Effect of Zinc Oxide Nanoparticles From Infant Formula Milk Powder on Colon Cells In Vitro.

Area of Science:

• Nanotechnology
• Toxicology
• Food Science

Background:

• Zinc oxide nanoparticles (ZnO NPs) are increasingly used in consumer products, including infant formula.
• Concerns exist regarding the safety of ZnO NPs due to potential interference with essential metal absorption and unclear toxicity mechanisms.
• While bulk zinc oxide is generally recognized as safe, ZnO NPs exhibit size- and shape-dependent cytotoxic effects.

Purpose of the Study:

• To investigate the cytotoxicity, reactive oxygen species (ROS) generation, and cell cycle effects of ZnO NPs found in commercial infant formula.
• To assess the potential health implications of ingesting ZnO NPs through fortified food products.
• To elucidate the biological effects of ZnO NPs on intestinal epithelial cell models.

Main Methods:

• Isolation of ZnO NPs from commercial infant formula milk powder.
• Exposure of Caco-2 and HT29 intestinal epithelial cells to varying concentrations of ZnO NPs.
• Assessment of cytotoxicity using cell viability assays.
• Measurement of intracellular ROS generation.
• Analysis of cell cycle progression.

Main Results:

• ZnO NPs isolated from infant formula induced concentration-dependent cytotoxicity in intestinal cells.
• Exposure to ZnO NPs triggered significant intracellular ROS overproduction.
• ZnO NPs caused cell-cycle arrest, predominantly in the S and G2/M phases.
• Oxidative stress appears to be a key mechanism underlying ZnO NP toxicity.

Conclusions:

• ZnO NPs in infant formula exhibit cytotoxic effects on intestinal epithelial cells.
• The observed toxicity is linked to increased oxidative stress and cell cycle disruption.
• Further investigation is warranted to understand the long-term health implications of ZnO NP ingestion from fortified foods.