Objective To investigate the effect and mechanism of puerarin on steroid-induced osteonecrosis of the femoral head (ONFH) in rabbits by regulating the expression of miR-30b-5p. Methods A total of 84 New Zealand white rabbits were grouped into a control group, ONFH group, low-dose puerarin group, high-dose puerarin group, positive control group, high-dose puerarin+antagonist NC group, and high-dose puerarin+miR-30b-5p antagonist group, with 12 rabbits in each group. Micro CT was applied to detect the number, thickness, and separation of trabeculae in the femoral head of rabbits; HE staining was applied to detect pathological changes in the femoral head tissue; ELISA was applied to detect the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in the femoral head tissue; TUNEL staining was applied to detect osteocyte apoptosis in femoral head tissue; qRT-PCR was applied to detect the expression of miR-30b-5p in femoral head tissue; Western blot was applied to detect the expression of Dickkopf-1 (DKK-1) protein in femoral head tissue. Results Compared with the control group, the number of trabeculae, thickness of trabeculae, SOD activity, and the expression of miR-30b-5p in the ONFH group decreased, the bone trabecular separation, empty bone lacuna rate, MDA content, bone cell apoptosis rate, and the expression of DKK-1 protein increased (P<0.05); compared with the ONFH group, the number of trabeculae, thickness of trabeculae, SOD activity, and the expression of miR-30b-5p in the low-dose, the high-dose puerarin group, and the positive control group increased, the bone trabecular separation, empty bone lacuna rate, MDA content, bone cell apoptosis rate, and the expression of DKK-1 protein decreased (P<0.05); miR-30b-5p antagomir attenuates the inhibitory effect of high dose puerarin on oxidative stress and apoptosis of ONFH rabbits. Conclusion Puerarin can inhibit oxidative stress and apoptosis of ONFH rabbits, and its mechanism may be related to the up-regulation of miR-30b-5p expression. |