Topical Anti-inflammatory Effect of Annona muricata (graviola) Seed Oil

Different parts of Annona muricata L., Annonaceae, are widely used for their biological activities. The fruit of this plant, called “graviola,” is recognized for its nutritional value, but its seeds are usually discarded, despite their potential as a source of substances with anti-inflammatory properties. This study investigated the effect of graviola seed oil in models of cutaneous inflammation after topical administration. Graviola seed oil was characterized regarding its fatty acid composition and evaluated in vitro for cytotoxicity in L929 fibroblasts. Acute cutaneous inflammation was induced by topical administration of 12-O-tetradecanoilphorbol-13-acetate, phenol, or capsaicin in the right ears of Swiss mice. Concomitantly, ears were treated with graviola seed oil (0.3, 1, and 3 mg/ear), oleic acid (0.3, 0.1, and 3 mg/ear), or dexamethasone (control). After the induction, inflammatory parameters were analyzed. The main fatty acids found in graviola seed oil were oleic (43.37%), linoleic (29.86%), palmitic (21.94%), and stearic acids (4.82%). Seed oil (10–150 μg/ml) did not alter L929 fibroblasts’ viability after 24 h of exposure. Treatment with seed oil, or dexamethasone reduced ear edema, myeloperoxidase activity, histological alterations, lipid peroxidation, and interleukin-1β and 6 levels induced by 12-O-tetradecanoilphorbol-13-acetate. Treatment with oleic acid reduced ear edema and lipid peroxidation, but not myeloperoxidase activity, in 12-O-tetradecanoilphorbol-13-acetate model. Treatment with seed oil and oleic acid reduced edema formation, but only treatment with seed oil reduced myeloperoxidase activity in phenol-induced ear inflammation. Administration of seed oil and oleic acid did not affect capsaicin-induced ear edema. These findings demonstrate the anti-inflammatory activity of graviola seed oil after skin injury, which is partially related to the presence of oleic acid. Graphical Abstract: [Figure not available: see fulltext.].