Berberine suppresses cecal ligation and puncture induced intestinal injury by enhancing Treg cell function

The gut is hypothesized to be the "motor " of critical illness and plays an important role in the development of sepsis. Berberine (BBR) is an alkaloid compound extracted from herbs, which has anti-inflammatory, anti-oxidative effects and can be used in intestinal infectious diseases and inflammatory bowel disease (IBD). BBR could promote differentiation of Treg cells which play a key role in maintaining intestinal immune homeostasis. However, its effect on sepsis-induced intestinal injury remains poorly understood. This study investigated the effect of BBR on cecal ligation and puncture (CLP)-induced intestinal injury and explained the underlying mechanism. These results showed that BBR treatment decreased the mortality of septic mice, alleviated intestinal injury and reduced serum endotoxin level; at the same time, BBR had a protective effect on CLP-induced lung and liver apoptosis. Meanwhile, BBR treatment increased the proportion of Treg cells and CTLA-4 in Treg cells. Treg cells from BBR treatment mice could decrease the pro-inflammatory response by inhibiting the activation of macrophages, thus exerting a protective effect on CLP-induced intestinal injury, and CTLA-4 mediated cell-cell contact pathway is required for this protective effect.