Original Articles
Venty Suryanti, Soerya Dewi Ma
Abstract
A study was performed on the antioxidant activity of the methanol extract of Luffa acutangula (L.) Roxb (ridge gourd) fruit (LAM) and its derived fractions, such as n-hexane (LAH), chloroform (LAC), ethyl acetate (LAE), nbutanol (LAB) and residual aqueous fraction (LAA) and their correlation to the total phenolics and flavonoids contents. The phytochemical screening demonstrated the presence of phenolic and flavonoid compounds in all the fractions except the n-hexane fraction. Carotenoids were present in the LAH and LAC, while absent in the LAE. The antioxidant activity was assessed using β-carotene bleaching method and the results showed that LAM, LAH and LAC have significant antioxidant activities in the comparison with those of BHT and PG. The total phenolics content of the extract/fractions was determined by the Folin-Ciocalteu procedure and ranged from 18.7±0.11 to 105.1±0.08 mg GAE/g of dried weight basis. The flavonoids content of extract/fractions was measured by aluminium chloride colorimetric assay and ranged from 34.9±0.09 to 105.3±0.09 mg QE/g of dried weight basis. The correlation coefficients between the antioxidant activities and the phenolics/flavanoids contents were found to be very small. The highest antioxidant activity was demonstrated by LAH and the highest total phenolics/flavonoids contents were presented by LAE. Thus, phenolics/flavanoids compounds were not the major contributor to the antioxidant activity of this fruit. The other antioxidant secondary metabolites, such as carotenoids, contributed considerably to the total antioxidant activity of the LAH and LAC. The results provided evidence that Luffa acutangula (L.) Roxb fruit could be potential rich source of natural antioxidant for use in food, cosmetic and pharmaceutical products.