Molecular regulators of exercise-mediated insulin sensitivity in non-obese individuals.

Insulin resistance is a significant contributor to the development of type 2 diabetes (T2D) and is associated with obesity, physical inactivity, and low maximal oxygen uptake. While intense and prolonged exercise may have negative effects, physical activity can have a positive influence on cellular metabolism and the immune system. Moderate exercise has been shown to reduce oxidative stress and improve antioxidant status, whereas intense exercise can increase oxidative stress in the short term. The impact of exercise on pro-inflammatory cytokine production is complex and varies depending on intensity and duration. Exercise can also counteract the harmful effects of ageing and inflamm-ageing. This review aims to examine the molecular pathways altered by exercise in non-obese individuals at higher risk of developing T2D, including glucose utilization, lipid metabolism, mitochondrial function, inflammation and oxidative stress, with the potential to improve insulin sensitivity. The focus is on understanding the potential benefits of exercise for improving insulin sensitivity and providing insights for future targeted interventions before onset of disease.

Antioxidant Activity of Humulus lupulus Phenolic Hop Extracts in Creating a New Pâté: An Element Affecting Fat Stability and Microbiological Quality during Storage.

The aim of this study was to evaluate the effect of hop extracts on changes in the primary and secondary fat oxidation products, physicochemical properties, and microbiological quality of pâté-type offal sausages obtained through the partial replacement of animal fat with vegetable fat. This study demonstrated that the extraction efficiency varied among hop cone varieties, with the highest efficiency observed for the Lubelski variety and the lowest for the Magnum variety. The phenolic compound content was higher in the Magnum cones (2.74 ± 0.11 mg/g dry matter) compared to the Lubelska cones (2.27 ± 0.05 mg/g of product). Additionally, the DPPH radical scavenging activity was greater in the extract from the Magnum cones (4.21 ± 0.09 mg TE/g d.w.) than in the extract from the Lublelski cones (3.87 ± 0.05 mg TE/ g d.w.). Similarly, the extracts from the Lubelski cones exhibited a higher antiradical activity against the ABTS radical compared to the extract from Magnum cones. Throughout storage, a significant increase in the pH value was observed in the control sample and in the samples with a 20% replacement of animal fat with rapeseed oil and Magnum hop extract. However, the addition of Lubelski hop extract resulted in a decrease in the pH value during the 15-day storage period. The samples with a 20% replacement of animal fat with rapeseed oil and 0.1% Lubelski hop extract showed the least changes in water activity during storage. The samples with a 20% replacement of animal fat with rapeseed oil and the addition of 0.2% Lubelski hop extract had the lowest peroxide value and TBARS index throughout the storage period. The addition of hop extract inhibited the growth of the total number of microorganisms in the tested sausages. In the samples with a 20% replacement of animal fat with rapeseed oil, the content of aerobic microorganisms, compared to the control sample, was statistically significantly lower.

The Effect of "Proanthocyanidin" on Ischemia-Reperfusion Injury in Skeletal Muscles of Rats.

Background and Objectives: Lower limb skeletal muscle ischemia-reperfusion (IR) injury is associated with increased morbidity and mortality, and it is common in several clinical situations such as aortic aneurysms repairment, peripheral arterial surgery, vascular injury repairment, and shock. Although it is generally accepted that oxidative stress mediators have a significant role in IR injury, its precise mechanism is still unknown. Anecdotally, it is sustained not only by structural and functional changes in the organ it affects but also by damage to distant organs. The purpose of this report is to illustrate the effect of proanthocyanidin on IR injury. Materials and Methods: In our study, 18 male Wistar albino rats were used. The subjects were divided into three groups containing six mice each (control, C; ischemia-reperfusion, IR; ischemia-reperfusion and proanthocyanidin; IR-PRO). Intraperitoneal proanthocyanidin was given to the IR and proanthocyanidin groups 30 min before laparotomy, and 1 h ischemia led to these two groups. After one hour, reperfusion started. Muscle atrophy-hypertrophy, muscle degeneration-congestion, fragmentation-hyalinization, muscle oval-central nucleus ratio, leukocyte cell infiltration, catalase enzyme activity, and TBARS were all examined in lower-limb muscle samples after one hour of reperfusion. Results: When skeletal muscle samples were evaluated histopathologically, it was discovered that muscle atrophy-hypertrophy, muscle degeneration-congestion, fragmentation-hyalinization, and leukocyte cell infiltration with oval-central nucleus standardization were significantly higher in the IR group than in the C and IR-P groups. Oval-central nucleus standardization was significantly higher in the IR and IR-PRO groups than in the control group. TBARS levels were significantly higher in the IR group than in the control and IR-PRO groups, while catalase enzyme activity was found to be significantly lower in the IR group than in the control and IR-PRO groups. Conclusions: As a consequence of our research, we discovered that proanthocyanidins administered before IR have a protective impact on skeletal muscle in rats. Further research in this area is required.

