High Dietary Fructose: Direct or Indirect Dangerous Factors Disturbing Tissue and Organ Functions

Approaches to nutritional research using organoids; Fructose treatment induces epigenetic changes in liver organoids

Nutritional researches have successfully used animal models to gain new insights into nutrient action. However, comprehensive descriptions of their molecular mechanisms of action remain elusive as appropriate in vitro evaluation systems are lacking. Organoid models can mimic physiological structures and reproduce in vivo functions, making them increasingly utilized in biomedical research for a better understand physiological and pathological phenomena. Therefore, organoid modeling can be a powerful approach for to understand the molecular mechanisms of nutrient action. The present study aims to demonstrate the utility of organoids in nutritional research by further investigating the molecular mechanisms responsible for the negative effects of fructose intake using liver organoids. Here, we treated liver organoids with fructose and analyzed their gene expression profiles and DNA methylation levels. Microarray analysis demonstrated that fructose-treated organoids exhibited increased selenoprotein p (Sepp1) gene expression, whereas pyrosequencing assays revealed reduced DNA methylation levels in the Sepp1 region. These results were consistent with observations using hepatic tissues from fructose-fed rats. Conversely, no differences in Sepp1 mRNA and DNA methylation levels were observed in two-dimensional cells. These results suggest that organoids serve as an ideal in vitro model to recapitulate in vivo tissue responses and help to validate the molecular mechanisms of nutrient action compared to conventional cellular models.

A tipping point in dihydroxyacetone exposure: mitochondrial stress and metabolic reprogramming alter survival in rat cardiomyocytes H9c2 cells

Exogenous exposures to the triose sugar dihydroxyacetone (DHA) occur from sunless tanning products and electronic cigarette aerosol. Once inhaled or absorbed, DHA enters cells, is converted to dihydroxyacetone phosphate (DHAP), and incorporated into several metabolic pathways. Cytotoxic effects of DHA vary across the cell types depending on the metabolic needs of the cells, and differences in the generation of reactive oxygen species (ROS), cell cycle arrest, and mitochondrial dysfunction have been reported. We have shown that cytotoxic doses of DHA induced metabolic imbalances in glycolysis and oxidative phosphorylation in liver and kidney cell models. Here, we examine the dose-dependent effects of DHA on the rat cardiomyocyte cell line, H9c2. Cells begin to experience cytotoxic effects at low millimolar doses, but an increase in cell survival was observed at 2 mM DHA. We confirmed that 2 mM DHA increased cell survival compared to the low cytotoxic 1 mM dose and investigated the metabolic differences between these two low DHA doses. Exposure to 1 mM DHA showed changes in the cell's fuel utilization, mitochondrial reactive oxygen species (ROS), and transient changes in the glycolysis and mitochondrial energetics, which normalized 24 h after exposure. The 2 mM dose induced robust changes in mitochondrial flux through acetyl CoA and elevated expression of fatty acid synthase. Distinct from the 1 mM dose, the 2 mM exposure increased mitochondrial ROS and NAD(P)H levels, and sustained changes in LDHA/LDHB and acetyl CoA-associated enzymes were observed. Although the cells were exposed to low cytotoxic (1 mM) and non-cytotoxic (2 mM) acute doses of DHA, significant changes in mitochondrial metabolic pathways occurred. Further, the proliferation increase at the acute 2 mM DHA dose suggests a metabolic adaption occurred with sustained consequences in survival and proliferation. With increased exogenous exposure to DHA through e-cigarette aerosol, this work suggests cell metabolic changes induced by acute or potentially chronic exposures could impact cell function and survival.

Pomegranate supplementation alleviates dyslipidemia and the onset of non-alcoholic fatty liver disease in Wistar rats by shifting microbiota and producing urolithin-like microbial metabolites

Non-alcoholic fatty liver disease (NAFLD), obesity and related chronic diseases are major non-communicable diseases with high mortality rates worldwide. While dietary sugars are known to be responsible for insulin resistance and metabolic syndrome (MetS), the underlying pathophysiological effects of sustained fructose consumption require further elucidation. We hypothesize that certain bioactive compounds (i.e. punicalagin and ellagic acid) from dietary pomegranate could counteract the harmful effects of sustained fructose consumption in terms of obesity and liver damage. The present study aimed to elucidate both the molecular mechanisms involved in the pathophysiology associated with fructose intake and the effect of a punicalagin-rich commercial pomegranate dietary supplement (P) used as a nutritional strategy to alleviate fructose-induced metabolic impairments. Thus, nineteen Wistar rats fed on a basal commercial feed were supplemented with either 30% (w/v) fructose in drinking water (F; n = 7) or 30% (w/v) fructose solution plus 0.2% (w/v) P (F + P; n = 6) for 10 weeks. The results were compared to those from a control group fed on the basal diet and provided with drinking water (C; n = 6). Body weight and energy intake were registered weekly. P supplementation decreased fat depots, counteracted the dyslipidemia caused by F and improved markers of liver injury including steatosis. The study of the microbiota by metagenomics and urine by untargeted MS-based metabolomics revealed microbial metabolites from P that may be responsible for these health benefits.

Fennel seeds extract prevents fructose-induced cardiac dysfunction in a rat model of metabolic syndrome via targeting abdominal obesity, hyperuricemia and NF-κβ inflammatory pathway

BACKGROUND

Metabolic syndrome (MetS) is commonly associated with increased risk of cardiac disease that affects a large number of world populations.

OBJECTIVE

This research attempted to investigate the efficacy of fennel seeds extract (FSE) in preventing development of cardiac dysfunction in rats on fructose enriched diet for 3 months, as a model of MetS.

MATERIALS & METHODS

Thirty adult Wistar male rats (160-170 g) were assigned into 5 groups including control, vehicle, FSE (200 mg/kg BW) and fructose (60%) fed rats with and without FSE. Following the last treatment, blood pressure, ECG and heart rate were measured. Next, blood and cardiac tissues were taken for biochemical and histological investigations.

RESULTS

Feeding fructose exhibited characteristic features of MetS involving, hypertension, abnormal ECG, elevated heart rate, serum glucose, insulin, lipids and insulin resistance, accompanied by abdominal obesity, cardiac hypertrophy and hyperuricemia. Fructose fed rats also showed significant reduction in cardiac antioxidants (GSH, SOD, CAT) with elevation in oxidative stress indices (NADPH oxidase, O2.-, H2O2, MDA, PCO), NF-κβ, pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), adhesion molecules (ICAM-1, VCAM-1) and serum cardiac biomarkers (AST, LDH, CK-MB, cTn-I). Histopathological changes evidenced by destruction of cardiac myofibrils, cytoplasmic vacuolization, and aggregation of inflammatory cells were also detected. Consumption of FSE showed high ability to alleviate fructose-induced hypertension, ECG abnormalities, cardiac hypertrophy, metabolic alterations, oxidative stress, inflammation and histological injury.

CONCLUSION

Findings could suggest FSE as a complementary supplement for preventing MetS and associated cardiac outcomes. However, well controlled clinical studies are still needed.

Effect of Administration of Selenium Nanoparticles Synthesized Using Onion Extract on Biochemical and Inflammatory Parameters in Mice Fed with High-Fructose Diet: In Vivo and In Silico Analysis

Fructose consumption has increased globally and has been linked to obesity, insulin resistance, and diabetes. Selenium nanoparticles (SeNPs) can regulate glucose and lipid concentrations and have immunoregulatory properties. Four study groups (n = 7/group) of eight-week-old male mice (Balb/c) were formed for this investigation. One group received a standard diet (C), another standard diet plus SeNPs (C + SeNPs), a high fructose diet (F), and a group with a high fructose diet plus SeNPs (F + SeNPs). Weight, glucose, triglycerides, and cholesterol were evaluated. In the end, mice were sacrificed, blood samples were obtained to assess cytokine profile, and liver, kidney, and pancreas were removed for histological examination. The study was complemented with an in silico analysis where the CTD, STITCH, ToppGene Suite, ShinyGO 0.76.3 databases, and Cytoscape software were implemented. The results of in vivo analysis showed that SeNPs regulated biochemical parameters and showed anti-inflammatory effects by decreasing the concentrations of TNF-alpha, IL-1beta, and IFN-gamma and increasing IL-10. No damage was observed in the studied organs. In addition, SeNPs regulate oxidative stress, preserve cell organelles, and regulate metabolic pathways to avoid the adverse effects of fructose consumption, according to bioinformatics analysis. In conclusion, SeNPs protect against the undesirable effects of a diet rich in fructose.

