Pueraria mirifica, a phytoestrogen-rich herb, prevents bone loss in orchidectomized rats

Objective: Estrogens and estrogen-like substances have been reported to play an important role in male bone homeostasis and to prevent bone loss. Pueraria mirifica (Leguminosae), a Thai herbal plant, containing a high amount of phytoestrogens was a choice of interest for this study. We examined the effects of crude P. mirifica on bone loss and influences on reproductive organs in male rats. Methods: Using fully mature and orchidectomized (ORX) rats, the effects of 0, 10, 100 and 1000 mg/kg B.W./day of P. mirifica and 0.1 mg/kg B.W./day of 17 alpha-ethinylestradiol (a positive control) were evaluated on bone mineral density (BMD) and bone mineral content (BMC) measured with a peripheral Quantitative Computerized Tomography (pQCT) densitometry. Results: Bone loss in trabecular and cortical bones of the various sites of axial bone (fourth lumbar vertebral body) and long bones (tibia and femur) after ORX was dose-dependently prevented by P. mirifica. The effects were specific on bone types and sites. The weights of the accessory sex organs, seminal vesicle and ventral prostrate gland, which significantly decreased after 3-month of ORX, were not altered by P. mirifica. Conclusion: The results suggest that P. mirifica treatment may be useful to prevent an osteoporosis in elderly hypogonadism subjects without influences on reproductive organs. © 2006 Elsevier Ireland Ltd. All rights reserved.