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 H2O2 to endothelial cell strain CRL1730 of human umbilical vein. H2O2 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 calciumions 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 [200mmol/L of H2O2] was significantly decreased by 5.7mg/mL versus 11.4 and 22.8mg/mL isorhamnetin. Also, the increased in TM and LDH in injured cells was reversed to normal level with 5.7 to 11.4mg/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, 5.7mg/mL and 11.4mg/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 H2O2. 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

Microbial community in a full-scale drinking water biosand filter.

To remove turbidity and minimize microbiological risks, rapid sand filtration is one of main drinking water treatment processes in the world. However, after a long-term operation, sand particles will be colonized by microorganisms which can remove biodegradable organic matters and nitrogen compounds. In this study, 16S rRNA gene clone library analysis was applied to characterize the microbial community in a full-scale biosand filter used for drinking water treatment. The results indicate that phylum Nitrospirae and class Alphaproteobacteria were the dominant bacterial groups in the biosand sample collected from the upper filter layer. The dominance of Sphingomonas species might pose a microbiological risk. This work could provide some new insights into microbial community in drinking water biofilter.