Biochemical and body condition markers in Rhinella icterica tadpoles exposed to atrazine, glyphosate, and quinclorac based herbicides in ecologically relevant concentrations

Amphibians have suffered population decline due to several factors, including exposure to pesticides. In the south of Brazil, rice cultivations use herbicides based on atrazine, glyphosate and quinclorac as the commercial formulations Primoleo (R), Roundup (R) and Facet (R), respectively. Rhinella icterica was chosen to evaluate oxidative balance markers and body condition after exposure to three concentrations of herbicides (10, 20 and 40 mu g/L of atrazine and quinclorac; 100, 250 and 500 mu g/L of glyphosate). These xenobiotics, regardless of the concentrations used, accelerated the development process of animals and seemed to act as modulators of development. We observed no significant variations for any of the oxidative balance markers studied (superoxide dismutase, catalase, TBARS and carbonylated proteins); however, we cannot rule out that other antioxidant system components prevent oxidative stress. In general, atrazine and glyphosate accelerated the development of tadpoles, and quinclorac retards this process, which could impact the survival of these animals.

Automated summary

Pesticides have contributed to the decline of amphibian populations, affecting their development and potentially impacting their survival and body condition. However, this study did not observe significant oxidative stress markers in the tested amphibians, suggesting that other antioxidant mechanisms may be at play.