Demethylbellidifolin protects against endothelial brsfunction due to lysophosphatidylcholine and low—density lipoprotein

Endogenous inhibitors of nitric oxide synthase are considered to be a contributor to endothelium dysfunction,and the increased level of them is related to the elevation of lipid peroxides.The present study examined the antioxidation of demethylbellidifolin(DMB),a xanthone compound,and the protective effect of the drug on endothelial cells in rats.DMB significantly inhibited Cu^2+-induced LDL oxidation and scavenged DPPH radicals.DMB(10 or 30μmol·L^-1) significantly attenuated the inhibition by lysophosphatidylcholine of endothelium-dependent relaxation.DMB(60 or 120mg·kg^-1) significantly improved the endothelium-dependent relaxation and decreased the concentrations of asymmetric dimethylarginine(ADMA) and malondialdehyde induced by a single injection of low density lipoprotein(LDL).The present results suggest that DMB preserves endothelial cells in the rats treated with LDL and the protective effect of DMB on endothelium is related to the reduction of ADMA concentration by inhibiting lipid peroxidation.