Genotoxic damage and apoptosis in rat glioma (F98) cell line following exposure to bromuconazole.

Bromuconazole, a fungicide from the triazole family, is widely used to protect the crop from various fungal contaminations to increase product quality and productivity. Although the massive use of bromuconazole poses a serious risk to human health, the exact mechanism of bromuconazole toxicity, especially on brain support cells, called glia cells, remains unclear so far. This study aimed to determine the mechanism of cytotoxicity and genotoxicity of bromuconazole via inspection of apoptotic death in rat glioma (F98) cells. We observed that bromuconazole treatment caused concentration-dependent cell death with an IC50 of 60 µM, and disruption of the cytoskeleton was observed via immunocytochemical analysis. Further, bromuconazole inhibits cell proliferation, it arrests the cell cycle in the G0/G1 phase and so inhibits DNA synthesis. Genotoxic analysis showed that bromuconazole exposition causes DNA fragmentation (comet assay) and nuclear condensation (DAPI staining). Apoptotic cell death was confirmed through: positive Annexin-V/FITC-PI dyes, p53 and Bax overexpression, Bcl2 repression, an increase in Bax/BCL-2 ratios of the mRNA, mitochondrial membrane depolarization, and an increase of caspase-3 activity. All these results demonstrate that bromuconazole exerts its cytotoxic and genotoxic effects through apoptotic cell death, which could implicate mitochondria.