The controversial effects of dehydrated powder of Gracilaria birdiae as a food supplement to juvenile male rats

The present study aimed to characterize in vitro antioxidant properties of red algae (Gracilaria birdiae) powder and to investigate its potential protective and antioxidant effects in male rats, with and without co-exposure to a ternary mixture of agrochemicals. The focus was on reproductive and DNA damage parameters, both known as vulnerable targets for oxidative stress induced by this class of toxicants. It is important to emphasize that the dehydrated powder of G. birdiae used in the present study is already commercialized for food purposes. In vitro tests revealed that G. birdiae dehydrated powder preserves important antioxidant features of the algae, demonstrating potential for use as food supplements. On the other hand, in vivo tests showed that dietary supplementation with 5% of the homogenate of dehydrated G. birdiae, per se, impaired spermatogenesis due to increased cell damage and consequent cell death in the seminiferous epithelium, without interfering with antioxidant enzymes and androgenic status of the animals. In addition, no beneficial or protective effect of G. birdiae homogenate was observed in animals co-exposed to the agrochemical mixture. Contrary to expectation, in the experimental conditions presented here, powder of G. birdiae was able to induce reproductive toxicity and provoke DNA damage. The data obtained call attention to the importance of discussing the use of food supplementation in the prevention and maintenance of health and the need for better regulating the processing procedures and market of natural supplements.