Huangqi decoction improved the inflammatory response of rats with diabetic nephropathy by inhibiting TLR4/NF-κB signal pathway

Objective To establish an animal model of lipopolysaccharide(LPS)-induced inflammation and observe whether Huangqi Decoction(HD) can improve the inflammatory response in rats with diabetic nephropathy(DN) by inhibiting the TLR4/NF-κB signaling pathway. Methods Fortyeightmale Sprague-Dawley(SD) rats were randomly divided into 6 groups of control, control plus LPS, model, model plus LPS, HD intervention and HD plus LPS. And animal model received an intraperitoneal injection of streptozotocin(STZ). Pathology, TLR4/NF-κB signaling pathway related proteins and their downstream related proteins were examined. Results TLR4/NF-κB signaling pathway was significantly activated in DN rats and LPS+ DN rats. The expression levels of TLR4, phosphorylated IKKα/β, phosphorylated NF-κB and downstream inflammatory factors were significantly up-regulated. Renal pathological and fibrosis parameters worsened. HD could improve the pathological parameters. It lowered the phosphorylation of IKK and NF-κB by reducing the expression of TLR4 and achievedan inhibition of TLR4/NF-κB signal. Thus there was a lower expression of such downstream inflammatory factors as IL-6, TNF-α and IL1β. Conclusion HD can improve the inflammatory response by lowering the expression level of TLR4/NF-κB signaling pathway-related protein, improve renal pathological parameters, alleviate renal damage and delay the progression of DN in LPS-induced DN rats.