Toxic cytological alteration and mitochondrial dysfunction in PC12 cells induced by 1-octyl-3-methylimidazolium chloride

Ionic liquids have recently received considerable attention due to their negligible vapor pressure and substitute for conventional organic solvents. However, their solubility in water and a great deal of literature regarding their toxicity on aquatic organisms have caused much concern in recent years. This study aims to evaluate the cytotoxicity of 1-octyl-3-methylimidazolium chloride ([C8mim][Cl]) on the rat pheochromocytoma (PC12) cell line by cell viability assay and to determine the cytological alterations and damages in PC12 cells after 24 h of exposure at the concentrations of 0.07, 0.14, and 0.28 mM of [C8mim][Cl]. The results show that [C8mim][Cl] inhibits PC12 cell growth and decreases their viabilities in a remarkable dose-dependent manner, and the 24 h EC50 of [C8mim][Cl] for PC12 cells is calculated to be around 0.56 mM. Our results also reveal that [C8mim][Cl]-exposure induces DNA damage, sustained increase of intracellular Ca2+, overproduction of reactive oxygen species, gradually exhausted cellular ATP, mitochondrial permeability transition, and apoptosis in PC12 cells. We suppose that mitochondrial permeability transition and mitochondrial dysfunction maybe the major cytotoxicity mechanism of [C8mim]Cl for PC12 cells.