Suplementação alimentar com açaí (Euterpe oleracea) como potencial modulador das defesas antioxidantes e dano oxidativo em zebrafish (Danio rerio)

Abstract

Diets enriched with Amazonian açaí (E. oleracea) provide great nutritional and therapeutic health benefits, related to the presence of bioactive compounds. The pulp of the açaí fruit is high in anthocyanins, plant pigments that have anti- inflammatory and antioxidant properties. The use of D. rerio (Teleostei: Cyprinidae) as an animal model in bioassays is important for evaluating possible molecular alterations caused by the pro-oxidants present in the cells, with direct applications in other fish and can also be extrapolated to humans, due to the genetic homology of 70% of the genome. The aim of this study was to characterize the effects of dietary supplementation with freeze-dried açaí pulp (AÇL), testing different concentrations of anthocyanins, as a potential modulator of the antioxidant defence system in D. rerio. The study was carried out in the Ecotoxicology section of LAPMAR at UFPA/Belém. A total of 40 D. rerio specimens were organized into: control group (CTR) - standard diet only; and according to the value of the standard diet, the amounts for supplementation in treatment were calculated T1 - standard diet and supplementation of 10% AÇL; T2 - standard diet and supplementation of 25% AÇL; T3 - standard diet and supplementation of 50% AÇL. Water physicochemical parameters, siphoning and partial water changes were analyzed over the course of 5 days. At the end of the 120-hour experiment, the fish were collected, euthanized by cryoanesthesia, biometrically measured, weighed and stored at -80 ºC in an ultrafreezer. Subsequently, the whole animals were homogenized, followed by the quantification of total proteins and measurements of biochemical biomarkers of oxidative stress: total antioxidant capacity (TACC), glutamate cysteine ligase (GCL), reduced glutathione (GSH), glutathione reductase (GR), glutathione s- transferase (GST) and lipoperoxidation (LPO). The results were analyzed by means of comparisons between independent groups with a quantitative response variable, using the non-parametric Kruskal-Wallis test, with a significance level of 5%. Of the physicochemical parameters evaluated, ammonia levels were the only ones monitored that showed a significant difference (p < 0.05) in the T3 - 50% AÇL treatment at the last analysis time. There was no statistically significant difference (p>0.005) for the biometric data and also for the biomarkers between the sample groups. The results indicate that the supplementary supply of açaí for longer periods can promote a neutralization of pro-oxidant agents in the cells. This supplementation can be considered a natural alternative to increase resistance to stress in the face of pro-oxidant conditions in the body, establishing chemoprotection strategies for human and animal health.