(−)-Huperzine A (HupA) is an acetylcholinesterase (AChE) inhibitor with an IC50 value of 82 nmol/L  and acts as an antagonist of the N-methyl-d-aspartate (NMDA) receptor .
AChE is the key brain enzyme responsible for the rapid degradation of the neurotransmitter acetylcholine. AChE inhibitors are probably useful in the amelioration of the Alzheimer’s symptomatology .
It was found that NMDA markedly reduced AChE activities . In rat dissociated hippocampal neurons, HupA inhibited the NMDA-induced current. In neurons, 100 µM HupA, NMDA-induced currents were 55.7 ± 4.9% of the control values. The binding molecular ratio of NMDA receptor: HupA is 1:1. The inhibition of NMDA receptor by HupA is not competitive . HupA significantly increased the phosphorylation levels of both glycogen synthase kinase (GSK)-3α protein and GSK-3β protein in APPsw-overexpressing cells . Activated GSK-3 consequently decreased acetylcholine (ACh) level in the striatum .
Treated with doses of (−)-huperzine A, AChE−/− mice showed no toxic symptoms and had normal levels of AChE. This demonstrated the specificity of (−)-huperzine A as an inhibitor of AChE at the dose used in vivo . In rat whole brain, oral administration of HupA at a dose of 1.5 μmol/kg (3.6 mg/kg) obtained a maximum inhibition of AChE at 60 min and this maximum inhibition was maintained for 360 min .
. MA Xiao-Chao, XIN Jian, WANG Hai-Xue, et al. Acute effects of huperzine A and tacrine on rat liver. Acta Pharmacol ogica Sinica, 2003, 24(3):247-250.
. Zhong Ming Qian and Ya Ke. Huperzine A: is it an effective disease-modifying drug for Alzheimer's disease? Frontiers in Aging Neuroscience, 2014, 6:216.
. V. Rajendran, Suo-Bao Rong, Ashima Saxena, et al. Synthesis of a hybrid analog of the acetylcholinesterase inhibitors huperzine A and huperzine B. Tetrahedron Letters, 2001, 42: 5359-5361.
. J. R. Delfs, D. M. Saroff, Y. Nishida, et al. Effects of NMDA and its antagonists on ventral horn cholinergic neurons in organotypic roller tube spinal cord cultures. J. Neural Transm., 1997, 104(1):31-51.
. J. M. Zhang and G. Y. Hu. Huperzine A, a nootropic alkaloid, inhibits N-methyl-D-aspartate-induced current in rat dissociated hippocampal neurons. Neuroscience, 2001, 105(3):663-9.
. L. Zhao, C. B. Chu, J. F. Li, et al. Glycogen synthase kinase-3 reduces acetylcholine level in striatum via disturbing cellular distribution of choline acetyltransferase in cholinergic interneurons in rats. Neuroscience, 2013, 255:203-11.
. Ellen G. Duysen, Bin Li, Sultan Darvesh, et al. Sensitivity of butyrylcholinesterase knockout mice to (−)-huperzine A and donepezil suggests humans with butyrylcholinesterase deficiency may not tolerate these Alzheimer’s disease drugs and indicates butyrylcholinesterase function in neurotransmission. Toxicology, 2007, 233:60-69.
. Rui Wang, Han Yan and Xi-can Tang. Progress in studies of huperzine A, a natural cholinesterase inhibitor from Chinese herbal medicine. Acta Pharmacologica Sinica, 2006, 27:1-26.
|Physical Appearance||A solid|
|Storage||Store at -20°C|
|Solubility||≥12.1mg/mL in DMSO|
|Canonical SMILES||C/C=C1[[email protected]@]2(N)C3=C(NC(C=C3)=O)C[[email protected]]/1([H])C=C(C)C2|
|Shipping Condition||Evaluation sample solution : ship with blue ice.All other available size: ship with RT , or blue ice upon request|
|General tips||For obtaining a higher solubility , please warm the tube at 37 ℃ and shake it in the ultrasonic bath for a while.Stock solution can be stored below -20℃ for several months.|
|Description||(-)-Huperzine A is a potent, highly specific and reversible inhibitor of acetylcholinesterase (AChE) with Ki of 7 nM, exhibiting 200-fold more selectivity for G4 AChE over G1 AChE.|
|Targets||Acetylcholinesterase (G4 form)|
|IC50||7 nM (Ki)|