Synthesized pyrrole ester ameliorates adjuvant‑induced arthritis in Wistar rats by alleviating inflammation and downregulating the pro‑inflammatory cytokines.

Piperine is an amide alkaloid responsible for producing the pungent smell that comes from black pepper. Piperine has been explained to exhibit significant properties such as anti-rheumatic, anti-inflammatory, and antihypertensive effects. The aim of the study was to synthesize pyrrole ester from piperine and evaluate its anti-arthritis effects in adjuvant-induced arthritis female Wistar rats. In this study, pyrrole ester (AU-5) was designed, synthesized and evaluated for ant-arthritic activity in adjuvant-induced arthritis Wistar rats. The synthesized pyrrole ester (AU-5) was administered in three selected doses (20, 10 and 5 mg/kg) to the arthritic-induced model. The administered ester significantly inhibited the increase in arthritis index, paw and ankle joint swelling compared to the arthritic control group. Similarly, the treated rats exhibited a remarkable increase in body weight increase, improved haematological, biochemical, histopathological and radiological parameters. Moreover, the excess production of rheumatoid factor (RF), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was noticeably attenuated in all AU-5-treated rats. However, the spleen index, tumour necrosis factor (TNF-α) and interleukin-6 (IL-6) were distinctly lowered compared to arthritic control rats. Moreover, AU-5 showed promising liver protection by lowering the level of liver function markers Serum glutamic pyruvic transaminase (SGPT), Serum glutamic-oxaloacetic transaminase (SGOT) and alkaline phosphatase (ALP) in serum. Henceforth, it might be concluded that AU-5 has an anti-arthritic effect which can be credited to the down regulation of inflammatory markers and the pro-inflammatory cytokines.