Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Respir Med. 2009 Nov;103(11):1746-54. doi: 10.1016/j.rmed.2009.04.027. Epub 2009 May 31.
Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage.
Sprague-Dawley rats were randomly divided into four groups, i.e. sham air (SA), 4% CS, 2% Lung Chen tea plus SA or 4% CS. Exposure to SA or 4% CS was performed for 1h/day for 56 days in ventilated smoking chambers. Sera and lung tissues were collected 24h after last CS exposure for histology and all biochemical assays.
Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone, which were abolished in the presence of green tea consumption. Serum 8-isoprostane level was significantly elevated (p<0.01) as well as lung superoxide dismutase (SOD) and catalase activities in CS-exposed rats compared to SA-exposed rats (p<0.05), which returned to the levels of SA-exposed rats after Chinese green tea consumption.
These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage. Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury.
表没食子儿茶素没食子酸酯（EGCG）具有很强的抗氧化作用，占中国绿茶儿茶素的 80%。本研究旨在探讨香烟烟雾（CS）暴露是否会诱导 CS 暴露大鼠模型的肺形态变化和氧化应激，以及中国绿茶（以 EGCG 为主要活性成分的 Lung Chen 茶）的摄入是否会改变血清和肺中的氧化应激，从而保护 CS 诱导的肺损伤。
将 Sprague-Dawley 大鼠随机分为四组，即假空气（SA）、4%CS、2%Lung Chen 茶加 SA 或 4%CS。在通风吸烟室中，每天暴露于 SA 或 4%CS 1 小时，共 56 天。最后一次 CS 暴露后 24 小时收集血清和肺组织进行组织学和所有生化测定。
单独 CS 暴露 56 天后，气道扩张和杯状细胞增生，而绿茶摄入可消除这些变化。与 SA 暴露大鼠相比，CS 暴露大鼠血清 8-异前列腺素水平显著升高（p<0.01），肺超氧化物歧化酶（SOD）和过氧化氢酶活性也升高（p<0.05），而在绿茶摄入后，这些指标恢复到 SA 暴露大鼠的水平。
这些结果表明，CS 暴露后全身氧化应激水平的升高在诱导肺损伤中起重要作用。中国绿茶可能具有抑制 CS 诱导的氧化应激的能力，从而保护肺损伤。
