Anti-inflammatory, antinociceptive and antioxidant activities of the hydromethanolic fraction from Annona nutans leaves

Abstract

Annona nutans (Annonaceae) is a plant species found in Bolivia, Paraguay, Argentina, and the Brazilian Cerrado, specifically in the states of Mato Grosso and Mato Grosso do Sul (Brazil). Its common names are Araticû-Mi and Araticû-Ñu. The research contributions regarding the chemical composition and biological activities of extracts from A. nutans are rare, with only four articles being found in the literature. Therefore, the present study evaluated the anti-inflammatory and antinociceptive activities of the hydromethanolic fraction (FHMeOH) using carrageenan-induced paw edema and hot-plate tests. In addition, the antioxidant activity was evaluated by DPPH radical scavenging, total phenolic, flavonoid and tannin content assays and quantification of the major metabolites by LC-MS were performed. Oral treatment with the FHMeOH (at a dose of 300 mg.kg^-1) significantly reduced paw edema 2 h and 4 h after the inflammatory stimulus. The intraperitoneal (i.p.) treatment with the FHMeOH (50 and 100 mg.kg^-1) proved to be most effective, and the inhibition of acute inflammation was still visible 6 h after carrageenan injection. At doses of 50 and 100 mg.kg^-1 (i.p.), FHMeOH exhibits central antinociceptive effects by increasing the latency of the reaction in the hot-plate model. The FHMeOH showed antioxidant potential, and the metabolites quercetin-3-O-galactoside, quercetin-3-O-glucoside, isorhamnetin-3-O-galactoside, quercetin-3-O-β-D-apiofuranosyl-(1→2)-galactopyranoside, and chlorogenic acid were identified and quantified by LC-MS. Our results indicate, for the first time, that FHMeOH has anti-inflammatory, antinociceptive and antioxidant potential, and it is a promising source of studies for new herbal medicines