Evaluation of antiarthritic activity of nimbolide against Freund's adjuvant induced arthritis in rats

Nimbolide, a triterpenoid isolated from flower of neem tree possess various therapeutic properties. The objective of the study was to assess the anti-arthritic activity of nimbolide in arthritis induced rats. Nimbolide (20 mg/kg per day) was given orally to arthritic rats induced with Complete Freund's Adjuvant and changes in paw volume, body weight, organ indices (thymus and spleen), arthritic score, biochemical parameters and proinflammatory cytokines levels were determined. Histopathological analysis was also performed. Western blot analysis was also performed. Rats treated with nimbolide displayed marked reduction in arthritic score, organ indices, volume of paw, edema formation, along with substantial enhancement in body weight. Histopathological findings showed significant reduction in destruction of joints and inflammation following nimbolide treatment. The protective action of arthritic rats treated with nimbolide was also substantiated by molecular and biochemical studies. The results of the study show that nimbolide treatment has markedly enhanced health and reduced inflammation via lessening the proinflammatory cytokines expression in arthritic rats. Hence, nimbolide may be used as a potent therapeutic drug in treating rheumatoid arthritis.