Search Results (53)

The activation mechanism of the reproductive axis in Kazakh ewes during the non-breeding season was explored by supplementation with glycerol complex (7% glycerol + tyrosine + vitamin B9). The experiment divided 50 ewes into five groups (n = 10). After 90 days of intervention, it was found that significant changes in serum DL-carnitine, N-methyl-lysine and other differential metabolites were observed in the GLY-Tyr-B9 group (p < 0.05, “p < 0.05” means significant difference, “p < 0.01” means “highly significant difference”). The bile acid metabolic pathway was specifically activated (p < 0.01). The group had a 50% estrus rate, ovaries contained 3–5 immature follicles, and HE staining showed intact granulosa cell structure. Serum E2/P4 fluctuated cyclically (p < 0.01), FSH/LH pulse frequency increased (p < 0.01), peak Glu/INS appeared on day 60 (p < 0.05), and LEP was negatively correlated with body fat percentage (p < 0.01). Molecular mechanisms revealed: upregulation of hypothalamic kiss-1/GPR54 expression (p < 0.01) drove GnRH pulses; ovarian CYP11A1/LHR/VEGF synergistically promoted follicular development (p < 0.05); the HSL of subcutaneous fat was significantly increased (p < 0.05), suggesting involvement of lipolytic supply. Glycerol activates the reproductive axis through a dual pathway—L-carnitine-mediated elevation of mitochondrial β-oxidation efficacy synergizes with kisspeptin/GPR54 signalling enhancement to re-establish HPO axis rhythms. This study reveals the central role of metabolic reprogramming in regulating seasonal reproduction in ruminants. Full article

Due to the health-driven demand for fat replacers in meat products, Lycopene (Lyc)-loaded yeast protein (YP) high internal phase Pickering emulsions (HIPPEs) were explored as fat replacers for 3D-printed meat products. HIPPEs with varying Lyc concentrations were formulated, and their encapsulation efficiency and antioxidant activity (DPPH and ABTS assays) were evaluated. The encapsulation efficiency of Lyc exceeded 90% for all samples. Microscopic analysis revealed significant droplet enlargement in emulsions containing Lyc concentrations of 1.25 mg/mL and 1.50 mg/mL. Antioxidant activity peaked at a Lyc concentration of 1.00 mg/mL. Three-dimensional-printed meat products with different fat replacement ratios (0%, 25%, 50%, 75% and 100%) were prepared using both Lyc-loaded and non-loaded emulsions, and their printing precision, cooking loss, color, pH, texture, and lipid oxidation were assessed. The replacement ratio had no significant impact on printing precision, while cooking yield improved with higher fat replacement levels. Lyc emulsions notably influenced meat color, resulting in lower lightness and higher redness and yellowness. pH values remained stable across formulations. Lipid oxidation decreased with increasing fat replacement levels. The results indicate that Lyc-loaded YP Pickering emulsions have great potential as effective fat replacers for 3D-printed meat products, enhancing antioxidant performance while preserving product quality. Full article

Background: This study aimed to evaluate the changes in fat utilization associated with transitioning from a traditional to a vegan Mediterranean diet in healthy, physically active men during a ramp exercise test. Methods: In a controlled crossover design, fourteen healthy, physically active men followed a traditional Mediterranean diet for three weeks (baseline). Then, participants transitioned to a four-week isocaloric vegan version of the Mediterranean diet, matched for macronutrient distribution but excluding all animal foods. Immediately after each dietary intervention, participants completed an incremental exercise test (from 30% to 70% of VO_2peak) on a cycle ergometer in a fasted state to determine peak fat oxidation (PFO) and its associated exercise intensity (Fatmax). Exercise heart rate and the rating of perceived exertion were also recorded at each exercise intensity. Results: The traditional and vegan Mediterranean diets provided comparable amounts of energy (2599.6 ± 180.8 and 2634.9 ± 148.3 kcal/day, p = 0.140) and total fat (97.0 ± 17.8 and 99.0 ± 13.2 g/day; p = 0.620). However, the vegan Mediterranean diet contained a lower proportion of saturated fat (25.2 ± 6.8 vs. 13.6 ± 4.4% of total fat, p < 0.010). Still, the dietary transition was not associated with modifications in PFO (0.323 ± 0.153 and 0.347 ± 0.147 g/min; p = 0.678) or Fatmax (40.51 ± 7.30 and 40.51 ± 10.71%VO_2peak; p = 1.000) during exercise. Moreover, the dietary transition did not significantly change the response curves across exercise intensities for fat oxidation (p = 0.553), heart rate (p = 0.280), or the rating of perceived exertion (p = 0.433). Conclusions: Switching from a traditional to a vegan Mediterranean diet did not affect fat oxidation, exercise intensity at peak fat oxidation, or perceptual responses during exercise in healthy, active men. These findings suggest that physically active individuals can adopt a vegan version of the Mediterranean diet without compromising fat utilization during submaximal aerobic exercise. Clinical Trial Registry: NCT06008886. Date of registration: 28 July 2023. Full article

