Evaluation of Antioxidant Activities of the Methanolic Extracts of Selected Ferns in Malaysia

Abstract

Malaysia is home to a diverse range of ferns, many of which have been used as traditional medicines in the treatment of various ailments or for general healthcare. The aim of this study was to explore new and natural sources of antioxidant in selected ferns found in Malaysia. Methanolic extracts of fifteen fern species were screened. Total phenolic content (TPC) was measured using the Folin-Ciocalteau method. Antioxidant properties were determined via the DPPH radical scavenging, ferric reducing power (FRP), ferrous ion chelating activity (FIC) and β-carotene bleaching (BCB) assays. Results showed very high total phenolic content, of above 2000 mg GAE/100 g fresh leaves in the methanolic extracts of five fern species. The ferns with strong antioxidant properties were Cyathea latebrosa, Cibotium barometez, Drynaria quercifolia, Blechnum orientale and Dicranopteris linearis. These ferns exhibited strong DPPH radical scavenging activity (ascorbic acid equivalents 2866 - 3111 mg/100 g), ferric ion reducing power (gallic acid equivalents 963 - 1417 mg GAE/100 g) and inhibition of lipid peroxidation. Strong chelating activity was found in Pteris vittata and Pteris venulosa. Positive correlation was observed between TPC and various antioxidant activities.