RESUMO
Objective:To investigate the mechanism of decomposed Zuoguiwan（ZGW） recipes in treating ovariectomized osteoporosis rats. Method:Forty Sprague-Dawley female rats were equally and randomly divided into Sham-operated group, ovariectomized model group, positive group, and low and high-dose ZGW groups. After 12 weeks of administration by gavage, the bone mineral density (BMD) of rats' distal femur was measured by micro-CT, the morphology of bone tissue were observed by hematoxylin-eosin staining (HE), β-cross-linked c-telopeptide of type Ι collagen (β-CTX) and bone-specific alkaline phosphatase (BALP) in serum were detected by enzyme-linked immunosorbent assay (ELISA), and the mRNA and protein expressions of β2AR, OPG and RANKL were evaluated by Western blot analysis and real-time quantitative polymerase chain reaction （PCR）. Result:Compared with Sham-operated group, BMD of rats in ovariectomized model group was decreased (P<0.01), morphology of bone tissue was destroyed, serum BALP was reduced, while β-CTX was boosted (P<0.01)，mRNA and protein expressions of OPG in tibia were reduced, while RANKL were increased, and mRNA and protein expressions of β2AR in the hypothalamus were decreased (P<0.05, P<0.01). Compared with ovariectomized model group, BMDs of rats in low and high-dose ZGW groups were increased (P<0.01), morphology of bone tissue was repaired, serum BALP and mRNA and protein expressions of OPG in tibia were up-regulated (P<0.05, P<0.01), whereas serum β-CTX and mRNA and protein expressions of β2AR in the hypothalamus and RANKL in tibia were down-regulated (P<0.05, P<0.01). Conclusion:Yang-nourishing components in decomposed Zuoguiwan recipes can improve BMD of ovariectomized rats by regulating OPG/RANKL pathway mediated by β2AR. "Seeking Yin in Yang" is a crucial mechanism of Zuoguiwan in treating ovariectomized osteoporosis in rats.