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The protein kinase C (PKC) is a serine/threonine kinase, consisting of different isoforms, implicated in numerous processes of signal transduction. To understand this enzyme well, different pharmacological tools were developed. To activate PKC specifically, phorbol esters were previously used but recent research has shown that these compounds are able to stimulate other proteins. Our model is the respiratory burst in the polymorphonuclear neutrophils. A decrease in the inflammatory process was measured using chelerythrine chloride. Action on PKC was proved by a binding study and by showing the absence of translocation of this enzyme from the cytoplasm to the plasmic membrane during stimulation.

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 , H 2 O 2 , HOCl) productions. BSA interacts with those reactive oxygen species (ROS) in a dose-dependent manner. The 50% inhibitory concentration (IC 50 ) of BSA estimated, after phorbol-12-myristate-13-acetate (PMA) stimulation were: 33.5 mg/ml for O − 2 , 6.5 mg/ml for H 2 O 2 , and 6.85 mg/ml for HOCl. When neutrophils were washed after pre-incubation with BSA, there was no significant decrease of ROS after stimulation of PMA (maximal: 15±1.2%). In the free cell experiments, IC 50 for H 2 O 2 and HOCl were 7.86 mg/ml and 0.67 mg/ml, respectively. The mechanism at which BSA acts may result from a simple chemical interaction with ROS rather than an intracellular mechanism by intervention in PMA oxidative metabolism. These antioxidant activities confer to BSA properties, which might be used to prevent damage inflicted by these ROS during inflammatory disorders.