Antigenotoxic and longevity-promoting potential of red seaweeds Porphyra umbilicalis and Grateloupia turuturu in Drosophila melanogaster

Abstract

Seaweeds have been increasingly explored for human food industry and, in particular, red seaweeds Porphyra umbilicalis and Grateloupia turuturu are often included in the diet (mainly in East Asia), displaying a rich chemical composition and beneficial effects. Nevertheless, there are knowledge gaps in studies focusing their potential to protect genome integrity, a critical premise for disease prevention and longevity-promotion. In line, in vivo studies assessing the effects of the full intake of these algae are lacking. Thus, Drosophila melanogaster diet was supplemented with P. umbilicalis and G. turuturu aiming the evaluation of their potential as genome integrity- and longevity-promoters, using somatic mutation and recombination test (SMART) and longevity assay, respectively. For longevity assay, seaweeds were incorporated in the media at 1.25, 2.5, 5, 10 and 20% (w/w). Alga supplementation occurred until eclosion. Flies were counted weekly until death. For SMART, the diet was supplemented with 5 and 10% P. umbilicalis and 10 and 20% G. turuturu until eye observation in adults. A DNA damage inducer, streptonigrin (SN), was added as genotoxic insult. Eye observation consisted in counting the total number of spots per eye, i.e., white phenotype ommatidia in red eyes. Supplementations with 10% P. umbilicalis and 20% G. turuturu were able to promote an increase of the longevity of D. melanogaster, with G. turuturu reaching the highest potential; there were no significant differences between males and females longevity. The spontaneous genotoxicity (without SN-challenge) was reduced in flies supplemented with 10% P. umbilicalis and 10 and 20% G. turuturu. On the other hand, all seaweed concentrations demonstrated antigenotoxic potential against SN-induced genotoxicity. The major promoter of genome integrity was 20% G. turuturu and 5% P. umbilicalis the lowermost. Furthermore, SN demonstrated its genotoxic capacity, depicted in the increased number of spots comparatively to unchallenged flies. Considering the seaweed supplementation level of 10% for SN- challenged conditions, a higher antigenotoxic potential was displayed by G. turuturu. Within the framework of nutrition-toxicology, the tested seaweeds proved to be promoters of a safe and healthy nutrition as functional foods.