|Chemical and physical data|
|Molar mass||242.32 g/mol|
|3D model (JSmol)|
|Melting point||217 to 219 °C (423 to 426 °F)|
|‹See TfM› (what is this?)|
Huperzine A is a naturally occurring sesquiterpene alkaloid compound found in the firmoss Huperzia serrata and in varying quantities in other Huperzia species, including H. elmeri, H. carinat, and H. aqualupian. Huperzine A has been investigated as a treatment for neurological conditions such as Alzheimer's disease, but a meta-analysis of those studies concluded that they were of poor methodological quality and the findings should be interpreted with caution. Huperzine A inhibits the breakdown of the neurotransmitter acetylcholine by the enzyme acetylcholinesterase. It is commonly available over the counter as a nutrient supplement, and is marketed as a cognitive enhancer for improving memory and concentration.
Huperzine A is extracted from Huperzia serrata. It is a reversible acetylcholinesterase inhibitor and NMDA receptor antagonist that crosses the blood-brain barrier. Acetylcholinesterase is an enzyme that catalyzes the breakdown of the neurotransmitter acetylcholine and of some other choline esters that function as neurotransmitters. The structure of the complex of huperzine A with acetylcholinesterase has been determined by X-ray crystallography (PDB code: 1VOT; see the 3D structure).
For some years, huperzine A has been investigated as a possible treatment for diseases characterized by neurodegeneration, particularly Alzheimer's disease. A 2013 meta-analysis found that huperzine A may be efficacious in improving cognitive function, global clinical status, and activities of daily living for individuals with Alzheimer’s disease. However, due to the poor size and quality of the clinical trials reviewed, huperzine A should not be recommended as a treatment for Alzheimer’s disease unless further high quality studies confirm its beneficial effects.
Huperzine A is also marketed as a dietary supplement with claims made for its ability to improve memory and mental function.
Huperzine A may present with mild cholinergic side effects such as nausea, vomiting, and diarrhea. The use of huperzine A during pregnancy and lactation is not recommended due to the lack of sufficient safety data.
Huperzine A may have additive effects if taken with drugs causing bradycardia, such as beta-blockers. which may decrease heart rate. Theoretically, there may be possible additive cholinergic effects if huperzine A is taken with other acetylcholinesterase inhibitors or cholinergic agents.
- Li YX, Zhang RQ, Li CR, Jiang XH (2007). "Pharmacokinetics of huperzine A following oral administration to human volunteers". European Journal of Drug Metabolism and Pharmacokinetics. 32 (4): 183–187. doi:10.1007/BF03191002. PMID 18348466.
- Zangara A (2003). "The psychopharmacology of huperzine A: an alkaloid with cognitive enhancing and neuroprotective properties of interest in the treatment of Alzheimer's disease". Pharmacology Biochemistry and Behavior. 75 (3): 675–686. doi:10.1016/S0091-3057(03)00111-4. PMID 12895686.
- Lim WH, Goodger JQ, Field AR, Holtum JA, Woodrow IE (2010). "Huperzine alkaloids from Australasian and southeast Asian Huperzia". Pharmaceutical Biology. 48 (9): 1073–1078. doi:10.3109/13880209.2010.485619. PMID 20731560.
- Yang G, Wang Y, Tian J, Liu J (2013). "Huperzine A for Alzheimer's Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials". PLoS ONE. 8 (9): e74916. doi:10.1371/journal.pone.0074916. PMC 3781107. PMID 24086396.
- Li J, Wu HM, Zhou RL, Liu GJ, Dong BR (16 April 2008). "Huperzine A for Alzheimer's disease". Cochrane Database of Systematic Reviews. CD005592 (2). doi:10.1002/14651858.CD005592.pub2. PMID 18425924.
- Wang, R; Yan, H; Tang, XC (January 2006). "Progress in studies of huperzine A, a natural cholinesterase inhibitor from Chinese herbal medicine". Acta Pharmacologica Sinica. 27 (1): 1–26. doi:10.1111/j.1745-7254.2006.00255.x. Retrieved 6 December 2017.
Huperzine A (HupA), a novel alkaloid isolated from the Chinese herb Huperzia serrata, is a potent, highly specific and reversible inhibitor of acetylcholinesterase (AChE).
- Meletis, Chris D.; Jason E. Barke (2004). Herbs and Nutrients for the Mind: A Guide to Natural Brain Enhancers. Greenwood Publishing Group. p. 191. ISBN 0275983943.
- Wang BS, Wang H, Wei ZH, Song YY, Zhang L, Chen HZ (2009). "Efficacy and safety of natural acetylcholinesterase inhibitor huperzine A in the treatment of Alzheimer's disease: an updated meta-analysis". Journal of Neural Transmission. 116 (4): 457–465. doi:10.1007/s00702-009-0189-x. PMID 19221692.
- Tang X, He X, Bai D (1999). "Huperzine A: A novel acetylcholinesterase inhibitor". Drugs of the Future. 24 (6): 647. doi:10.1358/dof.1999.024.06.545143.
- Coleman BR, Ratcliffe RH, Oguntayo SA, Shi X, Doctor BP, Gordon RK, Nambiar MP (2008). "[+]-Huperzine A treatment protects against N-methyl-d-aspartate-induced seizure/status epilepticus in rats". Chemico-Biological Interactions. 175 (1–3): 387–395. doi:10.1016/j.cbi.2008.05.023. PMID 18588864.
- Patocka J (1998). "Huperzine A - an interesting anticholinesterase compound from the Chinese herbal medicine" (PDF). Acta Medica (Hradec Kralove). 41 (4): 155–7. PMID 9951045.
- Raves ML, Harel M, Pang YP, Silman I, Kozikowski AP, Sussman JL (1997). "Structure of acetylcholinesterase complexed with the nootropic alkaloid, (–)-huperzine A". Nature Structural & Molecular Biology. 4 (1): 57–63. doi:10.1038/nsb0197-57. PMID 8989325.
- Bai DL, Tang XC, He XC (2000). "Huperzine A, A Potential Therapeutic Agent for Treatment of Alzheimer's Disease". Current Medicinal Chemistry. 7 (3): 355–374. doi:10.2174/0929867003375281. PMID 10637369.
- Talbott, SM (2012). Huperzine A (HupA). A Guide to Understanding Dietary Supplements. Routledge. pp. 304–. ISBN 978-1-136-80570-7.
- Pepping J (1 March 2000). "Huperzine A". American Journal of Health-System Pharmacy. 57 (6): 530, 533–534. PMID 10754762.
- "Huperzine A". Natural Standard: The Authority on Integrative Medicine. Natural Standard. Retrieved 29 October 2014.
- Skolnick AA (12 March 1997). "Old Chinese Herbal Medicine Used for Fever Yields Possible New Alzheimer Disease Therapy". JAMA. 277 (10): 776. doi:10.1001/jama.1997.03540340010004. PMID 9052690.
- Tun MK, Wüstmann D, Herzon SB (2011). "A robust and scalable synthesis of the potent neuroprotective agent (−)-huperzine A". Chemical Science. 2 (11): 2251–2253. doi:10.1039/C1SC00455G.
- Tudhope SR, Bellamy JA, Ball A, Rajasekar D, Azadi-Ardakani M, Meera HS, Gnanadeepam JM, Saiganesh R, Gibson F, He L, Behrens CH, Underiner G, Marfurt J, Favre N (2012). "Development of a Large-Scale Synthetic Route to Manufacture (−)-Huperzine A". Organic Process Research & Development. 16 (4): 635–642. doi:10.1021/op200360b.