Traditionally, the leaves of Annona muricata L., Annonaceae, are used to treat headaches, fever, toothache, cough and asthma. The decoction of the leaves has parasiticide, antirheumatic and antineuralgic effects when used internally, while the cooked leaves, applied topically, fight rheumatism and abscesses. The aim of this study was to investigate acute and chronic anti-inflammatory potential of an ethanolic leaf extract of A. muricata (AML) in animal models. The ethanolic extract of A. muricata leaf extract was prepared and administered orally to experimental animals used. The anti-inflammatory activity was determined by xylene-induced ear edema in mice and Complete Freund's adjuvant (CFA)-induced arthritis in rats. The results demonstrated that AML is effective for both acute and chronic inflammation. It also significantly attenuated both TNF-α and IL-1β levels in CFA-induced arthritis model. Thus, these results have suggested that AML possesses both anti-inflammatory and anti-arthritic activities. The findings also suggest that AML presents notable anti-arthritic activity that may be mediated by suppressing pro-inflammatory cytokines.

Ethanolic extract of Annona muricata L., Annonaceae, leaf (AML) was used to investigate its antinociceptive and anti-ulcerogenic activities and the involvement of the mechanism of ethanolic leaves extract of AML in various animal models. Antinociceptive activity of AML extract was done using acetic acid-induced abdominal writhing in mice, formalin test in rats and hot plate test in mice. Furthermore, the anti-ulcerogenic effect of AML extract was studied in ethanol-induced ulcer model in rats, ethanol-induced gastric lesions in L-NAME-pre-treated rats as well as ethanol-induced gastric lesions in NEM-pre-treated rats test model to determine its mechanism. AML exhibited significant and dose-dependent antinociceptive activity. It also significantly decreased the ulcerative lesion produced by ethanol in rats in a dose-dependent manner. Pre-treatment with N-ethymaleimide, a thiol blocker, including mucosal nonprotein sulfhydryl groups, reduced the anti-ulcerogenic effect of AML extract in the same ulcer model, suggesting that AML extract may have active substances such as tannins, flavanoids and triterpenes that increase the mucosal nonprotein sulfhydryl group content.