Arginase inhibitory properties of stilbenes from Cyperaceae species

Stilbenoids constitute a group of natural phenolic compounds, whose distribution within the plant kingdom is limited to species that have acquired ability to synthesize this kind of molecules during the evolution [1]. These compounds have received much attention because of their anticancer, antioxidant, anti-inflammatory and cardioprotective activities [2]. Recently the stilbene piceatannol-3'-O-β-D-glucopyranoside was described as an active component of rhubarb with rat arginase inhibitory activity [3]. We also showed that resveratrol and piceatannol possessed in vitro inhibitory activity against liver bovine arginase. The interest for arginase as a therapeutic target has grown in the last years when the excessive arginase activity in mammals was shown to be associated with an endothelial dysfunction leading to various diseases including hypertension. Then the use of arginase inhibitors has been proved to be beneficial in various diseases including cardiovascular diseases [4]. Therefore, continuing our systematic research of new arginase inhibitors from natural sources, we first looked into plants from Cyperaceae family, which is known to be a source of oligostilbenoids derived from piceatannol and resveratrol. Phytochemical studies on Cyperus and Carex species were performed using analytical and preparative HPLC leading to twelve compounds, including monomers, dimers, trimers and tetramers of resveratrol. LC-MS and NMR spectroscopy were used for identification of the compounds. We studied the potential of these stilbenes as inhibitors of mammal arginase (liver bovine arginase). Four compounds (cyperusphenols A and B, scirupsin and vitisin B) showed significant inhibition of arginase, with percentages inhibition ranging from 85 to 95% at 100µM, and confirming that stilbenes would be very useful for the development of new pharmaceutical products.

Keywords: Arginase inhibitors, stilbenes, cardiovascular diseases, Cyperaceae, Cyperus, Carex.

References:

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