Assessment of the effects of diet-induced obesity in zebrafish (Danio rerio): a comparative study
weight gain, diabetes mellitus, inflammation, dyslipidemia, high-fat diet.
Obesity is a public health problem and understanding the mechanisms involved requires experimental models that have excellent genetic equivalence with humans. In this work, a comparative study of obesity induction models in zebrafish was carried out, evaluating the resulting complications. Animals (n=200), adults of both sexes, were used, divided into 4 groups (n=50). Group 1: control, fed with Artemia Salina (15-30mg/day/fish); Group 2: control, fed with commercial fish food (3.5% of average weight); Group 3: obesity induced by hypernutrition with Artemia Salina (60-120mg/day/fish); Group 4: obesity induced by ingestion of pasteurized powdered egg yolk mixed with soybean oil in a ratio of 2.5:1 (5% of average weight). The experiment lasted eight weeks. The animals were evaluated for dietary intake, caloric intake and efficiency, body mass index (BMI), behavior, biochemical and inflammatory parameters in fat and brain. Furthermore, body, visceral and subcutaneous fat was measured and evaluated through morphological and morphometric studies. Weight gain was significant (p < 0.0001) in both obesity induction groups compared to control groups. It was higher in animals in the group with obesity induced by brine shrimp. A higher concentration of interleukin-6 (IL-6) was observed in the group of male zebrafish with obesity induced with brine shrimp (p=0.0015), and tumor necrosis factor (TNF-α) increased in both groups of inducing obesity. The results obtained in this study are of great contribution to the scientific world, as they guide with more specificity the paths to be followed in the study of obesity in zebrafish.