Single cell transcriptome analyses reveal the roles of B cells in fructose-induced hypertension

Rationale

While the immune system plays a crucial role in the development of hypertension, the specific contributions of distinct immune cell populations remain incompletely understood. The emergence of single-cell RNA-sequencing (scRNA-seq) technology enables us to analyze the transcriptomes of individual immune cells and to assess the significance of each immune cell type in hypertension development.

Objective

We aimed to investigate the hypothesis that B cells play a crucial role in the development of fructose-induced hypertension.

Methods and Results

Eight-week-old Dahl salt-sensitive (SS) male rats were divided into two groups and given either tap water (TW) or a 20% fructose solution (HFS) for 4 weeks. Systolic blood pressure was measured using the tail-cuff method. ScRNA-seq analysis was performed on lamina propria cells (LPs) and peripheral blood mononuclear cells (PBMCs) obtained from SS rats subjected to either TW or HFS. The HFS treatment induced hypertension in the SS rats. The analysis revealed 27 clusters in LPs and 28 clusters in PBMCs, allowing for the identification and characterization of various immune cell types within each cluster. Specifically, B cells and follicular helper T (Tfh) cells were prominent in LPs, while B cells and M1 macrophages dominated PBMCs in the HFS group. Moreover, the HFS treatment triggered an increase in the number of B cells in both LPs and PBMCs, accompanied by activation of the interferon pathway.

Conclusions

The significant involvement of B cells in intestinal and PBMC responses indicates their pivotal contribution to the development of hypertension. This finding suggests that targeting B cells could be a potential strategy to mitigate high blood pressure in fructose-induced hypertension. Moreover, the simultaneous increase in follicular B cells and Tfh cells in LPs, along with the upregulation of interferon pathway genes in B cells, underscores a potential autoimmune factor contributing to the pathogenesis of fructose-induced hypertension in the intestine.

Impact of Sustained Fructose Consumption on Gastrointestinal Function and Health in Wistar Rats: Glycoxidative Stress, Impaired Protein Digestion, and Shifted Fecal Microbiota

The gastrointestinal tract (GIT) is the target of assorted pathological conditions, and dietary components are known to affect its functionality and health. In previous in vitro studies, we observed that reducing sugars induced protein glycoxidation and impaired protein digestibility. To gain further insights into the pathophysiological effects of dietary sugars, Wistar rats were provided with a 30% (w/v) fructose water solution for 10 weeks. Upon slaughter, in vivo protein digestibility was assessed, and the entire GIT (digests and tissues) was analyzed for markers of oxidative stress and untargeted metabolomics. Additionally, the impact of sustained fructose intake on colonic microbiota was also evaluated. High fructose intake for 10 weeks decreased protein digestibility and promoted changes in the physiological digestion of proteins, enhancing intestinal digestion rather than stomach digestion. Moreover, at colonic stages, the oxidative stress was harmfully increased, and both the microbiota and the intraluminal colonic metabolome were modified.

Glucoregulatory effect of butyrate is associated with elevated circulating VEGF and reduced cardiac lactate in high fructose fed rats

Background

High fructose diet has been linked with impaired body metabolism and cardiovascular diseases. Sodium butyrate (NaB) was documented to improve glucoregulation and cardiometabolic problems associated with high fructose diet (HFrD) but the mechanisms behind it are unclear. As a result, the purpose of this study was to look into the effects of NaB on VEGF and cardiac lactate in HFrD-induced dysmetabolism.

Methods

Twenty male Wistar rats of weight 130-140 g were assigned randomly after a week of acclimation into four groups: Control diet (CTR), High fructose drink (HFrD); 10 % (w/v), NaB (200 mg/kg bw), and HFrD + NaB (200 mg/kg bw). The animals were induced to be unconscious with 50 mg/kg of pentobarbital sodium intraperitoneally, blood samples were taken via cardiac puncture and cardiac tissue homogenates were obtained for Fasting Blood Sugar (FBS) and plasma insulin, cardiac glycogen, plasma and cardiac glycogen synthase, plasma and cardiac nitric oxide as well as vascular endothelial growth factor (VEGF).

Result

HFrD resulted in statistical elevation body and cardiac weight, plasma glucose, plasma insulin, cardiac lactate, glycogen and decreased nitric oxide level (NO) when compared with the control group. Administration of NaB reduced cardiac weight, blood glucose, plasma insulin, cardiac lactate while nitric oxide and glycogen increased (P < 0.05). NaB increased plasma glycogen synthase in normal rats, plasma and cardiac circulating VEGF in HFrD administered rats (P < 0.05) while no change was produced in plasma and cardiac glycogen synthase level of HFrD treated rats.

Conclusion

Sodium butyrate improves glucoregulation by reducing cardiac lactate and increasing circulating VEGF in HFrD-treated rats.

Glutamine Ameliorates Liver Steatosis via Regulation of Glycolipid Metabolism and Gut Microbiota in High-Fat Diet-Induced Obese Mice

Obesity and its associated conditions, such as nonalcoholic fatty liver disease (NAFLD), are risk factors for health. The aim of this study was to explore the effects of glutamine (Gln) on liver steatosis induced by a high-fat diet (HFD) and HEPG2 cells induced by oleic acid. Gln demonstrated a positive influence on hepatic homeostasis by suppressing acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS) and promoting sirtuin 1 (SIRT1) expression while improving glucose metabolism by regulating serine/threonine protein kinase (AKT)/factor forkhead box O1 (FOXO1) signals in vivo and in vitro. Obese Gln-fed mice had higher colonic short-chain fatty acid (SCFA) contents and lower inflammation factor protein levels in the liver, HEPG2 cells, and jejunum. Gln-treated obese mice had an effective decrease in Firmicutes abundance. These findings indicate that Gln serves as a nutritional tool in managing obesity and related disorders.

Micropatterned primary hepatocyte co-culture (HEPATOPAC) for fatty liver disease modeling and drug screening

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent, progressive disorder and growing public health concern. To address this issue considerable research has been undertaken in pursuit of new NAFLD therapeutics. Development of effective, high-throughput in vitro models is an important aspect of drug discovery. Here, a micropatterned hepatocyte co-culture (MPCC) was used to model liver steatosis. The MPCC model (HEPATOPACTM) is comprised of hepatocytes and 3T3-J2 mouse stromal cells plated onto a patterned standard 96-well or 24-well plate, allowing the cultures to be handled and imaged in a standardized multi-well format. These studies employed high content imaging (HCI) analysis to assess lipid content in cultures. HCI analysis of lipid accumulation allows large numbers of samples to be imaged and analyzed in a relatively short period of time compared to manual acquisition and analysis methods. Treatment of MPCC with free fatty acids (FFA), high glucose and fructose (HGF), or a combination of both induces hepatic steatosis. MPCC treatment with ACC1/ACC2 inhibitors, as either a preventative or reversal agent, showed efficacy against FFA induced hepatic steatosis. Drug induced steatosis was also evaluated. Treatment with valproic acid showed steatosis induction in a lean background, which was significantly potentiated in a fatty liver background. Additionally, these media treatments changed expression of fatty liver related genes. Treatment of MPCC with FFA, HGF, or a combination reversibly altered expression of genes involved in fatty acid metabolism, insulin signaling, and lipid transport. Together, these data demonstrate that MPCC is an easy to use, long-term functional in vitro model of NAFLD having utility for compound screening, drug toxicity evaluation, and assessment of gene regulation.

From NAFLD to HCC: Advances in noninvasive diagnosis

Non-alcoholic fatty liver disease (NAFLD) has gradually become one of the major liver health problems in the world. The dynamic course of the disease goes through steatosis, inflammation, fibrosis, and carcinoma. Before progressing to carcinoma, timely and effective intervention will make the condition better, which highlights the importance of early diagnosis. With the further study of the biological mechanism in the pathogenesis and progression of NAFLD, some potential biomarkers have been discovered, and the possibility of their clinical application is gradually being discussed. At the same time, the progress of imaging technology and the emergence of new materials and methods also provide more possibilities for the diagnosis of NAFLD. This article reviews the diagnostic markers and advanced diagnostic methods of NAFLD in recent years.

