Search Results (56)

Beetroot juice (BRJ), a concentrated dietary source of nitrate alongside betalains and polyphenols, influences physiology through enhanced nitrate–nitrite–NO bioavailability, antioxidant activity, and interactions with oral and gut nitrate-reducing microbiota. The efficiency of these mechanisms depends on dose, timing, and preservation of oral bacteria, with antibacterial mouthwash or thiocyanate-rich foods potentially blunting NO₂⁻ generation. Acute BRJ ingestion consistently elevates circulating nitrate and nitrite, yet its impact on glucose, insulin, and lipid regulation is modest; chronic intake may reinforce nitrate-reduction capacity, improve redox balance, and shift microbial composition, though long-term metabolic outcomes remain variable. Cardiovascular adaptations appear more coherent, with acute reductions in systolic blood pressure and improved endothelial function complemented in some cases by microvascular enhancements during multi-week supplementation. Neuromuscular and cognitive effects are less uniform; BRJ does not reliably increase maximal strength or global cognition but may support electrophysiological recovery after muscle-damaging exercise and improve executive performance under fatigue. In exercise settings, dose and timing are critical, as BRJ most consistently benefits endurance performance by reducing oxygen cost, improving exercise economy, and enhancing time-trial or time-to-exhaustion outcomes, whereas effects on sprint, power, and team-sport tasks are more sensitive to contraction duration, recovery intervals, and athlete training status. Overall, available evidence supports a role for NO-mediated vascular and metabolic pathways in the physiological effects of BRJ, although marked inter-individual variability highlights the need for responder-focused dosing strategies and further mechanistic investigation integrating metabolic, microbial, and performance-related outcomes. Full article

Arterial hypertension (AH) is a highly prevalent, multifactorial cardiovascular condition characterized by endothelial dysfunction, increased oxidative stress, and impaired nitric oxide (NO) bioavailability. While pharmacological treatment is primarily directed toward blood pressure reduction, accumulating evidence indicates that several antihypertensive drug classes also confer antioxidant and vasculoprotective benefits. Concurrently, dietary intake of inorganic nitrate and nitrite has gained attention as an adjunctive approach to restore NO signaling and redox homeostasis. This narrative review summarizes current evidence regarding the antioxidant effects of major antihypertensive drug classes and examines the contribution of nitrate- and nitrite-rich diets to the modulation of oxidative stress and vascular dysfunction in AH. A systematic search of PubMed, EMBASE, Scopus, ScienceDirect, Web of Science, Google Scholar, and Food and Drug Administration (FDA) databases was performed for studies published between August and December 2025. Experimental and clinical investigations assessing oxidative stress markers, endothelial function, or NO-related outcomes in AH were selected following title and abstract screening and full-text evaluation. Available data indicate that angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, diuretics, β-blockers, and calcium channel blockers mitigate oxidative stress via mechanisms including NADPH oxidase suppression, decreased reactive oxygen species production, reinforcement of endogenous antioxidant systems, and restoration of endothelial NO bioavailability. Moreover, dietary nitrate and nitrite support vascular function through activation of the nitrate–nitrite–NO pathway. Combining nitrate- and antioxidant-rich dietary strategies with antihypertensive agents that lack inherent redox-modulating activity may enhance blood pressure control and lower cardiovascular risk. Nevertheless, well-designed long-term randomized clinical trials are needed to elucidate class-specific interactions and underlying redox mechanisms. Full article

The research investigates nitrate and nitrite concentrations in vegetables sold at agri-food markets in Craiova, Dolj County. Vegetable samples were purchased from markets and sourced from the primary agricultural regions of Dolj County, ensuring a representative selection. A total of 300 samples were collected, with 20 samples taken from each of 15 vegetable species at commercial maturity. This research also aimed to estimate the contribution of each type of vegetable to the intake of nitrates/nitrites ingested through consumption, as well as to carry out an assessment of the risk to human health associated with the consumption of these vegetables. Our analysis showed that only three vegetables (tomatoes, eggplants, and bell peppers) exceeded the maximum permissible nitrate levels (MPL). The MPL for nitrite content was exceeded in several vegetables, including eggplant, green bean, lettuce, cabbage, dill, spinach, and lovage. For nitrates, the Hazard Risk Index (HRI) was consistently below 1 across all samples, with the sole exception of children’s consumption scenario. The HRI for nitrite was also below 1 for all samples, suggesting an absence of exposure risk. The findings from this study suggest that the consumption of vegetable products poses an insignificant risk in terms of nitrate and nitrite intake. Full article

