Antioxidant characteristics of some potential anticataract agents. Studies of aspirin, paracetamol, and bendazac provide support for an oxidative component of cataract.

It is conceivable that drugs with anticataract potential possess antioxidant activity. Using defined chelating agents and reducing agents in a number of assays for antioxidant activity, we have demonstrated that paracetamol, aspirin, bendazac, and its metabolite 5-hydroxybendazac possess substantial reducing and/or metal-chelating activity. We found that paracetamol and 5-hydroxybendazac reduced the diphenylpicrylhydrazyl free radical; inhibited butyl peroxide-induced erythrocyte lysis as well as the haematin-catalyzed oxidative coupling of 4-aminoantipyrine and phenol by butyl peroxide. Furthermore, paracetamol, bendazac, and aspirin competed with 3-(2-pyridyl)-5,6-Diphenyl-1,2,4-triazine-4', 4"-disulphonic acid (ferrozine) for ferrous ion.