Top Qs
Timeline
Chat
Perspective
Huperzine A
Chemical compound From Wikipedia, the free encyclopedia
Remove ads
Huperzine A, a Lycopodium alkaloid, was first isolated in 1983 from Huperzia serrata,[2][3][4] a plant used in Chinese folk medicine. Huperzine A also exists in other Huperzia species, including H. elmeri, H. carinat, and H. aqualupian with varying quantities.[5]
Remove ads
Huperzine A has been investigated as a treatment for neurological conditions such as Alzheimer's disease, but a 2013 meta-analysis of those studies concluded that they were of poor methodological quality and the findings should be interpreted with caution.[6][7] Huperzine A inhibits the breakdown of the neurotransmitter acetylcholine (ACh) by the enzyme acetylcholinesterase. It is also an antagonist of the NMDA receptor. It is commonly available over the counter as a nutritional supplement and marketed as a memory and concentration enhancer.
Remove ads
Adverse effects
Huperzine A may present with mild cholinergic side effects such as nausea, vomiting, and diarrhea.[7] Slight muscle twitching and slurred speech might also occur, as well as hypersalivation and sweating. The use of huperzine A during pregnancy and lactation is not recommended due to the lack of sufficient safety data.[8]
Pharmacology
Huperzine A is a reversible acetylcholinesterase inhibitor[9][10][11][12] and NMDA receptor antagonist[13] that crosses the blood–brain barrier.[14] Acetylcholinesterase is an enzyme that catalyzes the breakdown of the neurotransmitter ACh and 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).[15]
Remove ads
Drug interactions
Huperzine A may have additive effects if taken with drugs causing bradycardia, such as beta-blockers,[16] 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.[17]
Safety
Huperzine A, in spite of the possible cholinergic side effects, seems to have a wide margin of safety. Toxicology studies show huperzine A to be non-toxic even when administered at 50-100 times the human therapeutic dose. The extract is active for 6 hours at a dose of 2 μg/kg with no remarkable side effects.[18]
Synthesis
Two scalable and efficient total syntheses of huperzine A have been reported.[19][20]
History
In 1989, a research study found[21] that the chemical structure of the alkaloid selagine reported in 1960 from a study of Lycopodium slago L.[22] (analyzed using 60-MHz NMR) was identical to that of Huperzine A.
Research
Effects
Huperzine A has been investigated as a possible treatment for diseases characterized by neurodegeneration such as Alzheimer's disease,[23][24] and there is some evidence from small-scale studies that it can benefit cognitive functioning, global clinical status, and ability to engage in activities of daily living (ADLs) among individuals with the disease. In a 2016 systematic review of systematic reviews,[25] huperzine A was associated with a standardized mean difference of 1.48 (95% CI, 0.95-2.02) compared to placebo on measures of ADL among people with dementia, but the evidence was very low-quality and uncertain. In a 2022 umbrella review,[26] huperzine A was associated with broad benefits to dementia patients' cognitive functioning, but the degree of heterogeneity in measurements and outcomes of the reviewed studies indicated publication bias toward huperzine A benefit.
Use in organophosphate poisoning
Huperzine A might be useful in the treatment of organophosphate nerve agent poisoning by preventing damage to the central nervous system caused by such agents.[27][28]
Remove ads
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads