Antioxidant Activity of Brown Seaweeds

Antioxidant potential of three brown seaweeds, Anthophycus longifolius, Sargassum plagiophyllum, and Sargassum myriocystum, obtained from the Gulf of Mannar region of India were evaluated utilizing different in vitro systems. Ethyl acetate (EtOAc) fraction of Anthophycus longifolius registered significantly greater hydroxyl radical scavenging ability (IC50 0.19 mg/mL) and was effective in stabilizing the 2,2'-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC50 1.23 mg/mL) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) radicals (IC50 0.48 mg/mL) (p < 0.05). No significant differences in hydrogen peroxide (H2O2) scavenging and ferrous ion chelating properties of the EtOAc extracts of the seaweeds were apparent. The utilities of the reverse-phase high-performance liquid chromatography (RP-HPLC) method hyphenated to diode-array detection for analyzing the fingerprints of phenolic constituents in the solvent extracts and fractions of the seaweeds were denoted. High-performance liquid chromatographic analysis indicated the presence of phenolic acids in the solvent extracts of seaweeds. This study demonstrated the potential use of A. longifolius as candidate species to be used as a nutritional food supplement/functional foods to increase the shelf life of food items for human consumption.