Dichlorofluorescein diacetate assay (DCFDA)

ROS (reactive oxygen species) levels were assessed by DCFDA assay (Abcam, Cambridge, MA, USA, ab113851). Cells were seeded in a 96-well plate at 1e4 cells/well. The following day cells were treated with indicated compounds in indicator-free media. At 24 hours post treatment, wells were over-layed with 2x diluted DCFDA reagent, as suggested by the manufacturer’s protocol. Fluorescence was read by microplate reader at Ex/Em = 485/535 nm. A ratio of untreated to treated wells was calculated to determine relative response. Wells were normalized to media only wells to account for background signal.