Objectives: In this study, we investigated the anti-inflammatory effects of silymarin on cerulein-induced acute pancreatitis (AP) in mice.
Methods: Cerulein (50 μg/kg) was injected intraperitoneally once hourly for 6 hours to induce AP. To investigate the prophylactic effects of silymarin, dimethyl sulfoxide or silymarin (25, 50, and 100 mg/kg) was injected intraperitoneally 1 hour before cerulein injection. To investigate the therapeutic effects of silymarin, dimethyl sulfoxide or silymarin (100 mg/kg) was injected intraperitoneally 1, 3, or 5 hours after the first cerulein injection. Blood, pancreas, and lungs were harvested 6 hours after the last cerulein injection.
Results: Pre- and posttreatment with silymarin decreased the pancreas weight/body weight ratio and serum amylase activity. Furthermore, silymarin treatment inhibited pancreas and lung injury and neutrophil infiltration during cerulein-induced AP. In addition, silymarin inhibited increased secretion of proinflammatory cytokines such as interleukin 1β, interleukin 6, and tumor necrosis factor α. Finally, mitogen-activated protein kinases (MAPKs) and nuclear factor-κB were activated by cerulein, and only p38 in MAPK was inhibited by silymarin.
Conclusions: These findings suggest that silymarin attenuates the severity of AP through inhibition of p38 MAPKs and that silymarin could be a potential prophylactic and therapeutic agent for the treatment of AP.