Antioxidant activity of three-marine algae methanol extract collected from North Sulawesi Waters, Indonesia

Abstract

This study was aimed at studying total phenol content and antioxidant activity of methanol 50, 70, and 95% extracts of marine algae, Caulerpa sertularoides, Laurencia tronoi, and Padina australis collected from Nain island waters, North Minahasa Regency, North Sulawesi, Indonesia. Total phenol content was measured using Fholin-Chiocalteau method, while the antioxidant activity measurement used 1,1- diphenyl-2-picrihydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), and Ferrous Ion Chelating (FIC) methods. Methanol 50% extract of Caulerpa sertularoides gave the highest antioxidant activities of DPPH radical scavenging, FRAP and FIC (p<0.05), 38.30±0.44%, 13.07±0.15mg GAE/g and 63.81±4.71%, respectively, while total phenol content of the three methanol concentration extract was not different (p>0.05). Methanol 50% extract of Laurencia tronoi gave the highest total phenol content, DPPH radical scavenging, FRAP, and FIC (p<0.05), 9.48±1.65mg GAE/g extract, 26.54±1.56%, 9.75±0.17mg GAE/g extract and 85.90±3.47%, respectively. Methanol 95% extract of Padina australis gave the highest total phenol content and FRAP (p<0.05), 8.37±0.60mg GAE/g extract and 7.91±0.29 mg GAE/g extract, respectively, while the highest DPPH radical scavenging and FIC (p<0.05) occurred in 50% methanol concentration of the extraction solvent, 21.65±0.50% and 92.29±1.12%, respectively. Keywords-