FLAVONOIDS AS SCAVENGERS OF NITRIC-OXIDE RADICAL

Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be ex cellent scavengers of oxygen free radicals. Since the nitric oxide rad ical ((NO)-N-.) probably plays a role in this pathology, the (NO)-N-. scavenging capacity of the flavonoids was determined. It was found tha t the flavonoids are very potent (NO)-N-. scavengers. The anthocyanidi ns were found to be more effective scavengers than the hydroxyethylrut osides, which correlated with their therapeutic activity. The values o f their scavenging rate constants are only 30 times less active than t he very potent endogenous (NO)-N-. scavenger haemoglobin. It is specul ated that (NO)-N-. scavenging plays a role in the therapeutic effect o f the flavonoids. (C) 1995 Academic Press, Inc.