Cardanol-Based Salophen-Modified Electrode for Analysing Nitric Oxide Bioavailability under Nitrosative Stress Conditions

High levels of nitric oxide (NO) can signal nitrosative stress, but its analysis is challenging considering the high reactivity, short half-life and transient behavior of this target molecule in biological milieu. In this work, a cardanol-based salophen-modified carbon paste electrode (CDN-salophen/MCPE) was developed and successfully applied to assess NO bioavailability in blood plasma of mice under induced stress. The results revealed that the modifier improved the device performance in terms of signal-to-noise ratio, charge-transport and fouling resistance. NO reactivity on CDN-salophen/MCPE was higher in 0.1 mol L‒1 H2SO4, and the resulting redox process involves adsorption steps that control the reaction kinetics. Monitoring molecule oxidation by square-wave voltammetry (100 s−1 frequency, 30 mV amplitude, 2 mV scan increment, after electrode preconditioning at 0.9 V for 15 s for analyte accumulation), it was possible to identify and quantify NO with great sensitivity (detection and quantification limit < 0.1 µmol L‒1) and low data variance (RSD ≤ 9.4% for repeatability and reproducibility tests), through a simple, fast and reliable electroanalytical protocol. The robustness acquired with CDN-salophen/MCPE allowed to detect changes in NO content in blood plasma during nitrosative stress, proving its efficiency for research on this subject.

Analysis of Pharmacokinetic Parameters of Acetylsalicylic Acid for Prediction of Potential Nephrotoxic Effects

Nonsteroidal anti-inflammatory drugs, including acetylsalicylic acid, can have a dose-dependent nephrotoxic effect. The study of the pharmacokinetics of acetylsalicylic acid products will contribute to timely detection and correction of side effects caused by this medicinal product.The aim of the study was to evaluate potential nephrotoxic effects following a single oral administration of 75 mg of acetylsalicylic acid, based on the analysis of the pharmacokinetic parameters.Materials and methods: the study involved 24 healthy volunteers who received 75 mg of acetylsalicylic acid (tablets) once orally. The measurement of the active metabolite of acetylsalicylic acid—salicylic acid—in blood plasma was performed by HPLC/MS using an Agilent 1200 liquid chromatography system coupled to an Agilent 6140 tandem mass spectrometer. Agilent Eclipse XDB-C18 column (4.6 mm×150 mm; 5.0 μm) was used for chromatographic separation. The test procedure used in the study was validated. The results obtained were used to calculate the pharmacokinetic parameters: Cmax (maximum concentration), Tmax (time to maximum concentration), T1/2 (half-life of the drug), AUC0-t (area under the pharmacokinetic curve from 0 to the last time point of the curve), AUC0-∞ (total area under the pharmacokinetic curve from 0 to ∞), MRT (mean residence time of the drug in the blood), Kel (elimination rate constant), Cl/F (total clearance), Vd/F (apparent volume of distribution). The Statistics (22.0.0.0) software was used for statistical processing of the results.Results: T1/2 of salicylic acid in blood plasma was determined to be 1.6 ± 0.5 h, Cmax was 4523.0 ± 725.0 ng/mL, and Tmax was 0.98 ± 0.4 h. AUC0–t was equal to 16183.0 ± 3823.0 ng×h/m, Vd/F was 12.0 ± 3.1 L/kg, and MRT was 2.9 ± 0.6 h.Conclusions: the analysis of the pharmacokinetic parameters demonstrated a high absorption rate, intensive distribution, and moderate elimination rate of salicylic acid (the main metabolite of acetylsalicylic acid), indicating a low risk of nephrotoxic effects associated with the studied dose of the drug.

