RÉSUMÉ
We examined the protective effects of ultrafiltered XinMaiJia (XMJ) extract in a hydrogen peroxide (H2O2)-induced injury model in human umbilical vein endothelial cells (HUVECs) and determined the corresponding changes in the Na(+)-H(+) exchanger (NHE1) protein content and NHE1 gene expression. H2O2-induced HUVECs were treated with different concentrations of XMJ extract and the corresponding changes in morphology, activity, membrane permeability, biochemical indicators, cytokine concentration, NHE1 protein content, and NHE1 gene expression were determined. H2O2 significantly promoted HUVEC injury, whereas ultrafiltered XMJ extract significantly improved the morphological changes in injured HUVECs, increased their activity, and decreased NHE1 gene and protein expression, as well as limited the decrease in membrane permeability and expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, interleukin (IL)-1, IL-6, and nuclear factor-kB. Ultrafiltered XMJ extract inhibited H2O2-induced HUVEC injury by inhibiting NHE1 activity.