Relation between Melatonin and Other Markers of Oxidant/Antioxidant Status in Epileptic Children: Effect of Valproate Therapy

Abstract

The aim of the present work was to investigate the relationship between serum melatonin levels and other markers of oxidant/antioxidant balance in epileptic children before and after treatment with the antiepileptic drug valproic acid (VPA). The study was conducted on twenty epileptic children prior to starting therapy, as well as on another twenty age and sex matched epileptic children receiving treatment with the antiepileptic drug VPA, for a minimum duration of one year. Fifteen age and sex matched healthy children were included as a control group. Serum melatonin, zinc, copper, and malondialdehyde (MDA) concentrations and erythrocyte superoxide dismutase (SOD) activity were measured in all subjects. Mean levels of melatonin and MDA were significantly increased while SOD activity was significantly decreased in both untreated and treated epileptics versus control. However, the melatonin and SOD were significantly lower in treated versus untreated epileptics. The serum zinc levels were significantly lower while the serum copper levels were significantly higher in treated versus untreated epileptics. Melatonin was negatively correlated to MDA and copper and positively correlated to SOD. It thus seems possible that oxidant stress is associated with epilepsy and is aggravated with VPA therapy leading to relative reduction in melatonin (in treated versus untreated epileptics) and absolute reduction in erythrocytic SOD and serum zinc concentrations.