Effect of GS-Rb1 on the production of ROS in H9c2 cells. The fluorescence intensity was positively correlated with the amount of ROS produced in the cells. A, control cells. B, H9c2 cells showing higher intensity fluorescence during HR compared with control cells. C, GS-Rb1 can significantly reduce the fluorescence intensity of H9c2 cells during HR compared with nontreated cells. D, The effect of GS-Rb1 is eliminated by simultaneous pretreatment with 5-HD. E, diazoxide can significantly reduce the fluorescence intensity of H9c2 cells during HR, compared with nontreated cells. Cells were visualized by a fluorescent microscope (Olympus, Japan). Magnification: 200x. HR, hypoxia-reoxygenation; GS-Rb1, ginsenoside Rb1; 5-HD, 5-hydroxydecanoate.