The homeostatic challenge may provide unique opportunities for quantitative assessment of the health-promoting effects of nutritional interventions in healthy individuals. Objective. The present study is aimed at characterizing and validating the use of acute aerobic exercise (AAE) on a treadmill at 60% of VO2max for 30 min, in assessing the antioxidative and anti-inflammatory effects of a nutritional intervention. In a controlled, randomized, parallel trial of Korean black raspberry (KBR) (n = 24/group), fasting blood and urine samples collected before and following the AAE load at either baseline or 4-week follow-up were analyzed for biochemical markers, 1H-NMR metabolomics, and transcriptomics. The AAE was characterized using the placebo data only, and either the placebo or the treatment data were used in the validation. The AAE load generated a total of 50 correlations of 44 selected markers, based on Pearson's correlation coefficient analysis of 105 differential markers. Subsequent mapping of selected markers onto the KEGG pathway dataset showed 127 pathways relevant to the AAE load. Of these, 54 pathways involving 18 key targets were annotated to be related to oxidative stress and inflammation. The biochemical responses were amplified with the AAE load as compared to those with no load, whereas, the metabolomic and transcriptomic responses were downgraded. Furthermore, target-pathway network analysis revealed that the AAE load provided more explanations on how KBR exerted antioxidant effects in healthy subjects (29 pathways involving 12 key targets with AAE vs. 12 pathways involving 2 key targets without AAE). This study provides considerable insight into the molecular changes incurred by AAE and furthers our understanding that AAE-induced homeostatic perturbation could magnify oxidative and inflammatory responses, thereby providing a unique opportunity to test functional foods for antioxidant and anti-inflammatory purposes in clinical settings with healthy subjects.

It is important to understand the association between oxidative stress-related parameters and to evaluate their status in advance of chronic disease development. Further development towards disease can then be prevented by dietary antioxidants. The present study was aimed at assessing the relationship between diet quality, blood antioxidants, and oxidative damage to determine whether the association between these markers differs by oxidative stress status. For a cross-sectional analysis, we used data and samples of baseline information from a prospective cohort study. A total of 1229 eligible adults were classified into apparently healthy subjects (66.5%) and those with oxidative stress conditions (35.5%). Diet quality was assessed using the recommended food score (RFS). Plasma carotenoids (blood antioxidants) and blood/urinary malondialdehyde (MDA; oxidative damage) were determined by high-performance liquid chromatography. We found that the healthy group was younger, and they had a lower RFS and plasma MDA level and higher plasma carotenoids compared to the oxidative stress condition group. This result is probably due to the quenching of the oxidative response in the tissues of those people. A positive association of RFS with plasma carotenoids (total and β-carotene) was found in both groups, suggesting that carotenoids are a robust reflection of diet quality. Negative associations were observed between plasma MDA and RFS in the oxidative stress condition group and between urinary MDA and plasma zeaxanthin in the healthy group. Erythrocyte MDA was positively associated with plasma carotenoids (total, lutein, zeaxanthin, β-cryptoxanthin, and α- and β-carotene), regardless of health condition, probably also as a result of the use of carotenoids as antioxidants. In conclusion, these results indicate that the above three factors may be associated with the oxidative stress response and depend on the oxidative status. Furthermore, it was also suggested that erythrocytes are important in the oxidative stress response and the quenching of this response is represented in plasma carotenoids.