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.

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.

Antioxidant Properties of Lyophilized Rosemary and Sage Extracts and its Effect to Prevent Lipid Oxidation in Poultry Pátê.

This study aimed to evaluate the antioxidant activities (AA) of lyophilized rosemary extract and lyophilized sage extract, and their effects on the oxidative stability of poultry pátê. For this purpose, four poultry pátê formulations with rosemary, sage, sodium erythorbate and a control (without antioxidants) were produced. The rosemary and sage were characterized according to total phenolic compounds (TPC) and AA by several methods. The poultry pátês stored at 4 °C were evaluated by the lipid oxidation. High concentrations of TPC were detected in the rosemary extract and sage extract (46.48 and 41.61 mg GAE/g (Gallic acid equivalent), respectively). The AA of the rosemary and sage extracts determined by free radical-scavenging were 4745.72 and 2462.82 µmol TE/g (Trolox equivalents), respectively. The high concentrations of catechin, rutin, myricetin and p-coumaric acids in these extracts may be responsible for the strong inhibitory action against food pathogens. Besides this, these compounds can be responsible for the best performance in inhibiting lipid oxidation in poultry pátês during storage. This study suggests that rosemary and sage extracts may be used as a natural antioxidant in meat products.

Effects of dietary lycopene on the protection against oxidation of muscle and hepatic tissue in finishing pigs.

OBJECTIVE: The objective of this study was to evaluate the effect of different levels of lycopene supplementation on the carcass traits, meat quality, concentration of lipid oxidation products and antioxidant potential in the meat and liver of finishing barrows and gilts. METHODS: A total of 40 barrows and 40 gilts were allotted in a completely randomized block design, arranged in a 2×5 factorial scheme, consisting of two sexes (barrows and gilts) and five dietary levels of lycopene (0, 12.5, 25.0, 37.5, and 50.0 mg/kg). In addition, four storage times (0, 24, 48, and 72 h), at 4°C, were added to the model to evaluate the longissimus lumborum muscle. RESULTS: An interaction (p = 0.010) was observed between storage periods and dietary lycopene levels. The unfolding of the interaction (lycopene×period) showed a decreasing concentration of malondialdehyde concentration as the dietary lycopene increased, at all storage periods. No interactions (p>0.050) were observed for the 2,2 diphenyl 1 picrylhydrazyl (DPPH) in the pork. However, the percentage of DPPH radical inhibition reduced (p = 0.001) up to 72 h. Additionally, there was a linear increase (p = 0.001) in the capture of DPPH radicals by antioxidants, as the dietary lycopene increased. No interactions were observed (p>0.05) between the evaluated factors in liver. However, lipid oxidation was reduced by supplementing lycopene in pig diets. The capture of the DPPH radical, resulted increase in the antioxidant power exerted by lycopene in the liver (p = 0.001). The concentrations of the thiobarbituric acid reactive substances and DPPH in the liver were affected by sex (p = 0.001). CONCLUSION: Dietary supplementation of lycopene reduced the water loss during thawing and was effective in protecting against oxidation of the longissimus lumborum muscle and liver until 72 hours of storage, and the best results were obtained by supplementing with 50.0 mg of lycopene/kg of diet.

Comparative mouse lung injury by nickel nanoparticles with differential surface modification.

