG and NPC were divided into 4 sub-groups: 1 d, 7d, 14d, 21d subgroup, according to the different time point since ischemia-reperfusion took place. And in CPG, Naotai formula extract was used. Cere-bral vascular endothelial cells of rats were removed and Hoechst 33258 staining and the DNA gradient bands were used to detect the apoptosis of these cells. Then the influence of Naotai formula extract on caspase-3, 8 and 9 activation, and Bid lysis was examined by Western-blot, and the mechanisms of Chinese traditional medicine mixture protection of vascular endothelial cell were investigated from apoptosis signal pathway. Result Naotai formula extract can inhibit the apoptosis of endothelial cells in ischemia-reperfusion injury, and it also can inhibit the activation of caspase-3, 8 and 9, thus inhibit the lysis of Bid into tBid. Conclusion Naomi formula extract inhibit the apoptosis of endo-thelial ceils in ischemia-reperfusion injury via apoptosis signal pathway.