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.