Estrogenicity of Metabolites of Benzophenone Derivatives Examined by a Yeast Two-Hybrid Assay.

Abstract

The estrogenic activities of S-9 metabolites of benzophenone derivatives (benzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2,4-dihydroxybenzophenone and 2,3,4-trihydroxybenzophenone) and benzhydrol were examined with a yeast two-hybrid screening system. After chemicals were incubated in an S-9 mix at 37°C for 4 hr prior to their incubation with the yeast strain, the S-9 mix containing metabolites was assayed for the estrogenic activity by the yeast two-hybrid assay. Benzophenone, 2-hydroxy-4-methoxybenzophenone and 2,2′-dihydroxy-4-methoxybenzophenone exhibited estrogenic activities after incubation with the S-9 mix. The estrogenic metabolites of 2-hydroxy-4-methoxybenzophenone were fractionated by high-performance liquid chromatography, one of which was identified as 2,4-dihydroxybenzophenone. This assay will be a useful tool for detecting proestrogens.

Differential binding with ERα and ERβ of the phytoestrogen-rich plant Pueraria mirifica

“…However, the YES assay revealed a much lower estrogenic activity of the plant extracts compared to 17β-estradiol than observed in the vaginal cornification assay (6-8). There was a difference between the two assays, i.e., there was no metabolic activation in the ordinary YES assay while metabolic activation was initiated by both intestinal microbes (29,30) and liver enzymes (31)(32)(33). Note that the results of metabolic activation of the plant samples with the S9 fraction were not in the same direction as the test without activation in which the plant extracts exhibited stronger estrogenic activity in YES-hERα + hTIF2 ( Figure 4A) than in YES-hERβ + hSRC1 ( Figure 2B).…”

“…In vitro metabolic activation with the aid of the rat liver S9 fraction (Wako Pure Chemical Industries, Ltd., Japan) was tested against plant samples that did not exhibit estrogenic activity in the normal YES assay according to the method of Takatori et al (29). A 10-μL aliquot of plant extract dissolved …”

Retinoid X receptor activities of source waters in China and their removal efficiencies during drinking water treatment processes

“…S9 was prepared from the livers of male Sprague-Dawley rats that were pre-treated with 3-methyl-cholanthrene and 3-phenobarbital according to the method described by Ames et al [19]. Water and cofactor (MgCl 2 ·6H 2 O, KCl, G-6-P, nicotinamide adenine dinucleotide phosphate, nicotinamide adenine dinucleotide, Na 2 HPO 4 and NaH 2 PO 4 ) were added to the SD/-Leu/-Trp medium according to the method described Takatori et al [23]. Next, 200 μL of the test cultures were transferred into each well of a 96-well plate.…”

Development of Miniaturized Hollow-fiber Assisted Liquid-phase Microextraction with in situ acyl Derivatization Followed by GC-MS for the Determination of Benzophenones in Human Urine Samples

“…1 However, BPs are also suspected to cause pruritus and contact allergies, 2 and to disrupt the endocrine system by exerting estrogenic and anti-androgenic action. [3][4][5] Recently, the migration of BPs from multilayer plastic-paper materials intended for food packaging and the contamination of food sample with BPs have been reported. 6,7 Due to the widespread usage of BPs, healthy humans may be exposed to BPs via a variety of daily activities.…”