Effect of elite physical exercise by triathletes on seven catabolites of DNA oxidation.

The oxidized nucleoside 8-hydroxy-2'-deoxyguanosine has been widely studied as a marker of DNA oxidation; however, data on the occurrence of other metabolites in plasma that are related to DNA damage are scarce. We have applied an improved, sensitive, robust, and reliable method, involving solid phase extraction and ultrahigh-performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS), to the precise quantitation of seven metabolites in the plasma of 15 elite triathletes after a 2-week training program. All compounds were eluted in the first 1.6 min, with limits of detection and quantification ranging between 0.001 and 0.3 ng.mL(-1) and 0.009 and 0.6 ng.mL(-1), respectively. Four compounds were detected in plasma: guanosine-3'-5'-cyclic monophosphate, 8-hydroxyguanine, 8-hydroxy-2'-deoxyguanosine, and 8-nitroguanosine. After two weeks of training, 8-hydroxyguanine exhibited the highest increase (from 0.031 ± 0.008 nM to 0.036 ± 0.012 nM) (p < 0.05), which could be related to the enhanced activity of DNA-repairing enzymes that excise this oxidized base. Increased levels of guanosine-3'-5'-cyclic monophosphate and 8-hydroxy-2'-deoxyguanosine were also observed. In contrast, levels of 8-nitroguanosine (p < 0.05) were significantly reduced, which might be a protective measure as this compound strongly stimulates the generation of superoxide radicals, and its excess is related to pathologies such as microbial (viral) infections and other inflammatory and degenerative disorders. The results obtained indicate an induced adaptive response to the increased oxidative stress related to elite training, and point to the benefits associated with regular exercise.

Non-targeted metabolomic approach reveals urinary metabolites linked to steroid biosynthesis pathway after ingestion of citrus juice.

Citrus juice intake has been highlighted because of its health-promoting effects. LC-MS based metabolomics approaches are applied to obtain a better knowledge on changes in the concentration of metabolites due to its dietary intake and allow a better understanding of involved metabolic pathways. Eight volunteers daily consumed 400 mL of juice for four consecutive days and urine samples were collected before intake and 24h after each citrus juice intake. Urine samples were analysed by nanoHPLC-q-TOF, followed by principal component analysis (PCA) and Student's t-test (p<0.05). PCA showed a separation between two groups (before and after citrus juice consumption). This approach allowed the identification of four endocrine compounds (tetrahydroaldosterone-3-glucuronide, cortolone-3-glucuronide, testosterone-glucuronide and 17-hydroxyprogesterone), which belonged to the steroid biosynthesis pathway as significant metabolites upregulated by citrus juice intake. Additionally, these results confirmed the importance of using the non-targeted metabolomics technique to identify new endogenous metabolites, up- or down-regulated as a consequence of food intake.

Physical activity increases the bioavailability of flavanones after dietary aronia-citrus juice intake in triathletes.

Control and triathlete volunteers (n=8 and n=15, respectively) were given 400 mL and 200 mL of aronia-citrus juice (AC-juice), respectively. The 24h urine samples were hydrolysed to determine the flavanones concentration by UPLC-QqQ-MS/MS. The flavanones metabolites in both groups of volunteers were glucuronides, sulfates, and sulfo-glucuronides, and the total excretion of flavanones increased fivefold in the triathletes compared with the control volunteers. The increase of ninefold in the homoeriodictyol of triathletes compared to control volunteers may suggest the overactivation of the microbiota metabolism caused by physical exercise. No differences concerning the bioavailability were detected between men and women in controlboth groups. The AC-juice could provide synergistic effects on health due to the increase in the bioavailability of flavanones, avoiding the deleterious effects caused by the overdosage of nutritional supplements.

A ultra-pressure liquid chromatography/triple quadrupole tandem mass spectrometry method for the analysis of 13 eicosanoids in human urine and quantitative 24 hour values in healthy volunteers in a controlled constant diet.

RATIONALE: Isoprostanes (IsoPs) are a series of prostaglandin (PG)-like compounds formed non-enzymatically through free-radical-induced peroxidation of arachidonic acid. They are considered as 'gold-standard' biomarkers for oxidative stress, in general, and lipid peroxidation, in particular. METHODS: A new qualitative and quantitative analytical method for the determination of 13 eicosanoids in human urine using solid-phase extraction (SPE) and ultra-pressure liquid chromatography coupled to tandem mass spectrometry (UPLC/MS/MS) has been developed. The SPE was optimized by comparison of the extraction efficiency and recoveries of three distinct cartridges: Strata X-AW, C18 Sep-Pak, and Oasis HLB. The UPLC/MS/MS approach in the multiple reaction monitoring (MRM) mode was developed using negative electrospray ionization (ESI). RESULTS: The validated method provides a high-throughput assay with an adequate linearity from 0.16 to 330 ng mL(-1). The limit of detection (LOD) and limit of quantification (LOQ) for each analyte showed low intervals (0.021-0.64 ng mL(-1) and 0.042-1.28 ng mL(-1), respectively). Urinary IsoPs were determined in 24 healthy volunteers and ranged from 685 to 3480 ng 24 h(-1) and from 864 to 7511 ng 24 h(-1) in urine from women and men, respectively. CONCLUSIONS: This analytical method could constitute a useful tool for the determination of oxidative stress biomarkers in clinical studies in which IsoPs may evidence early pathological conditions, as suggested by the determination of the baseline IsoPs content in human urine, since it improves upon the detection capacity of previously described methods. The quantity of IsoPs excreted in urine was higher than that found in previous reports due to the total hydrolysis of the conjugated forms.

[Dietary iron intake and deficiency in elite women volleyball players]. / Ingesta dietética de hierro y su deficiencia en las jugadoras de voleibol femenino de élite.

INTRODUCTION: Volleyball practice requires repeated impacts on arms and feet caused by vertical jumps, falls, auctions, sudden and rapid changes of direction, which is why might raise us problems in the metabolism of iron (Fe) and the recommended intake of 18 mg/day (in the women in general), is not sufficient to meet the needs of the players of volleyball female (JVF). OBJECTIVE: We analyzed the FS and IST of 10 JVF a team of Spanish SuperLeague (26.6 ± 5.9 years and height 178.05 ± 8.7 cm) in two moments of the season: Week 0 (pre-start of preseason) and week 11 (after 11 weeks of training and 6 games of the regular season). Also calculated Fe intake in this period with consumption frequency questionnaire developed and tested with food dietary records of 7 days. RESULTS: We observed that an intake of 25.8 mg/day of dietary Fe is not sufficient to prevent 30% of the JVF suffer pre-latent iron deficiency and 20% latent deficit (pre-anemia). CONCLUSION: It could be recommended conducting periodic blood analytical and a food education, teaching which foods containing a high content of Fe-type heme, and the factors that can interfere with absorption.