Background: Diabetic cardiomyopathy (DCM) is characterized by progressive cardiac dysfunction, metabolic dysregulation, myocardial fibrosis, and mitochondrial impairment. Existing animal models, such as streptozotocin (STZ)-induced models, suffer from high mortality and fail to replicate chronic metabolic dysregulation induced by high-fat diets (HFD), whereas HFD or HFD/STZ-combined rodent models require high maintenance costs. This study aimed to establish a zebrafish HFD-DCM model to facilitate mechanistic exploration and drug discovery. Methods: Eighty wild-type female zebrafish were divided into normal diet (N, 6% fat) and HFD (H, 24% fat) groups and fed the diet for 8 weeks. Metabolic phenotypes were evaluated using intraperitoneal glucose tolerance tests and insulin level analysis. Cardiac function was assessed by using echocardiography (ejection fraction, E peak). Structural, metabolic, and oxidative stress alterations were analyzed by histopathology (H&E, Masson, and Oil Red O staining), molecular assays (RT-qPCR, Western blotting), and mitochondrial structure/function evaluations (respiratory chain activity, transmission electron microscopy, and DHE staining). Results: HFD-fed zebrafish developed obesity, insulin resistance, and impaired glucose tolerance. Echocardiography revealed cardiac hypertrophy, reduced ejection fraction, and diastolic dysfunction. Excessive lipid accumulation, upregulated fibrosis/inflammatory markers, impaired mitochondrial respiration, elevated reactive oxygen species levels, and a disrupted redox balance were observed. Conclusions: We established a female zebrafish HFD model that recapitulates human DCM features, including hypertrophy, metabolic dysregulation, fibrosis, inflammation, and mitochondrial dysfunction. This model offers novel insights into DCM pathogenesis and serves as a valuable platform for mechanistic studies and targeted drug screening. Full article

Background/Objectives: Previous studies suggest that there is a genetically determined component of fat oxidation at rest and during exercise. To date, the FTO gene has been proposed as a candidate gene to affect fat oxidation during exercise because of the association of the “at-risk” A allele with different obesity-related factors such as increased body fat, higher appetite and elevated insulin and triglyceride levels. The A allele of the FTO gene may also be linked to obesity through a reduced capacity for fat oxidation during exercise, a topic that remains largely underexplored in the current literature. The aim of this study was to analyze the association between the FTO rs9939609 polymorphism with the rate of fat oxidation during exercise and metabolic syndrome criteria in healthy participants. Methods: A total of 80 healthy participants (41 men and 39 women) underwent comprehensive assessments, including measurements of anthropometric variables, blood pressure and blood measures of fasting glucose, triglycerides, low- and high-density lipoprotein cholesterol (LDL-c and HDL-c), insulin, interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations. Additionally, the Homeostatic Model Assessment (HOMA-IR) was used to evaluate insulin resistance. Peak oxygen uptake (VO_2peak) and maximal fat oxidation rate (MFO) were also measured during an incremental cycling test. FTO rs9939609 genotyping (TT, AT, AA) was performed using genomic DNA samples obtained from a buccal swab and measured with PCR. Results: There were 32 participants (40.0%) with the TT genotype; 31 (38.8%) with the AT genotype; and 17 (21.2%) with the AA genotype. Age, body characteristics, VO_2peak, blood pressure and blood variables were similar across all three genotypes. However, serum insulin concentration and HOMA-IR were associated with the FTO rs9939609 genotype with higher values in AA with respect to AT and TT participants (p < 0.050). Still, MFO was similar in TT, AT and AA participants (0.35 ± 0.13, 0.37 ± 0.11, 0.33 ± 0.11 g/min, p = 0.702). In the dominant model, there was no statistical difference between TT and A allele carriers. However, the recessive model revealed that AA participants had higher values of body mass, body mass index, blood insulin concentration and HOMA-IR than T allele carriers (p < 0.050), with no differences in MFO. Conclusions: In our sample of healthy individuals, the FTO rs9939609 polymorphism was associated with several phenotypes associated with obesity and insulin resistance, particularly under the AA vs. T allele/recessive model. However, the FTO rs9939609 polymorphism was not associated with MFO during exercise as fat oxidation was similar across genotypes. This suggests that reduced fat oxidation during exercise is unlikely to be a cause of the obesogenic influence of the FTO AA genotype. Clinically, these findings suggest that the obesogenic effects of the FTO AA genotype are unlikely driven by impaired fat oxidation during exercise. Instead, attention should focus on mechanisms like appetite regulation and energy intake. Moreover, exercise interventions may still effectively mitigate obesity risk, as AA individuals retain normal fat oxidation capacity during exercise. Full article

