Exogenous application of silicon and selenium improves the tolerance of tomato plants to calcium nitrate stress.

Silicon (Si) and selenium (Se) can improve the tolerance of plants to NaCl-induced salt stress. However, few studies are available on their regulatory effects on plants' tolerance to calcium nitrate stress, which often occurs in protected facilities, causing secondary soil salinization. In this study, we report the effects of Si (6 mM) and Se (20 µM) applied separately or in combination on the growth, photosynthesis, oxidative damage, and nitrogen metabolism of tomato plants, as well as fruit quality under calcium nitrate stress. The results showed that applications of Si or Se alone or in combination improved the plant growth and photosynthetic performance and reduced oxidative damage of the stressed plants. Applications of Si and Se did not decrease the calcium accumulation in leaves of the stressed plants. Under calcium nitrate stress, the concentrations of NO3-, NO2- and NH4+ in leaves were significantly increased, while the activities of nitrogen assimilation-related enzymes (including nitrate reductase, nitrite reductase, glutamine synthase, glutamine-2-oxoglutarate aminotransferase and glutamate dehydrogenase) were decreased. Applications of Si and Se, especially their combined treatment, decreased the NO3-, NO2-, and NH4+ concentrations and enhanced the activities of nitrogen assimilation-related enzymes in the stressed plants. Applied Si and Se also decreased the nitrate and titratable acid concentrations and increased vitamin levels in tomato fruits under calcium nitrate stress. It is suggested that Si and Se improved the tomato plant growth and fruit quality under calcium nitrate stress by alleviating oxidative damage and promoting both photosynthesis and nitrogen assimilation.

Insight into the potentiality of nano zero-valent iron on enhancing the nitrite accumulation and phosphorus removal performance of endogenous partial denitrification systems.

Endogenous partial denitrification (EPD) has drawn a lot of interest due to its abundant nitrite (NO2--N) accumulation capacity. However, the poor phosphate (PO43--P) removal rate of EPD restricts its promotion and application. In this study, the potentiality of various nano zero-valent iron (nZVI) concentrations (0, 20, 40, and 80 mg/L) on NO2--N accumulation and PO43--P removal in EPD systems had been investigated. Results showed that nZVI improved NO2--N accumulation and PO43--P removal, with the greatest nitrate-to-nitrite transformation ratio (NTR) and PO43--P removal rate of 97.74 % and 64.76 % respectively at the optimum nZVI level (80 mg/L). Microbial community analysis also proved that nZVI had a remarkable influence on the microbial community of EPD. Candidatus_Competibacter was contribute to NO2--N accumulation which was enriched from 24.74 % to 40.02 %. The enrichment of Thauera, Rhodobacteraceae, Pseudomonas were contributed to PO43--P removal. The chemistry of nZVI not only compensated for the deficiency of biological PO43--P removal, but also enhanced NO2--N enrichment. Therefore, nZVI had the huge potentiality to improve the operational performance of the EPD system.

Acute Beetroot Juice Supplementation Has No Effect on Upper- and Lower-Body Maximal Isokinetic Strength and Muscular Endurance in International-Level Male Gymnasts.

Nitrate (NO3-) has properties that can improve muscle function, leading to improvements in metabolic cost of exercise as well as enhance force production. Gymnastics is a whole-body sport, involving events that demand a high level of strength and fatigue resistance. However, the effect of NO3- supplementation on both upper- and lower-body function in gymnasts is unknown. This study examined the effect of acute beetroot juice (BRJ) supplementation on isokinetic strength and endurance of the upper- and lower-body in highly trained international-level male gymnasts. In a double-blind, randomized crossover design, 10 international-level male gymnasts completed two acute supplementation periods, consuming either 2 × 70 ml NO3--rich (∼12.8 mmol/L of NO3-) or NO3--depleted (PLA) BRJ. Maximal strength of the upper-leg and upper-arm at 60°/s, 120°/s, 180°/s, and 300°/s, and muscular endurance (50 repeated isokinetic contractions at 180°/s) were assessed. Plasma NO3- (BRJ: 663 ± 164 µM, PLA: 89 ± 48 µM) and nitrite (NO2-) concentrations (BRJ: 410 ± 137 nmol/L, PLA: 125 ± 36 nmol/L) were elevated following BRJ compared to PLA (both p < .001). Maximal strength of knee and elbow extensors and flexors did not differ between supplements (p > .05 for all velocities). Similarly, fatigue index of knee and elbow extension and flexion was not different between supplements (all p > .05). Acute BRJ supplementation, containing ∼12.8 mmol/L of NO3-, increased plasma NO3- and NO2- concentrations, but did not enhance isokinetic strength or fatigue resistance of either upper or lower extremities in international-level male gymnasts.

