Dietary exposure to pesticide residues represents a potential risk to intestinal epithelial integrity, particularly under realistic co-exposure scenarios. This study evaluated the toxicological effects of dicamba and 2,4-dichlorophenoxyacetic acid (2,4-D), alone and in mixture, on human Caco-2 intestinal cells. Cells were exposed for 24 and 72 hours, and cytotoxicity, oxidative stress, inflammation-related enzymatic biomarkers (NAG and MPO), apoptosis/necrosis assessment, DNA damage, and barrier permeability were assessed. After 72 hours of exposure, the IC 50 values were 699.7 mg/L for 2,4-D and 1484 mg/L for dicamba, indicating higher toxicity of 2,4-D. Both herbicides increased oxidative stress and cell death, with more pronounced effects at longer exposure. Notably, combined exposure induced stronger biological alterations compared to the isolated forms, including increased cytotoxicity, oxidative stress, reduced NAG activity, and elevated apoptosis. These findings demonstrate that the dicamba and 2,4-D mixture exerts greater toxicological effects on intestinal epithelial cells than isolated compounds, highlighting the importance of evaluating realistic pesticide mixtures in human health risk assessment. • Dicamba and 2,4-D mixture altered oxidative stress biomarkers; • The mixture elevated the number of cells in apoptosis and necrosis; • The mixture of dicamba and 2,4-D caused lipid peroxidation; • The dicamba and 2,4-D mixture caused greater toxicity after longer exposure; • The study shows possible harmful effects that may result from pesticide mixtures.
Kirsten et al. (Wed,) studied this question.