Assessment of The Toxic Effects of Parabens Commonly Used Preservatives in Cosmetics, and their Halogenated By-Products on Human Skin and Endothelial Cells




McGraw, Mackenna

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Parabens, commonly used preservatives in cosmetics, raise concerns for estrogen-like traits linked to health issues like breast cancer. Their chlorinated and brominated by-products, found in water, pose additional toxicity risks. To assess the impact of parabens, their primary metabolite, and three halogenated by-products, cytotoxicity and wound healing assays were performed. Human keratinocytes (HEK001) and dermal microvascular endothelial cells (HMEC-1) were used to evaluate their impact. Butylparaben (BuP) and benzylparaben (BeP) exhibited the highest toxicity to keratinocytes (EC50: 1.52 ± 0.51 µM and 3.34 ± 0.97 µM). Halogenated parabens showed notable cytotoxicity as well. Methylparaben (MeP), ethylparaben (EtP), and 4-hydroxybenzoic acid (HBA) displayed lower toxicity (EC50: 536 ± 178 µM to 1,313 ± 464 µM). In endothelial cells, MeP, EtP, and HBA were less toxic (EC50: 171 ± 78 µM to >10 mM). Halogenated by-products showed lower toxicity, too (EC50: 788 ± 140 µM to >10 mM). High concentrations (100 µM) of BuP, BeP, and halogenated by-products inhibited wound healing in both cell types, though these levels are not environmentally relevant. Halogenated parabens hindered keratinocyte proliferation significantly (p<0.05) at concentrations as low as 1 µM, unlike endothelial cells. This study showcased parabens’ impact on wound healing, aiding in assessing their safety and potential risks.



Evironmental science., Molecular toxicology., Parabens., Halogenated Parabens., Wound-healing.