INFLUENCE OF SOYBEAN ISOFLAVONES ON BONE DENSITY AND BIOMECHANICAL PROPERTIES IN OVARIECTOMIZED RATS

Objective: To study the preventive effects of soybean isoflavones (SI) on osteoporosis of ovariectomized rats. Methods: SD female rats, 4 mo old, were ovariectomized and randomized into 4 groups: group A, sham-operated; group B,C, D, ovariectomized; group A,B,i.g. water; group C, i.g. low dose SI; group D, i.g. high dose SI. All rats were killed after 2.5 mo. The weight of womb, bone density and biomechanical properties of femur and tibia were measured. Results: After 2.5 month, the weight of the rats of groups B, C was significantly higher than group A. group D was similar to group A. The rats of group A had the heaviest wombs, and groups B lightest, groups C and D significantly higher than group B. The rats of group B had the least bone density, and group A highest, the other groups in the middle. But all of them were statistically insignificant.The structural parameters of left femur of group B were lower than the others. For biomechanical properities, group C and D were higher than group B and similar to group A. Conclusion: Soybean isoflavones can improve the bone biomechanical properties and might increase bone density of ovariectomized female rats.