The NSAIDs Indomethacin and Diflunisal as scavengers of photogenerated reactive oxygen species

Abstract

Diflunisal (DFNS) and Indomethacyn (IMTC) are two profusely employed NSAIDs that provide antiinflammatory and analgesic effects in humans. The scavenging of reactive oxygen species (ROS) by both NSAIDs was systematically studied in pH 7 aqueous solution. The ROS O2(1g), O2?? and H2O2, generated by visible light irradiation of Riboflavin in the presence of DFNS and IMTC, are deactivated by the NSAIDs. It is well known that exacerbated signs of oxidative stress are considered an identifier mark for neurodegenerative disorders. Hence the ROS scavenging action by both NSAIDs constitutes an interesting result in the frame of beneficial actions of these drugs, and adds one more positive aspect to the list of the already attributed properties on the prevention-retardation of neurodegenerative illnesses. DFNS quenches ROS in a dominant physical fashion. It constitutes an excellent scavenger provided that is practically not destroyed/oxidized after the ROS quenching action. On the other hand, IMTC being also an efficient interceptor of ROS, belong to the so-called group of sacrificial-quenchers: It is easily degraded by ROS in the scavenging action. Nevertheless, this property, negative in the context of prolonged ROS elimination, exhibits a promissory aspect for the degradation of pharmaceutical contaminants, such as NSAIDs, in waste waters.