Unveiling the nitrogen and phosphorus removal potential: Comparative analysis of three coastal wetland plant species in lab-scale constructed wetlands.

It is well accepted that tidal wetland vegetation performs a significant amount of water filtration for wetlands. However, there is currently little information on how various wetland plants remove nitrogen (N) and phosphorus (P) and how they differ in their denitrification processes. This study compared and investigated the denitrification and phosphorus removal effects of three typical wetland plants in the Yangtze River estuary wetland (Phragmites australis, Spartina alterniflora, and Scirpus mariqueter), as well as their relevant mechanisms, using an experimental laboratory-scale horizontal subsurface flow constructed wetland (CW). The results showed that all treatment groups with plants significantly reduced N pollutants as compared to the control group without plants. In comparison to S. mariqueter (77.2-83.2%), S. alterniflora and P. australis had a similar total nitrogen (TN)removal effectiveness of nearly 95%. With a removal effectiveness of over 99% for ammonium nitrogen (NH4+-N), P. australis outperformed S. alterniflora (95.6-96.8%) and S. mariqueter (94.6-96.5%). The removal of nitrite nitrogen (NO2--N)and nitrate nitrogen (NO3--N)from wastewater was significantly enhanced by S. alterniflora compared to the other treatment groups. Across all treatment groups, the removal rate of PO43--P was greater than 95%. P. australis and S. alterniflora considerably enriched more 15N than S. mariqueter, according to the results of the 15N isotope labeling experiment. While the rhizosphere and bulk sediments of S. alterniflora were enriched with more simultaneous desulfurization-denitrification bacterial genera (such as Paracoccus, Sulfurovum, and Sulfurimonas), which have denitrification functions, the rhizosphere and bulk sediments of P. australis were enriched with more ammonia-oxidizing archaea and ammonia-oxidizing bacteria. As a result, compared to the other plants, P. australis and S. alterniflora demonstrate substantially more significant ability to remove NH4+-N and NO2--N/NO3--N from simulated domestic wastewater.

Effects of Acute Beetroot Juice and Sodium Nitrate on Selected Blood Metabolites and Response to Transient Ischemia: A Crossover Randomized Clinical Trial.

BACKGROUND: Modification of the nitrate (NO3)-nitrite (NO2)-nitric oxide (NO) pathway can be induced by oral intake of inorganic NO3 (NIT) or NO3-rich products, such as beetroot juice (BRJ). OBJECTIVES: The primary aim of this study was to evaluate the plasma changes in betaine, choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), and NO3/NO2 (NOx) concentrations over 4 h after single oral ingestion of NIT or BRJ. The flow-mediated skin fluorescence (FMSF) method was applied to measure the changes in nicotinamide adenine dinucleotide reduced form (NADH) in response to transient ischemia and reperfusion. We hypothesized that various sources of NO3 may differently affect endothelial and mitochondrial functions in healthy human subjects. METHODS: In a randomized crossover trial, 8 healthy young adults ingested 800 mg NO3 from either NIT or BRJ on 2 separate days with ≥3 d apart. Venous blood samples were collected every hour, and FMSF determination was applied bihourly. RESULTS: Plasma betaine and choline concentrations peaked at 1 h after BRJ ingestion, and remained significantly higher than baseline values at all time points (P < 0.001 and P < 0.001, compared to preingestion values). Over time, BRJ was more effective in increasing NOx compared with NIT (fixed-trial effect P < 0.001). Baseline fluorescence decreased after both NIT and BRJ consumption (fixed-time effect P = 0.005). Transient ischemia and reperfusion response increased because of NO3 consumption (fixed-time effect P = 0.003), with no differences between trials (P = 0.451; P = 0.912; P = 0.819 at 0, 2, and 4 h, respectively). CONCLUSIONS: Acute ingestion of BRJ elevated plasma betaine and choline, but not TMA and TMAO. Moreover, plasma NOx levels were higher in the BRJ trial than in the NIT trial. Various sources of NO3 positively affected endothelial and mitochondrial functions. This trial was registered at clinicaltrials.gov as NCT05004935.

Small villages and their sanitary infrastructure-an unnoticed influence on water quantity and a threat to water quality in headwater catchments.

