title: Extracts from Traditional Chinese Medicinal Plants Inhibit Acetylcholinesterase, a Known Alzheimer's Disease Target.
abstract: Inhibition of acetylcholinesterase (AChE) is a common treatment for early stages of the most general form of dementia, Alzheimer's Disease (AD). In this study, methanol, dichloromethane and aqueous crude extracts from 80 Traditional Chinese Medical (TCM) plants were tested for their in vitro anti-acetylcholinesterase activity based on Ellman's colorimetric assay. All three extracts of Berberis bealei (formerly Mahonia bealei), Coptis chinensis and Phellodendron chinense, which contain numerous isoquinoline alkaloids, substantially inhibited AChE. The methanol and aqueous extracts of Coptis chinensis showed IC50 values of 0.031 µg/mL and 2.5 µg/mL, therefore having an up to 100-fold stronger AChE inhibitory activity than the already known AChE inhibitor galantamine (IC50 = 4.33 µg/mL). Combinations of individual alkaloids berberine, coptisine and palmatine resulted in a synergistic enhancement of ACh inhibition. Therefore, the mode of AChE inhibition of crude extracts of Coptis chinensis, Berberis bealei and Phellodendron chinense is probably due to of this synergism of isoquinoline alkaloids. All extracts were also tested for their cytotoxicity in COS7 cells and none of the most active extracts was cytotoxic at the concentrations which inhibit AChE. Based on these results it can be stated that some TCM plants inhibit AChE via synergistic interaction of their secondary metabolites. The possibility to isolate pure lead compounds from the crude extracts or to administer these as nutraceuticals or as cheap alternative to drugs in third world countries make TCM plants a versatile source of natural inhibitors of AChE.
authors: Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Ruprecht Karls University Heidelberg, Heidelberg 69120, Germany. d.kaufmann@uni-heidelberg.de.
authors: Dorothea
authors: D
authors: Kaufmann
authors: Centre for Pharmacognosy and Phytotherapy, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK. anudeep.k.dogra@gmail.com.
authors: Anudeep
authors: A
authors: Kaur Dogra
authors: Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Ruprecht Karls University Heidelberg, Heidelberg 69120, Germany. mad.rani@gmail.com.
authors: Ahmad
authors: A
authors: Tahrani
authors: Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Ruprecht Karls University Heidelberg, Heidelberg 69120, Germany. Florian.Herrmann@t-online.de.
authors: Florian
authors: F
authors: Herrmann
authors: Institute of Pharmacy and Molecular Biotechnology, Department of Biology, Ruprecht Karls University Heidelberg, Heidelberg 69120, Germany. wink@uni-hd.de.
authors: Michael
authors: M
authors: Wink
mesh_terms: D000110:Acetylcholinesterase; D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000201:enzymology; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D058851:GPI-Linked Proteins / Q000037:antagonists & inhibitors; D006801:Humans; D008516:Medicine, Chinese Traditional
chemical_list: D000470:Alkaloids; D002800:Cholinesterase Inhibitors; D004365:Drugs, Chinese Herbal; D058851:GPI-Linked Proteins; C548244:ACHE protein, human; D000110:Acetylcholinesterase
keywords: Alzheimer’s; Coptis; Traditional Chinese Medicine; acetylcholinesterase; acetylcholinesterase inhibitor; berberine; coptisine; isoquinoline alkaloids; natural products; palmatine