Metabolomics Reveal That Octocrylene Accumulates in Pocillopora damicornis Tissues as Fatty Acid Conjugates and Triggers Coral Cell Mitochondrial Dysfunction

Octocrylene(OC) is an ingredient used in many sunscreens and cosmetics worldwide. Our group evaluated the toxicity of OC in corals. Adult Pocillopora damicornis coralwas treated with OC at concentrations of 5, 50, 300, and 1000 μg/L. Most polyps were closed at concentrations of 300 μg/L and higher. Further, metabolomic profiling provided crucial information regarding OC accumulation in coraltissues and OC toxicity. First, we demonstrated that OC was transformed into fatty acid conjugates via oxidation of the ethylhexyl chain, yielding very lipophilic OC analogues that accumulate in coraltissues. Second, the differential analysis of coralprofiles revealed higher levels of 15 acylcarnitines, suggesting abnormal fatty acid metabolismrelated to mitochondrial dysfunction. The formation of OC analogues suggests that OC concentrations measured in the environment, and organisms may have been largely underestimated. Overall, these results call for an in-depth evaluation of OC toxicity and the reevaluation of...