[Effects of Guben Zenggu Capsules on oxidative stress-mediated mitochondrial apoptosis and bone metabolism in bone tissue of postmenopausal osteoporosis rats].

This study aims to investigate the protective effects of Guben Zenggu Capsules(GBZG) on oxidative stress and mitochondrial apoptosis in bone tissue of a rat model with postmenopausal osteoporosis(PMOP). Sixty female Wistar rats(three months old) were randomly allocated into sham group, model group, low-dose GBZG(GBZGL) group, medium-dose GBZG(GBZGM) group, high-dose GBZG(GBZGH) group, and estrogen group. Except for the rats in the sham group, all rats underwent bilateral ovariectomy to establish the PMOP model. After 12 weeks of continuous administration, BMD was measured using dual-energy X-ray absorptiometry. Bone microarchitecture and pathological changes were evaluated by micro-CT imaging. Bone metabolism indicators, including BGP, ICTP, PICP, and TRAP-5b, as well as oxidative stress indicators, such as MDA, SOD, and ROS, were determined by ELISA. The protein expression levels of Bcl-2, Bax, Cyt C, Caspase-3, and Caspase-9 in bone tissue were analyzed by Western blot. The mRNA expression levels of Bcl-2, Bax, Cyt C, Caspase-3, Caspase-9, and AIF were quantified by RT-qPCR. Immunofluorescence staining was used to evaluate the fluorescence intensity of Caspase-3 and AIF proteins. The results showed that the rats in the model group exhibited reduced BMD, deterioration of bone microarchitecture, elevated oxidative stress, increased pro-apoptotic factors, and abnormal bone metabolism. GBZGH group could significantly reverse these pathological changes, exhibiting superior efficacy than GBZGM group and GBZGL group and effects similar to the estrogen group. These findings suggest that GBZG can exert a therapeutic effect on PMOP by inhibiting oxidative stress, regulating mitochondrial apoptosis pathways, and restoring bone metabolic homeostasis.