| Objective To investigate the effect of Peiminine on cartilage damage in knee osteoarthritis (KOA) rats by regulating the Ras homologous gene family, member A (RhoA)/Rho associated coiled coil-forming kinase (ROCK) signaling pathway. Methods A KOA rat model was prepared using the sodium iodoacetate (MIA) method and randomly grouped into a model group, a Peiminine (3.5mg/kg) group, and a Peiminine (3.5mg/kg)+LPA (RhoA activator, 1mg/kg) group, with 10 rats in each group, another 10 rats were selected as control group. Mechanical stimulation and thermal radiation methods were applied to detect knee joint pain symptoms in rats; the joint swelling degree and knee joint width of rats were measured, and their joint function was evaluated using gait scores; transmission electron microscopy was applied to detect the ultrastructure of knee joint chondrocytes in rats; TUNEL staining was applied to detect the apoptosis ratio of articular chondrocytes; enzyme-linked immunosorbent assay (ELISA) was applied to detect the levels of pro-inflammatory factors such as interleukin-18 (IL-18) and monocyte chemotactic protein-1 (MCP-1) in rat serum and joint fluid; immunoblotting was applied to detect apoptosis (Cleaved caspase-3, Bax) and the expression of RhoA/ROCK pathway related proteins in the articular cartilage tissue of rats. Results Peiminine decreased joint swelling, knee joint width, gait score, chondrocyte apoptosis ratio, serum and joint fluid IL-18, MCP-1 levels, and cartilage Cleaved caspase-3, Bax, RhoA, ROCK1, ROCK1 protein expression in KOA rats, and increased mechanical pain threshold and heat pain threshold (P<0.05); LPA could weaken the amelioration effect of Peiminine on articular cartilage injury in KOA rats..Conclusion Peiminine can inhibit joint inflammation and apoptosis of articular chondrocytes in KOA rats by inhibiting RhoA/ROCK signal activation, and alleviate cartilage injury. |