Hippocampal Oxidative Damage Due To Formaldehyde Neurotoxicity and Protective Effect of Melatonin Hormone: An Experimental Study

Abstract

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

Keywords

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Formaldehit Nörotoksisitesine Bağlı Hipokampusta Gelişen Oksidatif Hasar ve Melatonin Hormonunun Koruyucu Etkisi: Deneysel Bir Çalışma

Öz

Giriş: Bu çalışma, formaldehitin hipokampus üzerindeki nörotoksisitesinin ve bu toksisiteye karşı melatonin hormonunun koruyucu etkilerinin araştırılması amacıyla yapıldı. Gereç ve Yöntem: 21 adet Wistar-Albino cinsi erkek sıçan üç eşit gruba ayrıldı. Grup I'deki sıçanlar kontrol olarak kullanıldı. Grup II'deki hayvanlara gün aşırı olarak formaldehit enjeksiyonu yapıldı. Grup III'deki sıçanlara ise, formaldehit uygulaması ile birlikte günlük olarak melatonin enjekte edildi. İki haftalık deney süresi sonunda bütün sıçanlar dekapitasyon yöntemi ile öldürüldü. Daha sonra sıçanların beyin dokuları çıkartılarak, hipokampus doku örneklerinde süperoksit dismutaz (SOD), glutatyon peroksidaz (GSH-Px) enzim aktiviteleri ve malondialdehit (MDA) seviyeleri spektrofotometrik olarak belirlendi. Bulgular: Formaldehit enjeksiyonu yapılan sıçanlara ait hipokampus doku örneklerindeki SOD ve GSH-Px aktivitelerinin kontrol grubuna göre istatistiksel olarak anlamlı bir şekilde azaldığı, MDA düzeylerinin ise arttığı tespit edildi. Formaldehit enjeksiyonu ile birlikte melatonin uygulanan hayvanlarda, SOD ve GSH-Px enzim aktivitelerinde bir artışın meydana geldiği, MDA değerlerinde ise anlamlı bir düşüşün olduğu gözlendi. Sonuç: Deneysel olarak yapılan bu çalışmada, formaldehitin hipokampus dokusunda oksidatif hasara neden olduğu ve bu hasarın melatonin uygulaması ile baskılandığı tespit edildi. ©2007, Fırat Üniversitesi, Tıp Fakültesi

Anahtar Kelimeler

• Formaldehit, Melatonin, Hipokampus, Nörotoksisite, Oksidatif Hasar

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32. Kabul Tarihi: 17.05.2007