Li Hong Mei, Hwang Seung Hwan, Kang Beom Goo, Hong Jae Seung, Lim Soon Sung
Department of Pharmacology, College of Medicine, Hallym University, 200-702 Chuncheon, Korea.
Department of Food and Nutrition, Hallym University, 200-702 Chuncheon, Korea.
Molecules. 2014 Aug 27;19(9):13212-24. doi: 10.3390/molecules190913212.
The goal of this study was to determine the rat lens aldose reductase-inhibitory effects of 95% ethanol extracts from the leaves of C. esculenta and, its organic solvent soluble fractions, including the dichloromethane (CH2Cl2), ethyl acetate (EtOAc), n-butanol (BuOH) and water (H2O) layers, using dl-glyceraldehyde as a substrate. Ten compounds, namely tryptophan (1), orientin (2), isoorientin (3), vitexin (4), isovitexin (5), luteolin-7-O-glucoside (6), luteolin-7-O-rutinoside (7), rosmarinic acid (8), 1-O-feruloyl-d-glucoside (9) and 1-O-caffeoyl-d-glucoside (10) were isolated from the EtOAc and BuOH fractions of C. esculenta. The structures of compounds 1-10 were elucidated by spectroscopic methods and comparison with previous reports. All the isolates were subjected to an in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among tested compounds, compounds 2 and 3 significantly inhibited rat lens aldose reductase, with IC50 values of 1.65 and 1.92 μM, respectively. Notably, the inhibitory activity of orientin was 3.9 times greater than that of the positive control, quercetin (4.12 μM). However, the isolated compounds showed only moderate ABTS+ [2,29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] activity. These results suggest that flavonoid derivatives from Colocasia esculenta (L.) Schott represent potential compounds for the prevention and/or treatment of diabetic complications.
本研究的目的是使用dl-甘油醛作为底物，测定香芋叶95%乙醇提取物及其有机溶剂可溶部分（包括二氯甲烷（CH2Cl2）、乙酸乙酯（EtOAc）、正丁醇（BuOH）和水（H2O）层）对大鼠晶状体醛糖还原酶的抑制作用。从香芋的乙酸乙酯和正丁醇部分分离出10种化合物，即色氨酸（1）、荭草素（2）、异荭草素（3）、牡荆素（4）、异牡荆素（5）、木犀草素-7-O-葡萄糖苷（6）、木犀草素-7-O-芸香糖苷（7）、迷迭香酸（8）、1-O-阿魏酰基-d-葡萄糖苷（9）和1-O-咖啡酰基-d-葡萄糖苷（10）。通过光谱方法并与先前报道进行比较，阐明了化合物1-10的结构。对所有分离物进行体外生物测定，以评估它们对大鼠晶状体醛糖还原酶的抑制活性。在测试的化合物中，化合物2和3显著抑制大鼠晶状体醛糖还原酶，IC50值分别为1.65和1.92μM。值得注意的是，荭草素的抑制活性比阳性对照槲皮素（4.12μM）高3.9倍。然而，分离出的化合物仅表现出中等的ABTS+[2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)]活性。这些结果表明，香芋中的黄酮类衍生物是预防和/或治疗糖尿病并发症的潜在化合物。
