Bisphenol A, 17beta-estradiol, and Parabens increase rat uterine weights. - GreenMedInfo Summary
Uterotrophic effects of benzophenone derivatives and a p-hydroxybenzoate used in ultraviolet screens.
Environ Res. 2005 May;98(1):40-5. PMID: 15721882
Endocrine Disrupters Research Laboratory, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. email@example.com
Ultraviolet (UV) sunscreen products are popular because of concerns about UV radiation and skin cancer. Unfortunately, some of these products contain agents with estrogenic activity. We used an ovariectomized rat uterotrophic assay to measure the estrogenic activities of 2,4-dihydroxybenzophenone (2,4-DHBP), 2,2',4,4'-tetrahydroxybenzophenone (2,2',4,4'-THBP), and 4-hydroxybenzoic acid isobutyl ester (isobutyl-paraben), which are agents in UV sunscreens, and ethynyl estradiol (EE) and bisphenol A (BPA), which are positive controls. All chemicals increased rat uterine weights. The 10% effective doses (ED10, mg/kg/day) of EE, BPA, 2,4-DHBP, 2,2',4,4'-THBP, and isobutyl-paraben, as determined by Hill equation analysis, where 5E-5, 41.1, 544.6, 33.0, and 230.9, respectively, and their relative potencies against EE were about 1/800,000, 1/10,000,000, 1/600,000, and 1/4,000,000, respectively. Our findings indicated that UV screens contain weak estrogenic compounds.