Tomato genotype but not crop water deficit matters for tomato health benefits in diet-induced obesity of C57BL/6JRj male mice.

Several studies have linked the intake of lycopene and/or tomato products with improved metabolic health under obesogenic regime. The aim was to evaluate the differential impact of supplementations with several tomato genotypes differing in carotenoid content and subjected to different irrigation levels on obesity-associated disorders in mice. In this study, 80 male C57BL/6JRj mice were assigned into 8 groups to receive: control diet, high fat diet, high fat diet supplemented at 5 % w/w with 4 tomato powders originating from different tomato genotypes cultivated under control irrigation: H1311, M82, IL6-2, IL12-4. Among the 4 genotypes, 2 were also cultivated under deficit irrigation, reducing the irrigation water supply by 50 % from anthesis to fruit harvest. In controlled irrigation treatment, all genotypes significantly improved fasting glycemia and three of them significantly lowered liver lipids content after 12 weeks of supplementation. In addition, IL6-2 genotype, rich in ß-carotene, significantly limited animal adiposity, body weight gain and improved glucose homeostasis as highlighted in glucose and insulin tolerance tests. No consistent beneficial or detrimental impact of deficit irrigation to tomato promoting health benefits was found. These findings imply that the choice of tomato genotype can significantly alter the composition of fruit carotenoids and phytochemicals, thereby influencing the anti-obesogenic effects of the fruit. In contrast, deficit irrigation appears to have an overall insignificant impact on enhancing the health benefits of tomato powder in this context, particularly when compared to the genotype-related variations in carotenoid content.

Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids.

Drought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (-18.7% on average), especially ß-carotene (-32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matrix.

Vitamin D3 Supplementation Alleviates Left Ventricular Dysfunction in a Mouse Model of Diet-Induced Type 2 Diabetes: Potential Involvement of Cardiac Lipotoxicity Modulation.

PURPOSE: To evaluate the effectiveness of vitamin D3 supplementation, in secondary prevention, on cardiac remodeling and function, as well as lipid profile, in a mouse model of diet-induced type 2 diabetes. METHODS: Mice were fed a high fat and sucrose diet for 10 weeks. Afterward, diet was maintained for 15 more weeks and two groups were formed, with and without cholecalciferol supplementation. A control group was fed with normal chow. Glucose homeostasis and cardiac function were assessed at baseline and at the 10th and 24th weeks. Animals were killed at the 10th and 25th weeks for plasma and cardiac sample analysis. Cardiac lipid profile was characterized by LC-MS/MS. RESULTS: After 10 weeks of diet, mice exhibited pre-diabetes, mild left ventricle hypertrophy, and impaired longitudinal strain, but preserved myocardial circumferential as well as global diastolic and systolic cardiac function. After 15 more weeks of diet, animals presented with well-established type 2 diabetes, pathological cardiac hypertrophy, and impaired regional myocardial function. Cholecalciferol supplementation had no effect on glucose homeostasis but improved cardiac remodeling and regional myocardial function. After 25 weeks, non-supplemented mice exhibited increased myocardial levels of ceramides and diacylglycerol, both of which were normalized by vitamin D3 supplementation. CONCLUSION: This work brought to light the beneficial effects of cholecalciferol supplementation, in secondary prevention, on cardiac remodeling and function in a mouse model of diet-induced type 2 diabetes. Those cardioprotective effects may be, at least in part, attributed to the modulation of myocardial levels of lipotoxic species by vitamin D.

Combined Beneficial Effect of Voluntary Physical Exercise and Vitamin D Supplementation in Diet-induced Obese C57BL/6J Mice.

