# Oxidative and Inflammatory Damage by Environmental Polyethylene Microplastics in Caco‐2 Cells Is Prevented by Polyphenol‐Rich Limoncella Apple Extract

## TL;DR

This study shows that polyethylene microplastics harm intestinal cells, but a polyphenol-rich apple extract can protect against this damage.

## Contribution

The study demonstrates the protective effect of Limoncella apple extract against microplastic-induced cellular damage for the first time.

## Key findings

- Polyethylene microplastics reduced cell viability and increased oxidative stress in intestinal cells.
- Limoncella apple extract counteracted the harmful effects of microplastics by reducing inflammation and oxidative damage.
- The extract preserved cell structure and function, suggesting potential as a nutraceutical intervention.

## Abstract

Humans are constantly exposed to environmental microplastic (MP) particles, which can be absorbed through the gut and exert adverse health effects. This study aimed to investigate the harmful effects of environmental polyethylene MPs (PE, 2.6 μm) on differentiated Caco‐2 (D‐Caco‐2) intestinal epithelial cells and to assess the protective potential of Limoncella apple polyphenol extract (LAPE).

D‐Caco‐2 cells were exposed to PE, LAPE, or their combination. Cell viability and lipid peroxidation were evaluated using MTT and TBARS assays, respectively. The organization of F‐actin and alkaline phosphatase proteins was evaluated by immunofluorescence, whereas occludin and NF‐κB were evaluated by Western blot analysis.

PE reduced D‐Caco‐2 viability and impaired cell differentiation by increasing lipid peroxidation. In addition, PE destructured F‐actin organization and altered the expression of occludin, a tight‐junction protein.

Our findings show that PE increases oxidative stress, triggering epithelial–mesenchymal transition and dedifferentiation in Caco‐2 cells. Interestingly, LAPE, owing to its antioxidant and anti‐inflammatory properties, counteracted the harmful effects of PE, suggesting its potential as a nutraceutical strategy to prevent MP‐induced damage in the gastrointestinal (GI) tract.