An improved nonisotopic test to screen a large series of new inhibitor molecules of poly(ADP-ribose) polymerase activity for therapeutic applications.

A reliable ELISA for screening large numbers of poly(ADP-ribose) polymerase (PARP) inhibitors is described. The test is based upon the drop in PARP activity estimated by the decrease in poly(ADP-ribose) synthesis in the presence of inhibitor. This ELISA is easy to perform, rapid, and specific. It is extremely sensitive because a clear inhibition of the total reaction could be visualized with molecules used in the nanomolar range. The assay uses no radioactivity, and automation is possible with robots for large-scale investigations. This test is of great interest for the screening of chemical libraries and the discovery of new inhibitors (and possibly activators) of PARP. Such molecules have important applications in all abnormal situations involving DNA damage and oxidative stress, such as cancer, autoimmunity, diabetes, myocardial dysfunctions, certain infections, aging, and radiation/chemical exposure.