The cytotoxic effects of a single and combined exposure to the mycotoxins, deoxynivalenol and zearalenone, on a rat Leydig cell line (LC-540)

Abstract

Deoxynivalenol (DON) and zearalenone (ZEA) are among the most prevalent mycotoxins synthesized by Fusarium species, with 60 % and 80 % prevalence in grains containing mycotoxins, respectively. These mycotoxins often co-contaminate feedstuffs and induce male reproductive toxicity. This study investigated in vitro cytotoxicity, the structure of selected cytoskeletal proteins, mitochondrial morphology, lysosomal activity, and ultrastructural changes associated with individual and combined DON and ZEA exposure in rat Leydig cells (LC-540). Deoxynivalenol (IC50: 2.66, 0.50, and 0.44 μM) induced higher cytotoxicity than ZEA (IC50: 117.0, 69.1, and 34.4 μM) after 24, 48, and 72 h, respectively. Combined DON + ZEA exposure revealed concentration- and time-dependent cytotoxic effects that were synergistic at low concentrations (0.125 + 10 μM), but additive or antagonistic at higher concentrations (2 + 30 and 5 + 50 μM). Microscopic analysis revealed both mycotoxins disrupted F-actin and β-tubulin, impaired mitochondrial morphology, and increased lysosomal acidification. Ultrastructurally, marked cellular alterations included mitochondrial damage, autophagosome formation, and apoptosis. The observed cytotoxicity, disruption of cytoskeletal proteins, and mitochondrial damage in the Leydig cells may play a role in clarifying the male reproductive toxicity induced by DON and ZEA or their co-exposure.

HIGHLIGHTS • DON and ZEA induced time- and concentration-dependent cytotoxicity in rat Leydig cells (LC-540). • Combined DON and ZEA exposure showed synergistic effects at low concentrations in LC-540 cells. • DON and ZEA disrupted F-actin and β-tubulin cytoskeletal proteins in LC-540 cells. • DON and ZEA exposure caused mitochondrial damage and increased lysosomal acidification in LC-540 cells. • Combined mycotoxin exposure induced autophagy and apoptosis in LC-540 cells.