Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study

• Published in: Psychopharmacologia Vol. 212; no. 3; pp. 345 - 356
• Main Authors: Scholey, Andrew, Ossoukhova, Anastasia, Owen, Lauren, Ibarra, Alvin, Pipingas, Andrew, He, Kan, Roller, Marc, Stough, Con
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-10-2010; Springer; Springer Nature B.V
• Subjects: Adolescent; Adult; Affect - drug effects; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Blood Glucose - drug effects; Cognition & reasoning; Cognition - drug effects; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Female; Herbal medicine; Humans; Male; Medical sciences; Memory; Memory, Short-Term - drug effects; Neurology; Neurosciences; Original Investigation; Panax - chemistry; Panax ginseng; Panax quinquefolius; Pharmacology/Toxicology; Plant Extracts - pharmacology; Psychiatry; Psychopharmacology; Reaction Time - drug effects; Time Factors; Young Adult; Cognitive; Mood; Working memory; Nootropic; Ginseng; Herbal extract; Acute; Cognition; Extract; Crossover study; Panax ginseng; Randomization; Dicotyledones; Angiospermae; Plant origin; Placebo; Double blind study; Spermatophyta; Araliaceae
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-010-1964-y

Rationale
Over the last decade, Asian ginseng (
Panax ginseng
) has been shown to improve aspects of human cognitive function. American ginseng (
Panax quinquefolius
) has a distinct ginsenoside profile from
P. ginseng
, promising cognitive enhancing properties in preclinical studies and benefits processes linked to human cognition.
Objectives
The availability of a highly standardised extract of
P. quinquefolius
(Cereboost™) led us to evaluate its neurocognitive properties in humans for the first time.
Methods
This randomised, double-blind, placebo-controlled, crossover trial (
N
 = 32, healthy young adults) assessed the acute mood, neurocognitive and glycaemic effects of three doses (100, 200 400 mg) of Cereboost™ (
P. quinquefolius
standardised to 10.65% ginsenosides). Participants' mood, cognitive function and blood glucose were measured 1, 3 and 6 h following administration.
Results
There was a significant improvement of working memory (WM) performance associated with
P. quinquefolius.
Corsi block performance was improved by all doses at all testing times. There were differential effects of all doses on other WM tasks which were maintained across the testing day. Choice reaction time accuracy and ‘calmness’ were significantly improved by 100 mg. There were no changes in blood glucose levels.
Conclusions
This preliminary study has identified robust working memory enhancement following administration of American ginseng
.
These effects are distinct from those of Asian ginseng and suggest that psychopharmacological properties depend critically on ginsenoside profiles. These results have ramifications for the psychopharmacology of herbal extracts and merit further study using different dosing regimens and in populations where cognition is fragile.