Phthalates and alternative plasticizers differentially affect phenotypic parameters in gonadal somatic and germ cell...

Area of Science:

• Toxicology and Environmental Health
• Reproductive Toxicology
• Cell Biology

Background:

• Phthalates are associated with developmental and reproductive toxicity, driving the search for safer alternatives.
• Limited knowledge exists regarding the adverse effects of many potential phthalate substitutes.
• High-content imaging offers a method to assess chemical toxicity and cellular responses.

Purpose of the Study:

• To compare the toxicological profiles of mono (2-ethylhexyl) phthalate (MEHP) with six alternative plasticizers.
• To evaluate the effects of these chemicals on various cell lines using high-content imaging.
• To assess cytotoxicity and phenotypic changes induced by plasticizers in reproductive and steroidogenic cells.

Main Methods:

• Utilized high-content imaging to analyze cellular responses to MEHP and six alternative plasticizers (DEHTP, DINP, DINCH, DEHA, TXIB, DIDA).
• Exposed four cell lines (C18-4 spermatogonial, TM4 Sertoli, MA-10 Leydig, KGN granulosa) to chemicals (0.001–100 μM) for 48 hours.
• Assessed cytotoxicity and phenotypic endpoints including lipid droplets, oxidative stress, lysosomes, and mitochondrial activity.

Main Results:

• Mono (2-ethylhexyl) phthalate (MEHP) was cytotoxic only in C18-4 cells at 100 μM.
• Several plasticizers induced distinct phenotypic effects across cell lines, including oxidative stress, altered lipid droplets, lysosome counts, and mitochondrial activity.
• The Toxicological Priority Index (ToxPi) visually demonstrated cell line-specific effects, with MEHP showing the lowest administered equivalent doses.

Conclusions:

• Alternative plasticizers can elicit specific cellular effects distinct from MEHP, underscoring the complexity of substitute safety assessment.
• High-content imaging is a valuable approach for screening alternative plasticizers and understanding their cell-specific toxicological profiles.
• Further investigation is warranted to fully characterize the safety of these alternative plasticizers for developmental and reproductive health.