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- Bacopa (Bacopa monnieri)
- Adaptogens
- Nervines
| | Date:
08-15-2011 | HC#
041157-430
|
Re: Review of Clinical Potential of Bacopa in Treatment of Central Nervous System-related Ailments
Abascal
K, Yarnell E. Bacopa for the brain: a smart addition to Western medicine. Altern Complement Ther. Feb
2011;17(1):21-25.
Bacopa (Bacopa monnieri) is an herb with adaptogenic and
nervine properties. Adaptogenic herbs are used to strengthen the immune
response and increase the ability to cope with physical and mental stress.
Adaptogens increase overall vitality and health and are not typically used to
treat specific ailments. Nervine herbs are used to treat mild-to-moderate
anxiety and depression and used to promote sleep. For approximately 3000 years,
bacopa has been used in traditional Ayurvedic medicine to treat anxiety,
epilepsy, insomnia, poor memory, and asthma. This article reviews the
adaptogenic and nervine properties of bacopa.
Bacopa's
mechanism of action is not well understood. Bacopa contains the alkaloid
brahmine and the glycoside asiaticoside. Its constituents are lipophilic, and
thus have the ability to cross the blood brain barrier. This explains its
ability to affect the brain. Animal studies support the use of bacopa to reduce
anxiety and depression as well as to enhance learning. Bacopa has antispasmodic
effects on intestinal smooth muscle and can prevent (or enhance healing) of
gastric ulcers. Bacopa also functions as an antioxidant.
The
authors summarize 9 clinical studies that evaluate the effect of bacopa on mood
and learning. Most of the studies evaluated 300 mg/day of bacopa extract for 12
weeks. The following study details were described. Study 1: Healthy
subjects (n = 46, aged 18-60 years) were treated with 300 mg/day bacopa for 12
weeks. Significant improvements in learning rate, speed of information
processing, and anxiety reduction were evident at 12 weeks but not at 5 weeks. Study
2: Adults (n = 98, > 55 years old) without signs of dementia were
treated with 300 mg/day BacoMind® extract (derived from 6 g of crude herb;
Natural Remedies; Bangalore, India) for 12 weeks. Bacopa improved memory
acquisition and retention. Study 3: In a randomized, placebo-controlled
study, healthy subjects were treated for 12 weeks with 300 mg/day of KeenMind®
(Flordis; Crows Nest, NSW, Australia), a bacopa extract standardized to contain
at least 55% bacosides A and B, with each capsule equivalent to 3 g of dried
herb. Bacopa treatment improved working memory performance in various computerized
tasks and increased energy. Study 4: Healthy adults (n = 76, aged 40-65
years) treated with 300 mg/day bacopa for 3 months had improved retention of
new information. Follow-up tests suggested that the improvement was caused by a
decrease in the rate of forgetting rather than by an enhancement in the rate of
learning. This finding has not been replicated in other studies. Study 5:
Healthy subjects (n = 48, > 65 years old) without signs of dementia or
memory issues participated in a randomized, placebo-controlled, double-blind
study. They were treated with placebo or 300 mg/day bacopa (a 50:1 extract
standardized to 50% bacosides, and manufactured to be the equivalent of 15 g of
herb and 150 mg of bacosides A and B). Bacopa-treated subjects had improvements
on various measures of cognitive performance, depression, and anxiety. Study
6: Twenty-eight children with IQs between 70 and 90 (considered to be slow
learners) were treated with 225 mg/day BacoMind for 4 months. Bacopa improved
working memory and logical memory. Study 7: A randomized, double-blind,
placebo-controlled study investigated adults (n = 65, aged 50-75 years) who
complained of memory impairment for at least 1 year prior to the study but had
not showed any major cognitive deficits. Subjects were treated with placebo or
450 mg/day BacoMind for 12 weeks. They were also evaluated during a 12-week
withdrawal period. Bacopa improved attention and verbal memory. Study 8:
Adults (n = not reported, > 55 years old) with evidence of age-associated
memory impairment were treated with 250 mg/day bacopa for 3 months. At 12
weeks, they had an improvement in logical memory and paired associate learning
that persisted for 4 weeks after the study concluded. Study 9: Healthy
men (n = 40, age not reported) were randomized to take 500 mg of bacopa or 200
mg of caffeine daily for 16 weeks. In various cognitive tests, bacopa improved
reaction times.
There
are 2 negative studies on bacopa. In both studies, bacopa was administered for
only a brief period of time (duration not reported). One of these studies
examined the effect of a single dose. The authors state that this suggests that
the herb's effects build over time and that instant results should not be
expected.
Overall,
bacopa appears to be both safe and well-tolerated. It has a long history of
use, and the lethal dose in rats is very high. One study using BacoMind
reported a significant number of adverse gastrointestinal effects. The
researchers theorized that the adverse events (AEs) may have been caused by the
cholinergic effect of bacopa and urged caution when using the herb with
cholinergic drugs often used to treat dementia. In contrast, intestinal AEs
were much less frequent and much milder in a trial of BacoMind in which
subjects took an escalating amount of BacoMind (300-450 mg daily) over a 30-day
period. Bacopa may potentiate the sedative effects of phenobarbital and
chlorpromazine. Caution is advised when combining bacopa with these types of
drugs.
The
authors state that it is unrealistic to expect bacopa to cure a disease such as
Alzheimer's disease. However, they believe that bacopa may help people with
anxiety, depression, or problems with mental function. This review lacked
detailed study information, making it difficult for readers to draw their own
conclusions about the efficacy and safety of bacopa.
—Heather S. Oliff,
PhD
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