In rural catchments, villages often feature their own, separate urban water infrastructure, including combined sewer overflows (CSOs) or wastewater treatment plants (WWTPs). These point sources affect the water quantity and quality of the receiving low order streams. However, the extent of this impact is rarely monitored. We installed discharge and water quality measurements at the outlet of two small, neighbouring headwater catchments, one that includes a village, a WWTP, and two CSOs, while the other is predominantly influenced by agricultural activities. We also deployed electrical conductivity (EC) loggers at the CSOs to accurately detect discharge times. Discharge from the WWTP and CSOs led to higher peak flows and runoff coefficients during events. Less dilution of EC and increasing ammonium-N (NH4 - N) and ortho-phosphorus (oPO4 - P) concentrations indicate a significant contribution of poorly treated wastewater from the WWTP. During CSO events, water volumes and nutrient loads were clearly elevated, although concentrations were diluted, except for nitrite-N (NO2 - N) and particulate phosphorus (PP). Baseflow nitrate-N (NO3 - N) concentrations were diluted by the WWTP effluent, which led to considerably lower concentrations compared to the more agriculturally influenced stream. Concentrations of oPO4 - P, NH4 - N, and NO2 - N, which are most likely to originate from the WWTP, vary throughout the year but are always elevated. Our study shows the major and variable impact rural settlements can have on stream hydrology and water quality. Point sources should be monitored more closely to better understand the interaction of natural catchment responses and effects caused by sanitary infrastructure.

From nitrate to NO: potential effects of nitrate-reducing bacteria on systemic health and disease.

Current research has described improving multisystem disease and organ function through dietary nitrate (DN) supplementation. They have provided some evidence that these floras with nitrate (NO3-) reductase are mediators of the underlying mechanism. Symbiotic bacteria with nitrate reductase activity (NRA) are found in the human digestive tract, including the mouth, esophagus and gastrointestinal tract (GT). Nitrate in food can be converted to nitrite under the tongue or in the stomach by these symbiotic bacteria. Then, nitrite is transformed to nitric oxide (NO) by non-enzymatic synthesis. NO is currently recognized as a potent bioactive agent with biological activities, such as vasodilation, regulation of cardiomyocyte function, neurotransmission, suppression of platelet agglutination, and prevention of vascular smooth muscle cell proliferation. NO also can be produced through the conventional L-arginine-NO synthase (L-NOS) pathway, whereas endogenous NO production by L-arginine is inhibited under hypoxia-ischemia or disease conditions. In contrast, exogenous NO3-/NO2-/NO activity is enhanced and becomes a practical supplemental pathway for NO in the body, playing an essential role in various physiological activities. Moreover, many diseases (such as metabolic or geriatric diseases) are primarily associated with disorders of endogenous NO synthesis, and NO generation from the exogenous NO3-/NO2-/NO route can partially alleviate the disease progression. The imbalance of NO in the body may be one of the potential mechanisms of disease development. Therefore, the impact of these floras with nitrate reductase on host systemic health through exogenous NO3-/NO2-/NO pathway production of NO or direct regulation of floras ecological balance is essential (e.g., regulation of body homeostasis, amelioration of diseases, etc.). This review summarizes the bacteria with nitrate reductase in humans, emphasizing the relationship between the metabolic processes of this microflora and host systemic health and disease. The potential effects of nitrate reduction bacteria on human health and disease were also highlighted in disease models from different human systems, including digestive, cardiovascular, endocrine, nervous, respiratory, and urinary systems, providing innovative ideas for future disease diagnosis and treatment based on nitrate reduction bacteria.

Factors regulating interaction among inorganic nitrogen and phosphorus species, plant uptake, and relevant cycling genes in a weakly alkaline soil treated with biochar and inorganic fertilizer.

To highlight how biochar affects the interaction between inorganic nitrogen species (ammonium nitrogen, nitrate nitrogen, and nitrite nitrogen: NH4+-N, NO3¯-N, and NO2¯-N) and phosphorus species (calcium phosphate, iron phosphate, and aluminum phosphate: CaP, FeP and AlP) in soil and plant uptake of these nutrients, walnut shell (WS)- and corn cob (CC)-derived biochars (0.5 %, 1 %, 2 %, and 4 %, w/w) were added to a weakly alkaline soil, and then Chinese cabbages were planted. The results showed that the changes in soil inorganic nitrogen were related to biochar feedstock, pyrolysis temperature, and application rate. For soil under the active nitrification condition (dominant NO3¯-N), a significant decrease in the NH4+-N/NO3¯-N ratio after biochar addition indicates enhanced nitrification (excluding WS-derived biochars at 2 % and 4 %), which can be explained by the most positive response of ammonia-oxidizing archaeal amoA to biochar addition. The CC-derived biochar more effectively enhanced soil nitrification than WS-derived biochar did. The addition of 4 % of biochars significantly increased soil inorganic phosphorus, and the addition of CC-derived biochars more effectively increased Ca2P than WS-derived biochars. Biochars significantly decreased plant uptake of phosphorus, while generally had little influence on plant uptake of nitrogen. Interestingly, NO2¯-N in soil significantly positively correlated with total phosphorus in both soil and plant, and significantly negatively correlated with phoC, indicating that a certain degree of NO2¯-N accumulation in soil slightly facilitated plant uptake of phosphorus but inhibited phoC-harboring bacteria. The NO3¯-N in soil significantly positively correlated with Ca2P and Ca8P, while the NH4+-N/NO3¯-N ratio significantly negatively correlated with Ca10P and FeP, indicating that the enhanced nitrification seemed to facilitate the change in phosphorus to readly available ones. This study will help determine how to scientifically and rationally use biochar to regulate inorganic nitrogen and phosphorus species in soil and plant uptake of these nutrients.

