Detection of acetylcholinesterase-inhibiting natural products from Illicium angustisepalum by bioautographic screening

Alzheimer's disease (AD) is the most common type of dementia and a leading neurodegenerative disorder. According to the cholinergic hypothesis, memory impairment in AD patients results from the dysfunctions in the central neurotransmission of acetylcholine. Inhibitors of acetylcholinesterase (AChE) currently form the basis of pharmacotherapy of AD. In the course of a search for natural AChE inhibitors, Illicium angustisepalum A.C. Smith (Schisandraceae) was found to be active by using a bioautographic assay. Since former studies have identified the Illicium genus to be a potential source of AChE inhibitors, this under-studied member of Illicium was further investigated. In the present study, an essential oil and four extracts (i.e., ethyl acetate, butanol, petroleum ether and water extracts) of I. angustisepalum were tested for AchE-inhibiting activity, and positive results were observed in the essential oil and the ethyl acetate fraction. Isolation work is underway and this poster will report the most recent findings in the attempt to identify active principles based on bioautographic detection.