RESUMO
OBJECTIVE To investigate the effects of catalpol on H2O2-induced osteoblast injury and its mechanism. METHODS The osteoblasts MC3T3-E1 were separated into control group， model group， empty group （transfected with empty plasmid）， catalpol group （100 μmol/L）， catalpol+forkhead box O3 （FoxO3） overexpression group （100 μmol/L catalpol+ transfected with FoxO3 overexpression plasmid）. After catalpol treatment and transfection， except for control group， other groups were induced with H2O2 to establish osteoblast oxidative stress model. The cell viability， apoptotic rate， alkaline phosphatase （ALP） activity， optical density （OD） value of calcium nodule， mean fluorescence intensity （MFI） of reactive oxygen species （ROS）， antioxidant enzyme activity [superoxide dismutase （SOD）， catalase （CAT）]， the levels of inflammatory factors [interleukin-6 （IL-6）， IL-1β]， and the expressions of FoxO3/Wnt/β-catenin signaling pathway-related proteins were detected in each group. RESULTS Compared with the control group， the cell viability， ALP activity， OD value of calcium nodule， activities of antioxidant enzyme， and the protein expressions of Wnt and β-catenin were decreased significantly in the model group， while apoptotic rate， MFI levels of ROS， inflammatory factor levels and the protein expression of FoxO3 were all increased significantly （P＜0.05）. Compared with the model group， above indicators of the empty group had no significant change （P＞0.05）， while those of catalpol group were reversed significantly （P＜0.05）. Compared with the catalpol group， the reversal effect of the changes in the above indicators was significantly weakened in the catalpol+FoxO3 overexpression group cells （P＜0.05）. CONCLUSIONS Catalpol can activate Wnt/β-catenin signaling pathway by down-regulating FoxO3， thereby inhibiting H2O2-induced MC3T3-E1 oxidative stress and inflammation reaction， enhancing cell viability and osteogenic differentiation activity， and alleviating apoptosis injury.