Objective: This study aimed to investigate the antioxidant effect and spatial memory enhancement of the garlic synthetic complex (GSC) on scopolamine-induced neurotoxicity in male Wistar rats.
Method: Fifty-six adult rats (180±20 kg) were randomly assigned to seven groups (n=8). Groups 1 and 3 were orally treated with distilled water and GSC, respectively. Groups 2, 4–7 received 1 mg/kg intraperitoneal scopolamine for one week. On the eighth day, groups 5–7 were administered GSC at doses of 100 mg, 200 mg, and 300 mg/kg, respectively, for three weeks. Group 4 received 5 mg/kg donepezil for three weeks. Y-maze and Open-field tests were used to evaluate the effects on cognitive and motor functions. At the end of the treatment, the rats were sacrificed, and their brains were harvested for further studies, employing standard biochemical and histological techniques.
Results: Scopolamine-induced motor function impairment and anxiolytic behaviors were observed, characterized by a reduced time of movement, horizontal and vertical activities, the number of rearings, time spent in the center square, and an increase in resting time. Additionally, it induced cognitive impairment by decreasing the percentage of spontaneous and correct alternations, the number of entries, and spatial working memory in the Y-maze test. Scopolamine also induced oxidative stress by significantly elevating Malondialdehyde (MDA) levels but did not affect Superoxide Dismutase (SOD) levels. Histologically, the cerebral cortex presented with dilated vasculature, neuronal loss, and vacuolated cytoplasm with scopolamine treatments. Meanwhile, GSC, comparable to Donepezil, improved these changes in a dose-dependent manner.
Conclusion: GSC demonstrated its ameliorative effect on scopolamine-induced neurodegeneration by decreasing lipid peroxidation, improving spatial working memory, and regenerating cortical neurons in the cerebral cortex of rats.