Antioxidant activity of rosemary extract, acerola extract and a mixture of tocopherols in sausage during storage at 8 °C.

Sausage is an emulsified meat product that, due to its composition, undergoes physicochemical changes during its shelf life, which makes the use of additives for its conservation necessary. The goal of the present study was to evaluate the antioxidant capacity of rosemary extract, acerola extract, and a mixture of tocopherols applied to industrialized sausages during storage at 8 °C. The antioxidant activity (IC50) in vitro showed values of 0.043, 0.489, 0.494, and 0.509 mg/mL for sodium erythorbate, rosemary extract, acerola extract, and a mixture of tocopherols, respectively. Formulations of sausage obtained in industrial installations were evaluated in terms of physicochemical, microbiological, and sensorial analyses. The pH and acidity values were stable during 23 days of storage. Treatments 1 and 3 with acerola extract and a mixture of tocopherols associated with sodium erythorbate showed the best results against lipid oxidation (TBARs), respectively. The hydroperoxides were only found after the 12th day of storage, consequently reducing the formation of malondialdehyde. The treatments with natural antioxidants showed an antimicrobial effect for the group of mesophilic bacteria; their results did not exceed 4 log10 CFU/g, while the control reached 5 log10 CFU/g on the 23rd day of storage. In regard to other microorganisms evaluated, no significant differences were found between treatments with natural antioxidants. Thus, the natural extracts evaluated in association with sodium erythorbate contributed to the antioxidant action for the application on an industrial scale, as they improved the sausage characteristics after 23 days of storage at 8 °C. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05815-y.

Oxidative Damage and Post-COVID Syndrome: A Cross-Sectional Study in a Cohort of Italian Workers.

In addition to the acute symptoms after infection, patients and society are also being challenged by the long-term effects of COVID-19, known as long COVID. Oxidative stress, as a pivotal point in the pathophysiology of COVID-19, could potentially be also involved in the development of the post-COVID syndrome. The aim of the present study was to evaluate the relationship between changes in oxidative status and the persistence of long-COVID symptoms in workers with a previous mild COVID-19 infection. A cross-sectional study was conducted among 127 employees of an Italian university (80 with a previous COVID-19 infection, and 47 healthy subjects). The TBARS assay was used to detect malondialdehyde serum levels (MDA), while total hydroperoxide (TH) production was measured by a d-ROMs kit. A significant difference in mean serum MDA values was found between previously infected subjects and healthy controls and (4.9 µm vs. 2.8 µm, respectively). Receiver-operating characteristic (ROC) curves showed high specificity and good sensibility (78.7% and 67.5%, respectively) for MDA serum levels. A random forest classifier identified the hematocrit value, MDA serum levels, and IgG titer against SARS-CoV-2 as features with the highest predictive value in distinguishing 34 long-COVID from 46 asymptomatic post-COVID subjects. Oxidative damage persists in subjects with previous COVID-19 infection, suggesting a possible role of oxidative stress mediators in the pathogenesis of long COVID.

Reduction of Nitrite in Canned Pork through the Application of Black Currant (Ribes nigrum L.) Leaves Extract.