Phytochemical Analysis by FTIR of Zanthoxylum Acanthopodium, DC Fruit Ethanol Extract, N-hexan, Ethyl Acetate and Water Fraction.

Background: Andaliman fruit is used as spice in Batak cuisine, North Sumatera, Indonesia. The potency of andaliman fruit extract as herbal medicine is widely studied. Many studies elaborate the benefits of andaliman fruit extract as an antioxidant, antibacterial or anticancer. Objective: The aim of this study was to identify the phytochemical compounds of andaliman fruit extract and its fractions. Methods: The andaliman fruit was originated from Balige city, Tobasa Regency, North Sumatera. The extract was made by maceration within ethanol and followed by fractionation with n-hexan, ethyl acetate and water. The phytochemical screening by chemical reactions, thin layer chromatography, and Fourier Transform Infrared Spectrophotometer were performed. Results: This study found andaliman fruit ethanol extract consists of alkaloids, flavonoids, glycosides, tannins, triterpens, and steroids. The n-hexan fraction consists of triterpens and steroids, ethyl acetate fraction consists of flavonoids and glycosides, and water fraction consists of alkaloid, flavonoid, and glycosides. Andaliman fruit ethanol extract had eight color spots, n-hexan and ethyl acetate fraction had five color spots and water fraction had two color spots. Andaliman fruit ethanol extract had functional group of C-H alkanes, =C-H alkenes (aliphatic), O-H, C=C alkenes, C=C aromatics, C≡C alkynes, C-O, C=O, and NO2. The n-hexan fraction had C-H alkanes, =C-H alkenes (aliphatic), O-H, C=C alkenes, C-O, C=O, and NO2. The ethyl acetate fraction had C-H alkanes, =C-H alkenes (aliphatic), O-H, C=C alkenes, C=C aromatics, C-O, C=O, and NO2. The water fraction had C-H alkanes, =C-H alkenes (aliphatic), O-H, C=C aromatics, C≡C alkynes, and C-O. Conclusion: Phytochemical screening found that andaliman fruit ethanol extract, n-hexan, ethyl acetate and water fraction positive of phytochemical compounds. The FTIR of andaliman fruit ethanol extract, n-hexan fraction, ethyl acetate fraction, and water fraction showed the absorbance of C-H alkanes, O-H, C-O, and C=C alkenes indicating the presence of alkaloids, flavonoids, and triterpenoid saponin.

Air pollution, a worthy opponent? How pollution levels impair athlete performance across physical, technical, and cognitive domains.

INTRODUCTION: Air pollution is a global issue known to effect on human health and performance. In the context of highly skilled athletes, the influence of air pollution on players' physical and technical abilities are established, yet its effects on cognitive performance have received little consideration. This study aims to address this research gap by comprehensively examining the influence of air pollution on the performance of highly skilled athletes using a holistic approach, including both the athlete's brain and body. METHODS: Between 2016 and 2022, a total of 799 soccer players (578 males, 221 females) belonging to a German professional first division club were measured on a battery of performance assessments, including physical, technical, and cognitive tests. The performance data were combined with the average daily concentration of three pollutants: PM10, O3 and NO2. RESULTS: Increased levels of PM10 and O3 were primarily associated with decreased physical and technical performance, including slower sprinting times, impaired change of direction and worse speed and accuracy in the technical assessment. For instance, if the assessment test was held when PM10 levels were at 20 µg/m3, players ran an average 22 ms slower on the 30 m sprint test, 36 ms slower on the change of direction test and showed a 1 % decrease in accuracy on the technical assessment (p < .001). Furthermore, higher concentrations of NO2 negatively impacted cognitive performance across four separate tests of athletes' executive functions (p < .05). CONCLUSION: By encompassing physical, technical, and cognitive assessments, this study highlights the multifaceted nature of performance impairments resulting from air pollution exposure in a population characterized by have exceptional abilities across all three domains. These findings underscore the widespread impact of pollution on a diverse sample of athletes and emphasize the need to consider air pollution in the broader context of its effects on human health and the environment.

