The Screening For Acetylcholinesterase And Monoamine Oxidase Inhibitors From Medicinal Plants

In recent years，with the development of socio-demographic aging，the incidenceof neurodegenerative diseases such as Alzheimer’s disease，Parkinson’s disease，depression and anxiety disorders is gradually increasing which seriously affecting theelderly health. The present study showed that the acetylcholinesterase （AChE）inhibitors are the drugs for treating Alzheimer’s disease and the monoamine oxidase（MAO） inhibitors are effective drugs for treating and improving depression andParkinson’s disease，but most of present drugs usually have serious side effects. Thusscreening AChE and MAO inhibitors from medicinal plants is of great significance fordrug discovery.In this paper，the AChE inhibitory activity of13kinds of Caragana and13kindsof Rhododendron were tested，the MAO inhibitory activity of the alkaloid extracts of90kinds of medicinal plants were determined，the active constituents of Corydalisyanhusuo were separated and identified and the specific work is as follows:1The AChE inhibitory activity of13kinds of Caragana and13kinds ofRhododendron were determined by TLC bioautography and modified Ellman’smethod and the result demonstrated that Caragana korshinskii， Rhododendronthymifolium，Rhododendron capitatum，Rhododendron anthopogonoides have stronginhibitory activity and their inhibitory rates were more than50%at the concentrationof100μg/mL，indicating that the AChE inhibitors may exist in these plants.2The MAO inhibitory activity of90kinds of medicinal plants were determinedand the result showed that Raphanus sativus，Prunus mume，Buddleja officinalis，Corydalis yanhusuo，Pulsatilla chinensis，Coptis deltoidea，Impotiens platyceras，Clematis argentilucida，Geum aleppicum，Ilex pemyi，Medicago sativa，Glycyrrhizauralensis，the pericarp of Areca catechu，Areca catechu，Saxifraga stolonifera，Lamiophlomis rotata，Holarrhena antidysenterica have strong inhibitory activity andtheir IC₅₀less than50μg/mL， indicating that they may contain natural MAOinhibitors.3The active constituents of the total alkaloid of Corydalis yanhusuo werestudied.8alkaloids were isolated and compounds4and8are new AChE inhibitors.Kinetic studies showed that this two compounds are reversible noncompetitiveinhibitor of AChE. Compound7is a new MAO inhibitor and it preferentially inhibited the MAO-B activity than MAO-A with the IC₅₀value is58.94μg/mL.