Using the herbicide glyphosate on crops and green spaces leads to the secondary contamination of soil-dwelling animals. These animals are exposed not only through inhalation and contact with the substance, but also through ingestion via the food chain. Top predators, such as reptiles, birds and mammals, are particularly affected. This research summarizes the results of a study investigating the toxic effects of glyphosate on the wall lizard (Podarcis siculus), which, due to its lifestyle and habitat, is an ideal model organism.

For the study, P. siculus specimens collected from a pristine area were kept in a terrarium and orally exposed, every other day for three weeks, to two different concentrations of pure glyphosate. At the end of the treatment period, histological analyses, such as Mallory’s trichrome, PAS and Picrosirius red staining, were performed on liver and gonads, to reveal their cellular and tissue morphology. Immunocytochemical analyses and real-time PCR on the same organs revealed changes in gene and protein expression.

All tissues from animals exposed to the herbicide show morphological alterations, such as tissue disorganization, likely due to a lack of proper cellular communication, and fibrosis. The liver and gonads exhibit typical endocrine-disrupting effects, including vitellogenin synthesis in male livers and changes in the localization and expression of estrogen receptors.

Consequently, reproductive function is severely impaired. In the testes, spermatogenesis slows, the walls of the seminiferous tubules thin and spermatozoa in the lumen decrease. Hyperstimulation occurs in the ovaries, resulting in an increase in the number of primary follicles that begin to differentiate.

In conclusion, exposure to glyphosate causes structural and functional damage, indicating potential harm to the health of soil-dwelling vertebrates. Overall, these data highlight the risks faced by vertebrates living in glyphosate-treated areas.