Abstract

Background: Glycyrrhyza glabra L. is one of the most popular medicinal plant in the world, its roots having been used since ancient times in many traditional medicines. On the contrary, scarce attention has been dedicated to liquorice aerial parts. Previous studies showed the presence of a large group of polyphenols and a consistent amount of d-pinitol in the leaf extract.

Methods: The methanolic extract from G. glabra leaves was profiled for its content in polyphenols; the amount of d-pinitol was also measured with two independent methods (HPLC-ELSD and NMR). The extract was tested for its in vitro protective effects against insulin resistance-related endothelial dysfunction in human umbilical vein endothelial cells exposed to palmitic acid, which is the most prevalent saturated free fatty acid in circulation.

Results: Methanolic extract from liquorice leaves has a protective effect against the lipotoxicity-associated alterations of insulin pathway in human endothelial cells, similarly to what observed with pure d-pinitol.

Conclusions: Liquorice leaves are to be considered a waste product which gives a phytocomplex endowed with interesting potential therapeutic properties, moreover the use of a liquorice leaves phytocomplex rather than a pure compound allows avoiding a series of isolation/purification procedures and can be easily scaled up for industrial applications.

摘要

背景：光 果甘草是世界上最受欢迎的药用植物之一，其根自古以来就被用于许多传统药物中。相反，很少关注甘草地上部分。先前的研究表明，叶提取物中存在大量多酚和一致量的d-松醇。

方法：对光叶椴叶甲醇提取物的多酚含量进行分析；d-松醇的量也用两种独立的方法（HPLC-ELSD和NMR）测量。在暴露于棕榈酸（循环中最普遍的饱和游离脂肪酸）的人脐静脉内皮细胞中，测试了该提取物对胰岛素抵抗相关的内皮功能障碍的体外保护作用。

结果：甘草叶的甲醇提取物对人内皮细胞中胰岛素通路的脂毒性相关改变具有保护作用，与纯d-松醇观察到的相似。

结论：甘草叶被认为是一种废物，它赋予植物复合物具有有趣的潜在治疗特性，此外，使用甘草叶植物复合物而不是纯化合物可以避免一系列分离/纯化程序，并且可以轻松扩大规模用于工业应用。