Ethylparaben (Ethyl parahydroxybenzoate)

Ethylparaben is a paraben that has been found in A. bracteatus and has diverse biological activities.^1,2,3,4 It selectively induces activation of estrogen receptor β (ERβ) over ERα in yeast two-hybrid assays (EC₅₀s = 1.86 and 38.2 ?M, respectively). Ethylparaben inhibits carbonic anhydrase I (CAI), CAII, CAVII, CAIX, CAXII, and CAXIV (IC₅₀s = 7.9, 4.8, 8.7, 8.2, 8.6, and 7.7 ?M, respectively, for the human enzymes).² It is active against several strains of P. stutzeri and P. aeruginosa (MICs = 400-1,000 ?g/ml).³ Ethylparaben (0.01 and 0.1%) is cytotoxic to immortalized human meibomian gland epithelial cells.⁴ It has been found in influent and effluent wastewater.⁵ Formulations containing ethylparaben have been used as preservatives in cosmetics, food, and pharmaceuticals.

1.Cao, X., Jiang, J., Zhang, S., et al.Discovery of natural estrogen receptor modulators with structure-based virtual screeningBioorg. Med. Chem. Lett.23(11)3329-3333(2013) 2.Carta, F., Vullo, D., Maresca, A., et al.Mono-/dihydroxybenzoic acid esters and phenol pyridinium derivatives as inhibitors of the mammalian carbonic anhydrase isoforms I, II, VII, IX, XII and XIVBioorg. Med. Chem.21(6)1564-1569(2013) 3.Tattawasart, U., Maillard, J.-Y., Furr, J.R., et al.Comparative responses of Pseudomonas stutzeri and Pseudomonas aeruginosa to antibacterial agentsJ. Appl. Microbiol.87(3)323-331(1999) 4.Wang, J., Liu, Y., Kam, W.R., et al.Toxicity of the cosmetic preservatives parabens, phenoxyethanol and chlorphenesin on human meibomian gland epithelial cellsExp. Eye Res.196108057(2020) 5.Wang, W., and Kannan, K.Fate of parabens and their metabolites in two wastewater treatment plants in New York state, United StatesEnviron. Sci. Technol.50(3)1174-1181(2016)