Detection of Reactive Oxygen Species (ROS) Level
The ROS level in the cells was measured using a ROS detection kit (Beyotime Institute of Biotechnology, Jiangsu, China). Briefly, cells were trypsinized, harvested, and then stained with dichlorofluorescein diacetate (DCFH-DA) according to the instructions of the manufacture. The signal was detected using a spectroscopic cytometer (Becton Dickinson (BD) Biosciences, San Jose, CA, USA) at an excitation wavelength of 488 nm and an emission wavelength of 525 nm (Luo, Zheng, 2015). The positive control were cells treated only by the ROSup which was provided by the ROS detection kit.