Lemon grass (Cymbopogon citratus (D.C) Stapf) polyphenols protect human umbilical vein endothelial cell (HUVECs) from oxidative damage induced by high glucose, hydrogen peroxide and oxidised low-density lipoprotein

Abstract

The aromatic herb Cymbopogon citratus Stapf is widely used in tropical and subtropical countries in cooking, as a herbal tea, and in traditional medicine for hypertension and diabetes. Some of its properties have been associated with the in vitro antioxidant effect of polyphenols isolated from their aerial parts. However, little is known about C. citratus effects on endothelial cells oxidative injury. Using chromatographic procedures, a polyphenol-rich fraction was obtained from C. citratus (CCF) and their antioxidant properties were assessed by cooper-induced LDL oxidation assay. The main constituents of the active CCF, identified by high-performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD–MS), were chlorogenic acid, isoorientin and swertiajaponin. CCF 10 and 100μg/ml diminishes reactive oxidative species (ROS) production in human umbilical vein endothelial cell (HUVECs), challenged with high d-glucose (60% inhibition), hydrogen peroxide (80% inhibition) or oxidised low-density lipoprotein (55% inhibition). CCF 10 or 100μg/ml did not change nitric oxide (NO) production. However, CCF was able to inhibit vasoconstriction induced by the thromboxane A2 receptor agonist U46619, which suggest a NO-independent vasodilatador effect on blood vessels. Our results suggest that lemon grass antioxidant properties might prevent endothelial dysfunction associated to an oxidative imbalance promoted by different oxidative stimuli.