Protective effect of Chaihu Shugan San on emotional stress-induced liver injury

Chaihu Shugan San (CHSGS), a classic traditional Chinese medicinal formula, has been widely used in clinics for emotional disease. Here the protective effect and possible mechanisms of Chaihu Shugan San in stress-induced liver injury were investigated. The animal experimental protocol has been reviewed and approved by Laboratory Animal Ethics Committee of Jinan University, in compliance with the Institutional Animal Care Guidelines. Mice were administered CHSGS for 7 days and subjected to 18-h acute stress before being killed. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) levels in serum were measured with commercial kits. Histomorphology of the liver was analyzed by hematoxylin-eosin staining and immunohistochemistry. Glutathione (GSH) content, 4-hydroxynonenal (4-HNE), brain and muscle Arnt-like protein-1 (BMAL1) and arachidonate 15-lipoxygenase (ALOX15) protein were detected by LC-MS and Western blot, respectively. The results showed that CHSGS ameliorated acute stress-induced liver damage by reducing ALT and AST levels in serum and inflammatory infiltration in liver tissue. Network pharmacology analysis showed that CHSGS was associated with lipid peroxidation. Further analysis confirmed that MDA and 4-HNE levels declined and GSH level increased in livers of stressed mice after CHSGS administration. CHSGS also lowered BMAL1 expression, a pivotal factor in circadian rhythm, in livers of stressed mice. In conclusion, CHSGS ameliorated stress-induced liver injury by repressing lipid peroxidation and regulating circadian rhythm. Our studies implicate that CHSGS is promising as a therapy for stress-induced liver injury, and lay foundation for designing novel prophylactic and therapeutic strategies for stress-induced liver injury.