RESUMO
RATIONALE: Extracts of Bacopa monniera have been reported to exert cognitive enhancing effects in animals. However, the effects on human cognition are inconclusive. OBJECTIVE: The current study examined the chronic effects of an extract of B. monniera (Keenmind) on cognitive function in healthy human subjects. METHODS: The study was a double-blind placebo-controlled independent-group design in which subjects were randomly allocated to one of two treatment conditions, B. monniera (300 mg) or placebo. Neuropsychological testing was conducted pre-(baseline) and at 5 and 12 weeks post drug administration. RESULTS: B. monniera significantly improved speed of visual information processing measured by the IT task, learning rate and memory consolidation measured by the AVLT (P<0.05), and state anxiety (P<0.001) compared to placebo, with maximal effects evident after 12 weeks. CONCLUSIONS: These findings suggest that B. monniera may improve higher order cognitive processes that are critically dependent on the input of information from our environment such as learning and memory.
Assuntos
Cognição/efeitos dos fármacos , Ayurveda , Adolescente , Adulto , Análise de Variância , Cognição/fisiologia , Método Duplo-Cego , Feminino , Humanos , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Extratos Vegetais/farmacologiaRESUMO
RATIONALE: Selective cholinergic receptor agonists and antagonists have been shown to modulate inspection time, a measure of speed of early information processing. OBJECTIVE: The present study aimed to examine the effects of globally increasing cholinergic function with the acetylcholinesterase inhibitor donepezil on inspection time. METHODS: Fourteen healthy subjects participated in a randomised double-blind, placebo controlled trial in which all subjects were tested under either acute placebo or donepezil (5 mg) treatment conditions. Testing was conducted pre- and 90 min post-drug administration. RESULTS: There was a significant decrease in inspection time in the donepezil condition compared to the placebo condition (F = 12.86; P < 0.01). DISCUSSION: The decrease or improvement of inspection time following donepezil administration is consistent with the role of the cholinergic system in modulating speed of information processing, and adds evidence that inspection time may serve as a physiological index of the integrity of the cholinergic system.
Assuntos
Indanos/farmacologia , Processos Mentais/efeitos dos fármacos , Sistema Nervoso Parassimpático/efeitos dos fármacos , Piperidinas/farmacologia , Desempenho Psicomotor/efeitos dos fármacos , Adulto , Donepezila , Método Duplo-Cego , Feminino , Humanos , MasculinoRESUMO
The Ayurvedic medicine Bacopa monniera (Brahmi) has been shown to exert cognitive enhancing effects in animals. The current study examined the acute effects of an extract of Bacopa monniera on cognitive function in normal healthy human subjects. The study was a double-blind, placebo-controlled independent group design in which subjects were randomly allocated to one of two treatment conditions, Bacopa monniera (300 mg) (n = 18) or placebo (n = 20). Neuropsychological testing was conducted before and 2 h after drug administration. No significant changes were found on any of the tests. The findings suggest that Bacopa monniera, at least for the dose administered, has no acute effects on cognitive functioning in normal healthy subjects. Copyright 2001 John Wiley & Sons, Ltd.
