Methoxyl methyl ether isoamylene quercetin （MIAQ） is one of the newly synthesized quercetin derivatives. The present study investigated the effect of MIAQ on rat aorta endothelial cells （RAECs） injured by hydrogen peroxide （H2O2）, as well as the potential mechanisms. We observed that MIAQ at 2.5-10μmol/L significantly enhanced the viability of injured RAECs, and the effect was more potent than quercetin and ct-tocopherol. However, M1AQ at the same concentration failed to show anti-oxidant activity in a cell-free system. In H2O2-injured endothelial cells treated with MIAQ （5-10μmol/L）, the level of nitric oxide （NO） and malondialdehyde was decreased, and the activities of superoxide dismutase and glutathione peroxidase was enhanced. In addition, RAECs treated with MIAQ （2.5-10 μmol/L） exhibited significant inhibiting apoptosis. In conclusion, MIAQ had protective effect on RAECs, possibly through increasing NO production and antioxidases activities, as well as inhibiting apoptosis. These findings suggest that MIAQ is possibly beneficial in the prevention of atherosclerosis and other diseases related to endothelial injury.
