Endocrine Disruptor effect of Atrazine herbicide on the nematode Caenorhabditis elegans

MOYA, AV; KRONBERG, MF; CLAVIJO, ARACELI; MAZZARELLA, DANIEL; PAGANO, EA; MUNARRIZ,E

Mérida, Yucatán, México

Congreso; IUTOX 2016-XIV International Congress of Toxicology (ICT) and X Mexican Congress of Toxicology; 2016

IUTOX (International Union of Toxicology) y la Sociedad Mexicana de Toxicología (SOMTOX)

Introduction: Endocrine disruptors compounds (EDC) are exogenous agents, which can act as pseudo hormones and the damage can be observed in the exposed organism offspring. A great quantity of EDC are pesticides, some of which were banned or restricted. Atrazine (ATZ) is a widely herbicide that is suspected of being an EDC. Objective: The aim of this study is to identify the affected physiological processes in nematode Caenorhabditis elegans treated with low doses of ATZ and the trans-generational damage to descendants.Materials and Methods: Acute toxicological tests were conducted exposing L4 larval stage (population F0) of C. elegans at different concentrations of ATZ (0.001; 0.01; 0.1; 1; 10 mg/l) for 24 hours. Nematode growth and reproduction were measured in nematodes tested and its successive two generations (F1 and F2). Finally, we analyzed the larval development in F1 and F2 populations and we discerned the different larval stages (L1 to L4) until adulthood. Results: We observed that the growth and reproduction dose-response curves exposed to ATZ and their offspring, showed a tendency to no-monotonic dose-response curves in ?W" form (typical of EDC). Most differences in growth output between nematodes in the control and the ATZ treatment occurred in F2, with a significant reduction in body sizes corresponding to the lowest concentration (0.001 and 0.01 mg/l ATZ). Similarly, the reproduction assays in F2 displayed a biphasic dose-response, characterized by a reduction of L1/adults at low doses treatments respect the control. Moreover, the results that show larval development demostrated a delay in the development of individuals during their life cycle of F1 and F2, compared to the control. The delay in the larval stages of the observed nematodes, would be the cause of the lower body length and fewer number of larvae per adult due to not all were adults at the same time.Conclusions: Our results show that ATZ affects the unexposed offspring of the exposed parental generation. This herbicide disrupts the larval development and consequently the growth and reproduction of C. elegans.