Preventive effect of melatonin against cyanide-induced seizures and lipid peroxidation in mice.

Subcutaneous injection of potassium cyanide (6, 8, and 9 mg/kg) caused a severe tonic seizure in a dose-dependent manner. However, the incidence of seizures induced by potassium cyanide was significantly inhibited by preadministration of melatonin (20 mg/kg, s.c.) Lipid peroxidation in homogenates from whole brain of mice was significantly increased (39%, 106% and 132%, respectively) by the exposure to potassium cyanide (0.01, 0.05, and 0.1 mM). The potassium cyanide (0.1 mM)-induced lipid peroxidation was prevented by melatonin (0.1, 0.5, 1.0, or 2 mM) in a concentration-dependent manner. These results suggest that free radicals formation and subsequent lipid peroxidation may contribute in part to the development of seizures induced by cyanide in mice.