Abstract
Osteoarthritis (OA) is the most common joint disease among late middle-aged or elderly people. The pathological process of OA mainly involves the degeneration of cartilage tissue and deficiency of joint function. Salvianolic acid B (Sal B) is the main active ingredient of Salvia miltiorrhiza Bge, which possesses anti-inflammatory, anti apoptotic and other pharmacological activities. In this study, primary chondrocytes were cultured to investigate the effects of Sal B on the inflammatory response and apoptosis of OA induced by IL-1β, and to explore the possible mechanism. First, we determined the cytotoxicity of Sal B; the results showed that the cell activity of chondrocytes was not influenced by Sal B when the concentration was below 150 μM. Moreover, Sal B (40 and 80 μM) suppressed the expression of iNOS in OA chondrocytes induced by IL-1β, and restrained the secretion of NO, IL-6, IL-17 and TNF-α in chondrocytes obviously. Sal B (40, 80 μM) significantly alleviated the inhibitory effect of cell activity stimulated by IL-1β and up-regulated the expression of Col II and reduced the expression of Col X. Besides, Sal B down-regulated the expression level of Bax and promoted the expression of Bcl-2, showed a significant effect on promoting proliferation and inhibiting cell apoptosis. In addition, we found that IL-1β significantly reduced the ratio of p-PI3K/PI3K, p-Akt/Akt induced the nuclear translocation of AKT and inhibited the activation of the PI3K/Akt signaling pathway. Finally, the PI3K inhibitor, LY-294002, was added in IL-1β-induced chondrocytes. The results suggest that Sal B ameliorates IL-1β induced inflammation and suppresses apoptosis in OA by activating the PI3K/Akt signaling pathway. Our study reveals the mechanism of Sal B acts on OA and may provide a basis for the treatment of OA with Sal B.