Lee Chia-Lin, Lee Shou-Lun, Chen Chao-Jung, Chen Hsin-Chun, Kao Ming-Ching, Liu Chuan-Hao, Chen Jau-Yang, Lai Yen-Ting, Wu Yang-Chang
Department of Cosmeceutics, China Medical University, Taichung 40402, Taiwan.
Chinese Medicine Research and Development Center, China Medical University Hospital, Taichung 40447, Taiwan.
Molecules. 2016 Jun 8;21(6):745. doi: 10.3390/molecules21060745.
Ipomoea batatas has long been used in folk medicine for the treatment of hyperglycemia or as a food additive for the prevention of type 2 diabetes. However, neither the plant extract nor its active components have been evaluated systematically. In this work four crude extracts, including n-hexane- (IBH), 95% MeOH- (IBM), n-BuOH- (IBB), and H₂O-soluble (IBW) fractions, were prepared by fractionation of a methanolic extract of purple I. batatas leaves. Twenty-four pure compounds 1-24 were then isolated by various chromatographic techniques and their structures identified from NMR and MS data. Glucose uptake assays in differentiated 3T3-L1 adipocytes and rat primary hepatocytes, as well as western blot analysis, were carried out to evaluate the antidiabetic activity of this species. The IBH crude fraction, with methyl decanoate (22) as a major and active compound, showed the greatest effect on glucose uptake, most likely via activation of Glut4 and regulation of the PI3K/AKT pathway. Quercetin 3-O-β-d-sophoroside (1), quercetin (3), benzyl β-d-glucoside (10), 4-hydroxy-3-methoxybenzaldehyde (12), and methyl decanoate (22) could be important components contributing to the antidiabetic effects. We conclude that purple I. batatas leaves have potential as an antidiabetic plant source and the active constituents 1, 3, 10, 12, and 22 are promising lead candidates for future investigation.
甘薯长期以来在民间医学中被用于治疗高血糖，或作为预防2型糖尿病的食品添加剂。然而，该植物提取物及其活性成分均未得到系统评估。在本研究中，通过对紫色甘薯叶甲醇提取物进行分馏，制备了四种粗提物，包括正己烷提取物（IBH）、95%甲醇提取物（IBM）、正丁醇提取物（IBB）和水溶性提取物（IBW）。然后通过各种色谱技术分离出24种纯化合物1 - 24，并根据核磁共振（NMR）和质谱（MS）数据确定了它们的结构。通过在分化的3T3 - L1脂肪细胞和大鼠原代肝细胞中进行葡萄糖摄取试验以及蛋白质免疫印迹分析，来评估该物种的抗糖尿病活性。以癸酸甲酯（22）作为主要活性化合物的IBH粗提物对葡萄糖摄取的影响最大，最有可能是通过激活葡萄糖转运蛋白4（Glut4）和调节磷脂酰肌醇3激酶/蛋白激酶B（PI3K/AKT）途径来实现的。槲皮素3 - O - β - D - 槐糖苷（1）、槲皮素（3）、苄基β - D - 葡萄糖苷（10）、4 - 羟基 - 3 - 甲氧基苯甲醛（12）和癸酸甲酯（22）可能是有助于产生抗糖尿病作用的重要成分。我们得出结论，紫色甘薯叶具有作为抗糖尿病植物来源的潜力，活性成分1、3、10、12和22是未来研究中有前景的潜在候选物。
