| Objective To investigate the effect of Liuwei Dihuang pill-containing serum on the autophagy in MC3T3-E1 cells under oxidative stress via ERK/mTOR signaling pathway, and to explore the mechanism of its treating of osteoporosis. Methods Hydrogen peroxide (H2O2) was used to simulate oxidative stress. Cells were divided into Control group (no intervention), Model group (H2O2 intervention), Blank group (blank serum, H2O2 intervention), LWDH group (LWDH-containing serum, H2O2 intervention), Rap group (mTOR pathway inhibitor, H2O2 intervention), U0126 group (ERK pathway inhibitor, H2O2 intervention), Rap+LWDH group (mTOR pathway inhibitor, LWDH-containing serum, H2O2 intervention), and U0126+LWDH group (ERK pathway inhibitor, LWDH-containing serum, H2O2 intervention). Cellular ROS levels were detected with cellular reactive oxygen species (ROS). The expressions of autophagy protein LC3B and ERK/mTOR signaling pathway-related proteins mTOR, p-mTOR, ERK1/2, and p-ERK1/2 were detected with Western blotting. Results ROS results showed that the ROS level in LWDH group, Rap group, and U0126 group was lower than that in Model group (P<0.05). Western blotting results showed that the LC3II/Ⅰ protein increased in the LWDH, Rap, and LWDH+Rap groups compared to that in the Model group (P<0.05). The p-mTOR protein decreased in the LWDH, Rap, and Rap+LWDH groups compared to that in the Model group (P<0.05). The p-ERK1/2 protein expression was down-regulated in the LWDH group and U0126 group (P<0.05). Conclusion The mechanism of Liuwei Dihuang pills for the treatment of postmenopausal osteoporosis may be related to the autophagy in osteoblasts under oxidative stress by inhibiting ERK/mTOR signaling pathway. |