BACKGROUND: Previous studies have demonstrated that exposure to nickel nanoparticles (Nano-Ni) causes oxidative stress and severe, persistent lung inflammation, which are strongly associated with pulmonary toxicity. However, few studies have investigated whether surface modification of Nano-Ni could alter Nano-Ni-induced lung injury, inflammation, and fibrosis in vivo. Here, we propose that alteration of physicochemical properties of Nano-Ni through modification of Nano-Ni surface may change Nano-Ni-induced lung injury, inflammation, and fibrosis. METHODS: At first, dose-response and time-response studies were performed to observe lung inflammation and injury caused by Nano-Ni. In the dose-response studies, mice were intratracheally instilled with 0, 10, 20, 50, and 100 µg per mouse of Nano-Ni and sacrificed at day 3 post-exposure. In the time-response studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni and sacrificed at days 1, 3, 7, 14, 28, and 42 post-instillation. At the end of the experiment, mice were bronchoalveolar lavaged (BAL) and the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BAL fluid (BALF) were determined. In the comparative studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni or with the same molar concentration of Ni as Nano-Ni of either partially [O]-passivated Nano-Ni (Nano-Ni-P) or carbon-coated Nano-Ni (Nano-Ni-C). At day 3 post-exposure, BAL was performed and the above cellular and biochemical parameters in the BALF were analyzed. The MMP-2/9 protein levels and activities in the BALF and mouse lung tissues were also determined. Mouse lung tissues were also collected for H&E staining, and measurement of thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the genomic DNA. At day 42 post-exposure, mouse right lung tissues were collected for H&E and Trichrome stainings, and left lung tissues were collected to determine the hydroxyproline content. RESULTS: Exposure of mice to Nano-Ni resulted in a dose-response increase in acute lung inflammation and injury reflected by increased neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF. The time-response study showed that Nano-Ni-induced acute lung inflammation and injury appeared as early as day 1, peaked at day 3, and attenuated at day 7 post-instillation. Although the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF dramatically decreased over the time, their levels were still higher than those of the controls even at day 42 post-exposure. Based on the results of the dose- and time-response studies, we chose a dose of 50 µg per mouse of Nano-Ni, and day 3 post-exposure as short-term and day 42 post-exposure as long-term to compare the effects of Nano-Ni, Nano-Ni-P, and Nano-Ni-C on mouse lungs. At day 3 post-exposure, 50 µg per mouse of Nano-Ni caused acute lung inflammation and injury that were reflected by increased neutrophil count, CXCL1/KC level, LDH activity, concentration of total protein, and MMP-2/9 protein levels and activities in the BALF. Nano-Ni exposure also caused increased MMP-2/9 activities in the mouse lung tissues. Histologically, infiltration of large numbers of neutrophils and macrophages in the alveolar space and interstitial tissues was observed in mouse lungs exposed to Nano-Ni. Nano-Ni-P exposure caused similar acute lung inflammation and injury as Nano-Ni. However, exposure to Nano-Ni-C only caused mild acute lung inflammation and injury. At day 42 post-exposure, Nano-Ni caused extensive interstitial fibrosis and proliferation of interstitial cells with inflammatory cells infiltrating the alveolar septa and alveolar space. Lung fibrosis was also observed in Nano-Ni-P-exposed lungs, but to a much lesser degree. Only slight or no lung fibrosis was observed in Nano-Ni-C-exposed lungs. Nano-Ni and Nano-Ni-P, but not Nano-Ni-C, caused significantly elevated levels of TBARS in mouse lung tissues and 8-OHdG in mouse lung tissue genomic DNA, suggesting that Nano-Ni and Nano-Ni-P induce lipid peroxidation and oxidative DNA damage in mouse lung tissues, while Nano-Ni-C does not. CONCLUSION: Our results demonstrate that short-term Nano-Ni exposure causes acute lung inflammation and injury, while long-term Nano-Ni exposure causes chronic lung inflammation and fibrosis. Surface modification of Nano-Ni alleviates Nano-Ni-induced pulmonary effects; partially passivated Nano-Ni causes similar effects as Nano-Ni, but the chronic inflammation and fibrosis were at a much lesser degree. Carbon coating significantly alleviates Nano-Ni-induced acute and chronic lung inflammation and injury.

Biomarkers of oxidative stress in blood of workers exposed to non-cholinesterase inhibiting pesticides.

