Wightman Emma L, Haskell Crystal F, Forster Joanne S, Veasey Rachel C, Kennedy David O
Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle upon Tyne, United Kingdom.
Hum Psychopharmacol. 2012 Mar;27(2):177-86. doi: 10.1002/hup.1263.
The aim of the study was to assess the effects of oral ingestion of the 'green tea' polyphenol epigallocatechin gallate (EGCG) on cognitive performance, mood and localised cerebral blood flow (CBF) parameters in healthy human adults.
In this double-blind, placebo-controlled, crossover study, 27 healthy adults received placebo and two doses (135 and 270 mg) of EGCG in counterbalanced order on separate days. Following a 45-min resting absorption period, participants performed a selection of computerised cognitive tasks that activate the frontal cortex for a further 42 min. CBF and haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed in the frontal cortex throughout the post-treatment period using Near-infrared spectroscopy (NIRS).
During the post-dose task performance period, the administration of 135 mg EGCG resulted in reduced CBF in the frontal cortex, as indexed by significantly lower concentrations of both oxygenated and total haemoglobin, in comparison with placebo. Heart rate was significantly reduced from pre dose to post dose across all treatments. No significant differences were observed for the level of deoxygenated haemoglobin or on any of the cognitive performance/mood measures.
These results demonstrate that a single dose of orally administered EGCG can modulate CBF parameters in healthy humans but that this is not associated with changes in cognitive performance or mood.
本研究旨在评估口服“绿茶”多酚表没食子儿茶素没食子酸酯（EGCG）对健康成年人认知能力、情绪及局部脑血流量（CBF）参数的影响。
在这项双盲、安慰剂对照、交叉研究中，27名健康成年人在不同日期按平衡顺序接受安慰剂及两剂（135毫克和270毫克）EGCG。在45分钟的静息吸收期后，参与者进行一系列激活额叶皮质的计算机化认知任务，持续42分钟。在整个治疗后期间，使用近红外光谱（NIRS）评估额叶皮质中以氧合血红蛋白和脱氧血红蛋白浓度变化为指标的CBF和血流动力学。
在给药后任务执行期间，与安慰剂相比，服用135毫克EGCG导致额叶皮质CBF降低，表现为氧合血红蛋白和总血红蛋白浓度显著降低。所有治疗中，心率从给药前到给药后均显著降低。在脱氧血红蛋白水平或任何认知能力/情绪测量指标上未观察到显著差异。
这些结果表明，单次口服EGCG可调节健康人的CBF参数，但这与认知能力或情绪变化无关。