Sodium nitrite is a multifunctional additive commonly used in the meat industry. However, this compound has carcinogenic potential, and its use should be limited. Therefore, in this study the possibility of reducing the amount of sodium(III) nitrite added to canned meat from 100 to 50 mg/kg, while enriching it with freeze-dried blackcurrant leaf extract, was analyzed. The possibility of fortification of canned meat with blackcurrant leaf extract was confirmed. It contained significant amounts of phenolic acids and flavonoid derivatives. These compounds contributed to their antioxidant activity and their ability to inhibit the growth of selected Gram-positive bacteria. In addition, it was observed that among the three different tested doses (50, 100, and 150 mg/kg) of the blackcurrant leaf extract, the addition of the highest dose allowed the preservation of the antioxidant properties of canned meat during 180 days of storage (4 °C). At the end of the storage period, this variant was characterized by antiradical activity against ABTS (at the level of 4.04 mgTrolox/mL) and the highest reducing capacity. The addition of 150 mg/kg of blackcurrant leaf extract caused a reduction in oxidative transformations of fat in meat products during the entire storage period, reaching a level of TBARS almost two times less than in the control sample. In addition, these products were generally characterized by stability (or slight fluctuations) of color parameters and good microbiological quality and did not contain N-nitrosamines.

Comparative physiological and coexpression network analyses reveal the potential drought tolerance mechanism of peanut.

BACKGROUND: Drought stress has negative effects on plant growth and productivity. In this study, a comprehensive analysis of physiological responses and gene expression was performed. The responses and expressions were compared between drought-tolerant (DT) and drought-sensitive (DS) peanut varieties to investigate the regulatory mechanisms and hub genes involved in the impact of drought stress on culture. RESULTS: The drought-tolerant variety had robust antioxidative capacities with higher total antioxidant capacity and flavonoid contents, and it enhanced osmotic adjustment substance accumulation to adapt to drought conditions. KEGG analysis of differentially expressed genes demonstrated that photosynthesis was strongly affected by drought stress, especially in the drought-sensitive variety, which was consistent with the more severe suppression of photosynthesis. The hub genes in the key modules related to the drought response, including genes encoding protein kinase, E3 ubiquitin-protein ligase, potassium transporter, pentatricopeptide repeat-containing protein, and aspartic proteinase, were identified through a comprehensive combined analysis of genes and physiological traits using weighted gene co-expression network analysis. There were notably differentially expressed genes between the two varieties, suggesting the positive roles of these genes in peanut drought tolerance. CONCLUSION: A comprehensive analysis of physiological traits and relevant genes was conducted on peanuts with different drought tolerances. The findings revealed diverse drought-response mechanisms and identified candidate genes for further research.

On 'The thiobarbituric acid reaction and the autoxidations of polyunsaturated fatty acid methyl esters' by Leland K.Dahle, Eldon G.Hill and Ralph T.Holman.

This commentary describes a highly cited paper by Dahle, Hill, and Holman, Arch Biochem Biophys. 1962; 98: 253-261. They showed that the oxidation products of polyunsaturated fatty acids reacted with thiobarbituric acid to give a colored product, which might be used to assess lipid oxidation.

In vitro and in silico trichomonacidal activity of 2,8-bis(trifluoromethyl) quinoline analogs against Trichomonas vaginalis.

Trichomoniasis is a great public health burden worldwide and the increase in treatment failures has led to a need for finding alternative molecules to treat this disease. In this study, we present in vitro and in silico analyses of two 2,8-bis(trifluoromethyl) quinolines (QDA-1 and QDA-2) against Trichomonas vaginalis. For in vitro trichomonacidal activity, up to seven different concentrations of these drugs were tested. Molecular docking, biochemical, and cytotoxicity analyses were performed to evaluate the selectivity profile. QDA-1 displayed a significant effect, completely reducing trophozoites viability at 160 µM, with an IC50 of 113.8 µM, while QDA-2 at the highest concentration reduced viability by 76.9%. QDA-1 completely inhibited T. vaginalis growth and increased reactive oxygen species production and lipid peroxidation after 24 h of treatment, but nitric oxide accumulation was not observed. In addition, molecular docking studies showed that QDA-1 has a favorable binding mode in the active site of the T. vaginalis enzymes purine nucleoside phosphorylase, lactate dehydrogenase, triosephosphate isomerase, and thioredoxin reductase. Moreover, QDA-1 presented a level of cytotoxicity by reducing 36.7% of Vero cells' viability at 200 µM with a CC50 of 247.4 µM and a modest selectivity index. In summary, the results revealed that QDA-1 had a significant anti-T. vaginalis activity. Although QDA-1 had detectable cytotoxicity, the concentration needed to eliminate T. vaginalis trophozoites is lower than the CC50 encouraging further studies of this compound as a trichomonacidal agent.