Cardiovascular diseases (CVDs), which include multiple disorders of the heart and blood vessels, are the leading causes of death. Nitric oxide (NO) is a vasodilator that regulates vascular tension. Endogenous NO is produced via the L-arginine–nitric oxide synthase (NOS) pathway. In conditions of cardiovascular dysfunction, NOS activity is impaired, leading to NO deficiency. In turn, the reduction in NO bioactivity exacerbates the pathogenesis of CVDs. Exogenous intake of inorganic nitrate supplements endogenous production via the nitrate–nitrite–NO pathway to maintain the NO supply. Salivary glands play an essential role in the conversion of nitrate to NO, with approximately 25% of circulating nitrate being absorbed and secreted into saliva. As a result, salivary nitrate concentrations can exceed that in the blood by more than tenfold. This recycled nitrate in saliva serves as a reservoir for NO and performs NO-like functions when endogenous NO production is insufficient. In this review, we summarize the emerging benefits of dietary nitrate in CVDs, with a particular focus on salivary-gland-mediated nitrate recirculation in maintaining NO bioavailability and cardiovascular homeostasis. Salivary-gland-mediated nitrate recirculation provides a novel perspective for potential intervention of CVDs. Full article

Trypanosoma vivax infection is an emerging condition that causes damage and mortality among cattle and is transmitted by mechanical vectors or contaminated fomites. This disease has been spreading in southern Brazil, causing anemia, weight loss, diarrhea, abortion, and infertility; however, its behavior and host–parasite relationships are not yet fully understood. To clarify this issue, animals that presented clinical signs were subjected to an immunochromatographic screening test. An indirect immunofluorescence test was then performed on samples collected before treatment (the gold standard test), which showed that in the herd of 20 cows, we had 14 seropositive for T. vivax. Blood samples were collected before and after treatment to study the effects of the disease and treatment, with the cows divided into two groups: infected and uninfected. Cows were evaluated for hematologic, biochemical, and antioxidant responses, comparing them with uninfected and infected animals, as well as pre- and post-treatment (isometamidium chloride—1 mg/kg body weight [BW]). There was no difference (p > 0.05) between groups in milk production and feed intake; however, ten days after treatment, there was an increase of 1.72 kg of milk in cows diagnosed as infected with T. vivax. Seropositive cows had lower erythrocyte counts, hemoglobin concentrations, hematocrit, platelet counts, and lymphocyte and granulocyte counts. In seropositive cows, the higher total protein concentration is due to increased globulins, which the protein profile by electrophoresis showed to be related to higher levels of immunoglobulins (IgA and other heavy-chain immunoglobulins), ceruloplasmin, haptoglobin, ferritin, C-reactive protein; associated with lower transferrin levels. The activity of the enzymes aspartate aminotransferase, gamma-glutamyl transferase, cholinesterases, and creatine kinase were compared in seronegative and seropositive cows for T. vivax. Lower serum calcium levels were observed in seropositive cows. Cows diagnosed with trypanosomosis presented high levels of reactive oxygen species, lipid peroxidation, protein oxidation, nitrite/nitrate activity, superoxide dismutase, and glutathione peroxidase. The enzymes catalase and glutathione S-transferase presented lower activity in the blood of seropositive cows compared to the control on the day of diagnosis, which was no longer observed ten days after treatment. The animals exhibited hypogalactia, anemia, thrombocytopenia, leukopenia, and acute phase response accompanied by liver and muscle tissue damage and oxidative stress, demonstrating the effect of T. vivax infection in naturally infected Jersey cows. Full article

(1) Background: Advances in food processing practices and health care are some of the most significant advances in modern daily life. The goal of this study is to evaluate the safety of potassium and sodium nitrates and nitrites when they are used as fertilizers in agriculture and food additives, as well as the known conversion of nitrate to nitrite in humans. (2) Methods: Various bioassays were conducted to investigate the effects of nitrates and nitrites in the Drosophila melanogaster genetic tester system. These assays focused on the modulation of degenerative processes at the molecular, cellular, individual, and population levels. Additionally, we assessed the chemopreventive potential and the ability to induce DNA strand breaks in HL-60 tumour cells. (3) Results: All nitrate and nitrite concentrations tested were shown to not be toxic or genotoxic in Drosophila since none of the compounds reached the LD₅₀ and significant genetic mutation. A positive or null protective capacity against a toxic agent was found for nitrates, not for nitrites, showing that sodium nitrite has a synergistic effect when combined with the oxidant toxin hydrogen peroxide; and a nutraceutical potential in the lifespan only for sodium nitrate to improve the quality of life in 5 days at ADI concentration. The in vitro results in human leukemia cells showed a chemopreventive potential only for potassium nitrate and sodium nitrite due to reducing the viability of HL-60 cells growth to 18% and 29%, respectively, compared to the controls at ADI (acceptable daily intake) concentrations. However, neither of these showed DNA damage or methylation modifications. (4) Conclusions: The tested compounds were shown to be safe to use during in vivo and in vitro tests when used at the extrapolated ADI concentrations. Full article