BLOOD FATTY ACID COMPOSITION IN COWS DEPENDING ON THE TYPE OF AUTONOMIC REGULATION IN SUMMER PERIOD

Coordination of physiological activity and intensity of metabolism in various organs and tissues of a productive animal, depending on environmental conditions and own needs, is provided by the regulatory activity of the corresponding nerve centers. However, the features of the autonomic regulation of the nervous system in this matter can have a significant impact not only on the physiological activity of animals but also on their productivity. Therefore, the question of studying the influence of autonomic regulation on the animal body in general and the interaction of the autonomic system and lipid metabolism is quite relevant. Groups of animals were formed by determining the state of the cardiovascular system according to Baevskyi. Blood plasma was used for the study, lipid extraction was performed by the Folch method. Fatty acid analysis was performed on a Trace GC Ultra gas chromatograph (USA) with a flame ionization detector. Studies have shown that the relative content of saturated fatty acids in blood of normotonics was the highest compared with other groups: sympathotonics – by 1.9%; vagotonics – 0.48%. Regarding the concentration of saturated fatty acids in sympathotonics, it should be noted that the content of stearic acid was the highest (18.07 ± 0.01; P < 0.001) and saturated fatty acids from C6 to C16 were characterized by the lowest values (P < 0.01–0.05) in comparison with other groups The total content of unsaturated fatty acids in blood plasma of sympathotonics and vagotonics was 1.19% and 0.49% higher, respectively, compared with normotonics. Quite interesting is the fact that sympathotonics were characterized by the highest content of polyunsaturated fatty acids, the content of which decreased in the range C18:2n6 > C20:4n6 > C18:3n3 > C22:6n3 > C22:5n3, a similar sequence we observed in other groups, although the relative concentration of acids could fluctuate. Normotonics were characterized by the highest levels of some polyunsaturated fatty acids (C18:3n3, C22:5n3, C22:6n3) (P < 0.05-0.01), while levels of some unsaturated fatty acids (C18: 1n9, C20: 3n6) were the lowest. Thus, the type of nervous activity has a significant effect on the ratio of fatty acids in blood plasma of cows and autonomous regulation affects the metabolic processes in the animal’s body.

Assessment of the state of the oxidant-antioxidant system and lipid peroxidation in patients with chronic pancreatitis combined with hypothyroidism

Changes in oxidative-antioxidant homeostasis is one of the pathogenetic links in the onset and progression of many nosologies, including chronic pancreatitis (CP) and hypothyroidism (HТ), however, data on the development of oxidative stress (OS) with a combination of CP and HP are insufficient, therefore, determining the role of these systems with a comorbid course of these pathologies is an urgent issue of our time.The aim of the work is to study the state of the oxidative and antioxidant system in patients with CP and CP combined with HT.Material and methods. 96 people were examined, including 26 patients with chronic pancreatitis (group 1), 24 patients with hypothyroidism (group 2), 26 patients with chronic pancreatitis on the background of hypothyroidism (group 3), 20 almost healthy individuals (group 4). Evaluation of the oxidative-antioxidant system and lipid peroxidation was assessed by determining the content of malonic aldehyde in blood plasma (MA pl.) And erythrocytes (MA er.), The level of reduced glutathione, glutathione peroxidase (GP) and glutathione-S-trans-ion (GT). Enzyme activity was calculated per 1 g of hemoglobin (HB).Research results. The analysis of the obtained results revealed clear patterns of changes in the state of the oxidative-antioxidant system and lipid peroxidation in patients with chronic pancreatitis on the background of hypothyroidism. Namely, violation of lipid peroxidation in patients with comorbid pathology, accompanied by an increase in the content of MA er. by 44.87% and the content of MA in blood plasma by 46.42%; oxidative-antioxidant system: decrease in HF in the blood by 51,61%, combined of a compensatory increase in BP - by 48.03% and HT - by 34.76%.Conclusion. Under the conditions of comorbidity of CP and HT, there is a violation of the oxidative-antioxidant system and the state of lipid peroxidation, which is characterized by a significant increase in MA in erythrocytes and MA in plasma against a decrease in glutathione and which complicates the course of the underlying disease, its diagnosis and treatment.

Regulation of free radical processes in healthy volunteers during experimental hyperthermia and in patients with coronary artery disease during summer heat waves

Background. In view of the worsening forecast for global temperature rise worldwide, it seems relevant to study the effects of abnormal heat waves on systemic regulatory processes in people with chronic diseases, in particular coronary artery disease (CAD).Aims. This study aimed to investigate the effect of hyperthermia on oxidative stress parameters in patients with various severity of CAD and in healthy subjects.Materials and methods. We studied the level of malonic dialdehyde (MDA) and the activity of Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD) in healthy subjects under conditions of 30-day long simulated hyperthermia and in patients with different severity of CAD after the summer heat wavesResults. We revealed signs of oxidative stress in healthy volunteers during model hyperthermia that manifested as an increase in content of MDA in blood plasma. At the same time we observed increasing activity of Cu,Zn-SOD in erythrocytes that utilizes reactive oxygen species. The increase of Cu,Zn-SOD activity started with a certain latency what also can be explained by de novo enzyme biosynthesis induction. We also studied oxidative stress parameters in patients at high and moderate cardiovascular risk according to the SCORE risk chart with uncomplicated CAD course and in patients with complicated CAD with severe coronary damage according to angiography during the summer heat waves. We observed accumulation of MDA in blood plasma and increasing activity of erythrocyte Cu,Zn-SOD in patients with uncomplicated CAD. At the same time we noted that accumulation of MDA in blood plasma was not followed by any increase in activity of red blood cell Cu,Zn-SOD in patients with severe complicated CAD. This fact indicates dysregulation of free radical processes in patients with severe course of CAD during the heat waves.Conclusions. The dysregulation of free-radical processes in patients with a severe clinical course of CAD has been revealed.

