Fig. 2
Effects of the four extract fractions on vascular reactive oxygen species (ROS) production in HUVECs. a The top panel shows representative images of DHE-stained cells, which fluoresce red owing to ROS-mediated oxidation of DHE to ethidium. The middle panel shows representative images of DAPI-stained nuclei that fluoresce blue. The bottom panel shows the merged fluorescence images (× 400 magnification). b Quantitative analysis of DHE fluorescence intensity. The average DHE fluorescence intensities were normalized to the fluorescence intensity of DAPI. All data are expressed as mean ± SEM. n = 6. *P < 0.05 vs. control. #P < 0.05 and ##P < 0.01 vs. H2O2 alone. Con: control; PEF: petroleum ether fraction; EAF: ethyl acetate fraction; NBF: n-butanol fraction; AQF: aqueous fraction