부산대학교 도서관

Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat infl ammatory diseases,tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the propertyof selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulateor disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigatethe property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reportergene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the activeprinciples, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical columnchromatography, which yielded 16 fractions (LNs). LNE showed high binding affi nities for hERα and hERβ with IC50 values of 1.20×10-7 g/ml and 1.00×10-7 g/ml, respectively. LNE induced 17β-estradiol (E2)-induced MCF-7 cell proliferation, however, it reducedthe proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducingthe expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affi nities for binding on hER α andβ than other fractions. Our results indicate that LNE had higher binding affi nities for hERβ than hERα, and showed SERM propertiesin MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such asfemale cancers and menopause.