Unravelling the anti-inflammatory and antioxidant effects of standardized green and black caffeinated coffee, tea, and their mixtures in an obese male rat model: Insights from biochemical, metabolomic, and histopathological analyses

Obesity is one of the major metabolic syndrome risk factors upon which altered metabolic pathways follow. This study aimed to discern altered metabolic pathways associated with obesity and to pinpoint metabolite biomarkers in serum of obese rats fed on high fructose diet using metabolomics. Further, the effect of standardized green versus black caffeinated aqueous extracts (tea and coffee) in controlling obesity and its comorbidities through monitoring relevant serum biomarkers viz. Leptin, adiponectin, spexin, malondialdehyde, total antioxidant capacity. Liver tissue oxidative stress (catalase, super oxide dismutase and glutathione) and inflammation (IL-1β and IL-6) markers were assessed for green coffee and its mixture with green tea. Results revealed improvement of all parameters upon treatments with more prominence for those treated with green caffeinated extract (coffee and tea) especially in mixture. Upon comparing with obese rat group, the green mixture of coffee and tea exhibited anti-hyperlipidemic action through lowering serum triglycerides by 35.0% and elevating high density lipoprotein by 71.0%. Black tea was likewise effective in lowering serum cholesterol and low density lipoprotein by 28.0 and 50.6%, respectively. GC-MS- based metabolomics of rat serum led to the identification of 34 metabolites with obese rat serum enriched in fatty acids (oleamide).

CD38 Inhibition Protects Fructose-Induced Toxicity in Primary Hepatocytes

A fructose-enriched diet is thought to contribute to hepatic injury in developing non-alcoholic steatohepatitis (NASH). However, the cellular mechanism of fructose-induced hepatic damage remains poorly understood. This study aimed to determine whether fructose induces cell death in primary hepatocytes, and if so, to establish the underlying cellular mechanisms. Our results revealed that treatment with high fructose concentrations for 48 h induced mitochondria-mediated apoptotic death in mouse primary hepatocytes (MPHs). Endoplasmic reticulum stress responses were involved in fructose-induced death as the levels of phosho-eIF2α, phospho-C-Jun-N-terminal kinase (JNK), and C/EBP homologous protein (CHOP) increased, and a chemical chaperone tauroursodeoxycholic acid (TUDCA) prevented cell death. The impaired oxidation metabolism of fatty acids was also possibly involved in the fructose-induced toxicity as treatment with an AMP-activated kinase (AMPK) activator and a PPAR-α agonist significantly protected against fructose-induced death, while carnitine palmitoyl transferase I inhibitor exacerbated the toxicity. However, uric acid-mediated toxicity was not involved in fructose-induced death as uric acid was not toxic to MPHs, and the inhibition of xanthine oxidase (a key enzyme in uric acid synthesis) did not affect cell death. On the other hand, treatment with inhibitors of the nicotinamide adenine dinucleotide (NAD)+-consuming enzyme CD38 or CD38 gene knockdown significantly protected against fructose-induced toxicity in MPHs, and fructose treatment increased CD38 levels. These data suggest that CD38 upregulation plays a role in hepatic injury in the fructose-enriched diet-mediated NASH. Thus, CD38 inhibition may be a promising therapeutic strategy to prevent fructose-enriched diet-mediated NASH.

The effect of exenatide (a GLP-1 analogue) and sitagliptin (a DPP-4 inhibitor) on asymmetric dimethylarginine (ADMA) metabolism and selected biomarkers of cardiac fibrosis in rats with fructose-induced metabolic syndrome

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, is a risk factor for endothelial dysfunction, a common pathophysiological denominator for both atherogenesis and cardiac fibrosis. We aimed to investigate whether the cardioprotective and antifibrotic effects of incretin drugs, exenatide and sitagliptin, may be associated with their ability to affect circulating and cardiac ADMA metabolism. Normal and fructose-fed rats were treated with sitagliptin (5.0/10 mg/kg) or exenatide (5/10 µg/kg) for 4 weeks. The following methods were used: LC-MS/MS, ELISA, Real-Time-PCR, colorimetry, IHC and H&E staining, PCA and OPLS-DA projections. Eight-week fructose feeding resulted in an increase in plasma ADMA and a decrease in NO concentration. Exenatide administration into fructose-fed rats reduced the plasma ADMA level and increased NO level. In the heart of these animals exenatide administration increased NO and PRMT1 level, reduced TGF-ß1, α-SMA levels and COL1A1 expression. In the exenatide treated rats renal DDAH activity positively correlated with plasma NO level and negatively with plasma ADMA level and cardiac α-SMA concentration. Sitagliptin treatment of fructose-fed rats increased plasma NO concentration, reduced circulating SDMA level, increased renal DDAH activity and reduced myocardial DDAH activity. Both drugs attenuated the myocardial immunoexpression of Smad2/3/P and perivascular fibrosis. In the metabolic syndrome condition both sitagliptin and exenatide positively modulated cardiac fibrotic remodeling and circulating level of endogenous NOS inhibitors but had no effects on ADMA levels in the myocardium.

Low-Intensity Exercise Affects Cardiac Fatty Acid Oxidation by Increasing the Nuclear Content of PPARα, FOXO1, and Lipin1 in Fructose-Fed Rats

Background and Aim: Excessive fructose consumption along with a sedentary lifestyle provokes metabolic disorders and cardiovascular diseases. Fructose overload causes cardiac insulin resistance and increases reliance on fatty acid (FA) uptake and catabolism. The cardiometabolic benefits of exercise training have long been appreciated. The goal of the presented study is to shed a new light to the preventive role of exercise training on cardiac lipid metabolism in fructose-fed rats. Methods: Male Wistar rats were divided into control (C), sedentary fructose (F), and exercised fructose (EF) groups. Fructose was given as a 10% fructose solution in drinking water for 9 weeks. Low-intensity exercise training was applied for 9 weeks. The protein expression and subcellular localization of Lipin1, peroxisome proliferator-activated receptor α (PPARα), and peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC1) were analyzed in the heart using Western blot. Cardiac forkhead box transcription factor 1 (FOXO1) and sirtuin 1 (SIRT1) protein levels were also evaluated. Gene expression of long-chain acyl-CoA dehydrogenase was analyzed by quantitative polymerase chain reaction. Results: Exercise training has augmented the expression of main regulators of FA oxidation in the heart and achieves its effect by increasing the nuclear content of PPARα, Lipin1, and FOXO1 compared with the fructose group (P = 0.0422, P = 0.000045, P = 0.00958, respectively). In addition, Lipin1, FOXO1, and SIRT1 were increased in nuclear extract after exercise compared with the control group (P = 0.000043, P = 0.0417, P = 0.0329, respectively). In cardiac lysate, low-intensity exercise caused significantly increased protein level of PPARα, PGC1, FOXO1, and SIRT1 compared with control (P = 0.0377, P = 0.0275, P = 0.0096, P = 0.0282, respectively) and PGC1 level compared with the fructose group (P = 0.0417). Conclusion: The obtained results imply that the heart with a metabolic burden additionally relies on FA as an energy substrate after low-intensity running.

High-Fructose Diet-Induced Hyperuricemia Accompanying Metabolic Syndrome-Mechanisms and Dietary Therapy Proposals

Fructose is often used as a food ingredient due to its low production costs and sweetening power. In recent years, it has been noticed that people on a Western diet high in fructose have high levels of uric acid in their blood. It was recognized that the specific metabolism of fructose in the body might cause increased production of uric acid, which then may affect the intensification of lipogenesis and the development of metabolic syndrome (MetS), insulin resistance, gout, cardiovascular diseases, leptin resistance, or non-alcoholic fatty liver disease. So far, to treat hyperuricemia, it has been recommended to use a low-purine diet characterized by limiting protein-containing products. However, this recommendation often leads to an increased intake of carbohydrate-rich foods that may contain fructose. Increased fructose consumption may enhance the secretion of uric acid again and, consequently, does not have therapeutic effects. Therefore, instead of a low-purine diet, using healthy diets, such as DASH or the Mediterranean diet, which can benefit metabolic parameters, could be a better proposal. This article provides an overview of this approach, focusing on MetS and hyperuricemia among high-fructose dieters.

