绿茶及其成分对小鼠体重、脂肪沉积和肝脏脂肪代谢酶活性的影响

目的研究绿茶及其成分的减肥作用机制。方法 50只雌性昆明小鼠随机分成5组,分别为对照组、2%绿茶组、0.05%咖啡碱组、0.3%儿茶素组及0.05%咖啡碱+0.3%儿茶素组。混合饲料投喂8 w后,摘取肝脏和腹腔脂肪(IPAT)并称重。分析血清中血糖、甘油三酯(TG)、总胆固醇、瘦素及胰岛素浓度和肝脏中脂类含量。测定肝脏中脂肪酸合成酶(FAS)、肉毒碱脂酰转移酶(CAT)和酰基辅酶A氧化酶(ACO)的活性。结果绿茶、咖啡碱、咖啡碱+儿茶素组体重增加和IPAT重量比对照组明显减少,特别是咖啡碱+儿茶素效果极显著。咖啡碱+儿茶素显著降低血中TG和瘦素浓度。绿茶、儿茶素、咖啡碱+儿茶素组小鼠肝脏中TG含量显著减少。咖啡碱+儿茶素明显降低肝脏中FAS活性,提高CAT和ACO的活性。结论咖啡碱和儿茶素组合通过调节脂肪代谢酶活性,抑制脂肪沉积和体重增加,并且咖啡碱和儿茶素对降脂减肥有协同作用。[营养学报,2012,34(6):605-608,612]

EFFECT OF GREEN TEA AND ITS COMPONENTS ON BODY WEIGHT, FAT ACCUMULATION AND ACTIVITY OF HEPATIC FAT METABOLISM RELATED ENZYMES IN MICE

Objective To investigate the anti-obesity mechanism of green tea and its components in mice.Method Fifty female Kunming mice were randomly assigned to 5 groups and fed on commercial powder diets containing none(control),2% green tea,0.05% caffeine,0.3% catechins and 0.05% caffeine + 0.3% catechins for 8 w respectively.Liver and intraperitoneal adipose tissues(IPAT) were weighed at the end of experiment.Serum levels of glucose,triglycerides(TG),total cholesterols,leptin and insulin,and lipids in liver were measured.Fatty acid synthese(FAS),carnitine acyltransferase(CAT) and acyl-CoA oxidase(ACO) in liver were determined.Results The body weight gain and IPAT weight were significantly reduced by green tea,caffeine and caffeine + catechins.Serum TG and leptin concentrations were significantly decreased by caffeine + catechins.Green tea,catechins and caffeine + catechins reduced TG level in liver.Caffeine + catechins significantly reduced FAS activity,and remarkably increased CAT and ACO activities in liver.Conclusion Caffeine + catechins can inhibit fat accumulation and body weight gain in mice through regulating fat metabolism related enzymes activities.Moreover,caffeine and catechins possess synergistic anti-obesity effect.[ACTA NUTRIMENTA SINICA,2012,34(6):605-608,612]