Background: 2′-Fucosyllactose (2′-FL) is an oligosaccharide contained in human milk and possesses prebiotic and anti-inflammatory effects, which may alleviate skeletal muscle atrophy under caloric restriction. This study evaluated the impacts of 12 weeks of 2′-FL supplementation in conjunction with exercise (10,000 steps/day, 5 days/week) and energy-reduced (−300 kcals/day) dietary interventions on changes in body composition and health-related biomarkers. Methods: A total of 41 overweight and sedentary female and male participants (38.0 ± 13 years, 90.1 ± 15 kg, 31.6 ± 6.6 kg/m², 36.9 ± 7% fat) took part in a randomized, double-blind, and placebo-controlled study. The participants underwent baseline assessments and were then assigned to ingest 3 g/day of a placebo (PLA) or Momstamin 2′-F while initiating the exercise and weight-loss program. Follow-up tests were performed after 6 and 12 weeks. Data were analyzed using general linear model statistics with repeated measures and mean changes from baseline values with 95% confidence intervals (CIs). Results: No group × time × sex interaction effects were observed, so group × time effects are reported. Participants in both groups saw comparable reductions in weight. However, those with 2′-FL demonstrated a significantly greater reduction in the percentage of body fat and less loss of the fat-free mass. Additionally, there was evidence that 2′-FL supplementation promoted more favorable changes in resting fat oxidation, peak aerobic capacity, IL-4, and platelet aggregation, with some minimal effects on the fermentation of short-chain fatty acids and monosaccharides in fecal samples. Moreover, participants’ perceptions regarding some aspects of the functional capacity and ratings of the quality of life were improved, and the supplementation protocol was well tolerated, although a small, but significant, decrease in BMC was observed. Conclusions: The results support contentions that dietary supplementation of 2′-FL (3 g/d) can promote fat loss and improve exercise- and diet-related markers of health and fitness in overweight sedentary individuals initiating an exercise and weight-loss program. Further research is needed to explore the potential health benefits of 2′-FL supplementation in both healthy and elderly individuals (Registered clinical trial #NCT06547801). Full article

(1) Background: The diversity of blood biomarkers used to assess the metabolic mechanisms of hydrogen limits a comprehensive understanding of its effects on improving exercise performance. This study evaluated the impact of hydrogen-rich gas (HRG) on metabolites following sprint-interval exercise using metabolomics approaches, aiming to elucidate its underlying mechanisms of action. (2) Methods: Ten healthy adult males participated in the Wingate Sprint-interval test (SIT) following 60 min of HRG or placebo (air) inhalation. Venous blood samples were collected for metabolomic analysis both before and after gas inhalation and subsequent to completing the SIT. (3) Results: Compared with the placebo, HRG inhalation significantly improved mean power, fatigue index, and time to peak for the fourth sprint and significantly reduced the attenuation values of peak power, mean power, and time to peak between the first and fourth. Metabolomic analysis highlighted the significant upregulation of acetylcarnitine, propionyl-L-carnitine, hypoxanthine, and xanthine upon HRG inhalation, with enrichment pathway analysis suggesting that HRG may foster fat mobilization by enhancing coenzyme A synthesis, promoting glycerophospholipid metabolism, and suppressing insulin levels. (4) Conclusions: Inhaling HRG before an SIT enhances end-stage anaerobic sprint capabilities and mitigates fatigue. Metabolomic analysis suggests that HRG may enhance ATP recovery during interval stages by accelerating fat oxidation, providing increased energy replenishment for late-stage sprints. Full article

