Daidzein ameliorates LPS-induced hepatocyte injury by inhibiting inflammation and oxidative stress

Endotoxin-induced acute liver injury (ALI) is a severe disease associated with a poor prognosis. Therefore, it is urgent to discover new effective therapies to prevent ALI. Daidzein, extracted from leguminous plants, possess anti-inflammatory and antioxidative bioactivities. However, little is known about whether daidzein could attenuate lipopolysaccharide (LPS)-induced ALI. We investigated the effects of daidzein on hepatocyte injury and its underlying mechanisms. In LPS-induced hepatocyte supernatant, 100 mu M daidzein decreased ALT and AST expression levels by 49.3% +/- 5.6% and 39.3% +/- 3.5%, respectively, with no cytotoxicity. In addition, the expression of inflammatory factors, including interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) were decreased by 100 mu M daidzein (73.8% +/- 5.3%, 58.8 +/- 9.0% and 55.5% +/- 7.2%, respectively) in LPS-treated hepatocytes. Western blot analysis showed that daidzein inhibited LPS-induced p-ERK1/2, p-I kappa B alpha and p-p65 expression levels. Moreover, 100 mu M daidzein reduced the LPS-induced production of Reactive oxygen species by 23.9 +/- 7.8% and increased SOD activity by 88.4% +/- 18.9% by downregulating Keap-1 and upregulating Nrf2 expression. In conclusion, these data indicate that daidzein ameliorates LPS-induced hepatocyte injury by inhibiting inflammation and oxidative stress.