PURPOSE: Physical exercise (PE) combined with nutritional approaches has beneficial effects that are widely advocated to improve metabolic health. Here we used voluntary PE together with vitamin D (VD) supplementation, which has already shown beneficial effects in primary and tertiary prevention in obese mice models, to study their combined additive effects on body weight management, glucose homeostasis, metabolic inflammation, and liver steatosis as key markers of metabolic health. METHODS: Ten-week-old male C57BL/6J mice were fed a high-fat/sucrose (HFS) diet for 10 wk, then assigned to a 15-wk intervention period with PE, VD supplementation, or both PE and VD supplementation. Morphological, histological, and molecular phenotype data were characterized. RESULTS: The HFS-induced increases in body mass, adiposity, and adipocyte hypertrophy were improved by PE but not by VD supplementation. The HFS-induced inflammation (highlighted by chemokines mRNA levels) in inguinal adipose tissue was decreased by PE and/or VD supplementation. Furthermore, the intervention combining PE and VD showed additive effects on restoring insulin sensitivity and improving hepatic steatosis, as demonstrated through a normalization of size and number of hepatic lipid droplets and triglyceride content and a significant molecular-level decrease in the expression of genes coding for key enzymes in hepatic de novo lipogenesis. CONCLUSIONS: Taken together, our data show beneficial effects of combining PE and VD supplementation on obesity-associated comorbidities such as insulin resistance and hepatic disease in mice. This combined exercise-nutritional support strategy could prove valuable in obesity management programs.

Artificial sweeteners impair endothelial vascular reactivity: Preliminary results in rodents.

BACKGROUND AND AIMS: Prospective epidemiological studies highlighted recently the link between artificial sweeteners (AS) consumption and the risk of developing cardiometabolic diseases. However, underlying mechanisms remain unknown. Thus, the aim of this preliminary study was to characterize, in a healthy rat population, the effect of chronic AS consumption on body composition and vascular function, an early marker for cardiovascular disease. METHODS AND RESULTS: Healthy Wistar rats followed a 10-week standard diet including the consumption of water sweetened or not with a sucralose/acesulfame potassium solution at different concentrations: for moderate consumption at 1 and 2 mg.kg-1.day-1, respectively or high intake at 15 and 15 mg.kg-1.day-1 for both molecules (acceptable daily intake). Body fat composition has been evaluated and ex vivo aortic vasomotor function has been investigated with a pharmacological approach. CONCLUSION: Both groups of AS-treated rats showed a significant increase in subcutaneous and perirenal adipose tissue mass storage, without changes in total body mass. However, rats that have consumed AS at Acceptable Daily Intake (ADI) concentration revealed a significant vascular endothelial dysfunction compared to other groups. These results are interesting because they will help to better explain the observed increase in cardiometabolic risk.

Murine double minute-2 mediates exercise-induced angiogenesis in adipose tissue of diet-induced obese mice.

OBJECTIVE: This study aimed to determine the effects of physical exercise on the angio-adaptive response in adipose tissue following weight loss in a mouse model of diet-induced obesity. We hypothesized that physical exercise stimulates angiogenesis through the regulation of Vascular endothelial growth factor-A (VEGF-A) pro-/Thrombospondin-1 (TSP-1) anti-angiogenic signal under the control of the Murine double-minute 2/Forkhead box Os (Mdm2/FoxOs) axis, as reported in skeletal muscle. METHODS: We studied the effects of 7 weeks-voluntary exercise (Ex) in C57Bl/6 control or diet-induced obese (HFS) mice on vascularization of white adipose tissue (AT). RESULTS: Diet-induced obese sedentary (HFSsed) mice presented a powerful angiostatic control in all adipose tissues, under FoxOs protein regulation, leading to capillary rarefaction. Exercise increased expression of Mdm2, repressing the angiostatic control in favor of adipose vascular regrowth in normal chow (NCex) and HFSex mice. This phenomenon was associated with adipocytes microenvironment improvement, such as decreased adipocytes hypertrophy and adipose tissue inflammation. In addition, adipose angiogenesis stimulation by exercise through Mdm2 pro-angiogenic action, improved visceral adipose insulin sensitivity, activated browning process within subcutaneous adipose tissue (ScWAT) and decreased ectopic fat deposition (muscle, heart and liver) in obese HFSex mice. The overall result of this approach of therapy by physical exercise is an improvement of all systemic cardiometabolic parameters. CONCLUSIONS: These data demonstrated the therapeutic efficacy of physical exercise against obesity-associated pathologies, and also offer new prospects for molecular therapies targeting the adipose angio-adaptation in obese humans.

