Antiarthritic Effect of Polar Extract of Curcuma longa on Monosodium Iodoacetate Induced Osteoarthritis in Rats

Background: Curcuma longa Linn, “the golden spice” is a common spice used in Southern Asia and Middle East countries. It has a history of ethnopharmacological use for its various activities like anti-septic, anti-inflammatory, anti-oxidant, anti-microbial, anti-cancer and so on. Objective: To investigate the effects of polar extract of C. longa (PCL) against monosodium iodoacetate (MIA) induced osteoarthritis in rat and to compare with curcuminoids, which are contemporarily believed to be the only active phytochemicals of C. longa for relieving pain in osteoarthritis. Method: Osteoarthritis in rats was induced by intra-articular injection of monosodium iodoacetate (MIA) in right knee. PCL or curcuminoids or tramadol was administered orally as single dose on the 5th day post MIA injection to rats. Weight bearing capacity and percentage inhibition of nociception of PCL treated groups were determined and compared with curcuminoids and tramadol (reference drug). In addition, gene expression levels of type II collagen and matrix metalloproteinases (MMP) in joint cartilage was measured by Reverse transcription polymerase chain reaction. Results: PCL significantly decreased the difference in weight distribution between left and right limb in a dose dependent manner. Anti-arthritic activity of PCL is evident from significant up regulation of type II collagen gene (COL2A1) and down regulation of MMP-3 and MMP-7. Conclusion: Polar extract of C. longa showed beneficial effects on joints by exhibiting antiosteoarthritic effects via maintaining equilibrium between anabolic and catabolic factors of joint cartilage.