Antioxidant effects of a single dose of acetylsalicylic acid and salicylic acid in rat brain slices subjected to oxygen-glucose deprivation in relation with its antiplatelet effect.

The aim of the present study was to analyze the relative participation of the antiplatelet and the antioxidant effects of acetylsalicylic acid (ASA) and salicylic acid (SA) after a single dose (1 or 10 mg/kg i.p.) in an in vitro model of anoxia in slices of rat brain. After 20 min of drug administration, blood and brain were obtained (n=6 rats per group). We measured: lipid peroxidation, glutathione levels and lactate dehydrogenase efflux (LDH), ASA and SA concentrations and platelet aggregation in whole blood. An increase in lipid peroxidation (80%) and in LDH efflux (520%) and a decrease in glutathione levels (35%) were observed after 120 min anoxia in saline-treated rats. SA reduced this oxidative stress and LDH efflux, but it did not modify platelet aggregation. ASA strongly inhibited platelet aggregation but exerted a poor antioxidant effect. ASA was not detectable in brain tissue. We conclude that repeated doses of ASA are necessary to obtain a tissular antioxidant effect, probably when liver generates enough SA.