Acute beetroot juice supplementation did not enhance intermittent running performance in trained rugby players.

ABSTRACTPurpose: Since the effect of dietary nitrate (NO3-) supplementation on rugby performance is unclear, the aim of the present study was to determine the effect of acute NO3- supplementation, on the modified Yo-Yo intermittent recovery level 1 (IR1) performance test in trained male rugby players.Methods: In a randomised, counterbalanced, double-blind, placebo-controlled crossover design, 12 trained rugby union players performed two experimental trials three hours after supplementation of either 140 mL NO3--rich (BRJ; ∼12.8 mmol NO3-) or NO3--depleted (PLA) BRJ. After blood sampling, players performed the modified Yo-Yo IR1 test. Countermovement jumps (CMJ) were also measured before (pre-CMJ) and after (post-CMJ) the prone Yo-Yo IR1 test.Results: Plasma NO3- (BRJ: 570 ± 146 µM vs. PLA: 72 ± 23 µM) and nitrite (NO2-) concentrations (BRJ: 320 ± 123 nM vs. PLA: 103 ± 57 nM) were increased after BRJ compared to PLA supplementation (both P < 0.001). Performance in the modified Yo-Yo IR1 test did not differ between BRJ (542 ± 209 m) and PLA (498 ± 185 m, P = 0.3). The jump height in pre-CMJ and in post-CMJ were similar between trials (both P > 0.05).Conclusions: Acute BRJ supplementation increased plasma NO3- and NO2- concentrations but had no benefit on an intermittent running test that reflects the demands of rugby performance, and CMJ performances. The findings do not support acute high-dose NO3- supplementation as an ergogenic aid to enhance physical performance in trained male rugby players.

It has been suggested that NO₃^- supplementation might have ergogenic potential for team sport athletes, however, the impact of nitrate supplementation on intermittent running performance of rugby players is unclear. Therefore, we aimed to assess the impact of acute NO₃^- supplementation on the Prone Yo-Yo IR1 performance in trained male rugby players.Acute supplementation of high-dose nitrate supplementation substantially increased plasma NO₃^- and NO₂^- concentrations but did not improve the Prone Yo-Yo IR1 performance and countermovement jump performance in trained rugby players.The findings of the present study do not support acute BRJ supplementation as a nutritional ergogenic aid for trained rugby players, at least for the Prone Yo-Yo IR1performance, but are in line with the notion that supplementation of NO₃^- is less likely to be ergogenic in well trained athletes.

Response of microalgae size-class structure to nutrients differences in northern Yellow Sea, China.

Marine phytoplankton size-class structure affects ecological functions and shellfish culture. We use high-throughput sequencing and size-fractioned grading techniques to identify and analyze responses of phytoplankton differences in environmental variables at Donggang, northern Yellow Sea (high inorganic nitrogen (DIN)) and Changhai (low DIN) for 2021. The main environmental variables that correlate with differences in the proportional contributions of pico-, nano-, and microphytoplankton to the total phytoplankton community are inorganic phosphorus (DIP), nitrite to inorganic nitrogen ratio (NO2/dissolved inorganic nitrogen (DIN)), and ammonia nitrogen to inorganic nitrogen ratio (NH4/DIN), respectively. DIN, which contributes most to environmental differences, mainly positively correlates with changes in picophytoplankton biomass in high DIN waters. Nitrite (NO2) correlates mostly with changes in the proportional contribution of microphytoplankton in high DIN waters and nanophytoplankton in low DIN waters, and negatively correlates with changes in the biomass and proportional representation of microphytoplankton in low DIN waters. For near-shore phosphorus-limited waters, an increase in DIN may increase total microalgal biomass, but proportions of microphytoplankton may not increase; for high DIN waters, an increase in DIP may increase proportions of microphytoplankton, while for low DIN waters, an increase in DIP may preferentially increase proportions of picophytoplankton and nanophytoplankton. Picophytoplankton contributed little to the growth of two commercially cultured filter-feeding shellfish, Ruditapes philippinarum and Mizuhopecten yessoensis.

Reduction in blood pressure following acute dietary nitrate ingestion is correlated with increased red blood cell S-nitrosothiol concentrations.

