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

## TL;DR

This study tested a new pyrazoline compound in rats with arthritis and found it reduced inflammation and joint damage, suggesting potential as a treatment for rheumatoid arthritis.

## Contribution

The study demonstrates the anti-arthritic potential of a novel pyrazoline derivative in a rat model of arthritis.

## Key findings

- The compound reduced paw edema and arthritis scores in a dose-dependent manner.
- Levels of pro-inflammatory cytokines like TNF-α and NF-κB were significantly lowered.
- Histopathological analysis showed reduced joint inflammation and synovial hyperplasia.

## Abstract

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.