Puerarin alleviates the high glucose-induced oxidative stress via the RAGE/PKC/NOX4 axis in renal mesangial cells.

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes, of which progression is related to high glucose (HG)-induced oxidative stress in renal mesangial cells. Our study aims to explore the antioxidant activity and the underlying mechanism of Puerarin (Pu) in renal mesangial cells exposed to HG. After the cells finished different treatments, DCFH-DA was used to detect the generation of ROS while the expression of AGE, MDA, SOD, and GSH-PX was measured by the ELISA and corresponding kits. The cell morphology was captured by optical microscopy. The mRNA expressions of RAGE, PKCα, PKCβ, PKCγ, and NOX4 were calculated by RT-PCR assays, while the protein expressions of RAGE, NOX4, and PKCβ were quantified via western blotting. Compared with the normal glucose (NG) group, the ROS level, SOD activity, and GSH-PX expression were markedly reduced in the HG group while the MDA expression was increased in the HG group. Then, Pu treatment was proved to significantly prevent the HG-induced up-regulation of ROS level, MDA expression, and down-regulation of SOD activity and GSH-PX expression. Besides, Pu treatment can notably inhibit the AGE expression and reverse the increased RAGE, PKCβ, and NOX4 expressions by HG environment at both RNA and protein levels. Moreover, the antioxidant effect of Pu against access glucose could not be observed in PKCβ knockdown cells. Pu can alleviate the HG-induced oxidative stress via the RAGE/PKC/NOX4 axis in renal mesangial cells, which innovatively suggests the therapeutic potential of Pu for DN treatment.