Cheng Diana M, Pogrebnyak Natalia, Kuhn Peter, Poulev Alexander, Waterman Carrie, Rojas-Silva Patricio, Johnson William D, Raskin Ilya
Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.
Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.
Nutrition. 2014 Jul-Aug;30(7-8 Suppl):S52-8. doi: 10.1016/j.nut.2014.02.022. Epub 2014 Mar 12.
The aims of the following experiments were to characterize antidiabetic in vitro and in vivo activity of the polyphenol-rich aqueous extract of Rutgers Scarlet Lettuce (RSL).
RSL extract (RSLE) and isolated compounds were evaluated for inhibitory effects on glucose production as well as tumor necrosis factor alpha-dependent inhibition of insulin activity in H4IIE rat hepatoma cells. Additionally, high-fat diet-induced obese mice were treated with RSLE (100 or 300 mg/kg), metformin (250 mg/kg), or vehicle (water) for 28 d by oral administration and insulin and oral glucose tolerance tests were conducted. Tissues were harvested at the end of the study and evaluated for biochemical and physiological improvements in metabolic syndrome conditions.
A polyphenol-rich RSLE, containing chlorogenic acid, cyanidin malonyl-glucoside, and quercetin malonyl-glucoside, was produced by simple boiling water extraction at pH 2.0. In vitro, RSLE and chlorogenic acid demonstrated dose-dependent inhibition of glucose production. In vivo, RSLE treatment improved glucose metabolism measured by oral glucose tolerance tests, but not insulin tolerance tests. RSLE treated groups had a lower ratio of liver weight to body weight as well as decreased total liver lipids compared with the control group after 28 d of treatment. No significant differences in plasma glucose, insulin, cholesterol, and triglycerides were observed with RSLE-treated groups compared with vehicle control.
RSLE demonstrated antidiabetic effects in vitro and in vivo and may improve metabolic syndrome conditions of fatty liver and glucose metabolism.
以下实验旨在表征罗格斯红生菜（RSL）富含多酚的水提取物在体外和体内的抗糖尿病活性。
评估RSL提取物（RSLE）和分离出的化合物对H4IIE大鼠肝癌细胞中葡萄糖生成的抑制作用以及肿瘤坏死因子α依赖性胰岛素活性抑制作用。此外，通过口服给药，用RSLE（100或300mg/kg）、二甲双胍（250mg/kg）或赋形剂（水）对高脂饮食诱导的肥胖小鼠进行28天治疗，并进行胰岛素和口服葡萄糖耐量试验。在研究结束时收集组织，并评估代谢综合征条件下的生化和生理改善情况。
通过在pH 2.0下简单的沸水提取制备了一种富含多酚的RSLE，其含有绿原酸、矢车菊素丙二酰葡萄糖苷和槲皮素丙二酰葡萄糖苷。在体外，RSLE和绿原酸表现出对葡萄糖生成的剂量依赖性抑制作用。在体内，RSLE治疗通过口服葡萄糖耐量试验改善了葡萄糖代谢，但未改善胰岛素耐量试验。治疗28天后，与对照组相比，RSLE治疗组的肝重与体重之比更低，肝脏总脂质减少。与赋形剂对照组相比，RSLE治疗组在血浆葡萄糖、胰岛素、胆固醇和甘油三酯方面未观察到显著差异。
RSLE在体外和体内均表现出抗糖尿病作用，可能改善脂肪肝和葡萄糖代谢的代谢综合征状况。
