Free radical scavenging and antioxidant effects of lactate ion: an in vitro study

Divergent literature data are found concerning the effect of lactate on fre e radical production during exercise. To clarify this point, we tested the pro- or antioxidant effect of lactate ion in vitro at different concentrati ons using three methods: 1) electron paramagnetic resonance (EPR) was used to study the scavenging ability of lactate toward the superoxide aion (O-2( -).) and hydroxyl radical ( . OH); 2) linoleic acid micelles were employed to investigate the lipid radical scavenging capacity of lactate; and 3) pri mary rat hepatocyte culture was used to study the inhibition of membrane li pid peroxidation by lactate. EPR experiments exhibited scavenging activitie s of lactate toward both (3, and OH; lactate was also able to inhibit lipid peroxidation of hepatocyte culture. Both effects of lactate were concentra tion dependent. However, no inhibition of lipid peroxidation by lactate was observed in the micelle model. These results suggested that lactate ion ma y prevent lipid peroxidation by scavenging free radicals such as O-2(-). an d . OH but not lipid radicals. Thus lactate ion might be considered as a po tential antioxidant agent.