Vitamin D Supplementation Improves Adipose Tissue Inflammation and Reduces Hepatic Steatosis in Obese C57BL/6J Mice.

The beneficial effect of vitamin D (VD) supplementation on body weight gain limitation and inflammation has been highlighted in primary prevention mice models, but the long-term effect of VD supplementation in tertiary prevention has never been reported in obesity models. The curative effect of VD supplementation on obesity and associated disorders was evaluated in high-fat- and high-sucrose (HFS)-fed mice. Morphological, histological, and molecular phenotype were characterized. The increased body mass and adiposity caused by HFS diet as well as fat cell hypertrophy and glucose homeostasis were not improved by VD supplementation. However, VD supplementation led to a decrease of HFS-induced inflammation in inguinal adipose tissue, characterized by a decreased expression of chemokine mRNA levels. Moreover, a protective effect of VD on HFS-induced hepatic steatosis was highlighted by a decrease of lipid droplets and a reduction of triglyceride accumulation in the liver. This result was associated with a significant decrease of gene expression coding for key enzymes involved in hepatic de novo lipogenesis and fatty acid oxidation. Altogether, our results show that VD supplementation could be of interest to blunt the adipose tissue inflammation and hepatic steatosis and could represent an interesting nutritional strategy to fight obesity-associated comorbidities.

The Potential Synergistic Modulation of AMPK by Lippia citriodora Compounds as a Target in Metabolic Disorders.

Lippia citriodora (LC) represents a complex plant-derived source of polyphenols and iridoids that has shown beneficial properties against obesity-related metabolic disorders. The complete extract and its major compound, verbascoside, have shown AMPK-activating capacity in cell and animal models. In this work, we aimed to elucidate the contribution of the different compounds present in the LC extract on the AMPK activation capacity of the whole extract. Semipreparative reversed-phase high-performance liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (RP-HPLC-ESI-TOF-MS) was used to identify the major compounds with bioassay-guided fractionation in an adipocyte cell model for the measurement of AMPK activity. Twenty-two compounds were identified and purified almost to homogeneity in 16 fractions, and three compounds, namely verbascoside, luteolin-7-diglucuronide and loganic acid, showed the highest AMPK-activating capacity. The synergy study using the checkerboard and fractional inhibitory concentration index (FICI) methods exhibited synergistic behavior between loganic acid and luteolin-7-diglucuronide. Molecular docking experiments revealed that these three compounds might act as direct agonists of AMPK, binding to the AMP binding sites of the gamma subunit and/or the different sites of the interaction zones between the gamma and beta subunits. Although our findings conclude that the bioactivity of the extract is mainly due to verbascoside, the synergy found between loganic acid and luteolin-7-diglucuronide deserves further research aimed to develop optimized combinations of polyphenols as a new nutritional strategy against obesity-related metabolic disorders.

Microparticle miRNAs as Biomarkers of Vascular Function and Inflammation Response to Aerobic Exercise in Obesity?

OBJECTIVE: This study aimed to explore the role of nine microRNAs (miRNAs) in microparticles (MPs) on the efficacy of aerobic exercise in the regulation of inflammation and vascular function in obesity. METHODS: Sedentary women with normal weight (n = 6, BMI < 25 kg/m2 ) and women with obesity (n = 9, BMI > 30 kg/m2 ) were recruited at F. Hached Hospital (Sousse, Tunisia) and enrolled in an 8-week aerobic program. Vascular function was assessed using laser Doppler flowmetry/iontophoresis, circulating MPs by flow cytometry, miRNAs by real-time polymerase chain reaction, and inflammation by ELISA, before and after exercise. RESULTS: Women with obesity presented with high prevalence of cardiovascular risk factors and a higher circulating MP level compared with healthy subjects. The MP miRNA profile was significantly different in the two groups. Exercise reduced BMI and inflammation in both groups and significantly improved endothelial-dependent response (acetylcholine cutaneous vascular conductance) for healthy subjects, with a trend for women with obesity. Circulating MP level was increased after exercise, and miRNA expression was differentially modulated in both populations. Pearson analysis revealed a correlation between MPs miR-124a and miR150 and adiponectin, TNFα, or IL-6 levels. CONCLUSIONS: The relation between MPs and miRNA profile, inflammation, vascular function, and exercise is of particular interest for defining "miRNA biomarker signature" in patients with cardiovascular disease who are potentially susceptible to respond to exercise.

