School of Biomedical Sciences, The University of Queensland, Brisbane, 4072, Australia.
Curr Pharm Biotechnol. 2010 Dec;11(8):881-6. doi: 10.2174/138920110793261980.
Excess carbohydrate in the diet may initiate a chronic state of oxidative stress exacerbating the clinical and biochemical symptoms of diet-induced type 2 diabetes, especially glucose intolerance, lipid abnormalities and cardiovascular complications. This study has tested whether green tea, rich in antioxidants, improves both cardiovascular symptoms and glucose intolerance and also reduces oxidative stress in rats fed a high carbohydrate diet. Male 8 week old Wistar rats were fed a diet including fructose and condensed milk (each 40%) for 16 weeks (112 days); control rats were fed corn starch. Green tea-containing food was started from day 1 for the prevention protocol and from day 56 for the reversal protocol. High carbohydrate diet-fed rats showed glucose intolerance, hypertension, mild left ventricular hypertrophy, approximate doubling of cardiac interstitial and perivascular collagen deposition, increased passive diastolic stiffness and increased plasma malondialdehyde concentrations. Administration of green tea to high carbohydrate diet-fed rats prevented and reversed glucose intolerance and the increased systolic blood pressure, left ventricular wet weight, interstitial collagen and passive diastolic stiffness. Plasma malondialdehyde concentrations were also normalized. In summary, treatment with green tea both prevented and reversed the cardiovascular remodelling and metabolic changes seen in high carbohydrate-fed rats suggesting a chronic state of oxidative stress plays a key role in the symptom initiation and progression. Further, green tea may be a useful complementary therapy in diet-induced type 2 diabetes.
饮食中过多的碳水化合物可能会引发慢性氧化应激状态，从而加剧饮食诱导的 2 型糖尿病的临床和生化症状，尤其是葡萄糖耐量降低、脂质异常和心血管并发症。本研究旨在测试富含抗氧化剂的绿茶是否能改善心血管症状和葡萄糖耐量，降低高碳水化合物饮食喂养大鼠的氧化应激。雄性 8 周龄 Wistar 大鼠给予包含果糖和炼乳（各 40%）的饮食 16 周（112 天）；对照组大鼠给予玉米淀粉饮食。预防方案从第 1 天开始给予含绿茶的食物，逆转方案从第 56 天开始给予。高碳水化合物饮食喂养的大鼠表现出葡萄糖耐量降低、高血压、轻度左心室肥厚、心肌间质和血管周围胶原沉积增加约两倍、被动舒张僵硬增加和血浆丙二醛浓度升高。给予绿茶可预防和逆转高碳水化合物饮食喂养大鼠的葡萄糖耐量降低和收缩压升高、左心室湿重增加、间质胶原和被动舒张僵硬。血浆丙二醛浓度也恢复正常。综上所述，绿茶的治疗作用既可以预防，也可以逆转高碳水化合物喂养大鼠的心血管重构和代谢变化，提示慢性氧化应激状态在症状的发生和进展中起着关键作用。此外，绿茶可能是饮食诱导的 2 型糖尿病的一种有用的辅助治疗方法。
