Direct adverse effects of fipronil sulfone, diisopentyl phthalate and disperse red 60 on zebrafish hepatocytes

The major concerns about emerging pollutants fipronil sulfone, disperse red 60 (DR60), and diisopentyl phthalate (DiPP) include their environmental persistence, difficulty in its removal from water sources, and bioaccumulation in aquatic organisms. They could eventually enter the food chain and raise potential risks to human health. This research investigated whether the above-mentioned emerging contaminants directly affect cellular processes supporting metabolic homeostasis and female reproductive success in teleost fish, using zebrafish hepatocytes (ZFL liver cell line) in vitro. RT-qPCR analysis demonstrated that exposure to all three chemicals led to significant alterations in several key reproductive and metabolic genes. For example, DiPP and DR60 caused an increase in cytochrome P450 family 1 alpha (cyp1α), kisspeptin 1 (kiss1), and vitellogenin 1 (vtg1), and a decrease in cytochrome P450 family 3 subfamily A polypeptide 65 (cyp3a65) and peroxisome proliferator activated receptor alpha (pparα). A significant increase in cellular vitellogenin and triglyceride levels was also caused by all three compounds. Additionally, triglyceride levels in ZFL cells were increased by all three compounds, consistent with a gene expression profile, suggestive of a metabolic shift favoring lipid storage over catabolism. These findings show direct cellular adverse effects for fipronil sulfone, DiPP, and DR60, even at low yet environmentally relevant concentrations. The outcomes suggest their potential to disrupt metabolic and reproductive processes in teleosts in vivo.