Abstract: Objective To investigate the protective effect of pinocembrin (PIN) on hepatocytes induced by hypoxia/reoxygenation(H/R) as well as its relationship to the TLR4/NF-κB signaling pathway. Methods The cells were randomly divided into 4 groups：the control group, the PIN group, hypoxia/reoxygenation injury group and the PIN pretreatment group. The cell viability was measured with CCK-8. The apoptosis rate was determined by Annexin V-FITC/PI staining. The activity of ALT was detected. ELISA was used to evaluate the contents of TNF-α and IL-β. The mRNA and protein expression level of TLR4, IκB-α and NF-κB p65 in cells was observed by quantitative real-time PCR or Western blotting. Results The H/R stimulation decreased cell survival rate and enhanced the apoptosis. The activity of ALT was increased. The contents of TNF-α and IL-1β were enhanced significantly, and the expression level of TLR4 and NF-κB p65 were markedly increased while IκB-α decreased. After pretreatment with PIN, the cell survival rate increased while the apoptosis rate decreased. The activity of ALT was decreased. TNF-α and IL-1β were reduced significantly and the expression level of TLR4 and NF-κB p65 were decreased while IκB-α increased. Conclusions PIN has protective effects on hypoxia/reoxygenation injury, which might be mediated in part by TLR4/NF-κB signaling pathway.

Key words: Key words：pinocembrin, hypoxia/reoxygenation, hepatocyte injury, toll-like recepcor4, nuclear factor-κb p65