Ginkgo biloba Extract Decreases Scopolamine-Induced Congophilic Amyloid Plaques Accumulation in Male Rat's Brain

Abstract

Background: Scopolamine can induce amyloid β accumulation, oxidative stress, synaptic loss, and learning/memory deficit as seen in Alzheimer’s disease. Ginkgo biloba extract increases neurogenesis and suppresses the happening of pathological processes and cognitive decline. Objectives: Herein, we explored the effect of Ginkgo biloba extract on scopolamine-induced congophilic amyloid plaque accumulation and neurons density in the rats’ brain. Methods: Ginkgo biloba extract (40 and 80 mg/kg/day) was injected daily intraperitoneally for seven days before and after the scopolamine injection (3 mg/kg) in protective and treatment group rats. At the end of the experiments, the rats’ brains were removed and fixed in 4% paraformaldehyde. After histological processing, Congo red staining was used to assess amyloid plaques while cresyl violet staining was employed to determine the neuron density. Results: The administration of scopolamine led to increased congophilic amyloid plaque density in the hippocampus and cingulate cortex of the rats. Pretreatment with Ginkgo biloba extract significantly decreased congophilic amyloid plaque numbers in the hippocampus and cingulate cortex. In addition, scopolamine could reduce the hippocampal and cingulate cortex neuron numbers compared to the control group rats. However, Ginkgo biloba extract increased the hippocampal and cingulate cortex neuron numbers before and after the injection of scopolamine. Conclusions: Our results showed that Ginkgo biloba extract could play protective roles against some scopolamine-induced Alzheimer’s disease-like pathologic dysfunctions, including amyloid β accumulation and neuronal loss, suggesting that treatment with Ginkgo biloba extract might be a promising prophylactic target for Alzheimer’s disease.