Institute of Pharmacognosy, University of Szeged, Szeged, Hungary.
PLoS One. 2012;7(11):e50619. doi: 10.1371/journal.pone.0050619. Epub 2012 Nov 21.
The leaves of the white mulberry tree (Morus alba L.) are used worldwide in traditional medicine as anti-diabetics. Various constituents of mulberry leaves, such as iminosugars (i.e. 1-deoxynojirimicin), flavonoids and related compounds, polysaccharides, glycopeptides and ecdysteroids, have been reported to exert anti-diabetic activity, but knowledge about their contribution to the overall activity is limited. The objective of the present work was to determine the in vivo anti-diabetic activity of an extract of mulberry leaves (MA), and to examine to what extent three major constituents, chlorogenic acid, rutin and isoquercitrin, might contribute to the observed activity. Quantities of the three constituents of interest in the extract were determined by using HPLC-DAD. Activity was determined by using a type II diabetic rat model. After 11 days of per os administration of 250 or 750 mg/kg of MA or the corresponding amounts of each individual compound, a dose dependent decrease of non-fasting blood glucose levels were found for MA, chlorogenic acid and rutin, but not for isoquercitrin. Based on our results, chlorogenic acid and rutin might account for as much as half the observed anti-diabetic activity of MA, hence they can be considered as excellent markers for the quality control of mulberry products.
桑树（Morus alba L.）的叶子在世界各地的传统医学中被用作抗糖尿病药物。桑树叶子的各种成分，如亚氨基糖（即 1-脱氧野尻霉素）、类黄酮和相关化合物、多糖、糖肽和蜕皮甾酮，已被报道具有抗糖尿病活性，但对其对整体活性的贡献的了解有限。本工作的目的是确定桑叶提取物（MA）的体内抗糖尿病活性，并研究三种主要成分绿原酸、芦丁和异槲皮苷在多大程度上可能有助于观察到的活性。使用 HPLC-DAD 测定提取物中三种感兴趣成分的含量。通过使用 II 型糖尿病大鼠模型来确定活性。经过 11 天口服 250 或 750mg/kg MA 或相应量的每种单个化合物后，发现 MA、绿原酸和芦丁的非空腹血糖水平呈剂量依赖性下降，但异槲皮苷没有。基于我们的结果，绿原酸和芦丁可能占 MA 观察到的抗糖尿病活性的一半左右，因此它们可以被认为是桑树产品质量控制的良好标志物。