In occupational settings workers are often exposed to pesticides at relatively high doses compared to environmental exposures. Long-term exposure to pesticides has been associated with numerous adverse health effects in epidemiological studies, and oxidative stress is often claimed as one of the underlying mechanisms. In fact, different pesticides have been reported to induce oxidative stress due to the generation of free radicals and/or alteration in antioxidant defense enzymes. The present study examined greenhouse workers regularly exposed to diverse pesticides under integrated production system, and a group of controls of the same geographic area without any chemical exposure. Two different periods of the same crop season were assessed, one of high exposure (with greater use of pesticides) and other of low exposure (in which a less use of these compounds was made). Non-specific biomarkers of oxidative stress, e.g. thiobarbituric acid reactive substances (TBARS), ferric reducing ability of serum (FRAS), total thiol groups (SHT), gamma-glutamyl transpeptidase (GGT) and paraoxonase-1 (PON1) were measured in serum samples from all study subjects, alongside erythrocyte acetylcholinesterase (AChE). Results are suggestive of a mild increase in oxidative stress associated with pesticide exposure, which was compensated by an adaptive response to raise the antioxidant defenses and thus counter the detrimental effects of sustained oxidative stress. This response led to significantly increased levels of FRAS, SHT and PON1 in greenhouse workers relative to controls. Furthermore, AChE was decreased likely as a result of oxidative stress as workers did not use organophosphate insecticides.

Involvement of H2O2 in fluazifop-P-butyl-induced cell death in bristly starbur seedlings.

In order to understand the action mechanism of fluazifop-P-butyl (FB) in bristly starbur (Acanthospermum hispidum D.C.), a susceptible plant, the role of active oxygen species (ROS) in herbicide-induced cell death in shoots was investigated. FB-induced phytotoxicity was not reduced by the antioxidants, 1,4-diazabicyclooctane (dabaco), sodium azide, l-tryptophan, d-tryptophan, hydroquinone and dimethyl pyridine N-oxide (DMPO). The activities of superoxide dismutase (SOD) and catalase (CAT), in bristly starbur seedlings were significantly increased by FB at 12 HAT and 24 HAT, while ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased only at 12 HAT. The contents of H2O2 in FB-treated bristly starbur seedlings were significantly higher to that of control between 8 and 24 HAT. According to the analysis of potassium iodide - starch or 3,3-diaminobenzidine, the accumulation of hydrogen peroxide was observed in the apical growing point, stem, petiole and veins of FB-treated bristly starbur seedlings at 24 HAT. The cell viability of bristly starbur seedlings treated by 10µM FB decreased at 18 HAT. These results suggested that FB-induced cell death in bristly starbur shoots may be caused by ROS (O2- and H2O2) generation and lipid peroxidation.

Volatile compounds and some physico-chemical properties of pastirma produced with different nitrate levels.

OBJECTIVE: The aim of the study was to evaluate the effects of different nitrate levels (150, 300, 450, and 600 ppm KNO3) on the volatile compounds and some other properties of pastirma. METHODS: Pastirma samples were produced under the controlled condition and analyses of volatile compounds, and thiobarbituric acid reactive substances (TBARS) as an indicator of lipid oxidation, non-protein nitrogenous matter content as an indicator of proteolysis, color and residual nitrite were carried out on the final product. The profile of volatile compounds of pastirma samples was analyzed by gas chromatography/mass spectrometry using a solid phase microextraction. RESULTS: Nitrate level had a significant effect on pH value (p<0.05) and a very significant effect on TBARS value (p<0.01). No significant differences were determined in terms of aw value, non-protein nitrogenous substance content, color and residual nitrite between pastirma groups produced by using different nitrate levels. Nitrate level had a significant (p<0.05) or a very significant (p<0.01) effect on some volatile compounds. It was determined that the amounts and counts of volatile compounds were lower in the 450 and especially 600 ppm nitrate levels than 150 and 300 ppm nitrate levels (p<0.05). While the use of 600 ppm nitrate did not cause an increase in residual nitrite levels, the use of 150 ppm nitrate did not negatively affect the color of pastirma. However, the levels of volatile compounds decreased with an increasing level of nitrate. CONCLUSION: The use of 600 ppm nitrate is not a risk in terms of residual nitrite in pastirma produced under controlled condition, however, this level is not suitable due to decrease in the amount of volatile compounds.

