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 ß (ERß) 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-ß 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. CONCLUSION: 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.
Subject(s)
Estrogens/pharmacology , Hot Flashes/drug therapy , Propolis/chemistry , Animals , Bees , Cameroon , Ethanol , Female , HEK293 Cells , Humans , Mammary Glands, Animal/drug effects , Organ Size/drug effects , Ovariectomy , Propolis/pharmacology , Rats , Rats, Wistar , Uterus/drug effects , Vagina/drug effectsABSTRACT
To determine the apicultural value of Annona senegalensis Pers. 1806 (Annonaceae), Croton macrostachyus Hochst. Ex Del. 1847 (Euphorbiaceae), Psorospermum febrifugum Spach 1836 (Hypericaceae) and Syzygium guineense (Will.) DC var. guineense 1828 (Myrtaceae), Apis mellifera adansonii Latreille 1804 (Hymenoptera: Apidae) activity was observed on their flowers in the area of Ngaoundéré, from January to May, in 2002 and 2003. Flowers of each plant species were prospected at least four days per month, between 7 am and 6 pm, for the registration of the nectar and/or pollen foraging behaviour of A. m. adansonii workers. Results show that A. m. adansonii harvested nectar and pollen of each plant species. The greatest number of workers foraging simultaneously on a plant varied from 9 in P. febrifugum to 3600 in S. g. guineense. A. m. adansonii workers were faithful to each plant species. A. senegalensis, C. macrostachyus, P. febrifugum and S. g. guineense could be cultivated and protected to increase honey production. A. senegalensis could enable beekeepers to increase their pollen production as a hive product. During foraging, A. m. adansonii workers increased pollination possibilities of each plant species.