The three month's dietary brown rice intervention has not significantly decreased levels of CRP, TNF- α, and IL6 of type 2 diabetes mellitus patients

Introduction: The increased quantities of inflammatory biomarkers such as C-Reactive Proteins (CRP), Tumour Necrosis Factor-α (TNF-α), and Interleukin-6 (IL-6) have been reported to be associated with an increased risk of metabolic syndrome including type 2 diabetes mellitus (T2DM). However, brown rice is an alternative dietary food source that is known to have many health benefits including high fibre content. In addition to fibre, brown rice is also reported to have moderate amounts of proteins, unsaturated lipids, several minerals, and a lot of bioactive substances that are highly beneficial to health. This study aims to prove the role of brown rice dietary intervention in the reduction of inflammatory biomarkers in type 2 diabetes mellitus patients. Design and Methods: This was a cross-sectional study with a post-test conducted on 18 patients with type 2 diabetes mellitus. In the intervention phase I, all type 2 diabetes mellitus patients were given brown rice diet for 3 months and followed by a phase II intervention, in which white rice diet was given to the other group of type 2 diabetes mellitus patients for 3 months. Serum was collected at the end of each intervention stage and then serum for Tumour Necrosis Factor-α, Interleukin-6 and C-Reactive Proteins were analysed by the ELISA method. Statistical analysis of the t-test was conducted in order to determine the differences between the two groups allocated in the study. Results: At the end of the study, it was found that the levels of C-Reactive Protein, Tumour Necrosis Factor-α, and Interleukin-6 after the brown rice intervention was given to type 2 diabetes mellitus patients, it showed a decreasing trend compared to the white rice intervention although not significantly different (p = 0.6, p = 0.63, p = 0.59, respectively). Conclusions: This study concluded that the administration of brown rice dietary intervention to patients with type 2 diabetes mellitus for 3 months was able to reduce Tumour Necrosis Factor-α, C-Reactive Proteins, and Interleukin-6 however, the reduction was not significant to influence policy change.    

Fructose Diet-Associated Molecular Alterations in Hypothalamus of Adolescent Rats: A Proteomic Approach

BACKGROUND

The enhanced consumption of fructose as added sugar represents a major health concern. Due to the complexity and multiplicity of hypothalamic functions, we aim to point out early molecular alterations triggered by a sugar-rich diet throughout adolescence, and to verify their persistence until the young adulthood phase.

METHODS

Thirty days old rats received a high-fructose or control diet for 3 weeks. At the end of the experimental period, treated animals were switched to the control diet for further 3 weeks, and then analyzed in comparison with those that were fed the control diet for the entire experimental period.

RESULTS

Quantitative proteomics identified 19 differentially represented proteins, between control and fructose-fed groups, belonging to intermediate filament cytoskeleton, neurofilament, pore complex and mitochondrial respiratory chain complexes. Western blotting analysis confirmed proteomic data, evidencing a decreased abundance of mitochondrial respiratory complexes and voltage-dependent anion channel 1, the coregulator of mitochondrial biogenesis PGC-1α, and the protein subunit of neurofilaments α-internexin in fructose-fed rats. Diet-associated hypothalamic inflammation was also detected. Finally, the amount of brain-derived neurotrophic factor and its high-affinity receptor TrkB, as well as of synaptophysin, synaptotagmin, and post-synaptic protein PSD-95 was reduced in sugar-fed rats. Notably, deregulated levels of all proteins were fully rescued after switching to the control diet.

CONCLUSIONS

A short-term fructose-rich diet in adolescent rats induces hypothalamic inflammation and highly affects mitochondrial and cytoskeletal compartments, as well as the level of specific markers of brain function; above-reported effects are reverted after switching animals to the control diet.

Fructose consumption induces molecular adaptations involving thyroid function and thyroid-related genes in brown adipose tissue in rats

The increasing incidence of metabolic diseases is in part due to the high fructose consumption, a carbohydrate vastly used in industry, with a potent lipogenic capacity. Thyroid hormones (TH) are essential for metabolism regulation and are associated with changes in body weight, energy expenditure, insulin sensitivity, and dyslipidemia. This study aimed to investigate the influence of fructose intake on thyroid function and thyroid-related genes. Male Wistar rats were divided into Control (CT, n=8) and Fructose (FT - 10% in drinking water, n=8) groups for three weeks. The FT group showed higher glycemia and serum triacylglycerol, indicating metabolic disturbances, and increased thyroid mass, accompanied by higher expression of Srebf1c and Lpl, suggesting increased lipid synthesis. The FT group also presented higher expression of Tpo and Dio1 in the thyroid, suggesting activation of the thyroid gland, but with no alterations in serum TH concentrations. Brown adipose tissue (BAT) of the FT group exhibited higher expression of Dio2, Thra, and Thrb, indicating increased T3 intra-tissue bioavailability and signaling. These responses were accompanied by increased BAT mass and higher expression of Adrb3, Pparg, Srebf1c, Fasn, Ppara, and Ucp1, suggesting increased BAT adrenergic sensitivity, lipid synthesis, oxidation, and thermogenesis. Therefore, short-term fructose consumption induced thyroid molecular alterations and increased BAT expression of thyroid hormone-related signaling genes that potentially contributed to higher BAT activity.

The biomarkers discovery of hyperuricemia and gout: proteomics and metabolomics

Background

Hyperuricemia and gout are a group of disorders of purine metabolism. In recent years, the incidence of hyperuricemia and gout has been increasing, which is a severe threat to people's health. Several studies on hyperuricemia and gout in proteomics and metabolomics have been conducted recently. Some literature has identified biomarkers that distinguish asymptomatic hyperuricemia from acute gout or remission of gout. We summarize the physiological processes in which these biomarkers may be involved and their role in disease progression.

Methodology

We used professional databases including PubMed, Web of Science to conduct the literature review. This review addresses the current landscape of hyperuricemia and gout biomarkers with a focus on proteomics and metabolomics.

Results

Proteomic methods are used to identify differentially expressed proteins to find specific biomarkers. These findings may be suggestive for the diagnosis and treatment of hyperuricemia and gout to explore the disease pathogenesis. The identified biomarkers may be mediators of the link between hyperuricemia, gout and kidney disease, metabolic syndrome, diabetes and hypertriglyceridemia. Metabolomics reveals the main influential pathways through small molecule metabolites, such as amino acid metabolism, lipid metabolism, or other characteristic metabolic pathways. These studies have contributed to the discovery of Chinese medicine. Some traditional Chinese medicine compounds can improve the metabolic disorders of the disease.

Conclusions

We suggest some possible relationships of potential biomarkers with inflammatory episodes, complement activation, and metabolic pathways. These biomarkers are able to distinguish between different stages of disease development. However, there are relatively few proteomic as well as metabolomic studies on hyperuricemia and gout, and some experiments are only primary screening tests, which need further in-depth study.

Fructose diet ameliorate effects of macrophage migration inhibitory factor deficiency on prefrontal cortex inflammation, neural plasticity, and behavior in male mice

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that represents a link between diet-induced inflammation and insulin resistance. Our aim was to examine whether fructose diet affects inflammation and insulin signaling in the prefrontal cortex (PFC) of Mif knockout mice (MIF-KO), and their possible link to neural plasticity and behavior. We analyzed nuclear factor κB (NF-κB) and glucocorticoid signaling, expression of F4/80, IL-1β, TNF-α, TLR-4, MyD88, arginase 1 (Arg-1), mannose receptor (Mrc-1), and leukemia inhibitory factor (Lif) to assess inflammation in the PFC of C57/BL6J and MIF-KO mice consuming 20% fructose solution for 9 weeks. Insulin receptor (IR), IRS-1 serine phosphorylations (307 and 1101) and activity of PKCα, Akt, GSK-3β and AMPKα were used to analyze insulin signaling. Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) mRNA levels, together with synapthophysin and PSD-95 protein level and calcium calmodulin-dependent kinase 2 (CaMKII) activity, were used as plasticity markers. Behavior was examined in elevated plus maze, light dark box and novel object recognition test. The results showed concomitant increase of Tnf-α, Tlr-4, MyD88 and M2 microglia markers (Arg-1, Mrc-1, Lif) in the PFC of MIF-KO, paralleled with unchanged glucocorticoid and insulin signaling. Increase of BDNF and IGF-1 was paralleled with increased CaMKII activity, decreased PSD-95 protein level, anxiogenic behavior, and impaired memory in MIF-KO mice. Fructose feeding restored these parameters in the PFC to the control level and mitigated behavioral changes, suggesting that ameliorating effects of fructose on neuroinflammation and behavior depend on the presence of MIF.