During some trail running races, athletes have to carry hydration support, food, and technical and safety equipment, which generates an additional load that must be mobilized during the race. The aim of the present study was to determine the physiological responses to overload running and the effect they may have on metabolic zones. Seventeen well-trained male trail runners (n = 17) completed three maximal treadmill tests with weighted vests at 0%, 5%, and 10% of their body mass (L0, L5, and L10). Their gas exchange was monitored to assess their ventilatory thresholds 1 (VT1) and 2 (VT2), maximal fat oxidation zone (FatMax), and peak oxygen consumption (VO_2peak). Their heart rate (HR), power, and velocity (V) were tracked to compare their behavior. One-way ANOVA showed significant differences in the V (p < 0.001; ηp2 = 0.4620) as a limitation for reaching the peak velocity (V_peak), with a significant decrease in the V_peak with the L10 compared to the L0 (p = 0.002) and L5 (p = 0.004). In addition, one-way ANOVA showed significant differences in the peak absolute power (p < 0.001; ηp2 = 0.468) among the groups, detecting higher power production between the L10 and L0 (p < 0.001) and between the L10 and L5 (p = 0.015). Loads higher than L5 could generated important physiological and mechanical modifications, while a load of L5 managed to maintain the working conditions without overloading. These insights shed light on nuanced strategies for optimizing performance and endurance, offering valuable considerations for athletes seeking to enhance their training regimens during overload conditions. Full article

In the food industry, including the fat and oil sector, chemical methods are commonly used for routine quality analyses. These analyses are typically time-consuming and often require the use of toxic solvents and reagents. Moreover, in some cases, sophisticated instruments such as gas chromatographs are used, which are expensive and a form of advanced instrumentation. As an alternative approach, it is possible to use simpler methods utilizing spectroscopic techniques, like FTIR spectroscopy, the results of which have been reported to correlate with those obtained using wet chemical methods. In this study, we used the FTIR technique to assess the oxidative stability of some edible oils available on the Polish market. The oils studied were nigella seed, pumpkin seed, flax seed, linseed, evening primrose seed, and thistle seed oils. FTIR/ATR spectra of the undiluted oils were recorded in the range of 500–4000 cm⁻¹ with a resolution of 2 cm⁻¹. To monitor the oxidation process, the peak at 721 cm⁻¹, related to cis double bonds of unsaturated fatty acids (UFAs), and the peak intensity at 986 cm⁻¹, associated with the presence of conjugated diene groups of hydroperoxides (HPs), were analyzed. The content of free fatty acids (FFAs) and the ratio of unsaturated/saturated fatty acids (UFAs/SFAs) were qualitatively expressed by the intensity band at 1712 cm⁻¹ and the peak ratio of 3011/2925 cm⁻¹, respectively. Additionally, using the Triphenylphosphine/Triphenylphosphine Oxide (TPP/TPPO) assay, the peroxide value (PV) was calculated. The parameter analysis revealed significant variations among the tested oils. Moreover, all determined parameters from the FTIR spectrum changed during the oxidation process. However, the nature and degree of these changes differed depending on the oil tested. The findings indicated that the straightforward instrumental FTIR method could serve as a rapid analytical tool for evaluating the level of oxidation or comparing the quality of edible oils. Full article

