Department of Cell Biology, University of Calabria, Arcavacata di Rende (CS), Italy.
J Nutr Biochem. 2012 Jan;23(1):69-75. doi: 10.1016/j.jnutbio.2010.10.011. Epub 2011 Mar 16.
Root extract of liquorice is traditionally used to treat several diseases. Liquorice-derived constituents present several biological actions. In particular, glycyrrhizin and its aglycone, glycyrrhetinic acid, exhibit well-known cardiovascular properties. The aim of this research was to explore the direct cardiac activity of glycyrrhizin and glycyrrhetinic acid. The effects of synthetic glycyrrhizin and glycyrrhetinic acid were evaluated on the isolated and Langendorff perfused rat heart. The intracellular signaling involved in the effects of the two substances was analyzed on isolated and perfused heart and by Western blotting on cardiac extracts. Under basal conditions, both glycyrrhizin and glycyrrhetinic acid influenced cardiac contractility and relaxation. Glycyrrhizin induced significant positive inotropic and lusitropic effects starting from very low concentrations, while both inotropism and lusitropism were negatively affected by glycyrrhetinic acid. Both substances significantly increased heart rate. Analysis of the signal transduction mechanisms suggested that glycyrrhizin acts through the endothelin receptor type A/phospholipase C axis while glycyrrhetinic acid acts through endothelin receptor type B/Akt/nitric oxide synthase/nitric oxide axis. To our knowledge, these data reveal, for the first time, that both glycyrrhizin and glycyrrhetinic acid directly affect cardiac performance. Additional information on the physiological significance of these substances and their cardiac molecular targets may provide indication on their biomedical application.
甘草根提取物传统上被用于治疗多种疾病。甘草衍生成分具有多种生物活性。特别是甘草甜素及其苷元甘草次酸，具有众所周知的心血管特性。本研究旨在探讨甘草甜素和甘草次酸的直接心脏活性。评估了合成甘草甜素和甘草次酸对分离和 Langendorff 灌注大鼠心脏的影响。分析了两种物质对分离和灌注心脏的细胞内信号以及心脏提取物的 Western blot。在基础条件下，甘草甜素和甘草次酸均影响心脏收缩和舒张功能。甘草甜素从非常低的浓度开始就引起显著的正性变力和变时作用，而甘草次酸则对变力和变时作用产生负面影响。两种物质均显著增加心率。信号转导机制分析表明，甘草甜素通过内皮素受体 A/磷脂酶 C 轴起作用，而甘草次酸通过内皮素受体 B/Akt/一氧化氮合酶/一氧化氮轴起作用。据我们所知，这些数据首次表明，甘草甜素和甘草次酸均可直接影响心脏功能。关于这些物质的生理意义及其心脏分子靶点的更多信息可能为它们的生物医学应用提供依据。
