The present study was aimed to investigate the anti-arthritic effect of triphala and its underlying mechanism on adjuvant-induced rat model. For comparison purpose, non-steroidal anti-inflammatory drug indomethacin was used. Arthritis was induced by intradermal injection of complete Freund's adjuvant (0.1 ml) into the right hind paw of the Wistar albino rats. Triphala (100 mg/kg body weight [bwt]) was administered intraperitoneally (from 11th to 20th day) after the arthritis induction. Arthritis induction increased the levels of reactive oxygen species (LPO and NO), elastase, and mRNA expression of pro-inflammatory cytokines (TNF-α, IL-β, IL-17, IL-6 and MCP-1), inflammatory marker enzymes (iNOS and COX-2), receptor activator of nuclear factor kappa-B ligand (RANKL), and transcription factors (NF-kB p65 and AP-1) in the paw tissues of rats. The levels of bone collagen were found to decrease with increased urinary constituents (hydroxyproline and total glycosaminoglycans) in arthritic rats. In addition, the immunohistochemistry analysis revealed increased expression of NF-kBp65 and COX-2 in the paw tissues of arthritic rats. However, administration of triphala significantly inhibited the biochemical and molecular alterations in adjuvant-induced arthritic rats compared to indomethacin (3 mg/kg bwt) as evidenced by the radiological and histopathological analysis. In conclusion, our results suggest that triphala administration ameliorate bone and cartilage degradation during rheumatoid arthritis.
Keywords: Adjuvant-induced arthritis; pro-inflammatory cytokines; transcription factors; triphala.