Dietary nitrate (NO3-) supplementation can enhance nitric oxide (NO) bioavailability and lower blood pressure (BP) in humans. The nitrite concentration ([NO2-]) in the plasma is the most commonly used biomarker of increased NO availability. However, it is unknown to what extent changes in other NO congeners, such as S-nitrosothiols (RSNOs), and in other blood components, such as red blood cells (RBC), also contribute to the BP lowering effects of dietary NO3-. We investigated the correlations between changes in NO biomarkers in different blood compartments and changes in BP variables following acute NO3- ingestion. Resting BP was measured and blood samples were collected at baseline, and at 1, 2, 3, 4 and 24 h following acute beetroot juice (∼12.8 mmol NO3-, ∼11 mg NO3-/kg) ingestion in 20 healthy volunteers. Spearman rank correlation coefficients were determined between the peak individual increases in NO biomarkers (NO3-, NO2-, RSNOs) in plasma, RBC and whole blood, and corresponding decreases in resting BP variables. No significant correlation was observed between increased plasma [NO2-] and reduced BP, but increased RBC [NO2-] was correlated with decreased systolic BP (rs = -0.50, P = 0.03). Notably, increased RBC [RSNOs] was significantly correlated with decreases in systolic (rs = -0.68, P = 0.001), diastolic (rs = -0.59, P = 0.008) and mean arterial pressure (rs = -0.64, P = 0.003). Fisher's z transformation indicated no difference in the strength of the correlations between increases in RBC [NO2-] or [RSNOs] and decreased systolic blood pressure. In conclusion, increased RBC [RSNOs] may be an important mediator of the reduction in resting BP observed following dietary NO3- supplementation.

Improving nutrients removal of Anaerobic-Anoxic-Oxic process via inhibiting partial anaerobic mixture with nitrite in side-stream tanks: Role of nitric oxide.

A side-stream tank which was in parallel with the anoxic tank was used to improve the performance of an Anaerobic-Anoxic-Oxic process. The partial mixtures from the anaerobic tank were injected into the side-stream tank with the initial nitrite nitrogen (NO2--N) concentrations of 10 mg/L and 20 mg/L. When the initial NO2--N concentration in the tank was 20 mg/L, total nitrogen and total phosphorus removal efficiencies of the A2/O process increased from 72% and 48% to 90% and 89%, respectively. 2.23 mg/L of nitric oxide (NO) were observed in the side-stream tank. The abundance of Nitrosomonas sp. and Nitrospira sp. were varied from 0.98% and 6.13% to 2.04% and 1.13%, respectively. The abundances of Pseudomonas sp. and Acinetobacter sp. were increased from 0.81% and 0.74% to 6.69% and 5.48%, respectively. NO plays an important role for improving the nutrients removal of the A2/O process in the side-stream nitrite-enhanced strategy.

Short-term beetroot juice supplementation improves muscle speed and power but does not reduce blood pressure or oxidative stress in 65-79 y old men and women.

We have previously demonstrated that acute ingestion of inorganic nitrate (NO3-)-rich beetroot juice (BRJ), a source of nitric oxide (NO) via the NO3- → nitrite (NO2-) → NO pathway, can improve muscle speed and power in older individuals. It is not known, however, whether this effect is maintained or perhaps even enhanced with repeated ingestion, or if tolerance develops as with organic nitrates, e.g., nitroglycerin. Using a double-blind, placebo-controlled, crossover design, we therefore studied 16 community-dwelling older (age 71 ± 5 y) individuals after both acute and short-term (i.e., daily for 2 wk) BRJ supplementation. Blood samples were drawn and blood pressure was measured periodically during each ∼3 h experiment, with muscle function determined using isokinetic dynamometry. Acute ingestion of BRJ containing 18.2 ± 6.2 mmol of NO3- increased plasma NO3- and NO2- concentrations 23 ± 11 and 2.7 ± 2.1-fold over placebo, respectively. This was accompanied by 5 ± 11% and 7 ± 13% increases in maximal knee extensor speed (Vmax) and power (Pmax), respectively. After daily supplementation for 2 wk, BRJ ingestion elevated NO3- and NO2- levels 24 ± 12 and 3.3 ± 4.0-fold, respectively, whereas Vmax and Pmax were 7 ± 9% and 9 ± 11% higher than baseline. No changes were observed in blood pressure or in plasma markers of oxidative stress with either acute or short-term NO3- supplementation. We conclude that both acute and short-term dietary NO3- supplementation result in similar improvements in muscle function in older individuals. The magnitudes of these improvements are sufficient to offset the decline resulting from a decade or more of aging and are therefore likely to be clinically significant.

