Juśkiewicz Jerzy, Zduńczyk Zenon, Jurgoński Adam, Brzuzan Łucja, Godycka-Kłos Irena, Zary-Sikorska Ewa
Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Division of Food Science, 10-747 Olsztyn, Poland.
Nutr Res. 2008 May;28(5):343-9. doi: 10.1016/j.nutres.2008.03.004.
Rats with severe streptozotocin (STZ)-induced diabetes were subjected to dietary green tea extract supplementation at 2 doses (0.01% and 0.2%; GTL and GTH groups, respectively) to evaluate their effects on antioxidant, gastrointestinal, and renal parameters of experimental animals. The lower dietary supplementation reflects daily consumption of 3 cups of green tea for an average adult weighing 70 kg. Supplementation of a diet with green tea extract had no influence on elevated food intake, body weight loss, increased glucose concentration, or declined antioxidant capacity of water-soluble substances in plasma in the diabetic rats. In cases of intestinal maltase activity, attenuation of liver and kidney hypertrophy, triacylglycerol concentration, and aspartate aminotransferase activity in the serum, both dietary treatments normalized metabolic disorders caused by STZ injection to a similar extent. Unlike the GTL group, the GTH treatment significantly ameliorated development of diabetes-induced abnormal values for small intestinal saccharase and lactase activities, renal microalbuminuria, thiobarbituric acid-reactive substance content in kidney tissue, as well as total antioxidant status in the serum of rats. The GTH group was also characterized by higher antioxidant capacity of lipid-soluble substances in plasma and superoxide dismutase activity in the serum. Although the higher dose of green tea extract did not completely protect against STZ-induced hyperglycemia and oxidative stress in experimental rats, this study suggests that green tea extract ingested at high amounts may prove to be a useful therapeutic option in the reversal of diabetic dysfunction.
用大剂量链脲佐菌素（STZ）诱导患糖尿病的大鼠，分别给予2种剂量（0.01%和0.2%；分别为GTL组和GTH组）的膳食绿茶提取物补充剂，以评估其对实验动物抗氧化、胃肠道和肾脏参数的影响。较低剂量的膳食补充剂反映了体重70千克的普通成年人每日饮用3杯绿茶的摄入量。在糖尿病大鼠中，膳食补充绿茶提取物对食物摄入量增加、体重减轻、血糖浓度升高或血浆中水溶性物质抗氧化能力下降均无影响。在肠道麦芽糖酶活性、肝脏和肾脏肥大的减轻、血清中三酰甘油浓度以及天冬氨酸转氨酶活性方面，两种膳食处理均使由注射STZ引起的代谢紊乱恢复到相似程度。与GTL组不同，GTH处理显著改善了糖尿病诱导的大鼠小肠蔗糖酶和乳糖酶活性、肾脏微量白蛋白尿、肾组织中硫代巴比妥酸反应性物质含量以及血清总抗氧化状态的异常值。GTH组的特征还包括血浆中脂溶性物质的抗氧化能力较高以及血清中超氧化物歧化酶活性较高。虽然高剂量的绿茶提取物不能完全预防实验大鼠中由STZ诱导的高血糖和氧化应激，但本研究表明，大量摄入绿茶提取物可能被证明是逆转糖尿病功能障碍的一种有用的治疗选择。
