The Hepatoprotection by Oleanolic Acid Preconditioning: Focusing on PPAR Activation.

Objective: Previous studies have characterized the hepatoprotective and anti-inflammatory properties of oleanolic acid (OA). This study aimed to investigate the molecular mechanisms of OA hepatoprotection in concanavalin A- (ConA-) induced acute liver injury.

Materials And Methods: ConA (20 mg/kg) was intravenously injected to induce acute liver injury in Balb/C mice. OA pretreatment (20, 40, and 80 mg/kg) was administered subcutaneously once daily for 3 consecutive days prior to treatment with ConA; 2, 8, and 24 h after ConA injection, the levels of serum liver enzymes and the histopathology of major factors and inflammatory cytokines were determined.

Results: OA reduced the release of serum liver enzymes and inflammatory factors and prevented ConA mediated damage to the liver. OA elevated the expression levels of peroxisome proliferator-activated receptor alpha (PPAR) and decreased the phosphorylation of c-Jun NH2-terminal kinase (JNK).

Conclusion: OA exhibits anti-inflammatory properties during ConA-induced acute liver injury by attenuating apoptosis and autophagy through activation of PPAR and downregulation of JNK signaling.