Anti-arthritic activities of Annona muricata L. leaves extract on complete Freund's adjuvant (CFA) – induced arthritis in rats

Abstract

Annona muricata L. (Annonaceae) (AML) has been used as folkloric herbal medicine in many regions throughout the world in treating fever, cough, diarrhea, sedative, rash, ring worm and lactation for women afterbirth (1). The present study was carried out to investigate the anti-arthritic effects of AML ethanolic extract in complete Freund's adjuvant (CFA)-induced arthritis in rats. Edema in the left hind paw of rat was induced by the subcutaneous injection of 0.1ml of heat-killed Mycobacterium tuberculosis in mineral oil (5mg/ml). AML (3, 10, 30 and 100mg/kg) or indomethacin (10mg/kg) as positive control was administered orally once a day between days 1 and 14 post-CFA injection. Edema volume in each paw was measured by using a plethysmometer for 14 days. Levels of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) in local tissue were measured using enzyme-linked immunosorbent assay (ELISA) on day 14 post-CFA injection. The result exhibited that AML at all doses (3, 10, 30 and 100mg/kg) were significantly (p<0.05) reduced the edema by 48.39, 66.67, 79.57 and 72.04% respectively. AML at higher doses 30 and 100mg/kg significantly suppressed the local tissue TNF-α level by 42.81 and 51.82% and IL-1β level by 35.57 and 39.79% respectively on day 14 post-CFA injection. For TNF-α, the efficacies of the extract at doses 30 and 100mg/kg were higher compared to the effect of indomethacin (51.82%). In conclusion, the findings suggest that AML present notable anti-arthritic activities that may be mediated by suppressing pro-inflammatory cytokines.