Triclosan (TCS) exposure impairs lipid metabolism in zebrafish embryos

Triclosan (TCS) is an active antimicrobial ingredient used in many household products, such as skin creams and toothpaste. It is produced in high volumes, and humans are directly exposed to it and dispose it on a daily basis. TCS has been found to contaminate water worldwide. This study aimed to understand the potential developmental and metabolic abnormalities caused by TCS exposure by using zebrafish as the experimental model. Four developmental stages (70-85% epiboly, 10-12 somite, prim-5, and 5dpf) were selected to perform in situ hybridization staining to investigate the effects of TCS on dorsal ventral patterning, segmentation, brain development, and organ formation. Results showed, in terms of developmental toxicology, that neither phenotypic nor molecular changes were found after 5 days of 250μg/L TCS exposure. However, such dosage of TCS exposure resulted in lipid droplet accumulation in the yolk sac, which might due to the deregulated mRNA expression level of beta-oxidation transcripts. This study showed that 250μg/L TCS exposure does not affect normal embryogenesis or organogenesis; however, there are concerns regarding possible impairment of lipid metabolism.