Acute toxicity, oxidative stress, and apoptosis due to short-term triclosan exposure and multi- and transgenerational effects on in vivo endpoints, antioxidant defense, and DNA damage response in the freshwater water flea Daphnia magna

this study, we measured the acute toxicity of triclosan (TCS) in neonate and adult Daphnia magna water fleas. median lethal concentrations were 184.689 and 349.511 mu g/L, respectively. Oxidative stress induced by TCS was alyzed based on changes in reactive oxygen species (ROS) content and antioxidant enzymatic activities in D. magna. Based on these endpoints, TCS concentrations of 50 and 100 mu g/L induced oxidative stress. However, several apoptosis-mediated proteins showed TCS-induced oxidative-stress damage in response to 25 mu g/L, indicating that optotic proteins were the most sensitive mediators. We also evaluated the multi-and transgenerational effects of on D. magna over three generations in terms of various in vivo endpoints, DNA damage responses, and biochemical actions. The transgenerational group exposed to TCS exhibited greater negative impacts on antioxidant responses, DNA fragmentation status, and biological endpoints compared with the multigenerational exposure group, leading decreased reproductive rates and higher ROS content. The transcriptional expression levels of glutathione transferase genes in the transgenerational exposure group were upregulated compared to those in the multigenerational group but were fully recovered in F2 offspring. Our findings provide an in-depth understanding of the adaptive effects of multigenerational exposure to TCS.

Automated summary

In this study, the acute toxicity of triclosan (TCS) in Daphnia magna was measured. The results showed that TCS induced oxidative stress and damage to apoptotic proteins in D. magna. The study also investigated the multi- and transgenerational effects of TCS on D. magna, revealing negative impacts on antioxidant responses, DNA fragmentation, and reproductive rates.