Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) Alters Transcriptional Profiles, Lipid Metabolism and Behavior in Zebrafish Larvae

Abstract

Plasticizers are commonly used in different consumer goods and personal care products to provide flexibility, durability and elasticity to polymers. Due to their reported toxicity, the use of several plasticizers including phthalates has been regulated and/or banned from the market. Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) is an alternative plasticizer that was introduced to replace toxic plasticizers. Increasing global demand and lack of information regarding toxicity and safety assessment of DINCH have raised the concern to human and animal health. Hence, in the present study, we investigated the adverse effects of DINCH (at concentrations ranging from 0.01 to 10 μM) in early developmental stages of zebrafish using different endpoints such as hatching rate, developmental abnormalities, lipid metabolism, behavior analysis and gene expression. We found that DINCH caused hatching delay in a dose-dependent manner and altered the expression of genes involved in stress response. Lipid staining using Oil Red O stain showed a slight lipid accumulation around the yolk, brain, eye and neck with increasing concentration. Genes associated with lipid metabolism such as fatty acid synthesis, β-oxidation, elongation, lipid transport were significantly altered by DINCH. Behavioral analysis of larvae demonstrated a distinct locomotor activity including distance and acceleration upon exposure to DINCH both in light and dark. Genes involved in cholesterol biosynthesis and homeostasis were also affected by DINCH indicating possible developmental neurotoxicity. The present data shows that DINCH could induce physiological and metabolic toxicity to aquatic organisms. Hence, further analyses and environmental monitoring on DINCH should be conducted to determine its safety and toxicity levels.