Maternal fructose boosts the effects of a Western-type diet increasing SARS-COV-2 cell entry factors in male offspring

Fructose-rich beverages and foods consumption correlates with the epidemic rise in cardiovascular disease, diabetes and obesity. Severity of COVID-19 has been related to these metabolic diseases. Fructose-rich foods could place people at an increased risk for severe COVID-19. We investigated whether maternal fructose intake in offspring affects hepatic and ileal gene expression of proteins that permit SARS-CoV2 entry to the cell. Carbohydrates were supplied to pregnant rats in drinking water. Adult and young male descendants subjected to water, liquid fructose alone or as a part of a Western diet, were studied. Maternal fructose reduced hepatic SARS-CoV2 entry factors expression in older offspring. On the contrary, maternal fructose boosted the Western diet-induced increase in viral entry factors expression in ileum of young descendants. Maternal fructose intake produced a fetal programming that increases hepatic viral protection and, in contrast, exacerbates fructose plus cholesterol-induced diminution in SARS-CoV2 protection in small intestine of progeny.

Protective Effect of Hydroalcoholic Extract of Punica granatum Leaves on High Fructose Induced Insulin Resistance in Experimental Animals

BACKGROUND

Insulin resistance (IR) is a condition characterized by reduced sensitivity of body tissues to insulin, leading to impaired regulation of downstream metabolic pathways and elevated blood glucose levels. Diets rich in fructose have been proven to cause insulin resistance in test rats, resulting in decreased insulin sensitivity, particularly in the liver, and compromised disposal of glucose from the body. In the search for effective treatments, Plant-derived formulations have gained popularity because to their ability for treating a variety of ailments. One such plant is Punica granatum Linn. from the Punicaceae family, which has long been used in the treatment of diabetes and its consequences. This study investigates the insulin-resistant activity of an extract from Punica granatum leaves. The study goal is to assess the possible protective role of Punica granatum against insulin resistance through various analyses, including serum glucose and insulin levels, lipid profile assessment, measurement of liver enzymes (ALP, SGOT, SGPT), and histopathological examination of liver sections.

METHODS

The study involves several key methods to evaluate the insulin-resistant activity of Punica granatum extract in high fructose diet induced insulin resistance animal model. The extract was administered orally to the experimental animals. These methods include the measurement of serum glucose and serum insulin levels, analysis of the lipid profile, quantification of liver enzymes such as ALP, SGOT, and SGPT, and a detailed histopathological examination of liver tissue sections. These analyses collectively provide insights into the impact of Punica granatum extract on insulin resistance and related metabolic parameters.

RESULTS

Findings of this study provide insight on the possible benefits of Punica granatum extract on insulin resistance. Through the assessment of serum glucose and insulin levels, lipid profile analysis, and measurement of liver enzymes, the study elucidates the impact of the extract on key metabolic indicators. Additionally, the histopathological examination of liver sections provides visual insights into the structural changes that may occur as a result of the treatment.

CONCLUSION

In conclusion, this study highlights the ability of Punica granatum extract as a candidate for addressing insulin resistance. The findings suggest that the extract may have a protective role against insulin resistance, as evidenced by improvements in serum glucose and insulin levels, lipid profile, liver enzyme levels, and histopathological characteristics. Further research and investigations are warranted to fully understand the mechanisms underlying these observed effects and to validate the potential of Punica granatum extract as a therapeutic option for managing insulin resistance and its associated complications.

Maternal Fructose Intake, Programmed Mitochondrial Function and Predisposition to Adult Disease

Fructose consumption is now recognised as a major risk factor in the development of metabolic diseases, such as hyperlipidaemia, diabetes, non-alcoholic fatty liver disease and obesity. In addition to environmental, social, and genetic factors, an unfavourable intrauterine environment is now also recognised as an important factor in the progression of, or susceptibility to, metabolic disease during adulthood. Developmental trajectory in the short term, in response to nutrient restriction or excessive nutrient availability, may promote adaptation that serves to maintain organ functionality necessary for immediate survival and foetal development. Consequently, this may lead to decreased function of organ systems when presented with an unfavourable neonatal, adolescent and/or adult nutritional environment. These early events may exacerbate susceptibility to later-life disease since sub-optimal maternal nutrition increases the risk of non-communicable diseases (NCDs) in future generations. Earlier dietary interventions, implemented in pregnant mothers or those considering pregnancy, may have added benefit. Although, the mechanisms by which maternal diets high in fructose and the vertical transmission of maternal metabolic phenotype may lead to the predisposition to adult disease are poorly understood. In this review, we will discuss the potential contribution of excessive fructose intake during pregnancy and how this may lead to developmental reprogramming of mitochondrial function and predisposition to metabolic disease in offspring.

Hypercaloric Diet Promotes Metabolic Disorders and Impaired Kidney Function

Poor dietary habits such as overconsumption of hypercaloric diets characterized by a high content of fructose and fat are related to metabolic abnormalities development such as obesity, diabetes, and dyslipidemia. Accumulating evidence supports the hypothesis that if energy intake gradually exceeds the body's ability to store fat in adipose tissue, the prolonged metabolic imbalance of circulating lipids from endogenous and exogenous sources leads to ectopic fat distribution in the peripheral organs, especially in the heart, liver, and kidney. The kidney is easily affected by dyslipidemia, which induces lipid accumulation and reflects an imbalance between fatty acid supply and fatty acid utilization. This derives from tissue lipotoxicity, oxidative stress, fibrosis, and inflammation, resulting in structural and functional changes that lead to glomerular and tubule-interstitial damage. Some authors indicate that a lipid-lowering pharmacological approach combined with a substantial lifestyle change should be considered to treat chronic kidney disease (CKD). Also, the new therapeutic target identification and the development of new drugs targeting metabolic pathways involved with kidney lipotoxicity could constitute an additional alternative to combat the complex mechanisms involved in impaired kidney function. In this review article, we first provide the pathophysiological evidence regarding the impact of hypercaloric diets, such as high-fat diets and high-fructose diets, on the development of metabolic disorders associated with impaired renal function and the molecular mechanisms underlying tissue lipid deposition. In addition, we present the current progress regarding translational strategies to prevent and/or treat kidney injury related to the consumption of hypercaloric diets.

Nutritional Assessment of Baby Food Available in Italy

Adequate complementary feeding practices are important for short- and long-term child health. In industrialized countries, the formulation of several commercial baby foods (CBFs) and an increase in their consumption has been noticed.

AIM

To update and analyze the nutritional composition of CBFs available in the Italian market.

METHODS

Data collection carried out in two steps (July 2018-January 2019) and updated in May-September 2021. The information on CBFs was taken from the websites of the major CBF producers available in Italy. The collected information were: Suggested initial and final age of consumption; Ingredients; Energy value; Macronutrients (protein, lipids, and carbohydrates); Fiber; Micronutrients (sodium, iron, and calcium); Presence of salt and added sugars, flavorings, and other additives.

RESULTS

Time-space for which CBFs are recommended starts too early and ends too late; protein content is adequate and even too high in some food; Amount of fats and their quality must be improved, keeping the intake of saturated fats low; Sugar content is too high in too many CBFs and salt is unnecessarily present in some of them. Finally, the texture of too many products is purée, and its use is recommended for too long, hindering the development of infants' chewing abilities.

Sugars and Gastrointestinal Health

Sugar overconsumption is linked to a rise in the incidence of noncommunicable diseases such as diabetes, cardiovascular diseases, and cancer. This increased incidence is becoming a real public health problem that is more severe than infectious diseases, contributing to 35 million deaths annually. Excessive intake of free sugars can cause many of the same health problems as excessive alcohol consumption. Many recent international recommendations have expressed concerns about sugar consumption in Westernized societies, as current consumption levels represent quantities with no precedent during hominin evolution. In both adults and children, the World Health Organization strongly recommends reducing free sugar intake to <10% of total energy intake and suggests a further reduction to below 5%. Most studies have focused on the deleterious effects of Western dietary patterns on global health and the intestine. Whereas excessive dietary fat consumption is well studied, the specific impact of sugar is poorly described, while refined sugars represent up to 40% of caloric intake within industrialized countries. However, high sugar intake is associated with multiple tissue and organ dysfunctions. Both hyperglycemia and excessive sugar intake disrupt the intestinal barrier, thus increasing gut permeability and causing profound gut microbiota dysbiosis, which results in a disturbance in mucosal immunity that enhances infection susceptibility. This review aims to highlight the roles of different types of dietary carbohydrates and the consequences of their excessive intake for intestinal homeostasis.

