Araújo Rúben, Ramalhete Luís, Da Paz Helder, Ribeiro Edna, Calado Cecília R C
ISEL-Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, 1959-007 Lisboa, Portugal.
CSTL-T- Centro de Sangue e da Transplantação- Instituto Português do Sangue e Transplantação, IP, 1769-001 Lisboa, Portugal.
High Throughput. 2020 Apr 9;9(2):9. doi: 10.3390/ht9020009.
Epigallocatechin-3-gallate (EGCG), the major catechin present in green tea, presents diverse appealing biological activities, such as antioxidative, anti-inflammatory, antimicrobial, and antiviral activities, among others. The present work evaluated the impact in the molecular profile of human plasma from daily consumption of 225 mg of EGCG for 90 days. Plasma from peripheral blood was collected from 30 healthy human volunteers and analyzed by high-throughput Fourier transform infrared spectroscopy. To capture the biochemical information while minimizing the interference of physical phenomena, several combinations of spectra pre-processing methods were evaluated by principal component analysis. The pre-processing method that led to the best class separation, that is, between the plasma spectral data collected at the beginning and after the 90 days, was a combination of atmospheric correction with a second derivative spectra. A hierarchical cluster analysis of second derivative spectra also highlighted the fact that plasma acquired before EGCG consumption presented a distinct molecular profile after the 90 days of EGCG consumption. It was also possible by partial least squares regression discriminant analysis to correctly predict all unlabeled plasma samples (not used for model construction) at both timeframes. We observed that the similarity in composition among the plasma samples was higher in samples collected after EGCG consumption when compared with the samples taken prior to EGCG consumption. Diverse negative peaks of the normalized second derivative spectra, associated with lipid and protein regions, were significantly affected ( < 0.001) by EGCG consumption, according to the impact of EGCG consumption on the patients' blood, low density and high density lipoproteins ratio. In conclusion, a single bolus dose of 225 mg of EGCG, ingested throughout a period of 90 days, drastically affected plasma molecular composition in all participants, which raises awareness regarding prolonged human exposure to EGCG. Because the analysis was conducted in a high-throughput, label-free, and economic analysis, it could be applied to high-dimension molecular epidemiological studies to further promote the understanding of the effect of bio-compound consumption mode and frequency.
表没食子儿茶素-3-没食子酸酯（EGCG）是绿茶中的主要儿茶素，具有多种吸引人的生物活性，如抗氧化、抗炎、抗菌和抗病毒活性等。本研究评估了每天摄入225毫克EGCG，持续90天对人体血浆分子谱的影响。从30名健康人类志愿者采集外周血血浆，并通过高通量傅里叶变换红外光谱进行分析。为了在最小化物理现象干扰的同时获取生化信息，通过主成分分析评估了几种光谱预处理方法的组合。导致最佳类别分离的预处理方法，即在开始时和90天后采集的血浆光谱数据之间的分离，是大气校正与二阶导数光谱的组合。二阶导数光谱的层次聚类分析也突出了这样一个事实，即在EGCG摄入90天后，EGCG摄入前采集的血浆呈现出不同的分子谱。通过偏最小二乘回归判别分析，也能够正确预测两个时间框架内所有未标记的血浆样本（未用于模型构建）。我们观察到，与EGCG摄入前采集的样本相比，EGCG摄入后采集的血浆样本之间的成分相似性更高。根据EGCG摄入对患者血液、低密度和高密度脂蛋白比率的影响，归一化二阶导数光谱中与脂质和蛋白质区域相关的各种负峰受到EGCG摄入的显著影响（<0.001）。总之，在90天的时间里一次性摄入225毫克EGCG，对所有参与者的血浆分子组成产生了巨大影响，这提高了人们对人类长期接触EGCG的认识。由于该分析是在高通量、无标记且经济的分析中进行的，它可应用于高维分子流行病学研究，以进一步促进对生物化合物消费模式和频率影响的理解。
