ANTIOXIDANT POTENTIAL OF Annona muricata (SOUR SOP) STEM BARK EXTRACT

Abstract

Annona muricata Linn., a member of the Annonaceae family, is a widely cultivated tropical fruit tree commonly known as soursop, sir ap, or guanabana. Various parts of the plant including the fruit pulp, seeds, root bark, stem bark, and leaves have been extensively investigated for their phytochemical constituents and associated pharmacological activities, particularly antioxidant and anticancer properties. In this study, the stem bark of Annona muricata was subjected to ethanol extraction, and the phytochemical composition of the extract was evaluated using standard analytical methods. Antioxidant activity was assessed in vitro using three assays: 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging assay, Ferric Reducing Antioxidant Power (FRAP) assay, and the Thiobarbituric Acid Reactive Substances (TBARS) method. Phytochemical analysis revealed that alkaloids were present in the lowest concentration (21.04 ± 0.81 mg/100 g), while phenolic compounds were the most abundant (756.39 ± 2.10 mg/100 g). The antioxidant activity of the ethanol extract exhibited a concentration-dependent response across all assays. At 100 µg/mL, DPPH scavenging activity reached 64.00%, compared to 12.78% at 12.50 µg/mL. Similarly, FRAP activity was 72.48% at 100 µg/mL and 19.08% at 12.50 µg/mL. In the TBARS assay, lipid peroxidation inhibition was 59.08% at 100 µg/mL and 8.39% at 12.50 µg/mL. These findings suggest that the ethanol extract of Annona muricata stem bark contains significant levels of bioactive phytochemicals, particularly phenolics, which contribute to its strong antioxidant potential.