Antioxidant Potential of Two Red Seaweeds from the Brazilian Coasts

• Published in: Journal of agricultural and food chemistry 2011-05, Vol.59 (10), p.5589-5594
• Main Authors: Souza, Bartolomeu W. S, Cerqueira, Miguel A, Martins, Joana T, Quintas, Mafalda A. C, Ferreira, António C. S, Teixeira, José A, Vicente, António A
• Format: Article
• Language: English
• Subjects: Antioxidant; Antioxidants - analysis; Antioxidants - pharmacology; Apigenin - analysis; beta Carotene - chemistry; Biological and medical sciences; Brazil; Food Chemistry/Biochemistry; Food industries; Free Radical Scavengers - analysis; Free Radical Scavengers - pharmacology; Fundamental and applied biological sciences. Psychology; Gallic Acid - analysis; Gracilaria - chemistry; Oxidation-Reduction; Phenolic content; Phenols - analysis; Plant Extracts - chemistry; Plant Extracts - pharmacology; Seaweeds
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf200999n

In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was characterized. The total phenolic content, the radical-scavenging activity and the antioxidant activity were determined in two solvent extracts of the algae. Liquid chromatography–mass spectrometry (LC–MS/MS) allowed identification of important antioxidant compounds. The ethanol extract of G. birdiae was found to have the highest value of total phenolic content: 1.13 mg of gallic acid equiv (GAE)/g of extract. The radical-scavenging activity of G. birdiae and G. cornea extracts has been evaluated at different extract concentrations; the IC50 values of ethanolic extracts of G. cornea and G. birdiae were 0.77 and 0.76 mg mL–1, respectively, while for methanolic extracts, the IC50 values of G. cornea and G. birdiae were 0.86 and 0.76 mg mL–1, respectively. The antioxidant activities of these two seaweeds’ extracts as assessed by the β-carotene–linoleic acid assay were equally high, achieving values of β-carotene oxidation inhibition of up to 40%. Finally, in the methanolic extracts, LC–MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.