Objectives: In this study, neurotoxicity of formaldehyde on hippocampus and protective effects of melatonin hormone against these toxic effects were investigated.

Materials and Methods: Twenty one adult male Wistar-Albino rats were divided into three equal groups. Rats in group I were used as control. Rats in group II were injected with formaldehyde every other day. Rats in group III were received melatonin daily with administration of formaldehyde. At the end of two-week experimental period, all rats were killed by decapitation. Then the brain tissues of rats were removed. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) enzyme activities and malondialdehyde (MDA) levels were determined in the hippocampus specimens by using spectrophotometric methods.

Results: The hippocampal tissue activities of SOD and GSH-Px were significantly decreased in formaldehyde-exposed rats compared to controls, while MDA contents were significantly increased. It was observed an increase in activities of SOD and GSH-Px enzymes and a decrease of MDA levels in animals treated with formaldehyde plus melatonin.

Conclusion: In this experimental study, it was determined that exposure of formaldehyde caused oxidative damage in hippocampus and this damage was suppressed by administration of melatonin. ©2007, Fırat University, Medical Faculty