| Bacopa monniera and Its Potential to Enhance Brain Function: An Overview
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Russo A., Borrelli F. - American Botanical Council
Russo
A, Borrelli F. Bacopa monniera, a reputed nootropic plant: an
overview. Phytomed.
2005;12:305-317.
Nootropic
herbs and drugs are used to enhance memory, cognition, mood, and
other factors associated with mental functioning. Examples of herbs
with nootropic activity include ginkgo (Ginkgo biloba) and gotu kola
(Centella asiatica). Bacopa (Bacopa monniera) is an herb used in
Ayurvedic medicine to treat anxiety, mental illness, memory
disorders, and epilepsy and has demonstrated nootropic activity in
preliminary studies.
Bacopa is found in wetlands throughout
the Indian subcontinent and is a commonly naturalized in other parts
of the world including the United States. It is known locally in
India as Brahmi, due to the plant's association with the Hindu god
Brahma. Bacopa has been used for almost 3,000 years in Ayurvedic
medicine. The plant is mentioned in several Ayurvedic texts including
the Caraka Samhita and the Bravpra-kash Var-Prakarana as a treatment
for a range of mental conditions. Bacopa is a member of the
Scrophulariaceae family and is characterized by purple flowers that
appear in summer and fleshy oblong leaves. The plant is a creeping
herb that grows in wet and sandy areas near streams.
Alkaloids
isolated from Bacopa include brahmine, nicotine, and herpestine.
Bacoside A, which co-occurs with Bacoside B, has been suggested to be
the main constituent responsible for Bacopa's cognitive effects.
Other constituents isolated from Bacopa include dammarane-type
triterpenoid saponins, a dammarane-type psuedojujubogenin glycoside,
pseudojujubogenin glycosides, and phenylethnoid glycosides.
Bacopa
demonstrates antidementic, antioxidant, and cognitive-enhancing
effects in several in vivo and in vitro studies. One in vivo study
demonstrates that Bacopa enhances learning ability in rats, this
activity was attributed to the Bacopa saponins bacosides A and B.
Bacopa extracts administered to mice demonstrate antidementic
activity when tested against scopolamine. In addition, bacopa
demonstrates anxiolytic activity in rats, antidepressant activity
comparable to imipramine in rodent models of depression, and
anticonvulsive activity in mice and rats.
In vivo and in vitro
studies demonstrate that Bacopa has antioxidant activity that has
been attributed to the bacoside fraction. In addition, Bacopa
demonstrates hepatoprotective antioxidant activity when tested
against morphine, "…establishing its protective role in
morphine toxicity in rat liver."
In other in vitro and
in vivo studies, Bacopa has shown anti-inflammatory activity,
antiulcer activity, anti-Heliobacter pylori activity, adaptogenic
activity, anticancer activity, relaxant properties on blood vessels,
bronchodilatory properties, and spasmolytic activity.
Initial
clinical trials demonstrate that Bacopa has positive effects on
learning and memory. Two separate single-blind open clinical trials
demonstrate that long-term administration of Bacopa may enhance
memory and learning in patients with anxiety neurosis and in
children. In a double-blind, placebo controlled study, long-term
administration of Bacopa extracts (300 mg) improved "early
information processing, verbal learning, and memory consolidation in
humans." A larger clinical trial of 65 adults demonstrates that
Bacopa has a positive effect on "retention of new information"
but that "…rate of learning was unaffected." These
studies demonstrate that Bacopa may have a positive effect on
learning and cognition, especially when administered chronically.
However, a study on acute administration of Bacopa (300 mg) did not
show an effect on cognitive function, even when combined with
ginkgo.
In vivo studies and clinical trials showed no obvious
toxicity at doses commonly administered. An in vivo study in rats
reported no toxicity of Bacopa extracts. A phase 1 double-blind
placebo-controlled single-dose tolerance study with 31 healthy
subjects showed no apparent toxicity when bacosides A and B were
administered in doses ranging from 20 to 300 mg. Bacopa was
well-tolerated in two other studies involving human subjects,
including a multi-dose study.
Bacopa exhibits
"neuroprotective and cognitive enhancing effects" in both
in vitro and in vivo studies and in clinical trials. Clinical trials
indicate that Bacopa's positive effects on early information
processing and verbal learning are evident when Bacopa is
administered chronically; no acute effects have been demonstrated.
Bacopa's 3,000 year history of use, as well as in vivo studies and
clinical studies, demonstrate that the herb is
well-tolerated.
Larger clinical trials are needed to confirm
Bacopa's nootropic activity. In addition, herb-drug and herb-herb
interactions of Bacopa need to be studied. Bacopa's potential as an
anti-epileptic treatment and as a treatment to correct side effects
of anti-epileptic drugs is another area to be studied in the
future.
-Marissa Oppel, MS
American
Botanical Council, 6200 Manor
Rd, Austin, TX 78723 Phone: (512) 926-4900 Fax: (512) 926-2345 Email: abc@herbalgram.org
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