2.5. Measurement of Intracellular ROS

Cellular ROS was assessed using the 2′,7′-dichlorofluorescein diacetate (DCFDA) assay with a microplate reader [18]. In this study, the DCFDA assay was performed according to the manufacturer’s instructions (DCFDA Cellular ROS Detection Kit, Abcam, Cambridge, UK). In brief, the cells were incubated with 10 μL of DCFDA for 30 min in the dark and washed out with PBS. Accumulation of the oxidized fluorescent derivate (DCF) was measured using flow cytometry at an excitation/emission wavelength of 485/530 nm.