Description |
Galanthamine is a potent acetylcholinesterase (AChE) inhibitor with an IC50 of 500 nM.
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Related Catalog |
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Target |
IC50: 0.5 μM (AChE)[1]
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In Vitro |
Galanthamine inhibits AChE and BChE with IC50 of 0.5 and 8.5 μM[1]. Galanthamine acts as a positive allosteric modulator (PAM) of human α4β2 AChRs expressed in permanently transfected HEK 293 cells. Galanthamine increases the response of (α4β2)2α5 AChRs to 1 μM ACh by up to 220% with very low concerntration(EC50=0.25 nM). Only small potentiation (20%) of either α4β2 or (α4β2)2β3 AChRs is detected using FLEXstation assays. Galanthamine at concentrations of 1 μM and above inhibits all three AChR subtypes[2].
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In Vivo |
Acute administration of Galantamine (0.3-3 mg/kg, i.p.) increases IGF2 mRNA levels in the hippocampus, but not in the prefrontal cortex, in time- and dose-dependent manner. Galantamine (3 mg/kg, i.p.) causes a transient increase in fibroblast growth factor 2 mRNA levels and a decrease in brain-derived neurotrophic factor mRNA levels in the hippocampus, while it does not affect the mRNA levels of other neurotrophic/growth factors. The Galantamine-induced increase in the hippocampal IGF2 mRNA levels is blocked by Mecamylamine, a nonselective nicotinic acetylcholine (ACh) receptor (nAChR) antagonist, and Methyllycaconitine, a selective α7 nAChR antagonist, but not by Telenzepine, a preferential M1muscarinic ACh receptor antagonist. Moreover, the selective α7 nAChR agonist PHA-543613 increasea the IGF2 mRNA levels, while Donepezil, an acetylcholinesterase inhibitor, does not. Galantamine also increases hippocampal IGF2 protein, which is blocked by Methyllycaconitine[2].
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Animal Admin |
Mice[2] Eight-week-old male ddY mice are housed in cages (24 cm×17 cm×12 cm) in each group of five to six animals under controlled environmental conditions (22±1°C; 12:12-h light-dark cycle, lights on at 0800 hours, food and water ad libitum) for 1 week before use in the experiments. 453 mice are used in total and in single use for each purpose. The following drugs are used: mecamylamine, methyllycaconitine, oxotremorine, and telenzepine, and Galantamine, Donepezil, and PHA-543613. All drugs are dissolved in saline (0.9 % solution of NaCl). Drugs are administered in a volume of 10 mL/kg intraperitoneally (i.p.) (Galantamine, Donepezil, Mecamylamine, Methyllycaconitine, Oxotremorine) or subcutaneously (s.c.) (PHA-543613, Telenzepine).
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References |
[1]. Melanie-Jayne R. Howes, et al. Acetylcholinesterase inhibitors of natural origin. International Journal of Research in Pharmaceutical and Biomedical Sciences 3(SI 1):67-86. [2]. Kuryatov A, et al. Roles of accessory subunits in alpha4beta2(*) nicotinic receptors. Mol Pharmacol. 2008 Jul;74(1):132-43. [3]. Kita Y, et al. Galantamine increases hippocampal insulin-like growth factor 2 expression via α7 nicotinic acetylcholine receptors in mice. Psychopharmacology (Berl). 2013 Feb;225(3):543-51.
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