Abstract: Objective To investigate the effect of gastrodin ( GSTD) on the autophagy of chondrocytes in osteoarthritis and its mechanism. Methods The effect of GSTD on the chondrocyteviability was detected by CCK-8 assay. Chondrocytes were stimulated with IL-1β (10 ng / mL) to establish the osteoarthritis cell injury model in vitro. Cells were divided into 3 groups: control group,IL-1β group, and IL-1β + GSTD group. The apoptosis rate was detected by flow cytometry after 48 h culture. Western blotting was used to detect the expression levels of autophagy related proteins (LC3 and P62), AMPK, and mTOR. The secretion levels of COL2A1, MMP-13, TNF-α, and IL-6 in cell culture supernatant were determined by enzyme-linked immunosorbent assay ( ELISA). AMPK inhibitor (compound C) was used to observe the role of AMPK pathway in chondrocyte autophagy. Results GSTD treatment increased cell viability in the range of 12. 5 ~ 50 μmol / L. Cells pretreated with 25 μmol / L GSTD were selected for the subsequent experiments. IL-1β stimulated cellsto promote chondrocyte apoptosis (P < 0. 05), inhibited autophagy (P < 0. 05), increased the secretion of inflammatory factors (P < 0. 05), inhibited the expression level of COL2A1 and increased the expression level of MMP-13 (P < 0. 05), when compared with the control group. Compared with the cells in the IL-1β group, cells in the GSTD pretreated group had increased autophagy ( P <0. 05), decreased apoptosis ( P < 0. 05), decreased levels of inflammatory cytokines, decreasedexpression level of MMP-13 and phosphorylation of mTOR ( P < 0. 05), and increased expressionlevel of COL2A1 (P< 0. 05) and phosphorylation of AMPK. Treatment of cells with AMPK pathwayinhibitor (compound C) reversed the protective effect of GSTD on chondrocytes, resulting in thedecrease in apoptosis ratio, autophagy level and expression level of COL2A1, and the increased insecretion of inflammatory factors and expression level of MMP-13 (P < 0. 05). Conclusion GSTDpromotes the chondrocytes autophagy through the regulation of AMPK / mTOR signaling pathway,and protects chondrocytes from apoptosis and inflammatory response and by promotion of collagensynthesis.

Key words: gastrodin, osteoarthritis, autophagy, apoptosis, AMPK