Ursolic acid alleviates inflammation and against diabetes‑induced nephropathy through TLR4‑mediated inflammatory pathway.

Ursolic acid (UA) is a triterpenoid isolated from Chinese herbal medicine. It is extensively distributed in the plant kingdom in at least 63 Chinese herbal medicines of 26 families. UA has multiple bioactivities, including anti-viral hepatitis, antitumor, anti-oxidation, anti-bacterium and anti-inflammation. The aim of this in vitro study was to examine the effects of UA on diabetes-induced nephropathy and its possible mechanism. In mice with diabetes-induced nephropathy, UA increased the body weight, reduced kidney/body weight index, protected kidney cells, alleviated inflammation [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6 and IL-18 levels] and kidney cell damage. It was also indicated that UA suppressed Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 and nuclear factor-kappa B protein expression in mice with diabetes-induced nephropathy. The inhibition of TLR4 increased the anti-inflammation of UA on inflammation in rat with diabetes-induced nephropathy through the TLR4 signaling pathway. In conclusion, UA alleviates inflammation and inhibits diabetes-induced nephropathy through a TLR4-mediated inflammatory pathway. The present findings indicated that UA may be a possible therapeutic agent against diabetic nephropathy.