Preventive effects of Pueraria mirifica on bone loss in ovariectomized rats

Objective: Effects of Pueraria mirifica on bone loss in fully mature ovariectomized rats are examined. Methods: Two series of experiments were performed. In the first series, rats were kept with their ovaries intact and divided into two groups; initial control (IC) and sham control (SH). The IC rats were sacrificed on day 1 and their data were kept as baseline control. The SH rats were subjected to sham operation on day 0 and gavaged daily with distilled water for 90 days. In the second series, rats were subjected to ovariectomy, divided into five groups and gavaged daily with 0.1 mg/kg B.W./day of 17-alpha-ethinylestradiol (EE), 0, 10, 100 and 1000 mg/kg B.W./day of P. mirifica (P0, P10, P100 and P1000, respectively) for 90 days. Changes of bone mineral density and bone mineral content were measured using peripheral Quantitative Computerized Tomography. Results: Bone loss was significantly induced by ovariectomy and it was dose-dependently prevented by P. mirifica treatment for 90 days. The preventive effects of P. mirifica on bone loss depended on bone types (axial or long bone), bone sites (metaphysis or diaphysis), and bone compartments (trabecular and cortical). At P100 and P1000, bone loss was completely prevented both in trabecular bone mineral density and content. The effects of P. mirifica were, as expected, comparable to that in the EE group. Conclusion: These results suggest that P mirifica may be applicable to treat the osteoporosis in menopausal women; however, an undesirable side effect on stimulating reproductive organs should be concerned. (c) 2008 Elsevier Ireland Ltd. All rights reserved.