[The level of lipid peroxidation in milk replacer formulas for initial feeding of infants]. / Poziom peroksydacji lipidów w mlekozastepczych preparatach do zywienia poczatkowego niemowlat.

UNLABELLED: The products of lipids oxidation: peroxides, hydroxides, aldehydes, ketones, esters, alcohols and others show harmful activity against human organism. Presence of the compounds in baby's and children's food creates potential health hazard. Many of them cause infant's and children's diarrhoea, also, negatively influence development of nervous system, show cytotoxic, mutagenic and cancerogenic activity (e.g. malonicdialdehyde, 4-hydroxynonenal and others). AIM: The aim of the work was to assess the level of lipids peroxidation in milk substitute preparations for initial stage baby feeding, before their end of shelf-life. MATERIALS AND METHODS: The level of lipids peroxidation measured as TBARS (thiobarbituric acid reactive substances) concentrations was determined in 6 available on the Polish market milk substitute infant formulas. The determinations was carried out before the end of the shelf-life after 1,2,3,6,9 and 12 months after purchase. The level of lipid peroxidation was also determined after 3-4 and 21 days post opening. RESULTS: TBARS content in the infants food ready to be eaten depended on the time of preparation storage. The highest level of lipids peroxidation was observed in all the studied food after 12 months of storage and after 21 days after opening of the hermetical wrapping. Various level of lipids peroxidation in milk substitutes for infant nutrition resulted from different amounts and quality of plant oils used in production (different content of mono- and polyunsaturated fatty acids, presence of lack of linoleic and α-linolenic acids).

Measurement of cellular MDA content through MTBE-extraction based TBA assay by eliminating cellular interferences.

Malondialdehyde (MDA) has long been served as a crucial indicator for assessing cellular oxidative stress levels. In this study, we introduce a new approach to determine cellular MDA levels based on a methyl tert-butyl ether (MTBE) extraction, aimed at eliminating interferences from cellular components during thiobarbituric acid (TBA) derivatization of MDA. By leveraging the effective MTBE extraction, we identified that the determination of the MDA-TBA adduct formed from the MTBE extraction layer can effectively eliminate the interferences from cellular proteins and metabolites. This method demonstrated acceptable linearity and precision in cellular samples and showed significant differences in H2O2 treated cellular oxidative stress models. The MTBE extraction-based MDA-TBA approach provides a reliable, cost-effective, and feasible method to determine cellular MDA levels using batch microplate reader approach for the assessment of cellular oxidative stress.

Is Oxidative Stress an Emerging Player in the Thrombosis of Patients with Anti-Phosphatidylethanolamine Autoantibodies?

The detection of anti-phosphatidylethanolamine autoantibodies (aPEs) has been proposed to improve the diagnosis and management of patients presenting clinical manifestations of antiphospholipid syndrome (APS), such as thrombosis, and who are persistently negative for conventional markers. After selecting the most specific ELISA for their detection, we evidenced the interest of aPEs in the exploration of thrombosis when APS conventional markers were negative through a 1-year retrospective study including 1131 consecutive patients routinely tested for aPEs. To validate this result, we assessed aPEs in a newly selected population of 77 patients with unexplained deep vein thrombosis (DVT). With a total prevalence of 19.5%, we confirmed the interest of aPE detection in patients with unexplained DVT who were devoid of other aPLs markers. Since endosomal compartment, a source of ROS production, has been recently identified as the cellular target of aPEs in vitro, we then investigated an association between aPE positivity and reactive oxygen species (ROS) production by measuring the production of thiobarbituric acid-reactive substances. We showed, for the first time, a significant association between aPE positivity and systemic ROS production in patients which led us to hypothesize a new mechanism of action of aPEs in thrombosis through a signaling related to oxidative stress.

