The protective effect and mechanism of piperine (PIP), an active ingredient in plant Piper longum L., on acute alcoholic liver injury in mice were investigated. Fifty male C57BL/6 mice were randomly divided into five groups: normal control group, model group, low-dose, medium-dose and high-dose groups of PIP, with ten mice in each group. Except the normal control group, acute alcoholic liver injury model was established in the remaining mice. Reagent kits were used to detect the content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TG), total cholesterol (TC), alkaline phosphatase (AKP) in serum and malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), interleukin-6 (IL-6), IL-1β, IL-18 in liver tissue. The liver morphology was observed by HE staining and Sirius red staining. The expression of Kelch like ECH-associated protein 1 (Keap1) and nuclear factor E2-related factor 2 (NRF2) was observed by immunofluorescence, and the expression of both proteins was detected by Western blot. The results showed that PIP reduced the levels of serum AST, ALT, TG, TC and AKP in mice, decreased the levels of liver IL-6, IL-1β, IL-18 and MDA, increased the levels of SOD and GSH-Px (P < 0.05, P < 0.01). PIP improved liver morphological abnormalities, reduced Keap1 expression and increased NRF2 expression in the liver (P < 0.05, P < 0.01). In conclusion, PIP can ameliorate the acute alcoholic liver injury in mice, and the mechanism may be related to antioxidant stress effect.

piperine, acute alcoholic liver injury, inflammatory reaction; oxidative stress