Positive Health Online

Abstract

SOUZA and COLLEAGUES, IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Braga, Portugal, characterized the in vitro antioxidant activity of two Brazilian seaweeds.

Background

In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was characterized.

Methodology

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.

Results

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 IC(50) 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 IC(50) 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 beta-carotene-linoleic acid assay were equally high, achieving values of beta-carotene oxidation inhibition of up to 40%.

Conclusion

Finally, in the methanolic extracts, LC-MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.

References

Souza BW, Cerqueira MA, Martins JT, Quintas MA, Ferreira AC, Teixeira JA and Vicente AA. Antioxidant potential of two red seaweeds from the Brazilian coasts. Source Journal of Agricultural & Food Chemistry. 59(10):5589-94. May 25 2011.