The protective effect of kaempferol on high glucose-stimulated renal tubular epithelial cells

Abstract The oxidative stress and apoptosis of renal tubular epithelial play an important role in the progression of diabetic nephropathy. Blocking oxidative stress and apoptosis of renal tubular epithelial could be a novel therapeutic target for diabetic nephropathy. Kaempferol (KMP), a natural phytoestrogen and common dietary flavonoid, has various biological effects including anti-oxidation, anti-apoptosis and anti-inflammation. KMP has protective effect against oxidative stress-related diseases, such as ischemia-reperfusion induced myocardium injuries, osteoporosis, obesity and so on. In our research, we observed the influence of KMP on high glucose (HG) cultured HK-2 cells and explored its mechanisms from the aspect of oxidative stress and apoptosis. We found that HK-2 cells stimulated by both 10µM KMP and HG had better viability than those stimulated by HG only. Incubation with KMP could reverse the undesirable effects of HG on SOD2, catalase, cleaved caspase-3, Bax/Bcl-2 ratio and the generation of ROS. Furthermore, Western blot and Real-time PCR results showed that the expression levels of Sirt3, p-Akt/Akt ratio and p-FoxO3a/FoxO3a ratio were markedly increased in KMP plus HG group compared to HG group. In summary, KMP could alleviate HG-induced oxidative stress and apoptosis through increasing the expression of Sirt3 and regulating ROS-sensitive Akt/FoxO3a signaling pathway.