Antioxidant and Free Radical Scavenging Activity of Feijoa Sellowiana Fruits Peel and Leaves

Antioxidant activity of Feijoa sellowiana leaves and fruit peels was investigated employing various in vitro assay systems. IC50 for DPPH radical-scavenging activity was in the order: leaf aqueous extract, LW (7.25 ± 0.31) > leaf methanolic extract, LM (12.5 ± 0.34) > fruit peels aqueous extract, FW (20.25 ± 0.52) > fruit peels methanolic extract, FM (34.5.29 ± 0.44) μg ml, respectively. The extracts also showed weak nitric oxide-scavenging activity between 0.2 and 3.2 mg ml. Nearly all tested extracts exhibited good Fe chelating ability. IC50 for Fe chelating ability were LM (2.40 ± 0.11), LW (0.24 ± 0.02) and FM (1.51 ± 0.12) mg ml respectively. FW had shown only 19% inhibition at 3.2 mg ml. The peroxidation inhibition of extracts exhibited values from 91.9 to 98% (at 72 hrs). All tested extracts exhibited high antioxidant activity and manifested almost the same pattern of activity as Vit C at different incubation times (p> 0.05). The extracts exhibited different levels of antioxidant activity in all the models studied. The extracts had good reductive capability for reducing Fe to Fe by donating an electron Fe chelating activity and anti-lipid peroxidation activity.