Mechanistic insights into ferroptosis and apoptosis pathways: Synergistic effects of multi-organ toxicity and transgenerational effects induced by co-exposure of epoxiconazole and aflatoxin B1 in zebrafish.

Introduction: In the environment, mycotoxins and fungicides frequently coexist, potentially causing synergistic risks to organisms. Epoxiconazole (EPO) and aflatoxin B1 (AFB1) are a common fungicide and mycotoxins, respectively, which are widely present in the environment and have toxic effects on multiple organs once entering the organism, but it is still unclear whether the co-exposure has a synergistic toxic effect.

Objectives: This study delves into the molecular mechanisms underlying the co-exposure to EPO and AFB1, emphasizing multi-organ toxicity in female zebrafish (F0 generation) and potential transgenerational impacts on the offspring embryos (F1 generation) through multi-omics approaches.

Results: Findings indicate that exposure to either EPO or AFB1, individually or combined, intensified intestinal pathological damage, decreased the expression of tight junction proteins, altered gut microbiota composition, and induced intestinal inflammation, with co-exposure causing more severe effects. RNA-seq analysis revealed an enrichment of ferroptosis and apoptosis pathways in the liver and ovaries of F0 zebrafish. Co-exposure markedly altered the expression of associated molecules, exacerbating pathological damage in these organs. Molecular docking studies revealed that AFB1 exhibited lower binding energies to Caspase3, GPX4 and IL-1β compared to EPO, suggesting that it may have a higher binding capacity. Furthermore, both single and combined exposures modified the expression of molecules related to apoptosis, inflammatory response, and ferroptosis in unexposed F1 embryos, with co-exposure demonstrating more significant biological effects, thereby confirming transgenerational toxicity.

Conclusion: The present study provides preliminary evidence on the potential mechanisms of combined exposure-induced multi-organ toxicity, highlighting ferroptosis of the liver and apoptosis of the ovary as key pathways. These findings provide new perspectives and methods for risk assessment of multiple environmental pollutants.