Development and evaluation of novel rodent model of PCOS mimicking clinical phenotype in human disease

Background

Polycystic ovary syndrome is a most common female reproductive disorder, involving endocrine and metabolic disorders with unclear etiology. Androgen-based rodent animal models like DHEA and DHT are most suitable for PCOS induction, but still, these models fail to produce non-lean PCOS phenotypes such as hyperandrogenism, hyperinsulinemia, elevated estrogen levels, and ovary weight. Excess fructose consumption leads to hyperandrogenism, hyperinsulinemia, and insulin resistance. The purpose of this study is to investigate, whether fructose consumption along with androgens in rats, could develop all metabolic and endocrine phenotypes of non-lean human PCOS disease. 

Methods

Prepubertal SD rats were administered with DHT (83ug, s.c.) and fructose (20%, p.o.) for 90 days whereas DHEA (7 mg/kg, s.c) and fructose (20%, p.o.) for 30 days. During study duration, the blood glucose level for oral glucose tolerance test, estrus cyclicity, and ultrasonography was observed. Reproductive hormones LH, FSH, insulin, testosterone, and estradiol levels were assessed using ELISA. The ovary, uterus, abdominal fat, and subcutaneous fat were collected and weighed, and histopathology was done for any anomaly’s findings.

Results

DHT + fructose-treated rats showed significant (p < 0.05) increase in serum testosterone, LH, estradiol, decreased FSH levels, and caused multiple cystic follicles. Abdominal fat, subcutaneous fat, ovary, and uterine weight were higher in DHT + F and DHEA + F when compared to control groups. OGTT reveals impaired insulin sensitivity and glucose tolerance in both model groups. Ovarian histopathology of DHT + F shows more cysts than the DHEA + F groups. No significant changes in uterine histology of DHT + F and DHEA + F-treated rats.

Conclusion

DHT + F-treated rats mimic all clinical phenotypes and could be used as novel rodent model for non-lean type PCOS.

Baicalein Prevents Fructose-Induced Hepatic Steatosis in Rats: In the Regulation of Fatty Acid De Novo Synthesis, Fatty Acid Elongation and Fatty Acid Oxidation

Non-alcoholic fatty liver disease (NAFLD), ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), hepatic fibrosis and even hepatocellular carcinoma, is a liver disease worldwide without approved therapeutic drugs. Baicalein (BAL), a flavonoid compound extracted from the Traditional Chinese Medicine (TCM) Scutellariae Radix (Scutellaria baicalensis Georgi.), has been used in TCM clinical practice for thousands of years to treat liver diseases due to its “hepatoprotective effect”. However, the underlying liver-protecting mechanisms remain largely unknown. Here, we found that oral administration of BAL significantly decreased excess serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST) as well as hepatic TG in fructose-fed rats. Attenuation of the increased vacuolization and Oil Red O staining area was evident on hepatic histological examination in BAL-treated rats. Mechanistically, results of RNA-sequencing, western-blot, real-time quantitative PCR (RT-qPCR) and hepatic metabolomics analyses indicated that BAL decreased fructose-induced excessive nuclear expressions of mature sterol regulatory element-binding protein 1c (mSREBP1c) and carbohydrate response element-binding protein (ChREBP), which led to the decline of lipogenic molecules [including fatty acid synthase (FASN), stearoyl-CoA desaturase 1 (SCD1), elongation of very long chain fatty acids 6 (ELOVL6), acetyl-CoA carboxylase (ACC)], accompanying with the alternation of hepatic fatty acids composition. Meanwhile, BAL enhanced fatty acid oxidation by activating AMPK/PGC1α signaling axis and PPARα signal pathway, which elicited high expression of carnitine palmitoyl transferase 1α (CPT1α) and Acyl-CoA oxidase 1 (ACO1) in livers of fructose-fed rats, respectively. BAL ameliorated fructose-induced hepatic steatosis, which is associated with regulating fatty acid synthesis, elongation and oxidation.

Integrating the effects of sucrose intake on the brain and white adipose tissue: Could autophagy be a possible link?

Excess dietary sucrose is associated with obesity and metabolic diseases. This relationship is driven by the malfunction of several cell types and tissues critical for the regulation of energy balance, including hypothalamic neurons and white adipose tissue (WAT). However, the mechanisms behind these effects of dietary sucrose are still unclear and might be independent of increased adiposity. Accumulating evidence has indicated that dysregulation of autophagy, a fundamental process for maintenance of cellular homeostasis, alters energy metabolism in hypothalamic neurons and WAT, but whether autophagy could mediate the detrimental effects of dietary sucrose on hypothalamic neurons and WAT that contribute to weight gain is a matter of debate. In this review, we examine the hypothesis that dysregulated autophagy in hypothalamic neurons and WAT is an adiposity-independent effect of sucrose that contributes to increased body weight gain. We propose that excess dietary sucrose leads to autophagy unbalance in hypothalamic neurons and WAT, which increases caloric intake and body weight, favoring the emergence of obesity and metabolic diseases.

Impact of a long‐term high‐fructose diet on systemic metabolic profiles of mice

Evidence is mounting that chronic high‐fructose diets (HFrD) can lead to metabolic abnormalities and cause a variety of diseases. However, the underlying mechanism by which long‐term high fructose intake influencing systemic metabolism remains unclarified. This study, therefore, attempted to investigate the impact of a high‐fructose diet on metabolic profile. Four‐week‐old male C57BL/6 mice were fed with 15% fructose solution as their only source of water for 8 weeks. Afterward, gas chromatography–mass spectrometry (GC–MS) was employed to investigate the comprehensive metabolic profile of serum, muscle, liver, heart, white adipose, brain, and kidney tissues, and multivariate analyses including principal component analysis (PCA) and orthogonal partial least squared‐discriminant analysis (OPLS‐DA) were applied to screen for differential metabolite expression between the HFrD and control groups. Furthermore, the MetaboAnalyst 5.0 (http://www.metaboanalyst.ca) and Kyoto Encyclopedia of Genes and Genomes database (KEGG; http://www.kegg.jp) were employed to portray a detailed metabolic network. This study identified 62 metabolites related to HFrD and 10 disturbed metabolic pathways. The results indicated that high fructose intake mainly influenced amino acid metabolism and biosynthesis (glycine, serine, and threonine metabolism; aspartate, and glutamate metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis, and arginine biosynthesis pathways), glutathione metabolism, sphingolipid metabolism, and glyoxylate and dicarboxylate metabolism in serum, whereas these pathways were suppressed in the brain. Starch and sucrose metabolism in muscle was also disrupted. These results elucidate the effects of long‐term high fructose consumption on the metabolic profiles of various tissues and provide new insight for the identification of potential metabolic biomarkers and pathways disrupted by high fructose.

Fructose Intake, Hypertension and Cardiometabolic Risk Factors in Children and Adolescents: From Pathophysiology to Clinical Aspects. A Narrative Review

Arterial hypertension, dyslipidemia, alterations in glucose metabolism and fatty liver, either alone or in association, are frequently observed in obese children and may seriously jeopardize their health. For obesity to develop, an excessive intake of energy-bearing macronutrients is required; however, ample evidence suggests that fructose may promote the development of obesity and/or metabolic alterations, independently of its energy intake. Fructose consumption is particularly high among children, because they do not have the perception, and more importantly, neither do their parents, that high fructose intake is potentially dangerous. In fact, while this sugar is erroneously viewed favorably as a natural nutrient, its excessive intake can actually cause adverse cardio-metabolic alterations. Fructose induces the release of pro-inflammatory cytokines, and reduces the production of anti-atherosclerotic cytokines, such as adiponectin. Furthermore, by interacting with hunger and satiety control systems, particularly by inducing leptin resistance, it leads to increased caloric intake. Fructose, directly or through its metabolites, promotes the development of obesity, arterial hypertension, dyslipidemia, glucose intolerance and fatty liver. This review aims to highlight the mechanisms by which the early and excessive consumption of fructose may contribute to the development of a variety of cardiometabolic risk factors in children, thus representing a potential danger to their health. It will also describe the main clinical trials performed in children and adolescents that have evaluated the clinical effects of excessive intake of fructose-containing drinks and food, with particular attention to the effects on blood pressure. Finally, we will discuss the effectiveness of measures that can be taken to reduce the intake of this sugar.