Involvement of bilitranslocase and beta-glucuronidase in the vascular protection by hydroxytyrosol and its glucuronide metabolites in oxidative stress conditions.

Olive oil vascular benefits have been attributed to hydroxytyrosol (HT). However, HT biological actions are still debated because it is extensively metabolized into glucuronides (GCs). The aim of this study was to test HT and GC vasculoprotective effects and the underlying mechanisms using aorta rings from 8-week-old male Wistar rats. In the absence of oxidative stress, incubation with 100 µM HT or GC for 5 min did not exert any vasorelaxing effect and did not influence the vascular function. Conversely, in condition of oxidative stress [upon incubation with 500 µM tert-butylhydroperoxide (t-BHP) for 30 min], preincubation with HT or GC improved acetylcholine-induced vasorelaxation compared with untreated samples (no t-BHP). This protective effect was lost for GC, but not for HT, when a washing step (15 min) was introduced between preincubation with HT or GC and t-BHP addition, suggesting that only HT enters the cells. In agreement, bilitranslocase inhibition with 100 µM phenylmethanesulfonyl fluoride for 20 min reduced significantly HT, but not GC, effect on the vascular function upon stress induction. Moreover, GC protective effect (improvement of endothelium-dependent relaxation in response to acetylcholine) in oxidative stress conditions was reduced by preincubation of aorta rings with 300 µM D-saccharolactone to inhibit ß-glucuronidase, which can deconjugate polyphenols. Finally, only HT was detected by high-pressure liquid chromatography in aorta rings incubated with GC and t-BHP. These results suggest that, in conditions of oxidative stress, GC can be deconjugated into HT that is transported through the cell membrane by bilitranslocase to protect vascular function.

Hydroxytyrosol in the Prevention of the Metabolic Syndrome and Related Disorders.

Virgin olive oil (VOO) constitutes the main source of fat in the Mediterranean diet. VOO is rich in oleic acid, displaying health-promoting properties, but also contains minor bioactive components, especially phenolic compounds. Hydroxytyrosol (HT), the main polyphenol of olive oil, has been reported to be the most bioactive component. This review aims to compile the results of clinical, animal and cell culture studies evaluating the effects of HT on the features of Metabolic Syndrome (MetS) (body weight/adiposity, dyslipidemia, hypertension, and hyperglycemia/insulin resistance) and associated complications (oxidative stress and inflammation). HT was able to improve the lipid profile, glycaemia, and insulin sensitivity, and counteract oxidative and inflammatory processes. Experimental studies identified multiple molecular targets for HT conferring its beneficial effect on health in spite of its low bioavailability. However, rodent experiments and clinical trials with pure HT at biologically relevant concentrations are still lacking. Moreover, the roles of intestine and its gut microbiota have not been elucidated.

Antioxidant properties of tea blunt ROS-dependent lipogenesis: beneficial effect on hepatic steatosis in a high fat-high sucrose diet NAFLD obese rat model.

Oxidative stress could trigger lipid accumulation in liver and thus hepatic steatosis. Tea is able to prevent liver disorders, but a direct link between antioxidant capacities and prevention of steatosis has not been reported yet. We aimed to investigate such relationship in a rat model of high fat-high sucrose diet (HFS)-induced obesity and to explore more deeply the mechanisms in isolated hepatocytes. Wistar rats were divided into a control group (standard diet), an HFS group (high fat-sucrose diet) and an HFS+tea group (HFS diet with ad-libitum access to tea drink). Body weight, fat mass, glycemic parameters in blood, lipid and oxidative stress parameters in blood and liver were measured in each group after 14 weeks. Isolated hepatocytes were treated with the reactive oxygen species (ROS) inducer t-BHP in the presence or not of antioxidants (tempol or tea), and superoxide anion production and lipid accumulation were measured using specific fluorescent probes. We reported that the HFS diet highly increased hepatic lipids content, while tea consumption attenuated steatosis and improved the oxidative status (decrease in hepatic oxidative stress, increase in plasma total antioxidant capacity). The role of antioxidant properties of tea in such phenomenon was confirmed in primary cultured rat hepatocytes. Indeed, the increase of mitochondrial ROS production with t-BHP resulted in lipid accumulation in hepatocytes (positive linear regression), and antioxidants (tempol or tea) normalized both. We reported that the antioxidant properties of tea protect rats from an obesogenic HFS diet-induced hepatic steatosis by counteracting the ROS-dependent lipogenesis.

