Estrogen-like activity of ethanol extract of Ganoderma lucidum

Abstract

The ethanol extract from the fruiting body of Ganoderma lucidum was tested for its estrogen-like activity by using the cell proliferation assay (MCF-7 cells, human breast cancer cells), as well as the estrogen receptor binding assay, and pS2 mRNA expression assay in MCF-7 cells in vitro and uterotrophic assay in vivo. The ethanol extract of G. lucidum showed signifi cant positive effects on the proliferation of MCF-7 cells. This proliferation effect is related to the estrogenic activity of G. lucidum, because this proliferation activity was inhibited by the addition of the antiestrogenic compound ICI 182,780. The ability to bind to human estrogen receptors (hERs) α and β of the ethanol extract of G. lucidum was confi rmed by using the coactivator-bacterial alkaline phosphatase system. ER-dependent cell responsibilities were investigated by examining the regulation of gene transcription for pS2 in MCF-7 cells. Our results demonstrated that the pS2 mRNA levels are significantly increased by the ethanol extract of G. lucidum via an estrogen-like manner. Additionally, young rats that received the ethanol extract of G. lucidum (200 mg/kg per day) for 3 days showed a signifi cant increase (growth approximately twofold compared with the control group) in uterine weight after each treatment, which supports the estrogen-like activity of the ethanol extract of G. lucidum in vivo. It was concluded that the ethanol extract of G. lucidum showed estrogen-like activity, which may be useful in regulating hormone levels to treat related diseases such as osteoporosis if safety is fully guaranteed. © 2008 The Japan Wood Research Society.