High-Fructose Diet Increases Renal ChREBPβ Expression, Leading to Intrarenal Fat Accumulation in a Rat Model with Metabolic Syndrome

Simple Summary

Fructose consumption leads to the development of metabolic syndrome. Fatty liver and chronic kidney disease are closely related to metabolic syndrome. Lately, a transcription factor that regulates fructose metabolism in the liver, named ChREBPβ, which is responsible for de-novo lipogenesis and intra-hepatic fat accumulation (“fatty liver”), was described. In this study, we demonstrate that the effect of fructose consumption on the kidneys resembles its liver effect. Rats fed with a high-fructose diet exhibit bigger kidneys with higher triglycerides content, compared to control rats. The expression of ChREBPβ and its downstream genes was upregulated as well. Treating kidney-origin cells with fructose increased the expression of this factor as well, showing the direct effect of fructose on this factor. Thus, the appearance of fatty kidney in response to high-fructose consumption revealed a new mechanism linking metabolic syndrome to chronic kidney disease.

Abstract

Fructose consumption is associated with metabolic syndrome (MeS). Dysregulated lipid metabolism and ectopic lipid accumulation, such as in “fatty liver’’, are pivotal components of the syndrome. MeS is also associated with chronic kidney disease (CKD). The aim of this study was to evaluate kidney fructose metabolism and whether the addition of fructose leads to intrarenal fat accumulation. Sprague Dawley rats were fed either normal chow (Ctrl) or a high-fructose diet (HFrD). MeS features such as blood pressure and metabolic parameters in blood were measured. The kidneys were harvested for ChREBPβ and de novo lipogenesis (DNL) gene expression, triglyceride content and histopathology staining. HK2 (human kidney) cells were treated with fructose for 48 h and gene expression for ChREBPβ and DNL were determined. The HFrD rats exhibited higher blood pressure, glucose and triglyceride levels. The kidney weight of the HFrD rats was significantly higher than Ctrl rats. The difference can be explained by the higher triglyceride content in the HFrD kidneys. Oil red staining revealed lipid droplet formation in the HFrD kidneys, which was also supported by increased adipophilin mRNA expression. For ChREBPβ and its downstream genes, scd and fasn, mRNA expression was elevated in the HFrD kidneys. Treating HK2 cells with 40 mM fructose increased the expression of ChREBPβ. This study demonstrates that fructose consumption leads to intrarenal lipid accumulation and to the formation of a “fatty kidney”. This suggests a potential mechanism that can at least partially explain CKD development in fructose-induced MeS.

Added Fructose in Non-Alcoholic Fatty Liver Disease and in Metabolic Syndrome: A Narrative Review

Non-alcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease and it is considered the hepatic manifestation of metabolic syndrome (MetS). Diet represents the key element in NAFLD and MetS treatment, but some nutrients could play a role in their pathophysiology. Among these, fructose added to foods via high fructose corn syrup (HFCS) and sucrose might participate in NAFLD and MetS onset and progression. Fructose induces de novo lipogenesis (DNL), endoplasmic reticulum stress and liver inflammation, promoting insulin resistance and dyslipidemia. Fructose also reduces fatty acids oxidation through the overproduction of malonyl CoA, favoring steatosis. Furthermore, recent studies suggest changes in intestinal permeability associated with fructose consumption that contribute to the risk of NAFLD and MetS. Finally, alterations in the hunger–satiety mechanism and in the synthesis of uric acid link the fructose intake to weight gain and hypertension, respectively. However, further studies are needed to better evaluate the causal relationship between fructose and metabolic diseases and to develop new therapeutic and preventive strategies against NAFLD and MetS.

The Sweet and Salty Dietary Face of Hypertension and Cardiovascular Disease in Lebanon

According to the World Health Organization (WHO), an estimated 1.28 billion adults aged 30–79 years worldwide have hypertension; and every year, hypertension takes 7.6 million lives. High intakes of salt and sugar (mainly fructose from added sugars) have been linked to the etiology of hypertension, and this may be particularly true for countries undergoing the nutrition transition, such as Lebanon. Salt-induced hypertension and fructose-induced hypertension are manifested in different mechanisms, including Inflammation, aldosterone-mineralocorticoid receptor pathway, aldosterone independent mineralocorticoid receptor pathway, renin-angiotensin system (RAS), sympathetic nervous system (SNS) activity, and genetic mechanisms. This review describes the evolution of hypertension and cardiovascular diseases (CVDs) in Lebanon and aims to elucidate potential mechanisms where salt and fructose work together to induce hypertension. These mechanisms increase salt absorption, decrease salt excretion, induce endogenous fructose production, activate fructose-insulin-salt interaction, and trigger oxidative stress, thus leading to hypertension. The review also provides an up-to-date appraisal of current intake levels of salt and fructose in Lebanon and their main food contributors. It identifies ongoing salt and sugar intake reduction strategies in Lebanon while acknowledging the country’s limited scope of regulation and legislation. Finally, the review concludes with proposed public health strategies and suggestions for future research, which can reduce the intake levels of salt and fructose levels and contribute to curbing the CVD epidemic in the country.

The Role of Selenoprotein Tissue Homeostasis in MetS Programming: Energy Balance and Cardiometabolic Implications

Selenium (Se) is an essential trace element mainly known for its antioxidant, anti-inflammatory, and anti-apoptotic properties, as it is part of the catalytic center of 25 different selenoproteins. Some of them are related to insulin resistance (IR) and metabolic syndrome (MetS) generation, modulating reactive oxygen species (ROS), and the energetic sensor AMP-activated protein kinase (AMPK); they can also regulate the nuclear transcription factor kappa-B (NF-kB), leading to changes in inflammation production. Selenoproteins are also necessary for the correct synthesis of insulin and thyroid hormones. They are also involved in endocrine central regulation of appetite and energy homeostasis, affecting growth and development. MetS, a complex metabolic disorder, can appear during gestation and lactation in mothers, leading to energetic and metabolic changes in their offspring that, according to the metabolic programming theory, will produce cardiovascular and metabolic diseases later in life. However, there is a gap concerning Se tissue levels and selenoproteins’ implications in MetS generation, which is even greater during MetS programming. This narrative review also provides an overview of the existing evidence, based on experimental research from our laboratory, which strengthens the fact that maternal MetS leads to changes in Se tissue deposits and antioxidant selenoproteins’ expression in their offspring. These changes contribute to alterations in tissues’ oxidative damage, inflammation, energy balance, and tissue function, mainly in the heart. Se imbalance also could modulate appetite and endocrine energy balance, affecting pups’ growth and development. MetS pups present a profile similar to that of diabetes type 1, which also appeared when dams were exposed to low-Se dietary supply. Maternal Se supplementation should be taken into account if, during gestation and/or lactation periods, there are suspicions of endocrine energy imbalance in the offspring, such as MetS. It could be an interesting therapy to induce heart reprogramming. However, more studies are necessary.

Glut5 Knockdown in the Nucleus Tractus Solitarii Alleviates Fructose-Induced Hypertension in Rats

BACKGROUND

Several studies have suggested mechanisms whereby excessive fructose intake increases blood pressure (BP). Glucose transporter 5 (GLUT5) is a fructose transporter expressed on enterocytes, and its involvement in the nucleus tractus solitarius (NTS)-modulated increase in BP following fructose intake remains unclear.

OBJECTIVES

Herein, we investigated whether NTS Glut5 knockdown (KD) can alleviate fructose-induced hypertension in rat models.

