Environmentally persistent alkylphenolic compounds are estrogenic.

Abstract

We show that a number of alkylphenolic compounds, used in a variety of commercial products and found in river water, are estrogenic in fish, birds, and mammals. 4-Octylphenol (OP), 4-nonylphenol, 4-nonylphenoxycarboxylic acid, and 4-nonylphenoldiethoxylate were each capable of stimulating vitellogenin gene expression in trout hepatocytes, gene transcription in transfected cells, and the growth of breast cancer cell lines. The most potent of the chemicals is OP, which was able to stimulate these biological responses to a similar extent as 17 beta-estradiol itself, albeit at a 1000-fold greater concentration. The action of alkylphenols is mediated by the estrogen receptor, as their effects depended on its presence and was blocked by estrogen antagonists. OP, 4-nonylphenol, and 4-nonylphenoxycarboxylic acid appear to possess intrinsic estrogenic activity, because they compete for binding to the estrogen receptor. Moreover, it is likely that they interact with a similar region of the hormone-binding domain as 17 beta-estradiol, because the mutant receptor G-525R, which is defective in estrogen binding, is also insensitive to OP. Like 17 beta-estradiol, OP is capable of stimulating the activity of both transcriptional activation functions, TAF-1 and TAF-2, in the receptor, as judged by analyzing the activity of the wild-type and mutant receptors in transiently transfected cells. The significance of our results will depend to a large extent on the degree of exposure of wildlife and humans to these estrogenic alkylphenolic compounds.

Review of risk from potential emerging contaminants in UK groundwater

“…Octyl and nonyl phenol have been long established as endocrine disruptors in fish (Petrović et al, 2004;White et al, 1994). The APEs can also be used as pesticide adjuvants.…”

Trophodynamic Behavior of 4-Nonylphenol and Nonylphenol Polyethoxylate in a Marine Aquatic Food Web from Bohai Bay, North China: Comparison to DDTs

“…While several studies have examined the residues of 4-NP and NPEOs with short EO units (s < 6) in fish (3,10,13,14,16), there is little documenting the existence of NPEOs with more than five units in biota, and there are no reports of the occurrence of NPEOs in marine biota. As shown in the Supporting Information, each NPEO with 3 < s <16 was detected in all biota samples, which provided the first report on the occurrence of NPEOs with s > 5 in marine biota.…”

“…4-Nonylphenol (4-NP) is the biodegradation intermediate of nonylphenol polyethoxylate (NPEOs) surfactants in aquatic environments, and it is of particular concern because of its endocrine-disrupting effects in aquatic organisms, mammals, and birds (1)(2)(3)(4). NPEOs are commonly used worldwide as an emulsifying, dispersing, wetting, and foaming agent in various industrial, institutional, agricultural, and household applications (5).…”

Glucuronidation and Excretion of Nonylphenol in Perfused Rat Liver

“…The mean daily oral intake of nonylphenol by humans is estimated to be 0.16 mg/day (Muller et al, 1998). Nonylphenol has been shown to be a possible endocrine disrupter due to its estrogenic effects in MCF7 cell proliferation assays (Soto et al, 1991), binding assays to the estrogen receptor (White et al, 1994) and uterotropic assays in mice (Shelby et al, 1996). Exposure of male rainbow trout (Oncorhynchus mykiss) to four different alkylphenolic chemicals, including nonylphenol, resulted in synthesis of vitellogenin, a process normally dependent on endogenous estrogens, and a concomitant inhibition of testicular growth (Jobling et al, 1996).…”

“…Nonylphenol is used in a wide variety of detergents and plastics and has been reported to be environmentally persistent (White et al, 1994). The mean daily oral intake of nonylphenol by humans is estimated to be 0.16 mg/day (Muller et al, 1998).…”