title: Elucidation of Underlying Mechanisms by Which Millettia macrophylla Benth Induces Its Estrogenic Activity.
abstract: Millettia macrophylla is used traditionally to treat menopause related symptoms. This plant was shown to exhibit estrogenic effects in vitro on human embryonic kidney cells and in vivo on ovariectomized rats. The present study aimed at elucidating underlying mechanisms by which M. macrophylla induced its estrogenic effects. To accomplish our goal, kidney Hek293T cells transiently transfected with estrogen alpha or beta receptor expression plasmids were cotreated with a pure antiestrogen ICI 182,780 and the dichloromethane or methanol soluble fractions of M. macrophylla. To follow up, we cotreated ovariectomized rats with both extracts and ICI 182,780 for 3 days in the classical uterotrophic assay. Animals were then sacrificed and the uterine wet weight, total protein levels in uteri, uterine, and vaginal epithelial heights, and mammary gland were assessed. In vitro, the results suggested that the induction of the estrogenic activity by M. macrophylla is due to the binding of its secondary metabolites to ERα and ERβ. In vivo, the cotreatment of extracts and ICI 182,780 significantly abrogated the biological responses induced by the extracts alone. Taken together, these results indicate that the active principles of M. macrophylla induce their beneficial effects on menopausal symptoms by activating the ERs.
authors.affiliation: Laboratory of Physiology, Department of Life and Earth Sciences, Higher Teachers' Training College, University of Maroua, P.O. Box 55, Maroua, Cameroon; Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Zingue
authors.affiliation: MIMR-PHI Institute of Medical Research, Departments of Molecular and Translational Sciences, Monash University, 246 Clayton Road, Level 4, VIC 3168, Melbourne, Australia.
authors.forename: Chantal Beatrice
authors.initials: CB
authors.lastname: Magne Nde
authors.affiliation: MIMR-PHI Institute of Medical Research, Departments of Molecular and Translational Sciences, Monash University, 246 Clayton Road, Level 4, VIC 3168, Melbourne, Australia.
authors.forename: Colin
authors.identifier: 0000-0003-0526-2475
authors.initials: C
authors.lastname: Clyne
authors.affiliation: Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Njamen