Multicomponent investigations of the hydrogen peroxide- and hydroxyl radical-scavenging antioxidant capacities of biofluids: The roles of endogenous pyruvate and lactate - Relevance to inflammatory joint diseases

High field proton (H-1) nuclear magnetic resonance (NMR) analysis of biofluids (healthy human blood sera and inflammatory knee-joint synovial fluids) has been employed to evaluate the hydrogen peroxide (H2O2)- and hydroxyl radical (degrees OH)- scavenging antioxidant capacities of a range of polar, low-molecular-mass endogenous metabolites therein. Data obtained indicate that consumption of H2O2 by pyruvate (generating acetate and CO2 via an oxidative decarboxylation reaction) and degrees OH radical by lactate (generating pyruvate, and subsquently acetate and CO2) may serve to protect alternative biofluid components (e.g., macromolecules) against reactive oxygen species-mediated oxidative damage in vivo. The mechanistic, physiological and potential therapeutic implications of these results are discussed with special reference to inflammatory joint diseases.