| Objectives To observe the effect of GYY4137 on bone mass and bone mineral density (BMD) and autophagy in aged rats. Methods Ten young rats and twenty old female Sprague-Dawley rats were randomly divided into three groups: control group (Con, 10 young rats), model group (Mod, 10 old rats), and treatment group (Tre, 10 old rats), with 10 rats in each group. During the experiment, rats in the treatment group received GYY4137 treatment. After 12 weeks of treatment, serum oxidative stress indicators were measured. After 12 weeks, bone mass change was assessed using imaging and histology. Changes of key proteins in the autophagy signaling pathway were detected using Western blotting (WB). Results Compared with those in the Mod group, the serum MDA and ROS levels reduced significantly in the Tre group, and the GSH and SOD levels increased significantly after 12 weeks. The differences between the groups were statistically significant (P<0.05). Compared with those in the Mod group, there were more bone trabeculae, higher BMD, bone volume / total volume (BV / TV), trabecular thickness (Tb.Th), and the number of trabecular bones (Tb.N), and lower trabecular bone separation (Tb.Sp) in the treatment group, as evaluated with micro-CT and histology. The difference was statistically significant (all P<0.05). WB test results showed that the expression of Atg 5, LC3, and Beclin1 after H2S treatment was significantly higher than that in the control group (P<0.05), while p62 was significantly lower than that in the control group (P<0.05). Conclusion GYY4137 increases bone mass and BMD by increasing the level of autophagy and reducing the oxidative stress in aged rats. |