Roundup® induces oxidative stress in zebrafish liver cell line (ZF-L): Role of the Nrf pathway and uncoupling proteins.

Glyphosate is the most widely used herbicide worldwide and impacts non-target aquatic organisms through leaching processes. Previous studies have shown that this pesticide induces oxidative stress, however, the mechanisms responsible for mitigating ROS production and the associated cellular damage remain poorly understood. Therefore, the aim of this study was to examine the effects of Roundup® on the gene expression of uncoupling proteins (UCP2 and UCP3), its impact on ROS production, as well as the involvement of the Nrf2-ARE pathway in these processes. To this end, hepatocyte-like cells (ZF-L cell line) were exposed to three concentrations of Roundup (65 μg L⁻¹, 650 μg L⁻¹, and 6500 μg L⁻¹), along with a control group, for 24 and 48 h. The results indicate that exposure led to a significant increase in ROS levels only at the highest concentration after 24 h, with no sustained effect observed at 48 h. This result is consistent with the data observed for the Nrf2 and ucp3 genes, whose expression increased only after 24 h. Additionally, the ARE sequence was identified in this study in the promoter regions of the Nrf2 and ucp3 gene. Significant oxidative DNA damage was observed at the highest concentration after 24 h, and damage remained elevated after 48 h compared to the control. These findings indicate that Roundup elevates ROS levels, with this effect being attenuated after 48 h, possibly as a result of Nrf2 and ucp3 activation. However, DNA damage persisted after 48 h, even when ROS levels and gene expression no longer differed from the control.