Sublethal exposure to propylparaben leads to lipid metabolism impairment in zebrafish early-life stages

Parabens are widely used in cosmetics, toiletries, food and pharmaceuticals. Toxicological effects of parabens on human lipid metabolism are not well established. The present study used the early-life stages of zebrafish (Danio rerio) to determine the toxicity of propylparaben (PP). The embryos were exposed for 96 hours postfertilization (hpf) at five different concentrations of PP, and lethal and sublethal alterations were recorded daily. The lethal concentration 50 (LC50) value was 3.98 mg/L. The most common sublethal alterations recorded at 1 and 2 mg/L were an enlarged and misshaped yolk sac, hyperexcitability, and reduction in head size and swim bladder. At sublethal concentrations of 1 and 2 mg/L, we observed an altered lipid metabolism, in terms of decrease in neutral lipid mobilization from yolk and alteration of phospholipid metabolism, both in the body and in the yolk sac. These observations were combined with strong head cartilage defects, indicating a strong effect of PP on head development. This research demonstrates that PP interferes with lipid utilization in zebrafish during early-life stages that might be involved in neurological and skeletal abnormalities.