[摘要]：Background/Aim: This study examines the chemopreventive potential and action of the herb black cohosh on Sprague-Dawley rats. Materials and Methods: Female Sprague-Dawley rats were treated with an extract of black cohosh enriched in triterpene glycosides (27%) at 35.7 (Group I), 7.14 (Group II), 0.714 (Group III) or 0 mg/kg b.w. for 40 weeks starting from 56 weeks of age and the incidence of benign and malignant mammary tumors was determined at the end of observation. Results: Among female rats treated at 35.7 and 7.14 mg/kg b.w. there was a dose-related reduction (p<0.05) of the incidence of mammary adenocarcinomas when compared to the treatment of 0.714 mg/kg b.w., with a protection index (calculated relative to the group III; PI=[total tumours x 100 animals of group III] - [total tumours x 100 animals of the group I (or group II]/ [total tumours of group III] x 100) for mammary adenocarcinomas of 87.5 and 48.8%, respectively. Black cohosh reduced Ki-67 and cyclin D1 protein expression in fibroadenomas, by immunohistochemistry. Conclusion: Our results suggest that black cohosh may have chemopreventive potential for mammary cancer.
