| Objective To observe and study the effect of puerarin on bone metabolism, bone mineral density (BMD), and bone biomechanics in postmenopausal osteoporosis (PMOP) rats, and to explore the mechanism of Chinese herbal medicine in preventing and treatment of PMOP. Methods Forty-eight rats were randomly divided into the normal group, ovariectomized group, calctriol group, and puerarin group, with 12 rats in each group. Rat model of postmenopausal osteoporosis was established and rats received different drugs for 8 weeks. Rats in the normal group and ovariectomized group received 5 mL/kg of 0.9% NaCl, ih, qd. Rats in puerarin group received 35 mg/kg of puerarin, ih, qd. Rats in calcitriol group recieved 0.25 μg of calcitriol, po, qd. Drug administration was continued for 6 weeks. Serum bone metabolism indexes, BMD, BMC, and bone biomechanical indexes of rats were detected in each group. ER expression in bone tissue of each group was detected with SP method. morphological changes of bone tissue was observed with HE staining. Results The serum bone metabolism indexes, BMD and BMC of the lumbar spine and femur, and femoral bone biomechanical indexes of the ovariectomized rats were significantly lower than those of rats in the normal group (P<0.05). The above indexes in the ovariectomized group and puerarin group were significantly higher than those in the ovariectomized group (P<0.05). The above indexes in puerarin group were higher than in the calcitriol group (P<0.05). The expression of ER protein in bone tissue in ovariectomized group was significantly lower than that in the normal group (P<0.05). ER protein expression in the calcitriol group and puerarin group was significantly higher than that in the ovariectomized group (P<0.05). The expression of ER protein in puerarin group was higher than in the calcitriol group (P<0.05). In the ovariectomized group, the bone cortex was significantly thinner, the bone trabeculae were sparse, thin, or fractured, the arrangement was disordered, the medullary cavity was significantly enlarged, and the hematopoietic cells were significantly reduced. The structure of bone cortex in puerarin group was relatively complete, the number of bone trabeculae increased, the bone was dense, even, and strong, connected into a network, the medullary cavity became smaller, and the hematopoietic cells increased. Conclusion Puerarin improves the estrogen level of postmenopausal osteoporosis rats, regulates bone metabolism, improves bone mass and bone mineral density, improves bone biomechanical properties and bone morphological structure, and plays an anti-PMOP effect and bone protection role. |