Effects of 12-Week Bacopa monnieri Consumption on Attention, Cognitive Processing, Working Memory, and Functions of Both Cholinergic and Monoaminergic Systems in Healthy Elderly Volunteers

Abstract

At present, the scientific evidence concerning the effect of Bacopa monnieri on brain activity together with working memory is less available. Therefore, we aimed to determine the effect of B. monnieri on attention, cognitive processing, working memory, and cholinergic and monoaminergic functions in healthy elderly. A randomized double-blind placebo-controlled design was utilized. Sixty healthy elderly subjects (mean age 62.62 years; SD 6.46), consisting of 23 males and 37 females, received either a standardized extract of B. monnieri (300 and 600 mg) or placebo once daily for 12 weeks. The cholinergic and monoaminergic systems functions were determined using AChE and MAO activities. Working memory was assessed using percent accuracy and reaction time of various memory tests as indices, whereas attention and cognitive processing were assessed using latencies and amplitude of N100 and P300 components of event-related potential. All assessments were performed before treatment, every four weeks throughout study period, and at four weeks after the cessation of intervention. B. monnieri-treated group showed improved working memory together with a decrease in both N100 and P300 latencies. The suppression of plasma AChE activity was also observed. These results suggest that B. monnieri can improve attention, cognitive processing, and working memory partly via the suppression of AChE activity.

Source：Evid Based Complement Alternat Med. 2012;2012:606424. doi: 10.1155/2012/606424. Epub 2012 Dec 18.

An Acute, Double-Blind, Placebo-Controlled Cross-over Study of 320 mg and 640 mg Doses of Bacopa monnieri (CDRI 08) on Multitasking Stress Reactivity and Mood.

Abstract

Little research exists in humans concerning the anxiolytic, antidepressant, sedative, and adaptogenic actions the traditional Ayurvedic medicine Bacopa monnieri (BM) possesses in addition to its documented cognitive-enhancing effects. Preclinical work has identified a number of acute anxiolytic, nootropic, and adaptogenic effects of BM that may also co-occur in humans. The current double-blind, placebo-controlled cross-over study assessed the acute effects of a specific extract of BM (KeenMind® - CDRI 08) in normal healthy participants during completion of a multitasking framework (MTF). Seventeen healthy volunteers completed the MTF, at baseline, then 1 h and 2 h after consuming a placebo, 320 mg BM and 640 mg of BM. Treatments were separated by a 7-day washout with order determined by Latin Square. Outcome measures included cognitive outcomes from the MTF, with mood and salivary cortisol measured before and after each completion of the MTF. Change from baseline scores indicated positive cognitive effects, notably at both 1 h post and 2 h post BM consumption on the Letter Search and Stroop tasks, suggesting an earlier nootropic effect of BM than previously investigated. There were also some positive mood effects and reduction in cortisol levels, pointing to a physiological mechanism for stress reduction associated with BM consumption. It was concluded that acute BM supplementation produced some adaptogenic and nootropic effects that need to be replicated in a larger sample and in isolation from stressful cognitive tests in order to quantify the magnitude of these effects.

Source：Benson S, Downey LA, Stough C et al. Phytotherapy Research 2013.

An Acute, Double-Blind, Placebo-Controlled Crossover Study of 320 mg and 640 mg Doses of a Special Extract of Bacopa monnieri (CDRI 08) on Sustained Cognitive Performance

Abstract

Standardized extracts of the traditional Ayurvedic medicine Bacopa monnieri (BM) (Brahmi) have been recently shown to have cognitive enhancing effects in chronic administration studies. Pre-clinical work has also identified a number of acute anxiolytic, nootropic, and cardiovascular effects of BM. There has, however, been little research on the acute effects of BM on cognitive function. The current study aimed to assess the acute effects of a specific extract of BM (KeenMindW - CDRI 08) in a double-blind, placebo-controlled study in normal healthy participants who completed a cognitively demanding series of tests. Twenty-four healthy volunteers completed six repetitions of the Cognitive Demand Battery (CDB) after consuming a placebo, 320mg BM or 640mg of BM in a cross-over design and provided cardiovascular and mood assessments before and after treatment. Change frombaseline scores indicated that the 320mg dose ofBMimproved performance at the first, second, and fourth repetition post-dosing on the CDB, and the treatments had no effect upon cardiovascular activity or in attenuating task-induced ratings of stress and fatigue. It was concluded that assessment of an earlier pharmacological window and use of less memory-specific cognitive tests together with more temporally sensitivemeasures of brain activity may improve our understanding of the acute neurocognitive properties of BM.

Source：Downey et al. Phytotherapy Research 2012; 27:1407-1413.

Examining the Nootropic Effects of a special extract of Bacopa monniera on Human Cognitive Functioning

While Ayurvedic medicine has touted the cognitive enhancing effects of Bacopa monniera for centuries, there is a need for double-blind placebo-controlled investigations. One hundred and seven healthy participants were recruited for this double-blind placebo-controlled independent group design investigation. Sixty-two participants completed the study with 80% treatment compliance. Neuropsychological testing using the Cognitive Drug Research cognitive assessment system was conducted at baseline and after 90 days of treatment with a special extract of Bacopa monniera (2 × 150 mg KeenMind) or placebo. The Bacopa monniera product significantly improved performance on the ‘Working Memory’ factor, more specifically spatial working memory accuracy. The number of false-positives recorded in the Rapid visual information processing task was also reduced for the Bacopa monniera group following the treatment period. The current study provides support for the two other published studies reporting cognitive enhancing effects in healthy humans after a 90 day administration of the Bacopa monniera extract. Further studies are required to ascertain the effective dosage range, the time required to attain therapeutic levels and the effects over a longer term of administration.

Source:Stough et al.Phytotherapy Research, 2008; 22:1629-1634.