SCREENING OF POTENTIAL CANCER PREVENTING CHEMICALS AS ANTIOXIDANTS INAN IN-VITRO ASSAY

We used an azo-initiated fluorescence assay to rank a series of antiox idants, with the objective of selecting compounds for further evaluati on as chemopreventive agents. Trolox was the positive control for the assay and with an IC50 of 0.50 mu M, was more active than any of the o ther 16 compounds examined. Three compounds, U83836E, glutathione, and purpurgallin, were only slightly less active with IC50's in cite 1-3 mu M range. Four other compounds were almost as active: protochatechui c acid, N-acetyl-L-cysteine, U74389G, and lipoic acid (reduced). This fluorescence-based assay for antioxidant activity is a rapid economica l way of ranking antioxidants for further development in the National Cancer Institute's chemoprevention program.