Lactobacillus plantarum GKM3 Promotes Longevity, Memory Retention, and Reduces Brain Oxidation Stress in SAMP8 Mice.

(1) Background: An age-related cognitive decline is commonly affecting the life of elderly with symptoms involved in progressive impairments to memory and learning. It has been proposed that probiotics could modulate age-related neurological disorders via the gut-brain axis. (2) Methods: To investigate the anti-aging effect of probiotic Lactobacillus plantarum GKM3, both survival tests and cognitive experiments were conducted in the SAMP8 mice model. The six-month-old SAMP8 (n = 20 in each gender) were fed with probiotic GKM3 at a dosage of 5.1 × 109 and 1.0 × 109 cfu/ kg B.W./day until their natural death. Then, the life span was investigated. Three-month-old SAMP8 (n = 10 in each gender) were administered GKM3 for 14 weeks. Then, the behavior tests and oxidation parameters were recorded. (3) Results: GKM3 groups showed significantly increased latency in the passive avoidance test and time of successful avoidance in the active avoidance test. The TBARS and 8-OHdG from mice brains also showed a significant reduction in the groups treated with GKM3. In addition, lower accumulation of the amyloid-ß protein was found in SAMP8 mice brains with the supplement of GKM3. (4) Conclusions: These results indicated that L. plantarum GKM3 delayed the process of aging, alleviated age-related cognitive impairment, and reduced oxidative stress.

Malondialdehyde and bipolar disorder: A short comprehensive review of available literature.

BACKGROUND: The pathogenetic mechanisms of Bipolar Disorder (BD) have not been totally clarified. Oxidative stress seems to be involved in the etiology of BD, and malondialdehyde (MDA) represents a candidate biomarker for monitoring this aspect in different medical conditions including mood disorders. This article has the objective to critically summarize the available data about the association between MDA and BD. METHODS: A research in Pubmed, PsycINFO and Isi Web of Knowledge was fulfilled to identify studies in which MDA levels were measured in BD patients for the purpose of securing a comprehensive review concerning the issue. RESULTS: We detected 20 articles that satisfied the inclusion criteria: most of them observed higher MDA levels (or Thiobarbituric acid-reactive substances-TBARS) in BD patients compared to healthy controls (HC), although there are some contrasting results, depending in particular on the phase of illness or the inclusion criteria or the methodological differences. LIMITATIONS: We included studies, exclusively in English, that used different laboratory methods to measure MDA. CONCLUSIONS: The analysed articles suggest that MDA or TBARS are increased in BD patients with respect to HC, thus supporting the hypothesis that MDA may be a promising and potential biomarker to monitor the course of BD, although further studies are needed to confirm this hypothesis.

Moisture content, fatty acid profile and oxidative traits of aged beef subjected to different temperature-time combinations.

Temperature-time combinations (TTC) effects on beef fatty acid (FA) composition, moisture content and oxidative traits were investigated. TTC were designed so temperatures were constant over each time period, and there was at most one variation in temperature within a sample's combined (total) time period. Therefore, three temperatures (~ 3, 5 and 7 °C) and five time periods (6, 8, 10 and 12 d) resulted in 72 different TTC, which were compared to control samples held for 14 d at ~ 1 °C. It was found that moisture losses increased as TTC temperature and time periods increased. There were negligible effects of TTC on FA composition. Sample TBARS and vitamin E content did not respond to TTC. A positive relationship between beef vitamin E and long chain polyunsaturated FA contents was observed. We concluded that TTC could be applied to accelerate the rate of ageing for beef and achieve comparable yield, oxidative and FA characteristics compared to conventional ageing approaches.

A Comprehensive Review on Lipid Oxidation in Meat and Meat Products.

