Astragalus polysaccharide ameliorates H2O2-induced human umbilical vein endothelial cell injury

Endothelial dysfunction caused by reactive oxygen species (ROS) has been implicated in numerous cardiovascular diseases. Astragalus polysaccharide (APS), an important bioactive component extracted from the Chinese herb Astragalus membranaceus, has been widely used for the treatment of cardiovascular disease. The present study aimed to investigate the effects of APS on hydrogen peroxide (H2O2)-induced human umbilical vein endothelial cell (HUVEC) injury. Following treatment with 400 mu M H2O2 for 24 h, cell viability was decreased and apoptosis was increased. However, pretreatment with APS for 1 h significantly attenuated H2O2-induced injury in HUVECs. In addition, APS decreased intracellular ROS levels, increased the protein expression of endothelial nitric oxide synthase and copper-zinc superoxide dismutase, elevated intracellular cyclic guanosine monophosphate (an activity marker for nitric oxide) levels and restored the mitochondrial membrane potential, compared with cells treated with H2O2 only. In conclusion, the results of the present study suggested that APS may protect HUVECs from injury induced by H2O2 via increasing the cell antioxidant capacity and nitric oxide (NO) bioavailability, which may contribute to the improvement of the imbalance between ROS and NO levels.