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 inall 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.