Introduction: Aging is associated with increased reactive oxygen species (ROS) and reduced bioavailability of nitric oxide (NO). Curcumin has been shown to increase NO bioavailability due to its ability to neutralize ROS, preventing oxidative stress. The present study aimed to investigate the effect of curcumin intake on skeletal muscle oxygen parameters and exercise tolerance in response to exercise in older people. Changes in circulating levels of NO metabolites were also investigated. Methods: Older subjects consumed 10 g of turmeric root extract from Curcuma longa L. (containing 95.33% of the total curcuminoids) or placebo in a randomized, double-blind, crossover study. A time of 2 h after ingestion, the participants performed one set of rhythmic handgrip exercise until the limit of tolerance, followed by 5 min of recovery. During exercise and exercise recovery, skeletal muscle oxygen saturation parameters were recorded. Results: During exercise, the amplitude of deoxyhemoglobin was greater after curcumin intake compared to placebo (CUR: 13.11 ± 9.52 vs. PLA: 10.22 ± 8.39 μM, p = 0.030). Furthermore, a faster skeletal muscle oxygen resaturation during exercise recovery was observed after curcumin compared to placebo (CUR: 1.01 ± 0.65 vs. PLA: 0.32 ± 0.20%.s⁻¹, p = 0.004). These results were associated with significant changes in plasma nitrite (CUR: 6.82 ± 11.68 vs. PLA: −4.94 ± 17.28%, p = 0.028). There was no statistical difference in the total hemoglobin, exercise time until fatigue, and plasma nitrate between groups. Conclusions: The present study suggests that curcumin improves muscle oxygenation status at the capillary level in older adults by possibly improving muscle oxygen extraction and/or delivery, with no effect on exercise tolerance. Full article

This study aimed to assess the effect of a combination of aerobic exercise training (ET) and Chlorella (CH) intake on arterial nitric oxide (NO) production and arterial stiffness in obese rats. Twenty-week-old obese male rats were randomly grouped into four (n = 6): OBESE-SED (sedentary control), OBESE-ET (treadmill 25 m/min, 1 h, 5 d/week), OBESE-CH (0.5% Chlorella powder in normal diet), and OBESE-ET+CH (combination of ET and CH intake) groups. The carotid–femoral pulse wave velocity (cfPWV), an index of arterial stiffness, was significantly lesser in the OBESE-ET, OBESE-CH, and OBESE-ET+CH groups than in the OBESE-SED group, and in the OBESE-ET+CH group significantly further enhanced these effects compared with the OBESE-ET and OBESE-CH groups. Additionally, arterial nitrate/nitrite (NOx) levels were significantly greater in the OBESE-ET, OBESE-CH, and OBESE-ET+CH groups than in the OBESE-SED group, and the OBESE-ET+CH group compared with the OBESE-ET and OBESE-CH groups. Furthermore, arterial NOx levels were positively correlated with arterial endothelial NO synthase phosphorylation levels (r = 0.489, p < 0.05) and negatively correlated with cfPWV (r = −0.568, p < 0.05). In conclusion, a combination of ET and CH intake may reduce arterial stiffness via an enhancement of the arterial NO signaling pathway in obese rats. Full article

