The Effects of 24-h Fasting on Exercise Performance and Metabolic Parameters in a Pilot Study of Female CrossFit Athletes.

Many studies have tested intermittent fasting (IF) in athletes, but its effects on female CrossFit athletes remain relatively unexplored in the existing literature. The aim of this study was to evaluate and compare the effects of 24-h IF on the physical performance of female CrossFit practitioners. Eleven female CrossFit athletes (age: 30.91 ± 3.42, weight: 65.26 ± 7.55 kg, height: 1.66 ± 0.05 m) participated in the study. The study used a crossover design with fasting and eating conditions. Participants completed an exercise test, standing long jump, and handgrip strength assessment. Hydration status, heart rate, blood lactate, blood glucose, rates of perceived exertion, and hunger were measured. Results showed significant differences in blood lactate concentration (F = 5.435, p = 0.042, η2p = 0.352). Resting blood lactate concentration was significantly lower in the fasting trial than in the eating trial (p < 0.001), but post-exercise blood lactate concentrations were higher in the fasting trial than in the eating trial (p < 0.001). No differences were found in performance times (p > 0.05). In conclusion, this pilot study of females suggests that 24-h fasting does not impair exercise performance or negatively affect physiological parameters in CrossFit athletes.

Multiplatform metabolomic fingerprinting as a tool for understanding hypercholesterolemia in Wistar rats.

PURPOSE: The aim was to investigate the impact of hypercholesterolemic diet on the metabolome of male Wistar rats by a multiplatform metabolomic fingerprinting. METHODS: Male Wistar rats were fed with two different diets [control (C) and high-cholesterol diet (HC)-containing 2 % cholesterol and 0.5 % cholic acid]. After 7 weeks of experimental feeding, the rats were euthanized for blood collection and plasma recovery. The metabolite fingerprint was then achieved by applying a multiplatform comprising LC-MS, GC-MS and CE-MS. RESULTS: Multivariate statistical analysis showed a clear separation between the C and HC groups. Individual differences in metabolites were evaluated using univariate statistical analysis, and multiple metabolites were identified and confirmed in the plasma. A global profiling integrates for the first time pathways affected by high-cholesterol diet intake and allowed us to elucidate some of the associated alterations underlying the hypercholesterolemia event in Wistar rats. CONCLUSIONS: HC feeding stimulated the alteration of multiple pathways in Wistar rats, warning of the risk of developing important diseases, which can be modulated by the diet. Further studies are required to investigate the possibilities to revert or ameliorate the negative effects triggered by HC intake.

High-cholesterol diet enriched with onion affects endothelium-dependent relaxation and NADPH oxidase activity in mesenteric microvessels from Wistar rats.

BACKGROUND: The aim of the present study was to examine the effects of onion as functional ingredient on the oxidative status, lipoprotein levels (total cholesterol-TC, HDL-C, LDL-C), triacylglycerides (TAG) and vascular reactivity of mesenteric arteries in hypercholesterolemic Wistar rats. METHODS: Twenty-four animals were fed with three different diets [control, high-cholesterol diet (HC) and high-cholesterol enriched with onion diet (HCO)]. After seven weeks of experimental feeding the rats were euthanized for blood and tissues collection. TC, HDL-C, LDL-C and TAG were measured, and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(•+)) scavenging capacity and ferric reducing antioxidant power (FRAP) were determined in plasma. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were assayed in erythrocyte lysates. Endothelium-dependent vasodilation to acetylcholine was evaluated in mesenteric arterial segments. NADPH oxidase (NOX) was also measured by lucigenin-derived chemiluminiscence. RESULTS: The dietary cholesterol content significantly affected plasma lipoprotein levels, increased superoxide generation from NOX, and caused impaired endothelium-dependent vasodilation in the rat mesenteric arteries. Onion ingredient improved antioxidant status in HCO group, as it was evidenced by ABTS(•+) and FRAP values and SOD and GPx enzyme activities compared to the HC-fed group, reduced the increment in NOX activity and reversed endothelial dysfunction promoted by the HC diet. Scavenging of superoxide with TEMPOL or inhibition of NOX with apocynin improved endothelium-dependent vasodilation only in HC-fed rats. CONCLUSIONS: Enrichment of diet with onion as functional ingredient could be proposed as a complementary approach to prevent or partially modulate vascular dysfunction, reducing some of the risk indexes linked to initial development of atherosclerosis.

Effects of hypercholesterolemic diet enriched with onion as functional ingredient on fatty acid metabolism in Wistar rats.

