Pharmaco-toxicological assessment of chelate complexes using the Danio rerio test system

The introduction of chelated compounds as feed additives in aquaculture requires a mandatory assessment of their safety. The relevant test system for assessing toxicity is the aquarium fish Danio rerio . The use of Danio rerio is relevant for screening the safety of feed additives and medicinal products for aquaculture, as it helps reduce the costs associated with using valuable commercial fish in experiments. The pharmaco‑toxicological characteristics were carried out for the following chelate complexes: Helavit A (LLC “Yupiter”, Russia) - chelate complex I; Helavit B (LLC “Yupiter”, Russia) - chelate complex II; Helavit C (LLC “Yupiter”, Russia) - chelate complex III. The work was carried out on embryos, dechorionized embryos and sexually mature individuals of Danio rerio . The step size between the studied doses differed by a factor of two. The acute and chronic toxicity of chelate complexes was assessed. Survival rates were evaluated using Kaplan-Meier curve analysis; the log-rank test was used to compare survival curves. To assess the potential toxic effects of various doses of the chelate complex, morphological studies of the Danio rerio liver were conducted (n=5). A comparison of the three chelate complexes showed that Complex III is characterized by the best fish survival rates across the entire range of concentrations studied and can be recommended for further research in industrial aquaculture. Chelate complexes I and II demonstrate a dose-dependent decrease in the survival rate of test systems, and complex I is characterized by the worst survival rate of fish in a chronic experiment. Analysis of histological changes in liver tissues. revealed dystrophic changes and inflammatory infiltration when using chelate complex I at a dosage of 0.500 g/l.