Follicular development, morphological integrity, and oxidative stress in bovine preantral follicles cultured in vitro with ascorbic acid.

The aim of this study was to evaluate the follicular development, morphological integrity, and oxidative stress of preantral ovarian follicles from Bos taurus indicus females grown in vitro with ascorbic acid. Ovaries (n = 20) from Bos taurus indicus females were collected, fragmented, and were cultured in vitro for 6 or 12 days in minimum essential medium (MEM), or MEM supplemented with 50 or 100 ng/ml ascorbic acid, with an extracellular matrix of agarose gel, in an incubator at 38.5°C; every 2 days, 100% of the culture medium was replaced. The data were analyzed using the chi-squared test and/or Fisher's exact test. In the event of a significant effect, the proportions were compared using a 2 × 2 proportion test. The oxidative stress analysis data were submitted to analysis of variance followed by the Bonferroni test. Values were considered significant when P ≤ 0.05. The addition of 100 ng/ml of ascorbic acid to the in vitro culture medium of preantral ovarian follicles from bovine females promoted follicular development, was efficient in maintaining morphological integrity, as well as the stability of reactive oxygen species, after 6 days of in vitro culture.

MiADMSA abrogates sodium tungstate-induced oxidative stress in rats.

Tungsten (W) and its compounds have emerged as a relatively new area of environmental health concern in the last decade. Tungsten is environmentally benign due to its increasing use in armour-piercing munitions and as a replacement for lead in other ammunition. It has also been identified in various hazardous waste sites and therefore been proposed for inclusion in the Environmental Protection Agency National Priorities List. The major objective of this study was to evaluate the therapeutic efficacy of orally administered monoisoamyl 2, 3-dimercaptosuccinic acid (MiADMSA) against tungstate induced oxidative injury in blood, liver and kidneys of male Wistar rats. MiADMSA, a thiol chelator has gained wide recognition recently as a future chelating drug of choice specifically for arsenic and was chosen for this study as tungstate ions too have an affinity toward the -SH group thus, being less bioavailable in the body. We determined the effects of MiADMSA (50 mg/kg, p.o.) against sodium tungstate (500 ppm in drinking water, daily for 28 days) induced biochemical changes indicative of oxidative stress in blood, and other soft tissues of of male Wistar rats. Tungsten exposure led to an increased levels of Reactive Oxygen Species (ROS) in liver, kidney, spleen and blood accompanied also by an increase in TBARS levels. The GSH: GSSG ratio also showed a decrease on sodium tungstate intoxication. Treatment with MiADMSA restored most of the sodium tungstate-induced alterations in the biomarkers suggestive of oxidative stress. These preliminary results led us to conclude that sub-acute exposure to tungstate-induced oxidative stress could be effectively reduced by the administration of MiADMSA and thus might be a promising antidote for studying in detail its efficacy in reducing body tungstate burden and its excretion post tungstate exposure.

Effect of Prolonged Photoperiod on Light-Dependent Photosynthetic Reactions in Cannabis.