The complex biochemical composition of onions has been studied as a source of biological components with health-related properties. The evolution of hypercholesterolemia is associated with a large range of alterations considered as strong risk factors for many cardiovascular events. The objective of this study was to investigate the effects of onion as functional ingredient on plasma, erythrocyte, liver and adipose tissue fatty acid composition in hypercholesterolemic male Wistar rats. Rats (n=24) were randomly divided into three groups: control (C), high-cholesterol (HC), and high-cholesterol enriched with onion (HCO) groups. At the end of 7weeks, animals were anesthetized and euthanized by extracting blood by cardiac puncture. Plasma, erythrocytes, liver and adipose tissue were collected and immediately stored at -80°C. Fatty acid methyl esters were identified and quantified by GC/MS. Total fatty acid concentration decreased in liver and adipose tissue both in HC and HCO groups. SFA content was significantly higher in plasma, erythrocytes and liver in the C group compared to HC and HCO groups. In contrast, SFAs increased in adipose tissue both in HC and HCO groups compared to the C group. A significant increase in MUFA content in plasma was found in HC and HCO groups compared to the C group; in erythrocytes and liver the increase was lower. In plasma, PUFA content was significantly lower in HC and HCO groups compared to the C group. Interestingly, in liver and adipose tissue, PUFAs increased in HC and HCO groups compared to the C group. Results showed noticeable effects on individual fatty acid composition when assaying high-cholesterol diets in rats, in some cases enhanced by onion enrichment. Further research is needed to deeper understand the involved mechanisms and pathways.

Hyaluronidase inhibiting activity and radical scavenging potential of flavonols in processed onion.

The flavonol content and anti-inflammatory and antioxidant activities of onion treated by high-pressure processing (HPP) and HPP combined with freeze-drying and pulverization (HPP-FD-P) were evaluated. Allium cepa L. var. cepa, 'Recas' was treated at T1 (200 MPa/25 °C/5 min), T2 (400 MPa/25 °C/5 min), and T3 (600 MPa/25 °C/5 min). After treatment, HP-treated and untreated samples were frozen (diced onion, HP-treated). Subsequently, part of the diced samples was freeze-dried and pulverized (pulverized onion, HP-treated and freeze-dried). Flavonol content and anti-inflammatory and antioxidant activities (hyaluronidase inhibiting activity, NO(•), ABTS(•+), and DPPH(•) scavenging capacity, ferric reducing antioxidant power, and antioxidative capacity by photochemiluminescence) were measured in nonhydrolyzed and hydrolyzed extracts. Hydrolysis was carried out in order to evaluate the effect of HPP and HPP-FD-P on both anti-inflammatory and antioxidant activities of extracts mainly containing aglycone forms. HPP-FD-P increased quercetin 3,4'-diglucoside, quercetin 4'-glucoside, quercetin 3-glucoside, and isorhamnetin 3,4'-diglucoside extractability. The present study suggests that HPP (especially treatment at 400 MPa) and HPP-FD-P may be of benefit for obtaining functional ingredients from onion, as suggested by increased NO(•) scavenging capacity and maintenance of the antioxidant activity mainly in hydrolyzed extracts.

Novel approach for the determination of volatile compounds in processed onion by headspace gas chromatography-mass spectrometry (HS GC-MS).

A novel headspace gas chromatography-mass spectrometry (HS GC-MS) method was developed for analysis of volatile compounds in onion (Allium cepa L. var. cepa, 'Recas'). MS was operated using full scan mode and selective ion monitoring (SIM) mode in order to quantify some specific compounds with increased sensitivity relative to full scan mode. The limits of detection and quantitation ranged from 0.01 to 0.10 µg/g and from 0.02 to 3.83 µg/g fresh weight, respectively, for studied compounds. The procedure allowed the identification of eighteen compounds and quantitation of nine compounds in the volatile fraction of onion, belonging mainly to di-, and trisulfides and aldehydes. These methods were applied to evaluate how high-pressure (HP) as a processing technology affects onion volatile compounds, responsible in part of the onion biological activity. Onion samples were treated at T1: 200 MPa/25°C/5 min, T2: 400 MPa/25°C/5 min and T3: 600 MPa/25°C/5 min (treatments). In addition, the difference among diced, freeze-dried and pulverized onions (groups) was studied, in order to select the process more adequate for better preserving volatile compounds. The results obtained in full scan mode showed that both main factors (group and treatment) had a significant effect (P<0.001). There were also significant differences between groups and treatments for all compounds, being the main effect of group more marked by HS GC-MS using selective ion monitoring (SIM) mode. For 2-methyl 2-pentenal, dimethyl trisulfide, and methyl propyl trisulfide it has been observed an increase in freeze-dried and pulverized onion samples compared with diced samples regardless the HP treatment. However, freeze-drying and pulverization processes affected the stability of propionaldehyde, 1-propanethiol, hexanal, dipropyl disulfide, and dipropyl trisulfide, diminishing their content regardless the HP treatment. HP at 200 and 400 MPa/25°C/5 min were the least detrimental treatments to the total fraction of volatile compounds, not affecting or even increasing the levels of some volatile compounds.