Background: Since surgical trauma not only intensifies the oxidative stress by generating reactive oxygen species (ROS), but also weakens the biological defense system against ROS attack, the antioxidant activity of drugs used during the perioperative period, which possibly normalizes the Impaired redox state in the patient, is of fundamental importance and great clinical interest. Methods: We have applied the phycoerythrin fluorescence-based assay, in which 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-generated peroxyl radical attacks B-phycoerythrin (B-PE) to lead to a sensitive decrease in its fluorescence intensity linearly; to evaluate the antioxidant activity of major drugs in anesthetic practice. Results: By the protective effect on B-PE fluorescence decay, the antioxidant activities of the drugs were classified into three groups: Group I drugs, which only slowed B-PE fluorescence decay (nicardipine, verapamil, diltiazem, ephedrine, aminophylline, vecuronium, Lidocaine, mepivacaine, midazolam, thiamylal, droperidol, ketamine, hydroxyzine, butorphanol, prednisolone, hydrocortisone, betamethasone, dexamethasone, methylprednisolone, and furosemide); Group II drugs, which protected B-PE oxidation completely and stopped fluorescence decay in a certain duration (dopamine, epinephrine, norepinephrine, dobutamine, isoproterenol, and buprenorphine); and Group III drugs, which had no protective effect on B-PE oxidation (nitroglycerin, prostaglandin E-1, neostigmine, pancuronium, suxamethonium, atropine, bupivacaine, pentazocine, and heparin). Conclusion: These results indicate that Group I and II drugs exert some antioxidant activity in vitro, as measured by their protection of fluorescence decay of B-PE. Careful consideration of these properties might, then, serve to facilitate more efficient drug application. (C) Acta Anaesthesiologica Scandinavica 42 (1998).
