Department of Health Sciences, Faculty of Science, University of Mauritius, Réduit, Mauritius.
Food Funct. 2017 Nov 15;8(11):4194-4209. doi: 10.1039/c7fo01038a.
This study aimed at investigating and comparing the anti-diabetic potential of black and green teas. Biochemical analyses indicate higher antioxidant potency, significantly correlated with the phytochemicals present, in green teas compared to black teas. Both extracts afforded a similar level of protection to erythrocytes against peroxyl radical-induced lysis. Non-cytotoxic concentration of green and black tea extracts significantly reduced the reactive oxygen species (ROS) production (P < 0.01), lowered the oxidation of proteins (P < 0.05) and decreased the IL-6 secretion (P < 0.01) induced by AGEs or HO in 3T3-L1 preadipocytes. Both teas also inhibited the decline in the enzymatic activities of superoxide dismutase, catalase and glutathione peroxidase induced by the pro-oxidants. The teas further suppressed the glycation of BSA mediated by glucose, ribose and MGO by reducing fluorescent AGE, fructosamine, protein carbonyl and AOPP levels. Black and green teas also inhibited the activities of α-amylase (AA: 589.86 ± 39.51 and 947.80 ± 18.20 μg mL, respectively) and α-glucosidase (AA: 72.31 ± 4.23 and 100.23 ± 8.10 μg mL, respectively). The teas afforded a comparable level of protection at the cellular level and against glycation while black tea exerted the highest carbohydrate hydrolysing enzymes inhibitory activity. Our results clearly show that black and green teas represent an important source of antioxidants with anti-diabetic potential.
本研究旨在探究和比较黑茶和绿茶的降血糖潜力。生化分析表明,与黑茶相比,绿茶具有更高的抗氧化能力,这与其中存在的植物化学物质密切相关。两种提取物都能为红细胞提供相似水平的保护,防止过氧自由基诱导的溶血。非细胞毒性浓度的绿茶和黑茶提取物能显著减少活性氧(ROS)的产生(P<0.01),降低蛋白质的氧化(P<0.05),并减少AGEs 或 HO 在 3T3-L1 前脂肪细胞中诱导的 IL-6 分泌(P<0.01)。两种茶还能抑制由促氧化剂引起的超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性的下降。茶还能抑制葡萄糖、核糖和 MGO 介导的 BSA 糖化,通过降低荧光 AGE、果糖胺、蛋白质羰基和 AOPP 水平。黑茶和绿茶还能抑制α-淀粉酶(AA:分别为 589.86±39.51 和 947.80±18.20μg mL)和α-葡萄糖苷酶(AA:分别为 72.31±4.23 和 100.23±8.10μg mL)的活性。这两种茶在细胞水平和糖化方面都能提供相当水平的保护,而黑茶对碳水化合物水解酶的抑制活性最高。我们的研究结果清楚地表明,黑茶和绿茶是具有降血糖潜力的抗氧化剂的重要来源。