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Objective: The aim of this study was to evaluate the potential effect of the methanolic extract of plant Glycyrrhiza glabra roots on bone mineral density and femoral bone strength of ovariectomized rats. Methods: Thirty 10-month-old Wistar rats were randomly separated into three groups of ten, Control, Ovariectomy and Ovariectomy-plus-Glycyrrhiza in their drinking water. Total and proximal tibial bone mineral density was measured in all groups before ovariectomy (baseline) and after 3 and 6 months post ovariectomy. Three-point-bending of the femurs and uterine weight and histology were examined at the end of the study. Results: No significant difference was noted in bone density percentage change of total tibia from baseline to 3 months between Control and Ovariectomy-plus-Glycyrrhiza groups (+5.31% ± 4.75 and +3.30% ± 6.31 respectively, P = non significant), and of proximal tibia accordingly (+5.58% ± 6.92 and +2.61% ± 13.62, P = non significant) demonstrating a strong osteoprotective effect. There was notable difference in percentage change of total tibia from baseline to 6 months between groups Ovariectomy and Ovariectomy-plus-Glycyrrhiza (−13.03% ± 5.11 and −0.84% ± 7.63 respectively, P

Abstract: A protective effect of plant extract from Onobrychis ebenoides on ovariectomy-induced bone loss in rats has been shown. To investigate the molecular mechanisms that underly the beneficial effect of O. ebenoides (Onb) on bone loss, we studied its potential to activate ER subtypes (ERα and ERβ) on transiently transfected HeLa cells with HO-hERα or pSG5-hERβ and 3×ERE-TATA-Luc expression vectors. Its impact to stimulate differentiation and mineralization of osteoblasts (KS483 cell line) by Alizarin Red-S staining was also examined. Furthermore we sought to induce for its potential the IGFBP3, a known estrogen-dependent marker in MCF7 breast cancer cells. 17β-Estradiol and the pure antiestrogen ICI182780 were included to serve as control samples of the estrogenic and antiestrogenic activity respectively. Our data revealed: (1) Onb extract displayed a significant estrogenic activity on both ERα and ERβ subtypes. (2) It exhibited direct action on osteoblasts by inducing mineralization. (3) It showed estrogenic activity in MCF7 cells. These findings suggest that the beneficial effect of Onb extract on bone loss is mediated through an estrogen-like action via activation of ERα-ERE and ERβ-ERE pathways and via direct action on the mineralization process of osteoblasts. [Copyright &y& Elsevier]

Abstract: Objective: Certain plant extracts have been the object of recent studies due to their mild estrogenic action and their possible potential role in osteoporosis prevention and/or treatment. The present study was undertaken to investigate the possible protective effect of the aqueous solution of the plant Onobrychis ebenoides, with proven in vitro mild estrogenic action, on bone mass loss of the ovariectomized (Ovx) rat experimental model of osteoporosis. Methods: Forty intact female mature (10-month-old) Wistar rats were separated into three groups: Ovx, Ovx plus plant extract (Ph) and sham-operated (control). Ph administration in the drinking water at a dose of 300mg/kg body weight/day commenced immediately after Ovx. Bone mineral density (BMD) values, percentage change from the baseline measurement and histomorphometry of the tibia, as well as body and uterine weight, were examined and compared between groups. Results: Comparison of BMD absolute values of the whole tibia of Ovx+Ph and Ovx animals at both 3 and 6 months post-Ovx were highly significant (p <0.0005), showing a protective effect on treated animals. The extract did not appear to have such a beneficial effect on BMD of the proximal tibia of the treated animals compared to the Ovx animals after 3 months; however, a significant protective effect was observed at 6 months post-Ovx in treated animals compared to the Ovx (p =0.015). When the % changes from baseline measurement of the whole tibia of Ovx+Ph and controls were compared, there was no significant difference at 3 or 6 months, demonstrating a highly protective effect; the respective comparisons of proximal tibia % changes did not display such protection. Body and uterine weight comparisons showed no significant difference between Ovx and treated rats, whereas, the level of significance for each group compared to controls was p <0.0005. Conclusions: The Ph studied showed a highly significant protective effect on BMD of the whole tibia of Ovx rats after 3 and 6 months of treatment, compared to the non-treated animals. Its effect on the proximal tibia was less pronounced, but also statistically significant compared to non-treated rats after 6 months. The lack of significant effect on body and uterine weight is in favor of its selective estrogen receptor modulator-like activity, and merits further studies. [Copyright &y& Elsevier]