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Huperzine
A: Brain Booster
Research in
China Shows Benefits in Adolescents As Well As Alzheimer's Patients
by Will Block
to
order
Take acetylcholinesterase
- please. It's one of the more unloved substances in the human body, because it
acts as a kind of molecular butcher, cleaving other molecules in half with grim
efficiency. But at least it's highly selective, always seeking and destroying
only the acetylcholine molecule, which it splits into acetate and choline. Such
specificity is characteristic of all enzymes - proteins that are designed to
carry out just one task, through their catalytic activity.
Acetylcholine, as most readers probably know, is
a versatile neurotransmitter, a messenger molecule that acts throughout the
central and peripheral nervous systems to mediate a host of vital functions,
including many related to cognition and memory. It is a molecule devoutly to be
desired in ample quantities, not only so we can keep all our marbles, but so
they can stay bright and shiny for the endlessly varied game of life.
WHEN
GOOD MOLECULES GO BAD, AND VICE VERSA
Why then, did Mother Nature unleash an enzymatic assassin to keep cutting the
poor acetylcholine molecules in half? Because - and this is as true of
biomolecules as anything else - too much of a good thing is a bad thing (think
glucose and diabetes, e.g.). There must always be checks and balances and
feedback mechanisms to ensure that there is just enough of what we need,
neither too little nor too much. And so there are "good" molecules
that we need for optimal health, and "bad" molecules (which aren't
really bad, because they serve a necessary purpose) that keep the good ones from
creating havoc through overabundance.
Furthermore, in a chemical analogue to military
electronic countermeasures technology, there is a second tier of
"good" molecules that serve to jam the actions of the bad ones, when
necessary, by inhibiting their ability to perform their assigned functions. One
such is huperzine A, an acetylcholinesterase inhibitor - bad for
acetylcholinesterase and therefore good for acetylcholine. And, like Chinese
boxes, there are yet other molecules that inhibit the inhibitors.
In this cats-and-mice game, there is, as always
in living organisms, a delicate balance to be maintained. And, as always, the
balance can get skewed as we age, for some reasons that we understand and many
more that we don't. In any case, if acetylcholinesterase gains the upper hand
and unduly depletes our stores of acetylcholine, really bad things can happen,
such as Alzheimer's disease - not that there is a clear cause and effect there
(few things, including Alzheimer's, are that simple), but there is a strong
correlation that can't be ignored.
GOOD
MOLECULE, HUPERZINE!
Huperzine A (HupA for short), an alkaloid found in the Chinese herb Huperzia
serrata, is effective in improving cognitive and memory abilities in humans,
including those with Alzheimer's disease. In China,
where HupA is used for treating Alzheimer's and myasthenia gravis, medical
scientists have studied its effects on the mental functions of elderly
Alzheimer's patients.1
In a rigorously designed and controlled
experiment, 60 patients aged 52 to 80 with impaired faculties were treated with
synthetic HupA (200 micrograms twice daily) or placebo for 60 days. They were
evaluated with a huge array of both psychological and physiological tests to
determine their mental and physical health before and after the treatment - and,
in particular, to determine whether it made any difference if the HupA was
administered in the form of capsules or tablets.
Based on four of the most important psychological
tests, including memory function, the improvement rates in both groups ranged
from 43% to 70%; there was no statistically significant difference between the
capsule group and the tablet group.
The researchers also set out to observe the
action of HupA on the damaging effects of oxygen free radicals in the patients'
plasma and erythrocytes (red blood cells). Biochemical tests showed significant
improvement, although not to the reference values for healthy people in the same
age group. The authors speculate that long-term treatment with HupA might be
required to optimize the results.
The study also reconfirmed the previously
demonstrated safety as well as efficacy of HupA.2,3
The only side effects noted were mild to moderate nausea and insomnia, again
with no difference between the capsule and tablet groups.
YOUNGSTERS
ALSO BENEFIT FROM HUPERZINE
When a nutrient that improves mental function in the aged does the same in the
young, that's really interesting. And that is what Chinese researchers found, in
a study designed to determine the efficacy of HupA on memory and learning in
adolescents.4
They selected 34 matched pairs of apparently normal junior middle school
students whose only significant complaints were of poor memory and difficulty in
learning.
The pairing was done in terms of age, sex, memory
quotient, and overall psychological health, to ensure that comparisons would be
meaningful. Using these criteria, the researchers found no statistically
significant baseline differences between the students in the two groups, one of
which was to be treated with HupA, the other to receive a placebo.
In a double-blind trial, one member of each pair,
chosen randomly, was given 100 micrograms of synthetic HupA twice daily for four
weeks, while the other member received the placebo. The students' memory
quotients were measured before and after the trial, and their academic
performance in their Chinese, English, and mathematics lessons was monitored as
well.
The results: At the end of the study, the HupA
group scored significantly better than the control group on standard memory
tests described as "accumulation," "recognition,"
"reproduction," "association," "tactual [tactile]
memory," and "number of recitation," but not on tests of
"picture memory" or "understanding." They had also done
significantly better in their Chinese and English lessons, but not in math. No
side effects of any kind were noted.
HUPERZINE
IS PREFERABLE TO PRESCRIPTION DRUGS
Huperzine A is superior to the drugs tacrine and donepezil, which are
acetylcholinesterase inhibitors widely prescribed for Alzheimer's disease. There
is no question that these drugs are effective, but it is our view that chemical
compounds derived from natural sources are preferable to those invented by
chemists, because the natural ones are typically safer and freer from unwanted
side effects.
References
- Xu SS, Cai ZY, Qu ZW, Yang RM, Cai YL, Wang GQ,
Su XQ, Zhong XS, Cheng RY, Xu WA, Li JX, Feng B. Huperzine-A in capsules and
tablets for treating patients with Alzheimer's disease. Acta Pharmacol
Sin 1999 Jun;20(6):486-90.
- Xu SS, Guo ZX, Wang Z, Du ZM, Xu WA, Yang JS,
et al. Efficacy of tablet huperzine-A on memory, cognition, and behavior in
Alzheimer's disease. Acta Pharmacol Sin 1995;16:391-5.
- Xu SS, Xie HB, Du ZM, Tong ZH, Shi QC, Lu KM,
et al. Efficacy of tablet huperzine-A on memory and cognition in patients
with benign senescent forgetfulness. Chin J Clin Pharmacol Ther
1997;2:1-4.
- Sun QQ, Xu SS, Pan JL, Guo HM, Cao WQ.
Huperzine-A capsules enhance memory and learning performance in 34 pairs of
matched adolescent students. Acta Pharmacol Sin 1999 Jul;20(7):601-3.
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