The influence of acute dietary nitrate supplementation on skeletal muscle fatigue and recovery in older women.

Older individuals fatigue more rapidly during, and recover more slowly from, dynamic exercise. Women are particularly vulnerable to these deleterious effects of aging, which increases their risk of falling. We have shown that dietary nitrate (NO3 - ), a source of nitric oxide (NO) via the NO3 - → nitrite (NO2 - ) → NO pathway, enhances muscle speed and power in older individuals in the non-fatigued state; however, it is unclear if it reduces fatigability and/or improves recoverability in this population. Using a double-blind, placebo-controlled, crossover design, we studied 18 older (age 70 ± 4 years) women who were administered an acute dose of beetroot juice (BRJ) containing either 15.6 ± 3.6 or <0.05 mmol of NO3 - . Blood samples were drawn throughout each ~3 h visit for plasma NO3 - and NO2 - analysis. Peak torque was measured during, and periodically for 10 min after, 50 maximal knee extensions performed at 3.14 rad/s on an isokinetic dynamometer. Ingestion of NO3 - -containing BRJ increased plasma NO3 - and NO2 - concentrations by 21 ± 8 and 4 ± 4 fold, respectively. However, there were no differences in muscle fatigue or recovery. Dietary NO3 - increases plasma NO3 - and NO2 - concentrations but does not reduce fatigability during or enhance recoverability after high intensity exercise in older women.

Traffic-related air pollution and supplemental folic acid intake in relation to DNA methylation in granulosa cells.

BACKGROUND: Higher exposure to traffic-related air pollution (TRAP) is related to lower fertility, with specific adverse effects on the ovary. Folic acid may attenuate these effects. Our goal was to explore the relation of TRAP exposure and supplemental folic acid intake with epigenetic aging and CpG-specific DNA methylation (DNAm) in granulosa cells (GC). Our study included 61 women undergoing ovarian stimulation at a fertility center (2005-2015). DNAm levels were profiled in GC using the Infinium MethylationEPIC BeadChip. TRAP was defined using a spatiotemporal model to estimate residence-based nitrogen dioxide (NO2) exposure. Supplemental folic acid intake was measured with a validated food frequency questionnaire. We used linear regression to evaluate whether NO2 or supplemental folic acid was associated with epigenetic age acceleration according to the Pan-tissue, mural GC, and GrimAge clocks or DNAm across the genome adjusting for potential confounders and accounting for multiple testing with a false discovery rate < 0.1. RESULTS: There were no associations between NO2 or supplemental folic acid intake and epigenetic age acceleration of GC. NO2 and supplemental folic acid were associated with 9 and 11 differentially methylated CpG sites. Among these CpGs, only cg07287107 exhibited a significant interaction (p-value = 0.037). In women with low supplemental folic acid, high NO2 exposure was associated with 1.7% higher DNAm. There was no association between NO2 and DNAm in women with high supplemental folic acid. The genes annotated to the top 250 NO2-associated CpGs were enriched for carbohydrate and protein metabolism, postsynaptic potential and dendrite development, and membrane components and exocytosis. The genes annotated to the top 250 supplemental folic acid-associated CpGs were enriched for estrous cycle, learning, cognition, synaptic organization and transmission, and size and composition of neuronal cell bodies. CONCLUSIONS: We found no associations between NO2, supplemental folic acid, and DNAm age acceleration of GC. However, there were 20 differentially methylated CpGs and multiple enriched GO terms associated with both exposures suggesting that differences in GC DNAm could be a plausible mechanism underlying the effects of TRAP and supplemental folic acid on ovarian function.

Effect of Allium cepa extract on total and differential WBC, TP level, oxidant and antioxidant biomarkers, and lung pathology in ovalbumin-sensitized rats.

BACKGROUND: Previous studies have shown that Allium cepa (A. cepa) has relaxant and anti-inflammatory effects. In this research, A. cepa extract was examined for its prophylactic effect on lung inflammation and oxidative stress in sensitized rats. METHODS: Total and differential white blood cell (WBC) count in the blood, serum levels of oxidant and antioxidant biomarkers, total protein (TP) in bronchoalveolar lavage fluid (BALF), and lung pathology were investigated in control group (C), sensitized group (S), and sensitized groups treated with A. cepa and dexamethasone. RESULTS: Total and most differential WBC count, TP, NO2, NO3, MDA (malondialdehyde), and lung pathological scores were increased while lymphocytes, superoxide dismutase (SOD), catalase (CAT), and thiol were decreased in sensitized animals compared to controls (p < 0.01 to p < 0.001). Treatment with all concentrations of extract significantly improved total WBC, TP, NO2, NO3, interstitial fibrosis, and emphysema compared to the S group (p < 0.05 to p < 0.001). Two higher concentrations of the extract significantly decreased neutrophil and monocyte count, malondialdehyde, bleeding and epithelial damage but increased lymphocyte, CAT, and thiol compared to the S group (p < 0.05 to p < 0.001). Dexamethasone treatment also substantially improved most measured parameters (p < 0.05 to p < 0.001), but it did not change eosinophil percentage. It was proposed that A. cepa extract could affect lung inflammation and oxidative stress in sensitized rats.

