Division of Radiation Safety and Immune Tolerance, National Research Institute for Child Health and Development, Setagaya-ku, Tokyo, Japan.
Biochem Biophys Res Commun. 2012 Jan 6;417(1):287-93. doi: 10.1016/j.bbrc.2011.11.102. Epub 2011 Nov 29.
The incidence of non-alcoholic fatty liver disease (NAFLD) has been increasing, and there is a shortage of liver donors, which has led to the acceptance of steatotic livers for transplantation. However, steatotic livers are known to experience more severe acute ischemia-reperfusion (I/R) injury than normal livers upon transplantation. In the present study, we investigated the role of theaflavin, a polyphenol substance extracted from black tea, in attenuating acute I/R injury in a fatty liver model. We induced I/R in normal and steatotic livers treated with or without theaflavin. We also separated primary hepatocytes from the normal and steatotic livers, and applied RAW264.7 cells, a mouse macrophage cell line, that was pretreated with theaflavin. We observed that liver steatosis, oxidative stress, inflammation and hepatocyte apoptosis were increased in the steatotic liver compared to the normal liver, however, these changes were significantly decreased by theaflavin treatment. In addition, theaflavin significantly diminished the ROS production of steatotic hepatocytes and TNF-α production by LPS-stimulated RAW264.7 cells. We concluded that theaflavin has protective effects against I/R injury in fatty livers by anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms.
非酒精性脂肪性肝病 (NAFLD) 的发病率一直在上升，而肝源短缺，这导致了脂肪肝也被接受用于移植。然而，与正常肝脏相比，脂肪肝在移植后经历更严重的急性缺血再灌注 (I/R) 损伤。在本研究中，我们研究了从红茶中提取的多酚物质茶黄素在减轻脂肪肝模型中急性 I/R 损伤中的作用。我们诱导了正常和用茶黄素处理的脂肪肝的 I/R。我们还从正常和脂肪肝中分离了原代肝细胞，并应用 RAW264.7 细胞，即一种预先用茶黄素处理的小鼠巨噬细胞系。我们观察到，与正常肝脏相比，脂肪肝中的肝脂肪变性、氧化应激、炎症和肝细胞凋亡增加，然而，这些变化通过茶黄素处理明显减少。此外，茶黄素还显著减少了脂多糖刺激的 RAW264.7 细胞中脂肪肝细胞的 ROS 产生和 TNF-α 产生。我们得出结论，茶黄素通过抗氧化、抗炎和抗凋亡机制对脂肪肝的 I/R 损伤具有保护作用。
