Oral administration of Cimicifuga racemosa extract attenuates immobilization stress-induced reactions.

Dried rhizomes of Cimicifuga racemosa (CR), known as black cohosh, have been widely used as a herbal dietary supplement in the treatment of menopausal symptoms. Here we used experimental mouse stress models to investigate the role of anti-stress food factors, and found that a CR extract had stress-relieving effects. A single oral administration of CR extract (1,000 mg/kg) significantly attenuated plasma corticosterone and aspartate aminotransferase (AST) levels that had increased as a result of enforced immobilization. Bioassay-guided fractionation of the CR extract resulted in the isolation of 10 triterpenes, among which actein, 23-epi-26-deoxyactein, and cimiracemoside F (100 mg/kg, per os) were shown to contribute to the anti-stress effects. Furthermore, the CR extract significantly prevented the development of water immersion stress-induced gastric mucosal ulcers in rats. We propose that the CR extract might be suitable for the prevention and treatment of stress-related disorders.