Oleanolic acid prevents cartilage degeneration in diabetic mice via PPARγ associated mitochondrial stabilization

Hyperglycemia-induced cartilage degeneration induces osteoarthritis (OA). Since oleanolic acid (OLA) have several pharmacological effects such as anti-inflammatory, anti-oxidant, we hypothesized it possesses protection against high glucose injured cartilage. We now report that OLA decreased type X collagen and reversed the cartilage degeneration in growth plate from db/db mice. OLA increased type Ⅱ collagen expression in a concentration-dependent manner (10-50 μΜ) in high glucose-treated chondrocytes. OLA prevented the high glucose induced cell injury and decreased the level of MMP-13, PGE2 and IL-6 due to decreasing mitochondrial membrane potential and stimulated the ATP production. Moreover, OLA treatment inhibited apoptosis. And the reversed SOD2 expression and activity may be ascribed to decreased SOD2 protein degradation by OLA treatment, via PPPAγ. In conclusion, OLA protected against the high-glucose-induced cartilage injury via PPARγ/SOD2 pathway.