Wu Yu-Ting, Du Wan-Hong, Shi Ling, Liang Qin, Zou Xiao-Qing
Nat Prod Commun. 2017 Mar;12(3):387-390.
To investigate the preventive effects of tea on hyperglycemia and vascular complications of diabetes, we report the extraction and composition as well as the vasculoprotective effects of black tea extract (BTE), green tea extract (GTE), and dark tea extract (DTE). High Performance Liquid Chromatography (HPLC) and colorimetric methods were conducted to analyze for tea catechins, caffeine, polyphenols, amino acids and polysaccharides of BTE, GTE and DTE. The inhibitory effects of α-glucosidase, aldose reductase (AR), advanced glycation end-products (AGEs) and glucose uptake promotion effect in BTE, GTE and DTE were explored in vitro. Contents of six major catechin forms and total catechin as well as polyphenols are higher in GTE and DTE than BTE. BTE, GTE, and DTE showed the inhibitory effects of a-glucosidase, AR, and AGEs, but only DTE exhibited the glucose uptake promotion effect in HepG2 cells. The results suggest that regular consumption of tea can help prevent the progression of hyperglycemia and the vascular complications of diabetes.
为研究茶对糖尿病高血糖及血管并发症的预防作用，我们报告了红茶提取物（BTE）、绿茶提取物（GTE）和黑茶提取物（DTE）的提取、成分及其血管保护作用。采用高效液相色谱法（HPLC）和比色法分析了BTE、GTE和DTE中的茶儿茶素、咖啡因、多酚、氨基酸和多糖。体外探究了BTE、GTE和DTE对α-葡萄糖苷酶、醛糖还原酶（AR）、晚期糖基化终产物（AGEs）的抑制作用以及葡萄糖摄取促进作用。GTE和DTE中六种主要儿茶素形式、总儿茶素以及多酚的含量均高于BTE。BTE、GTE和DTE均表现出对α-葡萄糖苷酶、AR和AGEs的抑制作用，但只有DTE在HepG2细胞中表现出葡萄糖摄取促进作用。结果表明，经常饮茶有助于预防糖尿病高血糖的进展及血管并发症。
