Isorhamnetin protects endothelial cells model CRL1730 from oxidative injury by hydrogen peroxide.

To explore the protective effect and mechanism of isorhamnetin against oxidative injury caused by H2 O2 to endothelial cell strain CRL1730 of human umbilical vein. H2 O2 and endothelial cell strain CRL1730 were used, as a model of injured endothelial cell. Three levels of crude drugs areorhamnetin, 22.8μg/ml, 11.4μg/mL and 5.7μg/mL was added to the injured cell strain CRL1730 respectively. The cell injury was measured in terms of necrotic rate, quantities of von Wilebr and factor (vWf) and thrombomodulin (TM), lactate dehydrogenase (LDH) and intracellular free calcium ions through flow cytometry, ELISA, fluorescent spectrometer and laser scanning confocal microscopy respectively. Isorhamnetins @ 11.4μg/mL and 5.7μg/mL has significantly decreased EC necrotic rate, while the increased vWf concentration due to oxidant (200mol/L of H2 O2 ) was significantly decreased by 5.7μg/mL versus 11.4 and 22.8μg/mL isorhamnetin. Also, the increased in TM and LDH in injured cells was reversed to normal level with 5.7 to 11.4μg/mL isorhamnetin. These results suggest that isorhamnetin protect the integrity of cell membranes. Similarly, H2O2 treatment of cells elicited the release of intracellular calcium, however, 5.7μg/mL and 11.4μ g/mL isorhamnetin dramatically inhibited transient release of intracellular calcium. This suggests that isorhamnetin, at lower concentration, could inhibit the IP3-sensitive calcium pool from releasing calcium, protecting VECs from injury by H2 O2 . Traditional Chinese herbs, hippophaerhamnoides have been recognized as safe and as a source of flavonoids, with strong cardiovascular protection. The results of this study revealed that isorhamnetin produce a strong effect on some targetspresent in ECs and thus, provide a basis for the future work targeted towards endothelial cells protection.