Study of Bocopa Monnieri from Journal of Alternative and Complementary Medicine & The National Insitute of Health "Effercts of a Standardized Bocopa Monnieri Extract on Cognitive Performance, Anxiety, and Depression in the Elderly: A Rondomized, Double- Blind, Placebo- Controlled Trial"
Bacopa monnieri (L.) Pennel has been used for centuries in Ayurvedic medicine, either alone or in combination with other herbs, as a memory and learning enhancer, sedative, and anti-epileptic.1 It grows in wet tropical environments, and, under its common English name of water hyssop, is a popular aquarium plant. It has drawn the interest of phytotherapists and pharmacologists,2–4 and an Australian survey showed it to be one of the most popular aid for memory.
Animal studies of B. monnieri whole plant or alcohol extracts have reported cognition-enhancing effects including improved motor learning6 and acquisition, consolidation, and retention of memory in rats.7Memory-enhancing effects have been attributed to saponins (bacosides, bacopasides, or bacopasaponins). Bacopasaponin constituents have been shown to facilitate mental retention in avoidance response in rats,8and to reverse amnesic effects of neurotoxin, scopolamine, phenytoin, electroshock, and immobilization stress.9–11 Hypothesized mechanisms of action include cholinergic upregulation,3 γ-aminobutyric acid–ergic modulation,12 antioxidant effects,13,14 protein synthesis in the brain,7 5-HT agonism,15 and modulation of brain stress hormones.16 Bacopa extracts have also ameliorated neurotoxic effects of nicotine17 and aluminum18 and reduced β-amyloid levels in the brain of a doubly transgenic mouse model of rapid amyloid deposition (PSAPP mice), suggesting mechanisms of action relevant to Alzheimer's disease
Bacopa alcohol extract has shown memory-enhancing effects in three double-blind, randomized, placebo-controlled studies. A trial in 46 healthy volunteers 18–60 years old by Stough et al. evaluated their performance on a battery of cognitive tests after 5 weeks and after 12 weeks of 300 mg of B. monnieri extract daily.21 The investigators reported significant improvements in measures of the Rey Auditory Verbal Learning Test (AVLT)22 and in State Anxiety. Another 3-month study in 76 healthy adults, 40–65 years old, showed an effect of Bacopa on the retention of new information in delayed recall of word pairs.23 A third trial in those over 55 with age-associated memory impairment, again with 3 months of treatment, showed more improvements at 12 weeks on subsets of the Wechsler Memory Scale with no loss of the cognitive gains 4 weeks after ending active treatment.24 Conversely, in a single dose study of Bacopa extract in which neuropsychological testing was performed 2 hours after administration, no differences were found between groups.25 A study by the same investigators with 4 weeks' treatment by a combination of Gingko biloba(maidenhair tree) 120 mg and Bacopa 300 mg in 85 healthy participants also did not show cognitive enhancement.26 Stough's study showed effects at 12 weeks but not at 5 weeks, suggesting that cognitive effects with Bacopa may take months to appear. Two uncontrolled trials have reported memory- and learning-enhancing effects of Bacopa with long-term dosing in children27 and in patients with anxiety neurosis.28
Using a rigorous design, the results demonstrate that Bacopa has positive benefits on multiple measures of cognitive performance and affect. Bacopa recipients improved in delayed recall memory and Stroop task reaction times over the course of the study while placebo recipients remained stable on both. Bacoparecipients displayed a decrease in depression and combined state plus trait anxiety scores with the placebo recipients increasing on both. Participants also had slightly lower heart rates after taking Bacopa while those taking the placebo displayed an increase in heart rate. No effects were shown on the immediate recall task, divided attention task, the WAIS digit span task, mood states, blood pressure, and body temperature.
This study provides further evidence that standardized extracts of B. monnieri have potential for safely enhancing cognitive performance in aging, an indication that is closely comparable to the traditional uses of the herb. Whether this effect is due to a direct mechanism in which the active agents in B. monnieri act upon brain chemistry to influence memory processes or to greater tolerance for frustration, or due to decreasing the performance-degrading effects of arousal on complex tasks, or yet some other mechanism, remains to be explored.
Read More about this study from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153866/