Regulative effects of hawthorn leave flavonoids on cytotoxicity, NO and Ca2+ in hypoxia-treated human umbilical vein endothelial cells

To evaluate the potential effect of HLF (Hawthorn leave flavonoids, w/w, 80% flavonoids) against thrombus formation, effect of HLF on hypoxia-treated human umbilical vein endothelial cell (HUVECs) was studied.The levels of cytotoxicity and NO upon HUVECs were studied by flow cytometry. Moreover, the level of calcium ion in HUVECs was examined through laser scanning confocal microscopy.Data from this study showed that HLF at concentrations of 5 micrograms/ml and 10 micrograms/ml decreased the cytotoxicity of hypoxia to HUVECs (P0.05, P0.01). The intracellular levels of NO and calcium ion were downregulated by HLF at concentrations of 5 micrograms/ml (P0.01; P0.01) and 10 micrograms/ml (vs control, P0.01; P0.01) too.Results observed suggest that HLF protect HUVECs from hypoxia partly through its regulative effect on NO and calcium ion levels.