Food innovation that utilises agricultural waste while enhancing nutritional value is important for waste valorisation and consumer health. This study investigated incorporating spinach (Spinacia oleracea), as a model leafy agricultural waste, into wheat bread. We analysed the nutrient content, colour, texture, sensory attributes and purchase/consume intention ratings. Adding 10–40% spinach (w/w) yielded loaves with similar heights but significantly different colour and texture (p < 0.05) from white bread. Increasing spinach decreased total carbohydrates (including starch) while significantly increasing other nutrients (protein, fibre, iron, magnesium, potassium, zinc, calcium, vitamins A, C, E, folate, niacin, pyridoxine, nitrate/nitrite and polyphenols) (p < 0.05). Spinach addition increased bread porosity, linked to higher pasting parameters (peak, trough, breakdown, final and setback viscosity) with reduced pasting time and temperature. Texture analysis resulted in decreased hardness, chewiness, gumminess and firmness while increasing cohesiveness, with maximum resilience at 20% spinach enrichment. Sensory analysis with 21 untrained panellists revealed decreased visual appeal, less preferred taste, odour and overall liking (p < 0.05) with increasing spinach, with no significant difference in texture acceptance, but the 20% enrichment had comparable acceptance to white bread. Enriching staple foods like bread with leafy vegetable waste offers a promising approach for increasing daily vegetable intake. Full article

Dietary nitrate (NO₃⁻) supplementation is known to enhance nitric oxide (NO) activity and acts as a vasodilator. In this randomized crossover study, we investigated the effect of inorganic NO₃⁻ supplementation on the changes in calf venous volume during postural change and subsequent skeletal muscle pump activity. Fifteen healthy young adults were assigned to receive beetroot juice (BRJ) or a NO₃⁻-depleted control beverage (prune juice: CON). Two hours after beverage consumption, the changes in the right calf volume during postural change from supine to upright and a subsequent right tiptoe maneuver were measured using venous occlusion plethysmography. The increase in calf volume from the supine to upright position (total venous volume [VV]) and the decrease in calf volume during the right tiptoe maneuver (venous ejection volume [Ve]) were calculated. Plasma NO₃⁻ concentration was higher in the BRJ group than in the CON group 2 h after beverage intake (p < 0.05). However, VV and Ve did not differ between CON and BRJ. These results suggest that acute intake of BRJ may enhance NO activity via the NO₃⁻ → nitrite → NO pathway but does not change calf venous pooling due to a postural change or the calf venous return due to skeletal muscle pump activity in healthy young adults. Full article

SARS-CoV-2 induces a hyperinflammatory reaction due to the excessive release of cytokines during the immune response. The bacterial endotoxin lipopolysaccharide (LPS) contributes to the low-grade inflammation associated with the metabolic syndrome, enhancing the hyperinflammatory reaction induced by the SARS-CoV-2 infection. The intake of sodium nitrate, a precursor of nitrite and nitric oxide, influences the antioxidant and pro-inflammatory gene expression profile after immune stimulation with LPS in peripheral blood mononuclear cells from metabolic syndrome patients. We aimed to assess the inflammatory and antioxidant responses of immune cells from metabolic syndrome patients to exposure to the SARS-CoV-2 spike protein (S protein) together with LPS and the effect of nitrite in these responses. Whole blood samples obtained from six metabolic syndrome patients were cultured for 16 h at 37 °C with four different media: control medium, control medium plus LPS (100 ng/mL), control medium plus LPS (100 ng/mL) plus S protein (10 ng/mL), and control medium plus LPS (100 ng/mL) plus S protein (10 ng/mL) plus nitrite (5 µM). Immune stimulation with the LPS/S protein enhanced nitrate biosynthesis from nitrite oxidation and probably from additional organic precursors. In vitro incubations with the LPS/S protein enhanced the expression and/or release of pro-inflammatory TNFα, IL-6, IL-1β, and TLR4, as well as the expression of the anti-inflammatory IL-1ra and IL-10 and antioxidant enzymes. Nitrite attenuated the pro- and anti-inflammatory response induced by the S protein without interfering with the activation of TLR4 and antioxidant enzyme expression, raising the possibility that nitrite could have potential as a coadjutant in the treatment of COVID-19. Full article

Nitric oxide (NO) is an inorganic radical produced by both the non-enzymatic nitrate (NO₃⁻)—nitrite (NO₂⁻)—NO pathway and enzymatic reactions catalyzed by nitric oxide synthase (NOS). Also, as nitrate and nitrite from dietary and other endogenous sources can be reduced back to nitric oxide in vivo, the endogenous NO level can be increased through the consumption of nitrate–rich vegetables. Ingestion of dietary NO₃⁻ has beneficial effects which have been attributed to a subsequent increase in NO: a signaling molecule that may regulate various systems, including the cardiovascular system. A diet rich in NO₃⁻ from green leafy and root vegetables has cardioprotective effects, with beetroot products being particularly good sources of NO₃⁻. For example, various studies have demonstrated a significant increase in nitrite levels (regarded as markers of NO) in plasma after the intake of beetroot juice. The present review describes the current literature concerning the role of nitrate-rich vegetables (especially beetroot products) in the prophylaxis and treatment of cardiovascular diseases (CVDs). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, Web of Knowledge, Sci Finder, Web of Science, and SCOPUS. Full article

