Evaluation of the Neuroprotective Effects of Eugenol on Formaldehyde Induced Neurotoxicity in Wistar Rats

Abstract

Over the years, Formaldehyde (FA) has been linked to increased generation of reactive oxygen species (ROS), leading to oxidative stress and cognitive decline. However limited numbers of studies have shown the effect of eugenol on FA induced toxicity in Wistar rats. Therefore this study aimed at investigating the effects of eugenol on the FA induced toxicity in Wistar rats. A total of twenty male Wistar rats where divided into four groups: (Group I. 150 mg/kg eugenol; Group II, 5 mg/kg FA; Group III, 150 mg/kg eugenol + 5 mg/kg FA; Group IV/control, 2ml/kg distilled water) for thirty days. FA and eugenol were administered orally. Rats were humanely sacrificed under 0.8 mg/kg ketamine anaesthesia administered intraperitoneally. Cognitive tests using Morris water maze and Novel object recognition test were carried out, Oxidative stress parameters, acetylcholine activity and histometric analysis of hippocampal Cornu Ammonis (CA 1 and 3) pyramidal neuronal cells. Administration of FA resulted in significant (p<0.05) increased activity of malondialdehyde (MDA), intra-mitochondrial accumulation of 8-hydroxydeoxyguanosine (8-OHdG), reduced activity level of superoxide dismutase (SOD) and acetylcholine levels. However co-administration of eugenol and FA resulted in significant (p<0.05) enhancement of cognitive ability and also significantly (p<0.05) reduced MDA and 8-OHdG levels, and increased SOD and acetylcholine levels. Our results indicate that eugenol would provide therapeutic value against FA induced oxidative stress and cognitive impairments.