Protective efficacy of N-(2-hydroxyphenyl) acetamide against adjuvant-induced arthritis in rats

Rheumatoid arthritis is a chronic inflammatory joint disease characterized by synovial proliferation and tissue destruction. Proinflammatory cytokines like interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) play a key role in the disease process and elevate energy expenditure, which further increases the joint pain and stiffness. To explore the effects of N-(2-hydroxyphenyl) acetamide (NA-2) on the development of arthritis, clinical signs, histopathology of knee joints, nociception analysis, and the serum levels of IL-1β and TNF-α were monitored. Arthritis was induced by intradermal administration of heat-killed adjuvant Mycobacterium tuberculosis H37Ra in rats. NA-2 and indomethacin treatments were started in their respective group on the same day when adjuvant was administered. Experiments were terminated when arthritic score of 4 was observed in arthritic control group. NA-2 (5 mg/kg) treatment significantly ameliorated the disease severity. Reduction in body weight and increase in paw oedema were significantly reversed in arthritic animal receiving NA-2. The nociceptive sensation was also inhibited in the NA-2 treated arthritic rats. Remission was associated with improved histology and significant decreased expression of serum proinflammatory cytokines (P < 0.05 for IL-1β and TNF-α). Based on our observations, it can be suggested that NA-2 possesses promising anti-arthritic property, and it can be used as a therapeutic agent for arthritis.