The health-promoting properties of chokeberry fruit have been confirmed in numerous scientific studies. It has been shown that the consumption of these fruits, due to the high content of bioactive compounds, has beneficial effects in neurodegenerative diseases, in addition to having hypolipemic, hypotensive, hypoglycemic, and anti-inflammatory properties. However, different conditions and methods of fruit cultivation, as well as methods of juice and fiber production, may result in a high content of toxic substances, which reduce the health value of chokeberry products. Many substances are environmental pollutants. In this study, for the first time, we examined the content of toxic elements (As, Hg, Cd, Pb), nitrates, and nitrites in all chokeberry juices (organic, conventional, from concentrate, and not from fruit concentrate) without additives and in all chokeberry fibers available in Poland. In addition, risk indicators of adverse health effects were calculated. The median content of the contaminants tested in juices was 0.461 µg/kg for As, 1.170 µg/kg for Cd, 0.427 µg/kg for Hg, 1.404 µg/kg for Pb, 4.892 mg/kg for NO₂⁻, and 41.788 mg/kg for NO₃⁻. These values did not exceed the permissible standards for the calculated indicators. There were also no statistically significant differences in the content of Cd, Hg, and Pb, as well as nitrates (III) and nitrates (V), in the tested juices depending on the method of cultivation and juice production. However, statistically significant differences in As content were found between juices from conventional and organic cultivation (1.032 µg/kg vs. 0.458 µg/kg) and juices from concentrate and not from concentrate (1.164 µg/kg vs. 0.460 µg/kg). There were no statistically significant differences with respect to impurities in fibers. It is shown that the consumption of chokeberry juice and fiber in the amount normally consumed does not pose a health risk associated with the intake of toxic substances; in the case of long-term fiber consumption, the Pb content should be monitored. In particular, organic juices and those not from fruit concentrate are recommended due to the lower As content. Full article

Diet during pregnancy is one of the most important nutritional challenges associated with some risks for the mother and the fetus. For the first time, the study aims to estimate long-term (2018–2022) exposure to nitrate and phosphates in Serbian pregnant women, based on individual consumption data and accurate values measured in frequently consumed meat products. For this purpose, seven types of meat products, consisting of 3047 and 1943 samples, were collected from retail markets across Serbia, to analyze nitrites and phosphorus content, respectively. These data were combined with meat product consumption data from the Serbian National Food Consumption Survey to assess dietary intake of nitrites and phosphate. The results were compared with the acceptable daily intake (ADI) proposed by the European Food Safety Authority. The average dietary exposure (EDI) to phosphorus ranged from 0.733 mg/kg bw/day (liver sausage and pate) to 2.441 mg/kg bw/day (finely minced cooked sausages). Considering nitrite intake, the major sources were bacon (0.030 mg/kg bw/day) and coarsely minced cooked sausages (0.0189 mg/kg bw/day). In our study, average nitrite and phosphorus exposure in the Serbian pregnant women population are far below the EFSA recommendations (ADI 0.07 mg/kg bw/day and 40 mg/kg bw/day, respectively). Full article

Due to the high content of bioactive substances, beetroot and its preserves might be a valuable constituent of a diet. Research into the antioxidant capacity and content of nitrate (III) and (V) in beetroot-based dietary supplements (DSs) worldwide is limited. The Folin–Ciocalteu method, CUPRAC, DPPH, and Griess methods were used to determine total antioxidant capacity, total phenolic content, nitrites, and nitrates content in fifty DSs and twenty beetroot samples. Moreover, the safety of products was evaluated because of the concentration of nitrites, nitrates, and the correctness of labelling. The research showed that a serving of fresh beetroot provides significantly more antioxidants, nitrites, and nitrates than most daily portions of DSs. Product P9 provided the highest dose of nitrates (169 mg/daily dose). However, in most cases, the consumption of DSs would be associated with a low health value. The acceptable daily intake was not exceeded in the cases of nitrites (0.0015–0.55%) and nitrates (0.056–48%), assuming that the supplementation followed the manufacturer’s recommendation. According to European and Polish regulations, 64% of the products tested did not meet all the requirements for labelling food packaging. The findings point to the need for tighter regulation of DSs, as their consumption might be dangerous. Full article