Exposure to a high dose of amoxicillin causes behavioral changes and oxidative stress in young zebrafish.

Autistic spectrum disorder (ASD) is a group of early-onset neurodevelopmental disorders characterized by impaired social and communication skills. Autism is widely described as a behavioral syndrome with multiple etiologies where may exhibit neurobiological, genetic, and psychological deficits. Studies have indicated that long term use of antibiotics can alter the intestinal flora followed by neuroendocrine changes, leading to behavioral changes. Indeed, previous studies demonstrate that a high dose of amoxicillin can change behavioral parameters in murine animal models. The objective was to evaluate behavioral and oxidative stress parameters in zebrafish exposed to a high dose of amoxicillin for 7 days. Young zebrafish were exposed to a daily concentration of amoxicillin (100 mg/L) for 7 days. Subsequently, the behavioral analysis was performed, and the brain content was dissected for the evaluation of oxidative stress parameters. Zebrafish exposed to a high dose of amoxicillin showed locomotor alteration and decreased social interaction behavior. In addition, besides the significant decrease of sulfhydryl content, there was a marked decrease in catalase activity, as well as an increased superoxide dismutase activity in brain tissue. Thus, through the zebrafish model was possible to note a central effect related to the exposition of amoxicillin, the same as observed in murine models. Further, the present data reinforce the relation of the gut-brain-axis and the use of zebrafish as a useful tool to investigate new therapies for autistic traits.

Effects of omega-3 fatty acids supplementation on inflammatory parameters after chronic administration of L-tyrosine.

Tyrosinemia type II is an autosomal recessive inborn error of metabolism caused by hepatic cytosolic tyrosine aminotransferase deficiency. Importantly, this disease is associated with neurological and developmental abnormalities in many patients. Considering that the mechanisms underlying neurological dysfunction in hypertyrosinemic patients are poorly understood, in the present work we investigated the levels of cytokines - tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6 and IL-10 - in cerebellum, hippocampus, striatum of young rats exposed to chronic administration of L-tyrosine. In addition, we also investigated the impact of the supplementation with Omega-3 fatty acids (n-3 PUFA) on the rodent model of Tyrosinemia. Notably, previous study demonstrated an association between L-tyrosine toxicity and n-3 PUFA deficiency. Our results showed a significant increase in the levels of pro- and anti-inflammatory cytokines in brain structures when animals were administered with L-tyrosine. Cerebral cortex and striatum seem to be more susceptible to the inflammation induced by tyrosine toxicity. Importantly, n-3 PUFA supplementation attenuated the alterations on cytokines levels induced by tyrosine exposure in brain regions of infant rats. In conclusion, the brain inflammation is also an important process related to tyrosine neurotoxicity observed in the experimental model of Tyrosinemia. Finally, n-3 PUFA supplementation could be considered as a potential neuroprotective adjunctive therapy for Tyrosinemias, especially type II.