Industrial hemp is a fast-growing, short-day plant, characterized by high biomass yields and low demands for cultivation. To manipulate growth, hemp is usually cultivated under prolonged photoperiods or continuous light that could cause photooxidative damage and adjustments of photosynthetic reactions. To determine the extent of changes in photosynthetic response caused by prolonged light exposure, we employed chlorophyll a fluorescence measurements accompanied with level of lipid peroxidation (TBARS) and FT-IR spectroscopy on two Cannabis cultivars. Plants were grown under white (W) and purple (P) light at different photoperiods (16/8, 20/4, and 24/0). Our results showed diverse photosynthetic reactions induced by the different light type and by the duration of light exposure in two cultivars. The most beneficial condition was the 16/8 photoperiod, regardless of the light type since it brought the most efficient physiological response and the lowest TBARS contents suggesting the lowest level of thylakoid membrane damage. These findings indicate that different efficient adaptation strategies were employed based on the type of light and the duration of photoperiod. White light, at both photoperiods, caused higher dissipation of excess light causing reduced pressure on PSI. Efficient dissipation of excess energy and formation of cyclic electron transport around PSI suggests that P20/4 initiated an efficient repair system. The P24/0 maintained functional electron transport between two photosystems suggesting a positive effect on the photosynthetic reaction despite the damage to thylakoid membranes.

Diabetes Mellitus Alters the Immuno-Expression of Neuronal Nitric Oxide Synthase in the Rat Pancreas.

Nitric oxide is generated from nitric oxide synthase following hyperglycemia-induced oxidative stress during the course of diabetes mellitus (DM). We examined the temporal immuno-expression of neuronal nitric oxide synthase (nNOS) in the pancreas of diabetic and non-diabetic rats using immunohistochemical, immunofluorescence and western blot techniques 12 h, 24 h, 1 week, 2 weeks, 1, 8 and 15 months after induction of DM. nNOS co-localized with pancreatic beta cells but disappears 12 h after the onset of DM. In contrast, the nNOS content of pancreatic nerves increased significantly (p < 0.001) 24 h after the induction of DM, and decreased sharply thereafter. However, nNOS-positive ganglion cells were observed even 15 months post-diabetes. ROS increased by more than 100% two months after the onset of DM compared to non-diabetic control but was significantly (p < 0.000001) reduced at 9 months after the induction of DM. The pancreatic content of GSH increased significantly (p < 0.02) after 9 months of DM. Although, TBARS content was significantly (p < 0.009; p < 0.002) lower in aged (9 months) non-diabetic and DM rats, TBARS rate was markedly (p < 0.02) higher 9 months after the induction of DM when compared to younger age group. In conclusion, nNOS is present in pancreatic beta cell, but disappears 12 h after the onset of diabetes. In contrast, the tissue level of nNOS of pancreatic nerves increased in the first week of diabetes, followed by a sharp reduction. nNOS may play important roles in the metabolism of pancreatic beta cell.

Prediction of food quality parameters in fish burgers by partial least square models using RGB pattern of digital images.

Abstract: Rancid taste, pH, and TBARS are important quality parameters of food oxidation, analyzed in a time-consuming and destructive way. Non-destructive characterization of food can be achieved correlating this data with computational vision. Thus, the present study aimed to use RGB digital images to predict sensory rancid taste, pH, and TBARS results in fish burgers. A mobile obtained the digital images, in a controlled environment, and 768 grayscales were performed using RGB histograms. The pH, showed a peak at 21st day of storage, which PCA confirmed by isolating the 21st samples, corroborated by HCA grouping 21st day samples. PLS models from RGB digital images and sensory rancidity, pH and TBARS data, using mean center method and SIMPLS algorithm found models with > 0.97 R2. Thus, any digital image of this batch of burgers, inserted into the model to predict rancid taste, pH and TBARS has high confidence level of prediction.

Physiological and biochemical responses of strawberry crown and leaf tissues to freezing stress.

