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Cytotoxic effects and aromatase inhibition by xenobiotic endocrine disrupters alone and in combination

Nora Benachour1, Safa Moslemi, Herbert Sipahutar

  • 1Laboratoire de Biochimie, EA2608, IBFA, Université de Caen, Esplanade de la Paix, 14032 Caen, France.

Toxicology and Applied Pharmacology
|June 30, 2007
PubMed

Insights

This study reveals that common environmental chemicals (xenobiotics) harm human embryonic cells and disrupt androgen metabolism. Combined exposures show synergistic toxicity and significant aromatase inhibition, impacting development.

Area of Science:

  • Environmental Toxicology
  • Endocrinology
  • Cell Biology

Background:

  • Xenobiotics pose risks to human embryonic development, necessitating research into their exposure levels and combined effects.
  • Endocrine-disrupting chemicals (EDCs) are of particular concern due to their potential to interfere with hormonal pathways.

Purpose of the Study:

  • To investigate the interactions between specific EDCs, cellular viability, and androgen metabolism in human embryonic cells.
  • To assess the toxicity and aromatase inhibitory activity of various xenobiotics, both individually and in combination.

Main Methods:

  • Human embryonic 293 cells were exposed to a panel of xenobiotics (e.g., aroclor 1254, atrazine, bisphenol A).
  • Cellular toxicity and aromatase activity were measured using cellular assays, placental microsomes, and purified equine aromatase.
  • Combined effects and prolonged low-dose exposures were evaluated.

Main Results:

  • All tested xenobiotics exhibited cellular toxicity, with lower thresholds observed for TBTO and DES.
  • Aromatase inhibition occurred at non-toxic doses, with synergistic effects observed in combinations, reducing toxicity thresholds and inhibiting aromatase activity.
  • Prolonged low-dose exposures significantly amplified aromatase inhibition, suggesting bioaccumulation and interference with cell signaling.

Conclusions:

  • Xenobiotics can disrupt cellular viability and androgen metabolism in human embryonic cells, even at low, chronic exposure levels.
  • Synergistic interactions between xenobiotics enhance toxicity and aromatase inhibition, posing significant developmental risks.
  • Understanding these mechanisms is crucial for designing safer chemical compounds and mitigating environmental health risks.

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