Antioxidant and antitumoural activities of some Phaeophyta from Brittany coasts

In this study, the antioxidant activity exhibited by crude extracts from 10 Phaeophyta species from Brittany coasts was assessed by three methods (DPPH, reducing activity and b-carotene–linoleic acid system), and their phenolic contents were examined. Antitumoural activities were determined by a cytotoxic assay with three different tumoural cells lines (Daudi, Jurkat and K562). Among the species under study, four Fucales, i.e. Bifurcaria bifurcata, Cystoseira tamariscifolia, Fucus ceranoides and Halidrys siliquosa, displayed a high antioxidant activity. Further to the fractionation of these crude extracts, a significant correlation was found in most fractions between the high antioxidant activity and the high phenolic content. Five species, i.e. B. bifurcata, C. tamariscifolia, Desmarestia ligulata, Dictyota dichotoma and H. siliquosa, exhibited strong cytotoxic activities against all tumoural cells.