Evaluation of superoxide scavenging activity of OPC-14117 by electron spin resonance technique

OPC-14117 is a potent drug which has both brain function activating effect and protective effect against cerebral ischemia. Occurrences of these effects might be expected due to superoxide dismutase-like activity of OPC-14117. The present study has been conducted to evaluate the active oxygen scavenging activity of OPC-14117 and to explain the mechanisms of its pharmacological activities. The reaction of OPC-14117 and superoxide anion, generated in potassium superoxide, was examined by electron spin resonance technique at both liquid nitrogen (77 K) and room (22 degrees C) temperatures. OPC-14117 showed a higher superoxide scavenging activity than that of alpha-tocopherol in an aprotic solvent system. The active moiety of OPC-14117 to provide the scavenging effect was found due to the phenolic hydroxyl group of its indan skeleton.