Anti-Arthritic Potential of Pyrazoline Derivative Against Complete Freund's Adjuvant Induced Arthritis in Rats

This research explored the potential of a synthesised pyrazoline derivative 5-ethoxy 5-hydroxy 3-methyls 4, 5-dihydro 1Hpyrazol 1 yl (pyridine 4 yl) methanone [5-E-5-H-PD], against arthritis using a Complete Freund's Adjuvant (CFA)-induced arthritis in a rat model. Sprague-Dawley rats were used to induce arthritis via subplantar injection of CFA (0.1 mL) into their right hind paw. Animals were divided into 6 groups (n = 4): normal, arthritis, standard drug (methotrexate 1 mg/kg intraperitoneally), and 3 treatment groups receiving 5-E-5-H-PD, 10, 20 and 40 mg/kg orally for 21 days. Clinical signs (paw volume and arthritis score), pro-inflammatory cytokines, and histopathological alterations were evaluated. The 5-E-5-H-PD groups showed a reduction in paw edema in a dose-dependent manner. On day 21, paw volume in the 40 mg/kg dose animals decreased significantly to 2.31 ± 0.12 mm compared to 4.82 ± 0.14 mm in the disease animals (p < 0.001). Arthritis scores reduced from 3.8 ± 0.2 (control) to 1.5 ± 0.3 in the high-dose treatment group. Serum IL-10, TNF-α, and NF-κB levels were significantly reduced to 66.75 ± 3.0 pg/mL, 34.50 ± 1.8 pg/mL and 9.50 ± 0.6 pg/mL respectively, compared to the arthritis induced rats 129.8 ± 2.0 pg/mL, 77.75 ± 1.5 pg/mL and 28.50 ± 1.3 pg/mL respectively, compared to the arthritis induced rats (112.3 ± 5.5, 96.8 ± 4.3, 123.1 ± 6.2 pg/mL, p < 0.001). Histopathology analysis confirmed reduced synovial hyperplasia and inflammatory infiltration in treated joints. The pyrazoline derivative, 5-E-5-H-PD, demonstrated significant anti-arthritic effects in the CFA-induced rat model by reducing inflammation, cytokine expression and joint destruction. These findings support further investigation into pyrazoline-based compounds as promising therapeutic agents for RA.