Meat and meat products are a fundamental part of the human diet. The protein and vitamin content, as well as essential fatty acids, gives them an appropriate composition to complete the nutritional requirements. However, meat constituents are susceptible to degradation processes. Among them, the most important, after microbial deterioration, are oxidative processes, which affect lipids, pigments, proteins and vitamins. During these reactions a sensory degradation of the product occurs, causing consumer rejection. In addition, there is a nutritional loss that leads to the formation of toxic substances, so the control of oxidative processes is of vital importance for the meat industry. Nonetheless, despite lipid oxidation being widely investigated for decades, the complex reactions involved in the process, as well as the different pathways and factors that influenced them, make that lipid oxidation mechanisms have not yet been completely understood. Thus, this article reviews the fundamental mechanisms of lipid oxidation, the most important oxidative reactions, the main factors that influence lipid oxidation, and the routine methods to measure compounds derived from lipid oxidation in meat.

Heart rate variability and plasma biomarkers in patients with type 1 diabetes mellitus: Effect of a bout of aerobic exercise.

OBJECTIVE: The aim of this study was to evaluate: (1) the cardiovascular parameters and plasma biomarkers in people with type 1 diabetes mellitus (T1DM) at baseline; and (2) the heart rate variability (HRV) and blood glucose in response to a session of aerobic exercise (AE) and during recovery period. RESEARCH DESIGN AND METHODS: Adults (18-35 years) were divided into two groups: control (CT, n=10) and T1DM (n=9). Anthropometric, cardiovascular, and biochemical parameters, and aerobic capacity (indirect peak oxygen uptake, VO2peak) were evaluated at baseline. Thirty minutes of AE (40-60% intensity) was performed on a treadmill. Blood glucose and HRV were determined at rest, during AE, and during the recovery period. RESULTS: Anthropometric measurements, cardiovascular parameters, aerobic capacity, and biochemical parameters were similar between the groups at baseline. In the T1DM group, blood glucose, glycated hemoglobin, and thiobarbituric acid reactive substances concentrations were increased while nitrite/nitrate (NOx(-)) levels were reduced. During AE, the magnitude of the reduction of blood glucose was greater than that during the recovery period in the T1DM group. The RR intervals and SDNN were reduced at rest as well as in the recovery period in T1DM subjects, whereas the RMSSD and pNN50 were only reduced during the recovery period. No changes were observed in low frequency (LF), high frequency (HF), and LF/HF ratio. CONCLUSION: Our study shows that T1DM patients on insulin therapy have poor blood glucose control with greater lipid peroxidation and lower NOx(-) levels, accompanied by an imbalance in autonomic function detected by the challenge of AE.

Effects of Folic Acid Supplementation on Plasma Homocysteine and Thiobarbituric Acid Reactive Substances (TBARS) Levels and Liver SAM/SAH Ratio in Hyperhomocysteinaemia-induced Pregnant Rats

This study was performed to investigate effects of dietary folic acid supplementation on plasma homocysteine levels, thiobarbituric acid reactive substances (TBARS) levels and liver SAM/SAH ratio in hyperhomocysteinaemia-induced pregnant rats. Forty-two female Sprague-Dawley rats were divided three groups (C: control diet, HFD: 0.3% homocystine and 0 mg folic acid diet, HFS: 0.3 % homocystine and 8 mg/kg folic acid diet) according to homocystine and folic acid levels in the diet. They were fed experimental diets for 5 weeks prior to the mating and also during the entire period of pregnancy till gestational day 20. Dietary folic acid supplementation caused a significant decrease in plasma homocysteine levels which had been increased by a homocystine-diet, with a concomitant increase in plasma and liver folate levels. Liver TBARS levels in homocysteine-folic acid- deficient group (HFD) were higher than those in control group. Dietary folic acid supplementation increased hepatic SAM/SAH ratio in homocysteine-folic acid- supplemetantion group (HFS) when compared to the HFD (p < 0.05). These data suggest that folate depletion and elevated plasma homocysteine may promote oxidative stress in rat livers and influence the remethylation cycle of the homocysteine metabolism detrimentally. In conclusion, dietary folic acid supplementation was found to be effective for lowering plasma homocysteine levels, relieving oxidative stress, and improving the methylation status in the body.