Several environmental oestrogens are also anti-androgens

Area of Science:

• Endocrinology
• Environmental Toxicology
• Reproductive Science

Background:

• Endocrine disruption involves chemicals mimicking hormones, particularly sex steroids.
• Adverse effects in humans and wildlife are hypothesized to result from exposure to these chemicals.
• Research has primarily focused on xenoestrogens, but androgen receptor-mediated effects are increasingly recognized.

Purpose of the Study:

• To investigate the oestrogenic, anti-oestrogenic, androgenic, and anti-androgenic activities of various chemicals using in vitro yeast-based assays.
• To determine if chemicals identified as environmental estrogens also possess anti-androgenic properties.
• To assess the potential for multiple hormonal activities in single chemical compounds.

Main Methods:

• Utilized in vitro yeast-based assays to screen for hormonal activities.
• Tested a range of chemicals, including known environmental estrogens, for estrogenic and anti-androgenic effects.
• Confirmed previously reported anti-androgenic activities and identified new ones.

Main Results:

• Many "environmental estrogens" were found to possess significant anti-androgenic activity.
• Confirmed anti-androgenic activity for vinclozolin and p,p'-1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE).
• Identified o,p'-1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), bisphenol A, and butyl benzyl phthalate as anti-androgenic; nonylphenol showed weak androgenic activity.

Conclusions:

• Hormone-mimicking chemicals can exhibit multiple hormonal activities, complicating in vivo mechanism of action interpretation.
• Yeast-based assays are effective tools for investigating both agonist and antagonistic hormonal activities of chemicals.
• Findings highlight the complex nature of endocrine disruption and the need for comprehensive chemical screening.