Wightman Emma L, Reay Jonathon L, Haskell Crystal F, Williamson Gary, Dew Tristan P, Kennedy David O
Brain, Performance and Nutrition Research Centre, Northumbria University,Newcastle upon TyneNE1 8ST,UK.
School of Social Sciences and Law, Teesside University,MiddlesbroughTS1 3BA,UK.
Br J Nutr. 2014 Jul 28;112(2):203-13. doi: 10.1017/S0007114514000737. Epub 2014 May 7.
Previous research has shown that resveratrol can increase cerebral blood flow (CBF) in the absence of improved cognitive performance in healthy, young human subjects during the performance of cognitively demanding tasks. This lack of cognitive effects may be due to low bioavailability and, in turn, reduced bioefficacy of resveratrol in vivo. Piperine can alter polyphenol pharmacokinetics, but previous studies have not investigated whether this affects the efficacy of the target compound. Therefore, the objective of the present study was to ascertain whether co-supplementation of piperine with resveratrol affects the bioavailability and efficacy of resveratrol with regard to cognition and CBF. The present study utilised a randomised, double-blind, placebo-controlled, within-subjects design, where twenty-three adults were given placebo, trans-resveratrol (250 mg) and trans-resveratrol with 20 mg piperine on separate days at least a week apart. After a 40 min rest/absorption period, the participants performed a selection of cognitive tasks and CBF was assessed throughout the period, in the frontal cortex, using near-IR spectroscopy. The presence of resveratrol and its conjugates in the plasma was confirmed by liquid chromatography-MS analysis carried out following the administration of the same doses in a separate cohort (n 6). The results indicated that when co-supplemented, piperine and resveratrol significantly augmented CBF during task performance in comparison with placebo and resveratrol alone. Cognitive function, mood and blood pressure were not affected. The plasma concentrations of resveratrol and its metabolites were not significantly different between the treatments, which indicates that co-supplementation of piperine with resveratrol enhances the bioefficacy of resveratrol with regard to CBF effects, but not cognitive performance, and does this without altering bioavailability.
先前的研究表明，在健康的年轻受试者执行认知要求较高的任务时，白藜芦醇可增加脑血流量（CBF），但认知表现并未改善。这种缺乏认知效应的情况可能是由于生物利用度低，进而导致白藜芦醇在体内的生物功效降低。胡椒碱可改变多酚的药代动力学，但先前的研究尚未调查这是否会影响目标化合物的功效。因此，本研究的目的是确定胡椒碱与白藜芦醇共同补充是否会影响白藜芦醇在认知和脑血流量方面的生物利用度和功效。本研究采用随机、双盲、安慰剂对照、受试者内设计，23名成年人在至少相隔一周的不同日期分别服用安慰剂、反式白藜芦醇（250毫克）和含20毫克胡椒碱的反式白藜芦醇。在40分钟的休息/吸收期后，参与者执行一系列认知任务，并在整个期间使用近红外光谱法在额叶皮层评估脑血流量。在另一组（n = 6）中给予相同剂量后，通过液相色谱 - 质谱分析确认血浆中白藜芦醇及其共轭物的存在。结果表明，与单独使用安慰剂和白藜芦醇相比，胡椒碱和白藜芦醇共同补充时，在任务执行期间可显著增加脑血流量。认知功能、情绪和血压未受影响。各治疗组之间白藜芦醇及其代谢物的血浆浓度无显著差异，这表明胡椒碱与白藜芦醇共同补充可增强白藜芦醇在脑血流量方面的生物功效，但不影响认知表现，且不会改变生物利用度。
