Minsun Yi, Yongjoo Park and Kyuhyuck Chung
Posters: Nat Prod Chem Res
Background: The aromatase enzyme, which converts androstenedione to estrone, is well known to regulate the availability of estrogen to support the growth of hormone-dependent breast tumors. Cyperus rotundus L. is a sedge in the family Cyperaceae, that grows naturally in tropical, subtropical, and temperate regions. Its rhizome, Cyperi Rhizoma, has been used as a wellknown traditional herbal medicine for the treatment of dysmenorrhea, menstrual disorders, stomachache, bowel disorders, and several pains. Aim: Only few scientific studies about use of C. rotundus in the breast cancer prevention have been done so far. In continuation of our search for phytoestrogen from natural products that can be used in women?s postmenopausal treatment with less sideeffects, we found that MeOH extract of C. rotundus showed potent estrogenic activity by using E-screen assay. Methods: The MeOH extract was subjected to bioassay-guided fractionation and isolation. Six sesquiterpenes were isolated from the hexane fraction of C. rotundus rhizome (CRE) and each has evaluated for the estrogenic potency in E-screen assay. Also ?In-Cell? aromatase activity assay was done to compare aromatase inhibitory effects of CRE compounds. Results: The sesquiterpene compounds are supposed to act by ligand-binding to the estrogen receptors, which in turn showed anti-estrogenic effect as a result of competition with high concentration of estradiol. In the estrogen replacement therapy for post-menopausal women, these findings suggest CRE consists of phytoestrogens which also may prevent the side-effective breast cancer occurrence. Furthermore, CRE showed especially almost over 50% percent when compared to the other fractions. Among the sesquiterpenes, isocyperol and 2 other compounds showed strong aromatase inhibition in JEG-3 cells. Conclusions: This result indicates that CRE may be beneficial in the chemoprevention of hormone-dependent breast tumors in the replacement therapy for post menopausal women.
