Department of Food Science and Biotechnology, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143-747, Republic of Korea.
Pediatric Infectious Diseases, Johns Hopkins University, 600 N. Wolfe St, Park 256, Baltimore, MD 21287, USA.
Nutr Neurosci. 2020 May;23(5):363-373. doi: 10.1080/1028415X.2018.1507618. Epub 2018 Aug 15.
The present study investigated the effect of high-temperature-processed green tea extract (HTP_GTE) and its bioactive components on the reduction of reactive oxygen species (ROS) and amyloid-beta (Aβ) protein in human microvascular endothelial cells. Compared to Aβ-only treatment, pretreatment of HTP_GTE was revealed to effectively inhibit ROS generation (<0.05). HTP_GTE and catechins not only inhibit Aβ fibril formation but also destabilize preformed Aβ fibrils. The presence of HTP_GTE, Aβ fibril formation was significantly inhibited in a dose-dependent manner at 12.5-100 μg/ml of HTP_GTE, showing 86-56%, respectively. Treatment of various concentrations of HTP_GTE and catechins steadily destabilized the preformed Aβ fibrils for 24 h in a dose-dependent manner. It was observed that the gallated groups such as epigallocatechin gallate, epicatechin gallate, gallocatechin gallate, and catechin gallate more effectively disturbed Aβ fibril formation and destabilized the preformed Aβ fibrils than the non-gallated group. Taken together, these findings supported that sterilized green tea could be promising natural anti-amyloidogenic agents associated with therapeutic approaches in Alzheimer's disease by scavenging ROS generation and Aβ fibril in the brain tissue.
本研究探讨了高温处理绿茶提取物（HTP_GTE）及其生物活性成分对人微血管内皮细胞中活性氧（ROS）和淀粉样蛋白-β（Aβ）蛋白减少的影响。与仅用 Aβ 处理相比，HTP_GTE 的预处理能有效抑制 ROS 的产生（<0.05）。HTP_GTE 和儿茶素不仅能抑制 Aβ 纤维的形成，还能使已形成的 Aβ 纤维不稳定。HTP_GTE 的存在以 12.5-100μg/ml 的剂量依赖性方式显著抑制 Aβ 纤维的形成，分别为 86-56%。用各种浓度的 HTP_GTE 和儿茶素处理可在 24 小时内稳定地使预先形成的 Aβ 纤维不稳定，呈剂量依赖性。结果表明，与非没食子酸基团相比，没食子酸基团如表没食子儿茶素没食子酸酯、表儿茶素没食子酸酯、没食子儿茶素没食子酸酯和儿茶素没食子酸酯更有效地干扰 Aβ 纤维的形成并使预先形成的 Aβ 纤维不稳定。综上所述，这些发现表明，经过消毒的绿茶可能是一种有前途的天然抗淀粉样蛋白物质，通过清除大脑组织中的 ROS 生成和 Aβ 纤维，与阿尔茨海默病的治疗方法有关。
