Bone protection effects of a novel Chinese herbal formula, Taikong Yangxin Prescription (太空养心方), in hindlimb unloaded rats against bone deterioration.

Objective: To investigate the protective effects of a Chinese herbal formula, Taikong Yangxin Prescription (太空养心方, TKYXP) against bone deterioration in a hindlimb unloaded (tail-suspension) rat model. Methods: Thirty-two male Sprague-Dawley rats were divided into 4 groups: tail-suspension group fed with 2.5 g•kg•day of TKYXP extract (high dose), tail-suspension group fed with 1.25 g•kg•day (low dose), tail-suspended group treated with water placebo (placebo control group) and non tail-suspended group. The effects of TKYXP on bone were assessed using peripheral quantitative computed tomography (pQCT), microcomputerized tomography (micro-CT) and three-point bending biomechanical test on the femur in vivo. Results: TKYXP had a significant protective effect against bone loss induced by tail-suspension on day 28, as shown in the reduction in bone mineral density (BMD) loss, preservation of bone micro-architecture and biomechanical strength. The administration ofhigh dose TKYXP could significantly reduce the total BMD loss by 4.8% and 8.0% at the femur and tibia regions, respectively, compared with the placebo control group ( P<0.01) on day 28. Its bone protective effect on the femur was further substantiated by the increases of the trabecular BMD (by 6.6%), bone volume fraction (by 20.9%), trabecular number (by 9.5%) and thickness (by 11.9%) as compared with the placebo control group. Conclusion: TKYXP may protect the bone under weightless inflfl uence from gradual structural deterioration in the tail-suspension model. [ABSTRACT FROM AUTHOR]