Modulation of Ochratoxin A-Induced Oxidative Stress and Gene Expression by Bilberries (Vaccinium myrtillus L.) in an In Vitro Intestinal Model

TL;DR

Bilberries may help reduce the harmful effects of a toxic food contaminant called ochratoxin A in intestinal cells by lowering stress and supporting cell health.

Contribution

This study demonstrates that bilberries can mitigate ochratoxin A-induced oxidative stress and gene expression changes in an in vitro intestinal model.

Findings

Bilberries reduced necrotic cell death and reactive oxygen species levels caused by ochratoxin A.

Bilberry co-exposure partially restored gene expression related to intestinal barrier integrity and oxidative stress.

Bilberry-enriched bread showed cellular responses similar to the control group.

Abstract

Background/Objectives: Mycotoxin contamination in grain-derived foods is still a major food safety concern; thus, innovative mitigation approaches need to be continuously developed. This study investigated the influence of bilberry (Vaccinium myrtillus L.) incorporated into a food matrix on ochratoxin A (OTA)-induced cellular responses using a dietary-relevant in vitro intestinal model. Methods: Four bread types were prepared: control (C), OTA-contaminated (OTA), bilberry-enriched (VM), and OTA + VM (OTA-VM). Simulated intestinal digests of these breads were applied to differentiated Caco-2 cells for 24 h. Apoptotic and necrotic cell populations, as well as reactive oxygen species (ROS) levels, were quantified by flow cytometry, while RT-qPCR assessed the expression of 10 genes related to mitochondrial function, oxidative stress response, and intestinal barrier integrity. Results: Exposure to OTA resulted in increased cytotoxicity, reflected by a higher proportion of necrotic cells (5.11 ± 0.35%), and elevated ROS levels compared with control cells. Co-exposure to bilberry-enriched digests was associated with attenuation of apoptotic responses, a reduced proportion of necrotic cells (2.16 ± 0.61%) and a 16% decrease in ROS levels. Gene expression profiles in the VM group were comparable to control, whereas OTA exposure led to downregulation of several genes related to oxidative stress response and intestinal barrier integrity (e.g., CLDN2, OCLN, SLC7A11). In the OTA-VM group, a partial recovery of gene expression was observed. Conclusions: These findings suggest that bilberry incorporation into a food matrix may modulate OTA-induced cellular stress responses by attenuating oxidative imbalance and supporting the expression of genes associated with antioxidant defense and epithelial barrier integrity. Bilberries may therefore represent a promising functional ingredient for influencing intestinal cellular responses to dietary mycotoxin exposure.

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