Association between air pollutants and initiation of biological therapy in patients with ankylosing spondylitis: a nationwide, population-based, nested case-control study.

BACKGROUND: Outdoor air pollution has been found to trigger systemic inflammatory responses and aggravate the activity of certain rheumatic diseases. However, few studies have explored the influence of air pollution on the activity of ankylosing spondylitis (AS). As patients with active AS in Taiwan can be reimbursed through the National Health Insurance programme for biological therapy, we investigated the association between air pollutants and the initiation of reimbursed biologics for active AS. METHODS: Since 2011, hourly concentrations of ambient air pollutants, including PM2.5, PM10, NO2, CO, SO2, and O3, have been estimated in Taiwan. Using Taiwanese National Health Insurance Research Database, we identified patients with newly diagnosed AS from 2003 to 2013. We selected 584 patients initiating biologics from 2012 to 2013 and 2336 gender-, age at biologic initiation-, year of AS diagnosis- and disease duration-matched controls. We examined the associations of biologics initiation with air pollutants exposure within 1 year prior to biologic use whilst adjusting for potential confounders, including disease duration, urbanisation level, monthly income, Charlson comorbidity index (CCI), uveitis, psoriasis and the use of medications for AS. Results are shown as adjusted odds ratio (aOR) with 95% confidence intervals (CIs). RESULTS: The initiation of biologics was associated with exposure to CO (per 1 ppm) (aOR, 8.57; 95% CI, 2.02-36.32) and NO2 (per 10 ppb) (aOR, 0.23; 95% CI, 0.11-0.50). Other independent predictors included disease duration (incremental year, aOR, 8.95), CCI (aOR, 1.31), psoriasis (aOR, 25.19), use of non-steroidal anti-inflammatory drugs (aOR, 23.66), methotrexate use (aOR, 4.50; 95% CI, 2.93-7.00), sulfasalazine use (aOR, 12.16; 95% CI, 8.98-15.45) and prednisolone equivalent dosages (mg/day, aOR, 1.12). CONCLUSIONS: This nationwide, population-based study revealed the initiation of reimbursed biologics was positively associated with CO levels, but negatively associated with NO2 levels. Major limitations included lack of information on individual smoking status and multicollinearity amongst air pollutants.

Dietary nitrate supplementation increases nitrate and nitrite concentrations in human skin interstitial fluid.

Acute dietary nitrate (NO3-) supplementation can increase [NO3-], but not nitrite ([NO2-]), in human skeletal muscle, though its effect on [NO3-] and [NO2-] in skin remains unknown. In an independent group design, 11 young adults ingested 140 mL of NO3--rich beetroot juice (BR; 9.6 mmol NO3-), and 6 young adults ingested 140 mL of a NO3--depleted placebo (PL). Skin dialysate, acquired through intradermal microdialysis, and venous blood samples were collected at baseline and every hour post-ingestion up to 4 h to assess dialysate and plasma [NO3-] and [NO2-]. The relative recovery rate of NO3- and NO2- through the microdialysis probe (73.1% and 62.8%), determined in a separate experiment, was used to estimate skin interstitial [NO3-] and [NO2-]. Baseline [NO3-] was lower, whereas baseline [NO2-] was higher in the skin interstitial fluid relative to plasma (both P < 0.001). Acute BR ingestion increased [NO3-] and [NO2-] in the skin interstitial fluid and plasma (all P < 0.001), with the magnitude being smaller in the skin interstitial fluid (e.g., 183 ± 54 vs. 491 ± 62 µM for Δ[NO3-] from baseline and 155 ± 190 vs. 217 ± 204 nM for Δ[NO2-] from baseline at 3 h post BR ingestion, both P ≤ 0.037). However, due to the aforementioned baseline differences, skin interstitial fluid [NO2-] post BR ingestion was higher, whereas [NO3-] was lower relative to plasma (all P < 0.001). These findings extend our understanding of NO3- and NO2- distribution at rest and indicate that acute BR supplementation increases [NO3-] and [NO2-] in human skin interstitial fluid.