BACKGROUND: In northern Iran and other cold regions, winter freezing injury and resultant yield instability are major limitations to strawberry production. However, there is scarcity of information on the physiological and biochemical responses of strawberry cultivars to freezing stress. This study aimed to investigate the physiological and biochemical responses of strawberry cultivars (Tennessee Beauty, Blakemore, Kurdistan, Queen Elisa, Chandler, Krasnyy Bereg, and Yalova) to different freezing temperature treatments (- 5, - 10, - 15, - 20, and - 25 °C) under controlled conditions. RESULTS: All measured physiological and biochemical features were significantly affected by the interaction effect between low temperatures and cultivars. Tennessee Beauty showed the highest RWC at - 25 °C. The highest Fv/Fm was observed in Queen Elisa. Krasnyy Bereg had the least freezing injury (FI) in crown and leaf, while Yalova and Chandler showed the highest crown and leaf FI, respectively. At - 20 to - 25 °C, the highest carbohydrates contents of crown and leaf were noted in Blakemore and Krasnyy Bereg cultivars, respectively. The Yalova showed the highest protein content in both crown and leaf tissues at - 25 °C. The Tennessee Beauty and Blackmore cultivars showed the highest proline in crowns and leaves at - 15 °C, respectively. The highest ThioBarbituric Acid Reactive Substances (TBARS) contents in the crown and leaf were observed in Kurdistan and Queen Elisa, respectively. Queen Elisa and Krasnyy Bereg cultivars showed SOD and POD peaks in the crown at - 15 °C, respectively. CONCLUSION: Freezing stress was characterized by decreased Fv/Fm and RWC, and increased FI, TBARS, total carbohydrates, total proteins, proline content, and antioxidant enzyme activity. The extent of changes in above mentioned traits was cultivar dependent. FI and TBARS were the best traits among destructive parameters for evaluating freezing tolerance. Moreover, maximum quantum yield of PSII (Fv/Fm index), as non-destructive parameters, showed a significant efficiency in rapid assessment for screening of freezing tolerant strawberry cultivars. The cultivars Krasnyy Bereg, Queen Elisa, and Kurdistan were the most tolerant cultivars to freezing stress. These cultivars can be used as parents in breeding programs to develop new freezing tolerant cultivars.

Effect of extremely low frequency magnetic fields on oxidative balance in rat brains subjected to an experimental model of chronic unpredictable mild stress.

BACKGROUND: There has been an increasing interest in researching on the effects of extremely low-frequency magnetic fields on living systems. The mechanism of action of extremely low-frequency magnetic fields on organisms has not been established. One of the hypotheses is related to induce changes in oxidative balance. In this study, we measured the effects of chronic unpredictable mild stress induced-oxidative balance of rat's brain exposed to extremely low-frequency magnetic fields. METHODS: A first experiment was conducted to find out if 14 days of chronic unpredictable mild stress caused oxidative unbalance in male Wistar rat's brain. Catalase activity, reduced glutathione concentration, and lipoperoxidation were measured in cerebrum and cerebellum. In the second experiment, we investigate the effects of 7 days extremely low-frequency magnetic fields exposure on animals stressed and unstressed. RESULTS: The main results obtained were a significant increase in the catalase activity and reduced glutathione concentration on the cerebrum of animals where the chronic unpredictable mild stress were suspended at day 14 and then exposed 7 days to extremely low-frequency magnetic fields. Interestingly, the same treatment decreases the lipoperoxidation in the cerebrum. The stressed animals that received concomitant extremely low frequency magnetic fields exposure showed an oxidative status like stressed animals by 21 days. Thus, no changes were observed on the chronic unpredictable mild stress induced-oxidative damage in the rat's cerebrum by the extremely low-frequency magnetic field exposure together with chronic unpredictable mild stress. CONCLUSIONS: The extremely low-frequency electromagnetic field exposure can partially restore the cerebrum antioxidant system of previously stressed animals.

Changes in pulmonary and plasma oxidative stress and inflammation following eccentric and concentric cycling in stable COPD patients.

