Coexposure of Cyclopiazonic Acid with Aflatoxin B1 Involved in Disrupting Amino Acid Metabolism and Redox Homeostasis Causing Synergistic Toxic Effects in Hepatocyte Spheroids

Abstract

Cyclopiazonic acid (CPA), an emerging toxin, has been found in various foods such as corn, peanuts, and figs.Aspergillus flavus can produce CPA, leading to coexposure with highly toxic aflatoxin B1 (AFB1), but the mechanism of their combined action is not clear. In this study, cocultured hepatocyte spheroids were used as the evaluation model, and two concentration settings of isotoxicity and different toxicity ratios were used to investigate the combined toxic effects. Metabolomics was subsequently used to analyze the potential mechanisms underlying the effects of their exposure. AFB1 and CPA might exhibit stronger cytotoxicity, with significant combined effects on mitochondrial morphology, activity, and reactive oxygen levels. The gene expression analysis revealed that the overexpression of AKT genes could mitigate the combined effects of AFB1 and CPA to some extent. Metabolomics analysis indicated that AFB1 and CPA significantly downregulated the metabolism of L-aspartate and antioxidant substances (e.g., penicillamine, myricetin, and ethanolamine). The pathway enrichment analysis also revealed a large impact on amino acid metabolism, likely affecting intracellular redox homeostasis. In addition, the presence of CPA affects intracellular glucose metabolism and lipid metabolism pathways. This study suggested a direction for future research on relevant toxic pathways and provided possible ideas for inhibiting or mitigating toxicity.

Biodegradation Characteristics and Mechanism of Aflatoxin B1 by Bacillus amyloliquefaciens from Enzymatic and Multiomics Perspectives

“…To date, multiple studies have revealed the potential mechanisms of Bacillus species for the degradation of mycotoxins. , In this study, integrated metabolomics and transcriptomics analysis were used to explore the differential metabolites and DEGs in B. amyloliquefaciens ZG08 in relation to AFB 1 degradation or response to AFB 1 stress. Previous studies have highlighted the pivotal role of amino acid metabolism in the cellular response to adverse environmental conditions . Significant changes were noted in pathways such as alanine, aspartate, and glutamate metabolism, tryptophan metabolism, and arginine biosynthesis.…”

The Growing Importance of Three-Dimensional Models and Microphysiological Systems in the Assessment of Mycotoxin Toxicity

“…Similarly, in another study, the authors observed different interactions associated with the co-exposure of AFB1 with cyclopiazonic acid (CPA) compared with those reported in the literature. Synergistic effects were obtained in co-cultured hepatocyte spheroids at concentrations close to real-life exposure levels (0.625 µg/mL AFB1 and 3.125 µg/mL CPA) [ 134 ], and the authors speculated that this could be because the 3D culture environment might confer metabolic processes that differ from those of adherent cells, leading to differences in interactions between 3D and 2D cells. Since it is widely accepted that the carcinogenic and toxic effects of AFB1 are dependent on its metabolic activation [ 135 ], 3D cell culture seems to be a complex and suitable model for a more precise evaluation of mycotoxin co-exposure.…”

“…Individual and combined cell viability, mitochondria, oxidative stress, metabolomic analysis [134] STE Human neuroblastoma spheroids (SH-SY5Y and SK-N-DZ cells)…”