Influence of six medicinal herbs on collagenase-induced osteoarthritis in rats

Medicinal herbs have been effectively used for their anti-inflammatory activity, but their exact role has not yet been documented in scientific literature for the management of Osteoarthritis (OA). Since Sida cordifolia L., Piper longum L., Zingiber officinale Rosc., Ricinus communis L., Vitex negundo L. and Tribulus terrestris L. have been widely used in traditional medicine for their anti-inflammatory activity, to evaluate anti-osteoarthritic activity of these herbs, we used a collagenase type II-induced osteoarthritis (CIOA) rat model. Arthritis was induced in wistar rats by intra-articular injection of collagenase type II. Powders of herbs were given orally for 20 days as a suspension in water (270 mg/kg b. wt.). The effects of the treatment in the rats were monitored by physiological parameters like body weight, knee diameter, paw retraction, paw volume, glycosaminoglycan (GAG) release, radiography and histopathology of knee joint. Selected herbs have significantly prevented body weight loss and knee swelling compared to arthritic control (CIOA). All test groups, including indomethacin (standard drug, 3 mg/kg), significantly reduced paw volume compared to CIOA. GAG release in the serum was significantly lowered in herb treated groups compared to indomethacin. The anterior posterior radiographs of S. cordifolia and P. longum treated groups showed a protective effect against OA. Histopathology revealed protection in the structure of the articular cartilage and in chondrocyte pathology as well as reduced clefting. Treatment with herbs has shown chondroid matrix within normal limits. From the results, we observed that S. cordifolia and P. longum possess potent anti-osteoarthritic activity.