With the aim to produce solid fats with a high percentage of unsaturated fatty acids, oleogels based on olive and peanut oil with different concentrations of beeswax (BW) and glycerol monostearate (GMS) as oleogelators were studied and compared. The critical oleogelator concentration for both BW and GMS was 3%. Thermal properties of the developed GMS-based oleogels pointed to a polymorphic structure, confirmed by the presence of two exothermic and endothermic peaks. All developed oleogels released less than 4% of oil, highlighting their high oil binding capacity. A morphology evaluation of oleogels showed platelet-like crystals, characterized by a cross-sectional length of 50 μm in BW-based oleogels and irregular clusters of needle-like crystals with a higher diameter in GMS-based oleogels. BW-based oleogels showed a solid fat content ranging from 1.16% to 2.27%, and no solid fat content was found at 37 °C. GMS-based oleogels reached slightly higher values of SFC that ranged from 1.58% to 2.97% at 25 °C and from 1.00% to 1.75% at 37 °C. Olive oil-based oleogels with GMS showed higher firmness compared with BW-based ones. The stronger structure network in olive oil/GMS-based oleogels provided a real physical barrier to oxidants, showing a high oxidation stability. Full article

We propose a novel method for assessing metabolic flexibility (MF) through indirect calorimetry. A total of twenty healthy volunteers (10 females; 10 males) aged 45–65 were categorized into a Low-Intensity activity group (LI, 0–1 session of 1 h per week) and a High-Intensity activity group (HI, 5–6 sessions of 2 h per week). Volunteers underwent a stepwise exercise test on a cycle ergometer, connected to a calorimeter, to examine respiratory gas exchange to evaluate peak fatty acid Oxidation (PFO) and peak carbohydrate oxidation (PCO). Circulating peroxisome proliferator-activated receptor α (PPARα) biomarkers, docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio and N-oleoylethanolamine (OEA), and the endocannabinoid- 2-arachidonoylglycerol (2-AG), were evaluated. We developed two MF parameters: the MF index (MFI), calculated by the product of PFO normalized per kg of fat-free mass (FFM) and the percentage of VO_2max at PFO, and the peak energy substrates’ oxidation (PESO), computed by summing the kilocalories from the PFO and PCO, normalized per kg FFM. The MFI and PESO were significantly different between the HI and LI groups, showing strong correlations with the circulating bioactive substances. Higher DHA/EPA ratio (p ≤ 0.05) and OEA (p ≤ 0.01), but lower 2-AG levels (p ≤ 0.01) were found in the HI group. These new parameters successfully established a functional link between MF and the balance of PPARα/endocannabinoid systems. Full article

There is a growing interest in studies involving carbohydrate (CHO) manipulation and subsequent adaptations to endurance training. This study aimed to analyze whether a periodized carbohydrate feeding strategy based on a daily training session has any advantages compared to a high-carbohydrate diet in well-trained cyclists. Seventeen trained cyclists (VO_2peak = 70.8 ± 6.5 mL·kg⁻¹·min⁻¹) were divided into two groups, a periodized (PCHO) group and a high-carbohydrate (HCHO) group. Both groups performed the same training sessions for five weeks. In the PCHO group, 13 training sessions were performed with low carbohydrate availability. In the HCHO group, all sessions were completed following previous carbohydrate intake to ensure high pre-exercise glycogen levels. In both groups, there was an increase in the maximal lactate steady state (MLSS) (PCHO: 244.1 ± 29.9 W to 253.2 ± 28.4 W; p = 0.008; HCHO: 235.8 ± 21.4 W to 246.9 ± 16.7 W; p = 0.012) but not in the time to exhaustion at MLSS intensity. Both groups increased the percentage of muscle mass (PCHO: p = 0.021; HCHO: p = 0.042) and decreased the percent body fat (PCHO: p = 0.021; HCHO: p = 0.012). We found no differences in carbohydrate or lipid oxidation, heart rate, and post-exercise lactate concentration. Periodizing the CHO intake in well-trained cyclists during a 5-week intervention did not elicit superior results to an energy intake-matched high-carbohydrate diet in any of the measured outcomes. Full article

