Anti-rheumatic activity of Ananas comosus fruit peel extract in a complete Freund's adjuvant rat model

Rheumatoid arthritis is a chronic, autoimmune and systemic inflammatory disease, which targets synovial joints leading to joint destruction mediated in part by migration of inflammatory cells into the synovial tissue.

The present study evaluates the anti-rheumatic effect of a methanol extract of Ananas comosus (L.) Merr. (Bromeliaceae) peel in rats.

Anti-rheumatic activity of crude extract of peels of A. comosus in complete Freund's induced arthritis model in rats was studied at doses of 50, 100, 250 and 500 mg/kg b.w. for 21 days. Parameters such as paw size, levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), C-reactive proteins (CRP) and prostaglandins (PGE₂) were analysed.

Oral administration of the extract significantly reduced the swelling in the paw of rats (EC₅₀ 65.1 ± 2.95 mg/kg b.w.) with a maximal inhibition of 77.01 ± 10.53% on 21st day at 500 mg/kg b.w. The extract also significantly reduced the levels of SOD, CAT and GPx in liver (EC₅₀ 26.84 ± 16.37, 68.37 ± 19.22, 106.54 ± 34.81 mg/kg b.w., respectively), kidney (EC₅₀ 261.75 ± 81.5, 176.38 ± 8.08, 14.32 ± 6.64, mg/kg b.w., respectively) and spleen (EC₅₀ 152.14 ± 39.57, 83.97 ± 14.6, 47.1 ± 10.45 mg/kg b.w., respectively); and CRP (EC₅₀ 36.37 ± 12.4 mg/kg b.w.) and PGE₂ (EC₅₀ 191.06 ± 71.54 mg/kg b.w.) in tissue homogenate and serum, respectively, at 500 mg/kg b.w. as compared to arthritic control group.

These results suggest that A. comosus fruit peel extract exerts anti-rheumatic activity.