Antioxidant properties of extracts and spe fractions from annona muricata leaves

Abstract

Annona muricata L. (Magnoliales: Annonaceae) is a tropical plant species known for its edible fruit and well known for the medicinal value. In this study, the antioxidant properties of A. muricata leaves is evaluated for different extracts and fractions. The air-dried leaves of A. muricata leaves were successively extracted with n-hexane and methanol. The methanolic crude extract was further semi-purified by utilizing solid-phase extraction (SPE) in a mixture of mobile phase aqueous: methanol to methanol and resulted in four semi-purified fractions (ALM 1 – ALM 4). Antioxidant properties of extracts and fractions were evaluated by free radical scavenging activity against 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals comparing with standard ascorbic acid, quercetin, and catechin. Results indicated that methanolic extracts showed exceptionally higher radical scavenging activity compared with n-hexane crude extract with IC50 44.21 µg/mL and 302.41 µg/mL, respectively. Meanwhile, fractions ALM 2 (aqueous: methanol; 50: 50) exhibited the highest scavenging activity with the IC50 of 12.46 µg/mL followed by ALM 1 (aqueous: methanol; 80: 20) with 51.44 µg/mL, ALM 3 (aqueous: methanol; 20: 80) with 54.39 µg/mL and ALM 4 (100% methanol) with 89.02 µg/mL, respectively. In conclusion, ALM 2 could be potentially applied as a natural antioxidant agent in both food, nutraceuticals or pharmaceuticals fields for health promotion. However, ALM 2 has to be further purified to study the constituents which possibly condensed mainly with phenolic and flavonoids that known to possess the highest antioxidant effects.