Antioxidant properties of albumin: effect on oxidative metabolism of humanneutrophil granulocytes

The present study aims at investigating the effect of bovine serum albumin (BSA) on the trial of oxidative-stress. The antioxidant effects of BSA were determined by human neutrophil granulocytes oxygen free radicals and their by-products (O-2(-), H2O2, HOCl) productions. BSA interacts with those rea ctive oxygen species (ROS) in a dose-dependent manner. The 50% inhibitory c oncentration (IC50) of BSA estimated, after phorbol-12-myristate-13-acetate (PMA) stimulation were: 33.5 mg/ml for O-2(-), 6.5 mg/ml for H2O2, and 6.8 5 mg/ml for HOCl. When neutrophils were washed after pre-incubation with BS A, there was no significant decrease of ROS after stimulation of PMA (maxim al: 15 +/- 1.2%). In the free cell experiments, IC50 for H2O2 and HOCl were 7.86 mg/ml and 0.67 mg/ml, respectively. The mechanism at which BSA acts m ay result from a simple chemical interaction with ROS rather than an intrac ellular mechanism by intervention in PMA oxidative metabolism. These antiox idant activities confer to BSA. properties, which might be used to prevent damage inflicted by these ROS during inflammatory disorders. (C) 1999 Elsev ier Science S.A. All rights reserved.