PURPOSE: The purpose of this study was to compare pulmonary and plasma markers of oxidative stress and inflammation after concentric and eccentric cycling bouts in individuals with chronic obstructive pulmonary disease (COPD). METHODS: Ten patients with moderate COPD level (68.3 ± 9.1 years; forced expiratory volume in 1 s = 68.6 ± 20.4% of predicted) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum concentric cycling power output; POmax) and eccentric cycling (ECC-M: 50% POmax), and high-intensity eccentric cycling (ECC-H: 100% POmax) in a randomised order. Cardiometabolic demand was monitored during cycling. Indirect markers of muscle damage were assessed before, immediately after, 24 and 48 h after cycling (muscle strength, muscle soreness and creatine kinase activity). Plasma oxidative stress (malondialdehyde: MDA), antioxidant (glutathione peroxidase activity: GPx) and inflammatory markers (IL-6, TNF-α) were measured before and 5 min after cycling. Exhaled breath condensate (EBC) samples were collected before and 15 min after cycling and analysed for hydrogen peroxide (H2O2), nitrites (NO2-) and pH. RESULTS: Cardiometabolic demand was 40-50% lesser for ECC-M than CONC-M and ECC-H. Greater muscle damage was induced after ECC-H than ECC-M and CONC-M. MDA decreased immediately after CONC-M (- 28%), ECC-M (- 14%), and ECC-H (- 17%), while GPx remained unchanged. IL-6 increased only after ECC-H (28%), while TNF-α remained unchanged after exercise. Pulmonary H2O2, NO2- and pH remained unchanged after exercise. CONCLUSION: These results suggest that only moderate muscle damage and inflammation were induced after high-intensity eccentric cycling, which did not induce pulmonary or plasmatic increases in markers of oxidative stress. TRIAL REGISTRATION NUMBER: Trial registration number: DRKS00009755.

Lipid peroxidation in bull semen influences sperm traits and oxidative potential of Percoll®-selected sperm.

Although bovine embryo in vitro production (IVP) is a common assisted reproductive technology, critical points warrant further study, including sperm traits and oxidative status of sperm for in vitro fertilization (IVF). Our aim was to evaluate whether the lipid peroxidation index of commercial bull semen is influenced by sperm traits and oxidative status of sperm populations selected using Percoll® gradient. Semen straws from 48 batches from 14 Nelore bulls were thawed individually, analyzed for motility and subjected to Percoll selection. After Percoll, the lipid peroxidation index of the extender was evaluated, whereas selected sperm were analyzed for motility, acrosome and membrane integrity, mitochondrial membrane potential, chromatin resistance and oxidative potential under IVF conditions. Batches were divided retrospectively in four groups according to lipid peroxidation index. Sperm from Group 4 with the lowest index of lipid peroxidation had, after Percoll selection, greater plasma membrane integrity (81.3%; P = 0.004), higher mitochondrial potential (81.1%; P = 0.009) and lower oxidative potential (135.3 ng thiobarbituric acid reactive substances (TBARS)/ml; P = 0.026) compared with Group 1 with highest lipid peroxidation index (74.3%, 73% and 213.1 ng TBARS/ml, respectively). Furthermore, we observed negative correlations for the lipid peroxidation index with motility, membrane integrity and mitochondrial potential, and positive correlations with oxidative potential. In conclusion, oxidative stress in semen straws, as determined using lipid peroxidation in the extender, is associated with sperm traits and their oxidative potential under IVF conditions. These results provided further insights regarding the importance of preventing oxidative stress during semen handling and cryopreservation, as this could affect sperm selected for IVF. Finally, Percoll selection did not completely remove sperm with oxidative markers.

The effect of sulfamethoxazole on oxidative stress indices in zebrafish (Danio rerio).

The aim of this study was to assess the impact of sulfamethoxazole (SMX) on oxidative stress indices in zebrafish (Danio rerio). The test was completed after 14 days. The tested concentrations were 50, 100 and 500 µg/L of SMX. Glutathione peroxidase, glutathione reductase, glutathione S-transferase and lipid peroxidation were investigated to determine the effects of SMX on oxidative stress in zebrafish. Lipid peroxidation gradually increased slightly (but non-significantly) at all tested concentrations during the test as compared to the control. The evaluation of oxidative stress biomarkers showed no significant changes in the activity of antioxidant enzymes in any experimental group exposed to SMX as compared to the control. The gradual increase in lipid peroxidation after 3 and 14 days in the SMX treated groups as compared to the control group indicates increasing cell membrane damage.

Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage.

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10-11 g/m s Pa) than commercial chitosans films (from 16.06 × 10-11 to 64.30 × 10-11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.