Development of a novel method for monitoring the antioxidative effect of ascorbic acid in rat blood

A real time evaluation method for the ex vivo antioxidative effect in rat blood after administration of ascorbic acid (ASA) is described. The antioxidative effect in small amounts of samples (0.5 μL) could be measured by hyphenated semi-micro flow injection analysis-chemiluminescence detection and microdialysis methods. Antioxidative effects of blood microdialysates obtained from rats administered 50 mg/kg ASA through different routes (intravein: i.v., intraperitoneal: i.p. and per os: p.o.) were evaluated. The increased effects were maintained up to 360 min after administration. The AUC 0-360 (antioxidative effect % × min) were 16,260 ± 1739 (i.v.), 12,873 ± 2152 (i.p.) and 6668 ± 2251 (p.o.). Additionally, ASA was determined to be the source of the microdialysate antioxidative effect by diminishing its effect with ascorbic acid oxidase. Furthermore, the concentration of ASA in the microdialysate was correlated with the antioxidative effect (r = 0.915)