Preclinical Toxicological Evaluation of the Consumption of Fish from the Cachoeira River Hydrographic Basin in Rats

Fish is one of the healthiest food sources once it has proteins, vitamins, minerals and the omega-3 polyunsaturated lipids. Nevertheless, to be healthy, the protein in fish meat must not have contaminants further than allowed. This study aimed to investigate the preclinical toxicologic effects of consumption of fish meat from Cachoeira river (Joinville, Santa Catarina, Brazil). Groups of rats were divided and received for a month: standard ration, farmed fish meat and fish meat from Cachoeira river twice a week. One day after the last exposition, animals were euthanized and blood, spleen, heart, liver, kidney, cerebellum, and cerebral cortex were collected to measure oxidative stress, biochemical and hematological parameters. Metals levels were also analyzed in fish meat by atomic emission spectrometry. Significant elevation of carbonylated proteins were observed in heart and liver and thiobarbituric acid reactive substances in liver, plasma and cerebellum were observed. Total sulfhydryl content decreased significantly in cerebellum, liver and heart, and decreased catalase activity in the liver and superoxide dismutase activity in the kidneys were also present among rats who consumed fish meat from Cachoeira river. No modification of hematological parameters was observed, and only significant decrease of HDL occurred among biochemical parameters. Analysis of metals in river fish meat showed a fivefold increase in zinc and aluminum compared to farmed fish meat. Short-term exposure to fish meat from the Cachoeira River resulted in increased oxidative stress, liable to be transferred through the food chain, possibly associated with the increased presence of heavy metals.