Department of Pharmacognosy, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria.
Department of Pharmacognosy, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria.
J Ethnopharmacol. 2014 Mar 28;152(3):599-602. doi: 10.1016/j.jep.2014.02.017. Epub 2014 Feb 15.
Walnut, Juglans regia L. (Juglandaceae), is one of the medicinal plants used to treat diabetic symptoms in Austrian folk medicine. The air-dried green leaves are either used as aqueous decoctions or liquor preparations and are consumed on a daily basis. We investigated the hypoglycemic effect of a methanolic Juglans regia leaf extract on glucose uptake, protein tyrosine phosphatase 1B (PTP1B) inhibition and peroxisome proliferator-activated receptor gamma (PPARγ) activation.
Hypoglycemic activity was assessed by glucose-uptake in C2C12 myocytes, inhibition of PTP1B and activation of PPARγ. Phytochemical characterization of the extract was carried out by LC-MS and GC-MS.
Methanolic Juglans regia leaf extract enhanced the glucose uptake rate in C2C12 myocytes at concentrations of 25µg/mL compared to untreated cells. This activity may partly be explained by the inhibition of PTP1B but not PPARγ agonism. LC-MS analyses revealed chlorogenic acid (1), 3-p-coumaroylquinic acid (2), a trihydroxynaphthalene-hexoside (3), as well as eight flavonoids (4-11) as main phenolic constituents in the active extract.
The finding that Juglans regia leaf extract enhances glucose uptake and inhibits PTP1B provides an in vitro-based rationale for the traditional use of walnut leaf preparations against elevated blood-glucose levels.
胡桃，核桃（胡桃科），是一种用于治疗奥地利民间医学中糖尿病症状的药用植物。风干的绿叶可作为水性煎剂或酒剂使用，并每日服用。我们研究了甲醇提取的核桃叶对葡萄糖摄取、蛋白酪氨酸磷酸酶 1B（PTP1B）抑制和过氧化物酶体增殖物激活受体γ（PPARγ）激活的降血糖作用。
通过 C2C12 肌细胞的葡萄糖摄取、PTP1B 抑制和 PPARγ 激活来评估降血糖活性。通过 LC-MS 和 GC-MS 对提取物进行了植物化学表征。
与未处理的细胞相比，浓度为 25μg/mL 的甲醇核桃叶提取物可增强 C2C12 肌细胞的葡萄糖摄取率。这种活性部分可以通过抑制 PTP1B 但不是 PPARγ 激动剂来解释。LC-MS 分析显示绿原酸（1）、3-p-咖啡酰奎宁酸（2）、三羟基萘-己糖苷（3）以及八种类黄酮（4-11）是活性提取物中的主要酚类成分。
核桃叶提取物可增强葡萄糖摄取并抑制 PTP1B 的发现为传统上使用核桃叶制剂治疗高血糖提供了基于体外的依据。
