title: Ethanol-extracted Cameroonian propolis exerts estrogenic effects and alleviates hot flushes in ovariectomized Wistar rats.
abstract: BACKGROUND
  Since the biological properties of propolis depend to the plants that can be found in a specific region, propolis from unexplored regions attracts the attention of scientists. Ethanolic extract of Cameroonian propolis (EEP) is used to treat various ailments including gynecological problems and amenorrhea. Since there were no scientific data to support the above claims, the present study was therefore undertaken to assess estrogenic properties of Cameroonian propolis.
  
  
  METHODS
  To achieve our goal, the ability of EEP to induce MCF-7 cells proliferation in E-screen assay as well as to activate estrogen receptors α (ERα) and β (ERβ) in cell-based reporter gene assays using human embryonic kidney cells (HEK293T) transfected with ERs was tested. Further, a 3-day uterotrophic assay was performed and the ability of EEP to alleviate hot flushes in ovariectomized adult rats was evaluated.
  
  
  RESULTS
  In vitro, EEP showed an antiestrogenic activity in both HEK293T ER-α and ER-β cells. In vivo, EEP induced a significant increase in a bell shape dose response manner of the uterine wet weight, the total protein levels in the uterus, the uterine and vaginal epithelium height and acini border cells of mammary gland with the presence of abundant eosinophil secretions. Moreover, EEP induced a significant decrease in the total number, average duration as well as frequency of hot flushes after 3 days of treatment in rat (equivalent to a month in woman). The dose of 150 mg/kg exhibited the most potent estrogenic effects among all the tested doses. The UPLC-HRMS analysis showed the presence of caffeic acid derivatives and trirtepernoids in EEP, which are well known endowed with estrogenic properties.
  
  
  CONCLUSIONS
  These results suggest that Ethanolic extract of Cameroonian propolis has estrogen-like effects in vivo and may alleviate some menopausal problems such as vaginal dryness and hot flushes. Ethanol-extracted Cameroobian propolis exhibited in vitro and in vivo estrogen-like effects. This extract may contain promising phytoestrogens.
authors.affiliation: Laboratory of Physiology and Natural Products Research, Department of Life and Earth Sciences, Higher Teachers' Training College, University of Maroua, P.O. Box 55, Maroua, Cameroon. stephanezingue@gmail.com.|Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, P.O. Box 812, Yaoundé, Cameroon. stephanezingue@gmail.com.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Zingue
authors.affiliation: Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Chantal Beatrice Magne
authors.initials: CBM
authors.lastname: Nde
authors.affiliation: Institute of Chemistry of Nice, Faculty of Science, University Côte d'Azur, UMR CNRS 7272, Valrose Park, Nice, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Michel
authors.affiliation: Department of Applied Chemistry, Faculty of Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, 2028, South Africa.
authors.forename: Derek Tantoh
authors.initials: DT
authors.lastname: Ndinteh
authors.affiliation: Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, P.O. Box 812, Yaoundé, Cameroon.
authors.forename: Jules
authors.initials: J
authors.lastname: Tchatchou
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Ngaoundere, P.O. Box 454, Ngaoundere, Cameroon.
authors.forename: Moïse
authors.initials: M
authors.lastname: Adamou
authors.affiliation: Institute of Chemistry of Nice, Faculty of Science, University Côte d'Azur, UMR CNRS 7272, Valrose Park, Nice, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Fernandez
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Ngaoundere, P.O. Box 454, Ngaoundere, Cameroon.
authors.forename: Fernand-Nestor Tchuenguem
authors.initials: FT
authors.lastname: Fohouo
authors.affiliation: Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Colin
authors.initials: C
authors.lastname: Clyne
authors.affiliation: Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, P.O. Box 812, Yaoundé, Cameroon. dnjamen@gmail.com.|Department of Applied Chemistry, Faculty of Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, 2028, South Africa. dnjamen@gmail.com.
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Njamen
mesh_terms: D000818:Animals; D001516:Bees; D002163:Cameroon; D004967:Estrogens / Q000494:pharmacology*; D000431:Ethanol; D005260:Female; D057809:HEK293 Cells; D019584:Hot Flashes / Q000188:drug therapy*; D006801:Humans; D008321:Mammary Glands, Animal / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D011429:Propolis / Q000737:chemistry* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects; D014621:Vagina / Q000187:drug effects
chemical_list: D004967:Estrogens; D000431:Ethanol; D011429:Propolis
keywords: Cameroonian propolis; E-screen assay; Ethanolic extract of propolis; Hot flushes; Ovariectomized rat; Phytoestrogens