Bacopa monnieri grows in marsh areas of China, Taiwan, Vietnam, Sri Lanka, Nepal and India. It is also known as Brami or water hyssop. In Ayurvedic medicine, Bacopa is known as an adaptogenic, medhya rasayana herb, which contains plants that are used to enhance memory, intellect and longevity, among other functions. 1 However, recognition of Bacopa‘s benefits by the Western world and published research concerning the investigation of its properties have been relatively recent.
Preliminary research involving Bacopa monnieri extract revealed inhibition of cancer cell proliferation and retardation of tumor development in mice that received tumor cells.2 Other research has revealed antibacterial activity and a potential use as a thyroid-stimulating therapy.3-5 In wound healing, Bacopa compounds known as bacosides have been shown to be more effective than the skin ointment nitrofurazone.6 Yet it is in the brain that its best known benefits occur.
Experimental Research with Bacopa
Research in rats reported in the November 2002 issue of Phytotherapy Research revealed an association between orally administered bacosides and protection against some of the effects of stress.7 The authors propose that the compounds enable the brain to be prepared to act under stress or other adverse conditions.
Elsewhere, it was reported that Bacopa monnieri standardized extract could help normalize stress-induced alterations in plasma corticosterone and monoamines in the brain’s cortex and hippocampus.8 In roundworms subjected to heat and oxidative stress, Bacopa monnieri extended average lifespan and upregulated a gene that has been shown to extend the average lifespan of worms undergoing stress.9
Alzheimer’s and Dementia
Findings from a study that investigated the use of bacosides in rats suggest that long term use of the compounds could help delay some of the adverse effects of aging and prevent Alzheimer’s dementia.10 In a mouse model of Alzheimer’s disease, Bacopa monnieri extract given daily resulted in a reduction in cerebral cortex amyloid levels and reversed some behavioral changes.11 In cultured neurons, Bacopa protected the cells from beta amyloid induced death while lowering reactive oxygen species.12
While aluminum and other metal toxicity has been associated with Alzheimer’s disease, but not confirmed as a cause, Bacopa was shown to prevent lipid and protein damage, and the decline in endogenous antioxidant enzyme activity resulting from excess aluminum intake by rats.13 According to the researchers, Bacopa‘s potential to decrease aluminum-induced oxidative stress was similar to that of the drug deprenyl.
Other Effects on the Brain in Experimental Research
In an experiment in which Bacopa monnieri leaf powder was given to prepubertal mice for four weeks, markers of oxidative stress declined in the cells of all brain regions examined and activity of acetylcholinesterase, the enzyme that breaks down the neurotransmitter acetylcholine, also decreased.14 Concomitantly, there was an increase in brain glutathione and the activity of the antioxidant enzymes catalase, glutathione peroxidase and superoxide dismutase, leading the authors to conclude that the plant could be a preventive and therapeutic agent for neurodegenerative disorders that involve oxidative stress.
In rats given a compound that induces epilepsy, Bacopa monnieri demonstrateda neuroprotective role.15 Other research that investigated Bacopa monnieri and one of its bacosides found improved behavioral deficits in epileptic rats.16
Bacopa has also been shown to reduce cerebral injury caused by ischemia similar to that experienced during a stroke. A combination of Bacopa and another Ayurvedic herb, Valeriana wallichii, decreased the size of damaged areas while improving short term memory and motor coordination in mice in which ischemia was induced, followed by reperfusion.17
A rat study that found an increase in cerebral blood flow in association with Bacopa provides one mechanism for its brain benefits.18 An additional potential mechanism is Bacopa’s stimulating effect on the growth of neuronal dendrites that receive nervous impulses.19
Clinical Trials in Humans with Bacopa
Memory and Cognitive Function
A number of trials in humans have validated the positive findings of experimental research involving Bacopa monnieri. A randomized, double-blind trial reported in 2002 found improved retention of new information in association with Bacopa supplementation.20 A later trial of Bacopa revealed improvement in logical memory, mental control and learning after 12 weeks of treatment.21 Another double-blind, placebo-controlled 12 week trial resulted in improvements in delayed recall, learning and memory acquisition in older participants who received Bacopa.22
Ninety days of treatment with a Bacopa monnieri extract or a placebo resulted in improved spatial working memory accuracy in healthy subjects who received the extract.23 Another trial, involving participants aged 65 years and up, found enhanced learning and less anxiety and depression after 12 weeks of treatment with Bacopa monnieri standardized extract in comparison with a placebo.24 And in another 12 week trial of older men and women, Bacopa improved working memory as well as suppressed the activity of acetylcholinesterase.25
A placebo-controlled trial that evaluated the cognition one and two hours after consuming Bacopa extract found benefits at both time points, along with positive effects on mood and lower cortisol levels.26 The results suggest that Bacopa has an earlier effect on the brain than what has been revealed by previous research.
In a randomized trial that included healthy older participants and subjects with Alzheimer’s disease, an orally administered formula that contained Bacopa monnieri and two other herbs improved cognitive function in both groups while reducing inflammation and oxidative stress after 12 months.27
In addition to healthy adults and the elderly, Bacopa monnieri may benefit children with attention deficit hyperactivity disorder (ADHD). A trial that enrolled children with ADHD who were given a standardized Bacopa monnieri extract for six months resulted in reductions in restlessness, lack of self-control, lack of attention, learning problems, impulsivity and psychiatric problems in the majority of participants.28
A meta-analysis of nine trials that assessed the cognitive effects of Bacopa monnieri concluded that the herb improved cognition and shortened reaction time.29
The Bottom Line
“Research into the nootropic effects of Bacopa is in its infancy, with research still yet to investigate the effects of Bacopa across all human cognitive abilities,” note the authors of a review appearing a few years ago in the Journal of Alternative and Complementary Medicine.30 It is to be hoped that this effort matures into a healthy body of research providing more data on this mentally-stimulating subject.