Role of eNOS- and NOX-containing microparticles in endothelial dysfunction in patients with obesity.

OBJECTIVE: To explore the pathophysiological profile of patients who have obesity and to investigate the potential role of circulating microparticles (MPs) in endothelial dysfunction in patients who have obesity. METHODS: The inflammatory and oxidative status and the cutaneous microvascular blood flow were characterized in 69 patients with android obesity and 46 subjects with normal weight (controls) by using laser Doppler flowmetry. Circulating MP levels were measured by flow cytometry, and endothelial nitric oxide synthase (eNOS) and NADPH oxidase (NOX) expression in MPs was investigated by Western blotting. MP effect on vascular reactivity was assessed in rat aorta rings. RESULTS: Patients with obesity showed endothelial dysfunction, hyperglycemia, inflammation, and oxidative stress. In controls, low MP levels were positively correlated with normal microvascular function. Western blot analysis revealed reduced eNOS and increased NOX4D expression in MPs from subjects with obesity compared with controls. However, this was not correlated with endothelial dysfunction parameters and did not impair ex vivo endothelium-dependent vasodilation. CONCLUSIONS: These results suggest that MPs do not contribute directly to endothelial dysfunction associated with obesity. Conversely, eNOS- and NOX-containing MPs could be involved in the compensatory mechanism of vascular endothelial cells to counteract the pathologic mechanisms underlying endothelial dysfunction.

Exercise training protects against atherosclerotic risk factors through vascular NADPH oxidase, extracellular signal-regulated kinase 1/2 and stress-activated protein kinase/c-Jun N-terminal kinase downregulation in obese rats.

Exercise training reverses atherosclerotic risk factors associated with metabolic syndrome and obesity. The aim of the present study was to determine the molecular anti-inflammatory, anti-oxidative and anti-atherogenic effects in aorta from rats with high-fat diet-induced obesity. Male Sprague-Dawley rats were placed on a high-fat (HFD) or control (CD) diet for 12 weeks. The HFD rats were then divided into four groups: (i) sedentary HFD-fed rats (HFD-S); (ii) exercise trained (motor treadmill 5 days/week, 60 min/day, 12 weeks) HFD-fed rats (HFD-Ex); (iii) modified diet (HFD to CD) sedentary rats (HF/CD-S); and (iv) an exercise-trained modified diet group (HF/CD-Ex). Tissue levels of NADPH oxidase (activity and expression), NADPH oxidase (Nox) 1, Nox2, Nox4, p47(phox) , superoxide dismutase (SOD)-1, angiotensin AT1 and AT2 receptors, phosphorylated mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase (ERK) 1/2, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK)) and vascular cell adhesion molecule-1 (VCAM-1) were determined in the aorta. Plasma cytokines (tumour necrosis factor (TNF)-α and interleukin (IL)-6) levels were also measured. Obesity was accompanied by increases in NADPH oxidase activity, p47(phox) translocation, Nox4 and VCAM-1 protein expression, MAPK (ERK1/2, SAPK/JNK) phosphorylation and plasma TNF-α and IL-6 levels. Exercise training and switching from the HFD to CD reversed almost all these molecular changes. In addition, training increased aortic SOD-1 protein expression and decreased ERK1/2 phosphorylation. These findings suggest that protective effects of exercise training on atherosclerotic risk factors induced by obesity are associated with downregulation of NADPH oxidase, ERK1/2 and SAPK/JNK activity and increased SOD-1 expression.