Soluble fluoride in Na2FPO3/CaCO3-based toothpaste as an indicator of systemically bioavailable fluoride

Fluoride chemically soluble in toothpaste is an indicator of fluoride bioavailability when the teeth are brushed and the same should be expected systemically when toothpaste is ingested. A four-phases study was conducted, in which eight participants were subjected in each phase to one of the assigned treatment groups: Group I: fresh sample of a Na2FPO3/CaCO3 toothpaste with 1,334 μg F/g of total soluble fluoride (TSF); groups II–IV: aged samples of toothpaste presenting TSF concentrations of 1,128, 808, and 687 μg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 µg F/kg body weight, as total fluoride (TF). Blood was collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. Total urine (24 h before and 24 h after ingestion) was collected as indicator of absorbed fluoride that was excreted. F concentration in blood plasma and urine was determined with a fluoride ion-specific electrode. The areas under the curve of F concentration vs. time (AUC=ng F/ml x min) and the peaks of fluoride concentration in blood plasma (Cmax) were calculated. The net amount of fluoride excreted (mg/day) was calculated by subtraction. A significant correlation of the amount (mg) of TSF ingested was found between the AUC (r= 0.76; p<0.01) and Cmax (r= 0.86; p<0.01) in plasma, and the fluoride excreted (r= 0.65; p<0.01). For TF no statistical correlations were found (p>0.05). Data suggest that the concentration of TSF found in Na2FPO3/CaCO3-based toothpastes is a useful predictor of how much fluoride will be systemically bioavailable when this type of formulation is ingested.

Investigation of circulating DNA integrity after blood collection

Method summary Concentrations of circulating DNA in blood plasma were compared using NanoDrop, Qubit, quantitative PCR and Bioanalyzer, and DNA integrity was evaluated with the Bioanalyzer according to the time of plasma preparation.

PSX-A-18 Late-Breaking: Oxidative stress biomarkers in blood plasma of moderately exercised horses

Oxidative stress by physical stressors negatively impacts the performance of equine athletes. The present study was aimed to determine oxidative biomarkers in blood plasma of exercising horses. Stock-type horses were subject to a standardized moderate intensity exercise protocol following NRC guidelines 3 times per wk for 8 wk. Blood plasma was collected in wk 1, 2, 7, and 8 immediately before and 0, 30, 60, and 90 min after exercise and analyzed for total antioxidant capacity (TAC), thiobarbituric acid reactive substance (TBARS), glutathione peroxidase activity (GPx), and superoxide dismutase activity (SOD). Data were analyzed as repeated measures with wk, d, time, and their interactions as fixed effects. The TAC on d 2 (0.40 mM trolox) were 7.5% greater than that on d 3 (P = 0.013). There were wk × d × time interactions for SOD, TBARS, and GPx (P &lt; 0.001). The TBARS remained at d-1 wk-1 pre-exercise baseline (2.70 µM malondialdehyde) for most collection times within wk 1, 7, and 8 (P ≥ 0.058); however, TBARS increased by 0.24 to 0.41 µM on d 2 of wk 2 post-exercise (P &lt; 0.001) and remained similarly elevated on d 3 pre- and immediately post-exercise (P &lt; 0.001). The GPx similarly remained at baseline (172.57 µM/min; P ≥ 0.621) but increased by 48.18 to 83.36 µM/min at most collection times on d 1 and 2 of wk 2 (P ≤ 0.023). The SOD remained at baseline (167.21 µM/min; P ≥ 0.055) until increasing by 11.28 to 15.61 µM/min at 30 min post-exercise on d 1, wk 1 and at most collection times on d 3, wk 8 (P ≤ 0.043). The current study indicates the time-dependent nature of oxidative stress in relation to persistent stressors such as exercise.