Aflatoxin B1 modulates mixture-induced neurotoxicity under multi-contaminant exposure: insights from combination modeling in SH-SY5Y cells.

INTRODUCTION

The chemical exposome is increasingly implicated in neurodegenerative diseases (NDs). However, although human exposure to environmental and dietary contaminants typically occurs as complex mixtures, neurotoxicity assessments still largely focus on single compounds. This study investigated the neurotoxic interactions between aflatoxin B1 (AFB1), acrylamide (ACR), and cadmium in a neuronal cell model.

METHODS

SH-SY5Y cells were exposed to AFB1, ACR, and Cd2+ individually or in fixed-ratio mixtures for 72 h. Mixture interactions were evaluated from MTT data using the combination index (CI) approach implemented through the Chou-Talalay (CT) and CISNE frameworks.

RESULTS

Individual potency ranked Cd2+>AFB1>ACR. At low effect levels, AFB1-containing mixtures showed relevant deviations from additivity. The ACR/AFB1 combination displayed synergism at IC10 (CISNE CI 0.62), with concentrations reducing to 4.4-fold for ACR and 2.6-fold for AFB1. AFB1/Cd2+ interactions were model-dependent, with CT indicating synergism at IC10 (CI 0.43), whereas CISNE indicated near additivity. ACR/Cd2+ and ternary mixtures displayed strong antagonism at low effect levels (CISNE CI 7.07 at IC10). Interactions interpretation was generally consistent across models, but CT amplified deviations from additivity at low levels.

CONCLUSION

Overall, these findings identify AFB1 as a key contributor to mixture-induced neurotoxicity and support the use of CISNE modelling to improve low-effect interaction analysis in food contaminant risk assessment.