Interaction of curcumin with aflatoxins B1 (AFB1) and B2 (AFB2) in pistachios: Combined effects of temperature and curcumin on reducing aflatoxin toxicity using DFT and molecular docking studies

This study investigates the primary objective of evaluating the combined effects of temperature and curcumin (Cur) on the potential reduction of aflatoxin toxicity associated with aflatoxins B1 (AFB1) and B2 (AFB2) in pistachios using density functional theory (DFT) and molecular docking simulations. At 25°C, Cur formed stable and energetically favorable complexes with AFB1 and AFB2, suggesting its potential to reduce aflatoxin toxicity. Thermodynamic analysis revealed that complex formation is exothermic, releasing energy during the process, but at higher temperatures (up to 150°C), the spontaneity of complex formation decreased, suggesting that industrial processes like roasting may require additional energy input. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) decreased upon complex formation, suggesting increased chemical reactivity. Molecular docking predicted favorable binding affinities between the Cur/AFB complexes and a CYP heme active site using PDB ID: 7SV2 (human CYP3A5) as a structural surrogate; however, any downstream biological implications require experimental validation using native fungal enzymes or validated fungal models. Computed IR spectra indicated hydrogen bonding and charge transfer interactions, with significant shifts in O-H and C=O stretching frequencies. TDDFT-predicted UV–Vis spectra showed red-shifted absorption peaks, supporting electronic stabilization. Overall, these computational findings suggest that Cur may reduce aflatoxin toxicity across the studied temperature range; although thermodynamic spontaneity (ΔG) becomes less favorable at higher temperatures, the predicted complexes remain structurally stable and energetically supported by negative adsorption energies, and moderate processing temperatures (e.g., 90°C-120°C) may represent a practical compromise for industrial applications; however, this requires experimental verification. This study provides computational insights that may inform future strategies for enhancing food safety and managing fungal contamination during industrial processes such as roasting.