Anti-Amnesic Effect of Curculigo orchioides Plant Extract and Its Function on Acetylcholinesterase Enzyme

Abstract
Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, and one of the most predominant causes of dementia in older people. Preventing acetylcholine from breakdown by an excess amount of acetylcholinesterase is a proven therapy for AD. Traditionally Curculigo orchioides is known for its antioxidant activity, enzyme inhibition activity, and other medicinal uses. In this study, in vitro acetylcholinesterase, inhibitory activity was investigated, and methanolic extract of the plant showed significant activity. This study aims to investigate cholinesterase inhibitory activity, learning, and memory-enhancing activity of Curculigo orchioides. Materials and Methods: The crude methanol extract of the dried powder was prepared by the cold extraction method. In-vitro acetylcholinesterase (AChE) inhibitory activities were determined by the modified Ellman’s method. To confirm learning and memory-enhancing effects, the scopolamine-induced memory impairment Swiss-albino mice were used, and to find the anti-amnesic effect of the extract, a passive shock avoidance task was applied. Results: Results proved that scopolamine-induced cognitive dysfunction decreased significantly by administration of the plant extract solution in the passive avoidance task, and inhibited brain acetylcholinesterase activity. While running an in-vitro AChE inhibitory test the IC50 was 0.782±0.067μg/ml. Conclusion: The results suggested that methanolic extract of Curculigo orchioides can inhibit AChE in-vitro. Besides this, it provides data that proves its ability to improve whole brain AChE activity and enhance memory.