Scopolamine-induced brain injury and lipid peroxidation in Wistar rats ameliorated by garlic oil supplementation

Abstract

Background: Scopolamine induced toxicity has been linked to impaired learning and memory, lipid peroxidation, oxidative stress and impairment of cholinergic transmission resulting in brain injury; which are synonymous with features of neurodegenerative diseases such as Alzheimer’s disease. Garlic oil has been found to be a possible therapeutic intervention. Its antioxidant and  anticholinesterase activity were evaluated in scopolamine-induced brain toxicity in Wistar rats.
Methods: The animals were grouped into seven groups (n=5). Group I (Normal Control) was given 1mL/kg distilled water for 14days P.O, Group II was treated with 90 mg/kg garlic oil for 14days P.O while Group III was treated with 2 mg/kg scopolamine IP daily for 14 days. Group IV was co-administered garlic oil (90mg/kg) orally and scopolamine 2mg/kg IP daily for 14 days. Group V had garlic oil orally at 90mg/kg for 7 days after 14 days of scopolamine. Group VI had donepezil at 3mg/kg orally co-administered with scopolamine at 2mg/kg IP daily for 14 days, Group VII 3mg/kg donepezil was administered orally for 7 days after 14 days of scopolamine. Elevated plus maze (EPM), was used to assess memory and learning. Thereafter, the rats were anesthetized using diethyl ether and the frontal cortices of the brain were harvested, homogenized and centrifuged. The supernatant was used to assay for dopamine, and malondialdehyde (MDA). The frontal cortices of the animals’ brains were subjected to histomorphological analyses.
Results: Scopolamine significantly decreased (p<0.05) learning and memory while increasing MDA levels. Brain dopamine levels, and transfer latency in EPM were significantly reduced (p< 0.05) and neurodegenerative changes were seen in the brain. All these were significantly reversed in the garlic-oil treated groups.
Conclusions: According to this study, garlic oil has antioxidant and anticholinesterase activities and may have therapeutic benefits against scopolamine-induced toxicity and diseases related to loss of memory.