In vivo and in vitro estrogenic activity of extracts from Erythrina poeppigiana (Fabaceae)

Abstract

In developing countries, around 80% of the population still resorts on traditional medicine for their primary health care. Erythrina poeppigiana (Walp.) O.F. Cook, one of these medicinal plants, was found to be particularly rich in isoflavonoids which exhibited, individually, significant estrogenic activity in vitro. The possible combined effects of these bioactive isoflavones, as they are naturally found in the crude extracts of E. poeppigiana, prompted us to assess their in vivo estrogenicity. We first tested the ability of the extracts to transactivate estrogen receptor alpha (ERα) in vitro using U2OS human osteosarcoma cells. We next investigated their effects in vivo in an uterotrophic assay, using ovariectomized rats treated with the extracts at the doses of 50, 100, 200, and 400 mg/kg BW/d orally for 3 days. Finally, we assessed their ability to relieve hot flushes, using data loggers. At the end of treatments, animals were sacrificed, and organs (mammary glands, vagina, and uteri) were collected for histo-morphometric analyses. The methanol extract significantly and dose-dependently transactivated ERα at all tested doses. All extracts induced significant increases of vaginal and uterine epithelial heights. Only the dichloromethane extract could significantly relieve hot flushes as estradiol. These results indicate that E. poeppigiana extracts have estrogen-like effects in vivo, suggesting that its active principles act in synergy when they are taken in combination in the crude extract. These findings, therefore, support the traditional use of E. poeppigiana to alleviate some menopausal problems; our previous phytochemical investigations contribute to the standardization of this phytomedicine.

Evaluation of the estrogenic properties of aqueous extracts of <em>Tragia benthamii</em> Baker (Euphorbiaceae) and <em>Graptophyllum pictum</em> (Acanthaceae) and their ability to alleviate some menopausal symptoms induced by ovariectomy in Wistar rats

“…As far as the uterine epithelium thickness is concerned, a significant increase in the high of the uterine epithelium was induced by the aqueous extract of T. benthamii at the dose of 500 mg / kg BW, G. pictum at all the tested doses and the mixture of both plants at the doses of 50 and 275 mg / kg BW. These observations support those of Njamen et al (2013) [20] witch show that substances with estrogenic properties affect the uterus by fluid retention and/or cell proliferation, increasing its weight and / or the high of its epithelium. This suggests the presence in the aqueous extracts, of secondary metabolites capable of inducing cell proliferation that leads to the increase in the thickness of the epithelium, by initiating a cascade of genomic reactions after binding to the ER in the uterus (leading to cellular hypertrophy by protein synthesis).…”

“…Conversely, all doses of our extracts did not induce a significant increase in the size of the vaginal epithelium. However, substances with estrogenic properties are capable of increasing the size of the vaginal epithelium by stimulating proliferation, stratification and cornification of vaginal epithelial cells [20]. This has not been the case for our extracts.…”

“…Experiment 2. : Measurement of hot flushes The physiological rat model for hot flushes, introduced by Berendsen et al [19] was used to assess the ability of G. pictum extract to alleviate hot flushes, with the slight difference that data loggers were used instead of a telemetric transmitter. Data loggers were used to monitor the core temperature changes in the animals at 2 min intervals for 72h, as previously described by Njamen et al [20] and Nkeh-Chungag et al [21]. In this study, data loggers were pre-set to start measuring core temperatures 12h before the beginning of the treatment until the end of treatment.…”

Supplementation with extract of pumpkin seeds exerts estrogenic effects upon the uterine, serum lipids, mammary glands, and bone density in ovariectomized rats

“…For the in vivo experiments, we observed the estrogenic effects on uterine weight, mammary gland development, lipid profiles, bone density, and bone tissue profiles. Due to the lack information in same setting of experiments, we used two doses of EPS, 500‐ and 1000 mg/kg BW presenting the low and high doses referring to the same design of study as reported before (Adelina et al, ; Burdette et al, ; Njamen, Djiogue, Zingue, Mvondo, & Nkeh‐Chungag, ; Njamen, Ndé, Fomum, & Mbanya, ). In order to determine the success of the ovariectomy, we compared the uterine weight between Baseline SHAM and Baseline OVX before treatment with EPS and E2.…”

Erythroidine Alkaloids: A Novel Class of Phytoestrogens

“…Thus, we suggest that αand βerythroidine alkaloids contribute to the estrogenic activity of the medicinal plant E. poeppigiana. Whether it contributes to the estrogenic properties recently shown in an experimental rat model [26] remains open. From our in vitro study, it is not possible to assess the overall contribution of the erythroidines to the total estrogenic activity of the plant or how it is relative to the less polar isoflavones [6,7,27] or arylbenzofurans [28].…”