Comparative Biochem and Physiology 2017
In June 2017, Giulia Marras, Barbara Demeneix, David du Pasquier and colleagues (Muséum National d'Histoire Naturelle, CNRS, Paris, France) published a paper in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology.
Spirhanzlova P, De Groef B, Nicholson FE, Grommen SVH, Marras G, Sébillot A, Demeneix BA, Pallud-Mothré S, Lemkine GF, Tindall AJ, Du Pasquier D. Using short-term bioassays to evaluate the endocrine disrupting capacity of the pesticides linuron and fenoxycarb. Comp Biochem Physiol C Toxicol Pharmacol. 2017 Jun 17. pii: S1532-0456(17)30123-0.
Several short-term whole-organism bioassays based on transgenic aquatic models are now under validation by the OECD (Organization for Economic Co-operation and Development) to become standardized test guidelines for the evaluation of the endocrine activity of substances. Evaluation of the endocrine disrupting capacity of pesticides will be a domain of applicability of these future reference tests. The herbicide linuron and the insecticide fenoxycarb are two chemicals commonly used in agricultural practices. While numerous studies indicate that linuron is likely to be an endocrine disruptor, there is little information available on the effect of fenoxycarb on vertebrate endocrine systems. Using whole-organism bioassays based on transgenic Xenopus laevis tadpoles and medaka fry we assessed the potential of fenoxycarb and linuron to disrupt thyroid, androgen and estrogen signaling. In addition, we used in silico approach to simulate the affinity of these two pesticides to human hormone receptors. Linuron elicited thyroid hormone-like activity in tadpoles at all concentrations tested and, showed an anti-estrogenic activity in medaka at concentrations 2.5mg/L and higher. Our experiments suggest that, in addition to its previously established anti-androgenic action, linuron exhibits thyroid hormone-like responses, as well as acting at the estrogen receptor level to inhibit estrogen signaling. Fenoxycarb on the other hand, did not cause any changes in thyroid, androgen or estrogen signaling at the concentrations tested.