Concerns about the depletion of petroleum reserves and rising pollution led researchers to search for alternate and environmentally compatible fuels for compression ignition engines. As an excellent alternative fuel additive to biodiesel–diesel blends, higher alcohol exhibits outstanding fuel properties (such as high energy content and cetane number) and can operate in diesel engines without requiring engine changes. This study focuses on investigating the ternary blends comprising higher alcohols, namely 1-heptanol and n-octanol, in hybrid biodiesel (animal fat oil–rice bran oil–cottonseed oil) and diesel on compression ignition engine characteristics. The performance, combustion, and emissions of a diesel engine fuelled with mono (D100), binary (B20), and ternary fuel blends (B20H10, B20H20, B20O10, and B20O20) were analysed at a constant engine speed of 1500 rpm. The test fuels met the American Society for Testing and Materials standards for fuel properties and exhibited stable behaviour during testing. Experimental results showed that at 100% load, the least brake-specific fuel consumptions for diesel fuel, B20, B20H10, B20H20, B20O10, and B20O20 were 254.1 g/kWh, 302.14 g/kWh, 281.25 g/kWh, 310.94 g/kWh, 292.8 g/kWh, and 313.80 g/kWh, respectively. Meanwhile, the maximum brake thermal efficiency values were obtained as 38.65%, 37.01%, 37.76%, 36.84%, 37.12%, and 36.38%, respectively. At 100% load, the peak heat release rates for diesel, B20, B20H10, B20H20, B20O10, and B20O20 were found to be 64.65 J/deg, 59.07 J/deg, 62.34 J/deg, 56.12 J/deg, 57.95 J/deg, and 51.9 J/deg, respectively. The addition of 1-heptanol and n-octanol as oxygenated additives into the ternary blend resulted in decreased carbon monoxide and unburned hydrocarbon emissions while increasing carbon dioxide and nitrous oxide emissions compared to diesel fuel. Overall, the study concludes that ternary blends with 1-heptanol and n-octanol as additives improve performance and combustion behaviour and reduce exhaust emissions compared to binary blends. Full article

Grape consumption acts on the immune system to produce antioxidant and anti-inflammatory effects. Since immune activity demonstrates circadian rhythmicity, with peak activity occurring during waking hours, the timing of grape intake may influence the magnitude of its antioxidant effect. This study followed a 2 × 2 factorial randomized, controlled design wherein healthy men and women (n = 32) consumed either a grape or placebo drink with a high-fat meal in the morning or evening. Urine was collected for measurements of biomarkers of oxidative stress and grape metabolites at baseline and post-meal at hour 1 and hours 1–6. F-2 isoprostane levels showed main effects of time period (baseline < hour 1 < hours 1–6, p < 0.0001), time (a.m. > p.m., p = 0.008) and treatment (placebo > grape, p = 0.05). Total F2-isoprostane excretion expressed as % baseline was higher in the a.m. vs. p.m. (p = 0.004) and in the a.m. placebo vs. all other groups (p < 0.05). Tartaric acid and resveratrol excretion levels were higher in the grape vs. placebo group (p < 0.05) but were not correlated with F-2 isoprostane levels. The findings support a protective effect of grape consumption against morning sensitivity to oxidative stress. Full article

Girls often begin to skip breakfast during adolescence. This study compared the acute effect of breakfast omission versus consumption on cardiometabolic risk markers and perceived appetite and mood during rest and/or exercise in adolescent girls classified as habitual breakfast consumers. Girls (aged 13.2 ± 0.7 years) completed two 5.5 h conditions in a randomised crossover design: breakfast omission (BO) and standardised breakfast consumption (BC). A standardised lunch was provided at 3 h. Incremental cycling exercise was performed at 5 h. Blood and expired gas samples were taken at regular intervals. Whilst pre-lunch plasma glucose, insulin, and Metabolic Load Index incremental area under the curve (IAUC) were significantly lower in BO versus BC, post-lunch differences were reversed and larger in magnitude. Peak plasma glucose and insulin were significantly higher in BO versus BC. Pre-lunch perceived fullness and hunger were significantly lower and higher, respectively, in BO versus BC. Perceived energy and concentration were lower, and tiredness was higher, in BO versus BC. Exercise peak fat oxidation and Fatmax were unaffected. The lower physical activity enjoyment in BO versus BC approached significance. To conclude, acutely omitting breakfast adversely affects cardiometabolic risk markers and exercise enjoyment among adolescent girls who habitually consume breakfast. Full article