HYDROXYL RADICAL-SCAVENGING PROPERTY OF INDOMETHACIN

The ability of indomethacin to scavenge hydroxyl radical (.OH) using h igh pressure liquid chromatography (HPLC) was investigated. .OH radica l was generated by photolysis of H2O2 (1.5-1 0 mmoles/l) with UV light and was trapped with salicyclic acid (500 nmoles). H2O2 produced .OH in a concentration-dependent manner as estimated by .OH adduct product s 2,3- and 2,5-dihydroxybenzoic acid (DHBA). Indomethacin in increasin g concentrations (5-600 mu moles/L) produced increasing inhibition of generation of 2,3-DHBA (7-67%) and of 2,5-DHBA (7-77%). The results in dicate that indomethacin scavenges .OH in a concentration-dependent ma nner.