Antioxidant and Anti-inflammatory Activities of Extract and Fractions of Spondias mombin Leaf and Isolation of its Active Principles

Abstract

Spondias mombin L. (Anacardiaceae) leaves have shown remarkable efficacy in the ethnomedicinal management of inflammatory disorders. This study aims to examine the antioxidant and anti-inflammatory potentials of the plant material as well as identify its major phenolic components. The crude methanol extract (CME) and fractions [n-hexane (HF), dichloromethane (DF), ethyl acetate (EF), acetone (AF) and methanol (MF) fractions] of S. mombin were assessed for their antioxidant and anti-inflammatory effects using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method and egg-albumin induced rat paw edema model respectively. The total phenolic contents of the extract and fractions were quantified spectrophotometrically and some of the compounds were identified with the aid of HPLC, LC-ESI-MS/MS, and1H-NMR. CME, HF, DF, EF, AF, and MF exhibited dose-dependent DPPH scavenging property with IC50 values of 20, 350, 21, 78, 60, and 8 μg/mL, respectively. The activity of the methanol fraction was comparable to that of the regular drug, vitamin C (IC50 = 9.4 μg/mL). The crude extract and fractions, at the dose of 400 mg/kg showed poor antiinflammatory activity in the rat model. EF exhibited the highest content of phenolic compounds with a percent gallic acid equivalent of 20.57%. The plant phenolic compounds identified were mainly gallocatechin, kaempferol, and quercetin glycosides and their methoxy products as well as gallic and ellagic acid derivatives. The outcomes show that the leaves of S. mombin contain antioxidant phenolic compounds which could explain the remarkable efficacy in the ethnomedicinal management of oxidative stress, but had poor anti-inflammatory activity.