Anti-Osteoarthritic and Anti-Inflammatory Activities of Diazine: In Vitro and In Vivo Studies

BACKGROUND The present study evaluated the effects of diazine (DZN) on collagenase-induced osteoarthritis (OA) in rats. MATERIAL AND METHODS OA was produced via intra-articular injections of collagenase type II into the knee joint. The rats were then treated with DZN (25, 50, or 100 mg/kg, p.o.) for three weeks. At the end of the protocol, all rats were evaluated for paw latency, paw edema, and knee swelling. Additionally, serum concentrations of glycosaminoglycan (GAG), alkaline phosphatase (ALP), and C-reactive protein (CRP) were determined. X-rays were performed to estimate radiological and histopathological changes in the knee joint. The expressions of antioxidant enzymes, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) were estimated in the synovial tissues. RESULTS DZN treatment attenuated inflammation in osteoarthritic rats, as evidenced by decreases in paw edema and knee swelling and enhanced paw latency compared to the negative control group. Additionally, there were significant decreases in the serum levels of CRP and GAG and increases in ALP in the DZN-treated groups compared to the negative control group. The radiological and histopathological results showed that DZN protected against cartilage damage in the knee joint. Additionally, MMP levels decreased and there were significant reductions in the expressions of antioxidant enzymes and TIPMs in the DZN-treated groups compared to the negative control group. CONCLUSIONS The present findings demonstrated the chondroprotective effects of DZN via its modulation of the expressions of TIMP-1 and MMPs in the synovial tissues of osteoarthritic rats.