Antidotal efficacy of antioxidants against cyanide poisoning in vitro

Cyanide is a potent homicidal, genocidal and chemical warfare agent. Besides, its known inhibitory effects on various enzyme systems, its other pronounced toxic effects include lipid peroxidation (LPx), particularly in the central nervous system or neuronal cells in vitro. The present study assessed the cytotoxicity of potassium cyanide (KCN) in two non-neuronal mammalian cell cultures, viz,, human embryonic lung epithelium (L-132) and baby hamster kidney (BHK-21) cells. In addition, the cytoprotective potential of two antioxidant agents, namely, curcumin (CMN) and N-acetylcysteine (NAC) against KCN (2 and 4 mM) in vitro was evaluated.-In both the cell lines, KCN reduced cell viability as indicated by trypan blue dye exclusion, leakage of cytosolic lactate dehydrogenase and neutral red uptake. Protein content was unaffected in L-132 cells while cellular respiration (determined by MTT assay) was impaired in both the cells. A dose-dependent glutathione mediated LPx was observed in BHK-21 cells alone. The above cytotoxic changes produced by KCN were more effectively minimised by NAC as compared to CMN. Efficacy of CMN and NAC have therapeutic implications as adjuncts to existing cyanide antidotes.