Neuroscience Research Compound · For laboratory research use only
Also known as Hup A, Selagine
Huperzine A is an alkaloid originally isolated from Qiang Ceng Ta, a traditional Chinese preparation made from the whole plant of the club moss Huperzia serrata6. It is a reversible inhibitor of acetylcholinesterase (AChE), and it has attracted research attention since its anticholinesterase activity was described by Chinese scientists6.
Preclinical research covers the structural biology of its binding to AChE, cholinesterase selectivity, rodent memory models, neuronal and glial cell culture and rodent models of Alzheimer's disease1,2,3,4,5.
As described in the research literature
As described in the research literature, the crystal structure of AChE in complex with optically pure (-)-huperzine A, solved at 2.5 angstrom resolution, showed an unexpected orientation of the inhibitor in the active-site gorge with few strong direct interactions with protein residues. Comparison with structural analogues pointed to the importance of hydrophobic interactions with aromatic residues in the gorge1.
In a colourimetric comparison with E2020 (donepezil) and tacrine, huperzine A showed the highest ratio of butyrylcholinesterase to acetylcholinesterase inhibition, indicating selectivity for AChE2. Effects beyond cholinesterase inhibition have also been studied: in rat cortical astrocytes, huperzine A increased mRNA for nerve growth factor (NGF) and the p75 NGF receptor and raised NGF protein, and in PC12 cells it increased the number of neurite-bearing cells4.
What published studies have examined
X-ray crystallography of the AChE complex with (-)-huperzine A was compared with the native enzyme structure at the same resolution, and with the affinities of structural analogues1. Inhibition of AChE and butyrylcholinesterase was compared with E2020 and tacrine in vitro2.
Spatial working memory in a radial maze was examined in rats with scopolamine-induced impairment, comparing huperzine A with E2020 and tacrine2.
Sources [2]
PC12 cells subjected to oxygen-glucose deprivation were used to measure survival, lipid peroxide, superoxide dismutase activity and lactate after pretreatment with huperzine A or donepezil3. Cultured rat cortical astrocytes and PC12 cells were used to examine NGF expression, neurite outgrowth and AChE expression4.
A 2022 systematic review included 16 preclinical studies in rodent Alzheimer's disease models, assessed risk of bias with SYRCLE's tool, and meta-analysed Morris water maze, amyloid-beta, choline acetyltransferase and AChE outcomes. The authors noted uneven methodological quality across the studies5.
Sources [5]
Structure of acetylcholinesterase complexed with the nootropic alkaloid, (-)-huperzine A.
Raves ML, Harel M, Pang YP, et al. Nature Structural Biology, 1997.
Huperzine A, a novel promising acetylcholinesterase inhibitor.
Cheng DH, Ren H, Tang XC Neuroreport, 1996.
Huperzine A and donepezil protect rat pheochromocytoma cells against oxygen-glucose deprivation.
Zhou J, Fu Y, Tang XC Neuroscience Letters, 2001.
Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12 cells.
Tang LL, Wang R, Tang XC Acta Pharmacologica Sinica, 2005.
Disease-Modifying Activity of Huperzine A on Alzheimer's Disease: Evidence from Preclinical Studies on Rodent Models.
Yan YP, Chen JY, Lu JH International Journal of Molecular Sciences, 2022.
Huperzine A from Huperzia species--an ethnopharmacolgical review.
Ma X, Tan C, Zhu D, et al. Journal of Ethnopharmacology, 2007.
This page is provided for research and educational reference only. It does not constitute medical advice, dosing guidance, or a recommendation for use. All compounds are strictly for laboratory and in-vitro research purposes.