Monitoring reactive oxygen species in vivo using microdialysis sampling and chemiluminescence detection as an alternative global method for determination of total antioxidant capacity Original Research Article

A microdialysis sampling system coupled to chemiluminescence (CL) detection was developed to monitor the variation of lucigenin (Luc) CL emission in vivo in real time. The Luc CL emission is linearly correlated to the d-ROM test, thus providing evidence of equivalence to total antioxidant capacity (TAC). Furthermore, the system is simple, low cost, rapid and sensitive enough for real time monitoring of TAC variation in vivo under different physiological and pathological conditions. It is accurate and far more precise than the traditional methods since it overcomes uncontrolled conditions of handling samples. The production capacity of reactive oxygen species (proROS capacity) of individual antioxidant compounds mostly found in biological fluids was investigated using luminol CL emission. The implications of the proROS capacity of antioxidant compounds in biological fluids is further discussed under the perspective of explaining the appearance of certain pathological diseases, and on the basis of establishing a healthy diet for human beings. Further investigation showed that ascorbic acid (AA) plays a protective role in living organisms, so a diet rich in AA is important for health. Furthermore, it was found that lower physiological level of AA or higher physiological level of uric acid (UA) or glucose (GLU) may reduce O2 into reactive oxygen species (ROS, e.g. H2O2, O2radical dot−) in the presence of Fe(III). This may explain some syndromes in the cases of AA deficiency (e.g. scurvy) and related diseases, e.g. diabetes or gout. From the data obtained, there is a strong indication that the damage or pathological alternation is probably due to the higher level of ROS, which are generated from the reduced oxygen in the presence of pathological level of related reductants.