Triclosan is a biocide found in many products and is definitely not good for your health. While it is already suspected of being an endocrine disruptor, recent research suggests that it may affect the placenta.
An article that can be found in the magazineInsert #59
The noose around triclosan is getting tighter and tighter. In 2021 already a epidemiological study A study carried out by Inserm teams had shown that this biocide, contained in certain cosmetics and personal care products and to which we are all exposed, is associated with changes related to the expression of genes in the placenta, an organ that regulates the exchange between the mother regulates, is connected and the fetus. “ We have shown that triclosan is associated with more Methylation Placental DNA », recalls Claire Philippat, Inserm researcher at the Institute for the Promotion of Life Sciences in Grenoble, who carried out this work. In other words, the more future mothers were exposed to triclosan, the more specific sites in the placenta’s DNA underwent small changes in the sites associated with the expression of certain genes.
“ These results needed to be repeated “, she continues. And that is one of the goals of the study she led with Johanna Lepeule. Better ! In particular, thanks to a new cohort called Sepages. “ This cohort allows us to more accurately assess triclosan exposure. During the previous study with the cohort Eden, we had one urine sample per woman. However, triclosan is a compound whose Half-life is quite short, which means it is broken down quickly by the body. » Better sampling was needed. “ With Sépages we have 42 urine samples from each of the 400 women in the study. » This made it possible to better estimate the exposure to triclosan during pregnancy.
A new piece of the puzzle
The analyzes confirmed some observations from 2021. A positive connection between DNA methylation and triclosan exposure was actually found for 18 genes. “ Some of these are so-called “imprinted” genes, meaning they are involved in the development of the fetus. » reports the researcher. The analysis also shows that the effects may vary depending on the sex of the fetus. When the latter is female, associations with a larger number of genes were observed. Despite these convincing results, the interpretation is not trivial. “ That’s one piece of the puzzle, now we need the othersillustrated by Claire Philippat. DNA methylation is one of the mechanisms that can influence gene expression. However, our results do not suggest that the observed methylation reduces gene expression. To do this, we need to go further and focus on RNA. »
That’s good news, that’s the direction the research team is heading. “ We will verify whether the hypermethylation observed at the DNA level upon exposure to triclosan is reflected in a change in gene expression observed at the RNA level. » In addition, a statistical analysis, so-called “mediation analysis”, could make it possible to understand the possible effects on the child’s health. The team has also established partnerships to study mechanisms of action in cell and animal models. Triclosan is already suspected of being an endocrine disruptor and its toxicological situation may worsen further.
Claire Philippat and Johanna Lepeule are researchers at the Institute for the Promotion of Life Sciences (Inserm Unit 1209/Université Grenoble Alpes/CNRS), in the team Environmental epidemiology applied to development and respiratory health.
source : P. Jedynak et al. Prenatal exposure to triclosan assessed in multiple urine samples and placental DNA methylation. About Pollut., October 15, 2023; doi: 10.1016/j.envpol.2023.122197
Author: BS