Vitamin C inhibits GM-CSF–induced production of ROS.

(A) U937 cells incubated for 30 minutes with (black histogram) or without (white histogram) 500 μM dehydroascorbic (DHA) were analyzed for the production of ROS. (B) U937 cells treated (black histogram) or untreated (white histogram) for 30 minutes with 500 μM DHA were incubated for 10 minutes with 1 nM GM-CSF and the production of ROS analyzed. (C) Analysis of the production of ROS in U937 cells pretreated (closed circle) or untreated (open circle) with 500 μM DHA for 30 minutes before incubation with 1 nM GM-CSF. The relative production of ROS was measured by fluorescence using DFC in a flow cytometer.