METHODS

Male Wistar-Kyoto rats (6-8 weeks old; average weight: 230 g) were randomly assigned into 4 groups [control (Con), fructose (Fru), fructose + scrambled (Fru + S), and Fru +  KD]. The Con group rats had ad libitum access to regular water, and the other 3 groups were provided 10% fructose water ad libitum for 4 weeks (2 weeks before lentiviral transfection in the Fru + S and Fru + KD groups). Glut5 short hairpin RNA was delivered into the NTS of rats using a lentivirus system. Fructose-induced hypertension was assessed via the tail-cuff technique, a noninvasive blood pressure measurement approach. GLUT5-associated and other insulin signaling pathways in the NTS of rats were assessed using immunofluorescence and immunoblotting analyses. We evaluated between-group differences using the Mann-Whitney U test or Kruskal-Wallis 1-way ANOVA.

RESULTS

Compared with the Fru + S group, the Fru + KD group had reduced sympathetic nerve hyperactivity (48.8 ± 3.2 bursts/min; P < 0.05), improved central insulin signaling, upregulated protein kinase B (AKT; 3.0-fold) and neuronal NO synthase (nNOS; 2.78-fold) expression, and lowered BP (17 ± 1 mmHg, P < 0.05). Moreover, Glut5 KD restored signaling dependent on adenosine 5'-monophosphate-activated protein kinase and reduced fructose-induced oxidative stress 2.0-fold, and thus decreased NAD(P)H oxidase in p67-phox 1.9-fold within the NTS.

CONCLUSIONS

Fructose-induced reactive oxygen species generates in the NTS of rats through GLUT5 and receptor for advanced glycation end products signaling, thus impairing the AKT-nNOS-NO signaling pathway and ultimately causing hypertension.

The therapeutic effects of distinct exercise types on metabolic syndrome-induced reproductive system impairment in male rats: Potential contribution of mitochondria-related genes

A sedentary lifestyle and high fructose dietary habits cause diseases, such as metabolic syndrome (MS). The study was aimed to investigate the potential ameliorative effects of different exercise interventions on high fructose-induced MS-mediated reproductive system disruption of male rats. Rats were divided into four groups (n = 6): Control, MS, MS+aerobic exercise (AE) and MS+anaerobic exercise (ANE). MS was induced by using tap water containing 30% fructose for 8 weeks. After the induction of MS, AE/ANE implementations were started for 6 weeks. Testis tissue and serum samples of rats were stored for biochemical and molecular analyses. Serum total antioxidant status level increased in the MS+AE group compared to all groups. Also, serum total oxidant status level, which increased by MS, decreased with AE, but not altered with ANE. Moreover, MS markedly decreased serum luteinizing hormone, but not changed the follicle-stimulating hormone. However, serum hormone levels were similar to the control group in both MS+AE and MS+ANE groups. MS upregulated mitochondria-related genes' mRNA expressions (MFN2, PGC1A, PPARG, PARP2 and TXNL4B). These increases, except for PPARG, were normalized with both exercise types. These results revealed that mitochondria-related genes may have a crucial role in MS-mediated male reproductive impairment and therapeutic effects of exercises.

Maternal Fructose Intake Causes Developmental Reprogramming of Hepatic Mitochondrial Catalytic Activity and Lipid Metabolism in Weanling and Young Adult Offspring

Excess dietary fructose is a major public health concern, yet little is known about its influence on offspring development and later-life disease when consumed in excess during pregnancy. To determine whether increased maternal fructose intake could have long-term consequences on offspring health, we investigated the effects of 10% w/v fructose water intake during preconception and pregnancy in guinea pigs. Female Dunkin Hartley guinea pigs were fed a control diet (CD) or fructose diet (FD; providing 16% of total daily caloric intake) ad libitum 60 days prior to mating and throughout gestation. Dietary interventions ceased at day of delivery. Offspring were culled at day 21 (D21) (weaning) and at 4 months (4 M) (young adult). Fetal exposure to excess maternal fructose intake significantly increased male and female triglycerides at D21 and 4 M and circulating palmitoleic acid and total omega-7 through day 0 (D0) to 4 M. Proteomic and functional analysis of significantly differentially expressed proteins revealed that FD offspring (D21 and 4 M) had significantly increased mitochondrial metabolic activities of β-oxidation, electron transport chain (ETC) and oxidative phosphorylation and reactive oxygen species production compared to the CD offspring. Western blotting analysis of both FD offspring validated the increased protein abundances of mitochondrial ETC complex II and IV, SREBP-1c and FAS, whereas VDAC1 expression was higher at D21 but lower at 4 M. We provide evidence demonstrating offspring programmed hepatic mitochondrial metabolism and de novo lipogenesis following excess maternal fructose exposure. These underlying asymptomatic programmed pathways may lead to a predisposition to metabolic dysfunction later in life.

Fructose Induces Insulin Resistance of Gestational Diabetes Mellitus in Mice via the NLRP3 Inflammasome Pathway

BACKGROUND

Insulin resistance (IR), which is affected by dietary factors, is the main pathology underlying of gestational diabetes mellitus (GDM). Fructose (Fru), a sugar found in fruits, honey, and food sweeteners, has been reported to induce IR and inflammation. This study explored the effects and mechanisms of Fru on IR of GDM in pregnant and postpartum mice and their offspring.

METHODS

The 6-week-old female C57BL/6J mice were randomly divided into control (Chow) and fructose (Fru) groups, with the latter receiving 20% (w/v) Fru in drinking water from 2 weeks before pregnancy to the end of pregnancy. The effects of Fru on IR and inflammation were determined using serum parameters, glucose metabolism tests, immunohistochemistry, and western blotting.

RESULTS

Compared with the Chow group mice, pregnant mice treated with Fru exhibited greater gestational weight gain, higher fasting blood glucose and insulin concentrations, and a higher homeostasis model of assessment (HOMA) for IR index, but a lower HOMA for insulin sensitivity index. Treatment with Fru also increased the concentrations of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-17, and C-reactive protein in sera and the expression of IL-6, TNF-α, IL-17, and IL-1β mRNA in liver tissues of pregnant mice. Both CD68 and IL-1β positive cell were increased in Fru-treated mice compared with in Chow mice. Fru treatment also promoted IR and inflammation in mice at 4 weeks after delivery and in offspring mice. Mechanistically, Fru promoted the nuclear translocation of nuclear factor-kappa B (NF-κB) p65 to activate the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome.

CONCLUSIONS

Exposure to Fru before and during pregnancy induced IR in pregnant mice, which continued at 4 weeks postpartum and affected the offspring. The effects of Fru may be associated with activation of the NF-κB-NLRP3 pathway.

Low Dietary n6/n3 Ratio Attenuates Changes in the NRF 2 Gene Expression, Lipid Peroxidation, and Inflammatory Markers Induced by Fructose Overconsumption in the Rat Abdominal Adipose Tissue

The objective of this study was to examine the benefits of different n6/n3 polyunsaturated fatty acid ratios on the lipid metabolism, insulin resistance, and oxidative stress in the adipose tissue of rats fed a high-fructose diet. Male and female rats were divided into four groups: a control group (CON) (n6/n3 ratio ~7), a high-fructose group (HF) (n6/n3 ratio ~7), an N6-HF group (n6/n3 ratio ~50), and the DHA-HF group (n6/n3 ratio ~1, with the addition of docosahexaenoic (DHA) and eicosapentaenoic (EPA) acid). The CON group received plain water and the HF group received 15% fructose in their drinking water. Fructose induced an increase in the content of serum triglycerides, serum cholesterol, and HOMA-IR index. Among the fatty acids, elevated proportions of C18:1n9 and C16:1n7, as well as an increase in total monounsaturated fatty acid (MUFA), were found in the adipose tissue of the HF group. Fructose treatment also changed oxidative parameters, including a marked increase in the serum malondialdehyde (MDA) content. Meanwhile, DHA supplementation caused a significant decrease in the serum MDA concentration in comparison with the HF group. In addition, DHA/EPA supplementation attenuated oxidative stress by increasing NRF 2 gene expression. Fructose treatment also significantly decreased the adiponectin level, while DHA supplementation ameliorated it. The changes observed in this trial, including the decrease in the content of DHA and EPA, the decreased EPA/ARA ratio, and the increase in the expression of inflammatory genes, are characteristics of the low-grade inflammation caused by fructose treatment. These changes in the rat adipose tissue could be prevented by dietary intervention consisting of DHA supplementation and a low n6/n3 ratio.

Naringin Prevents Bone Damage in the Experimental Metabolic Syndrome Induced by a Fructose Rich Diet

We have analyzed the effect of naringin (NAR), a flavonoid from citric fruits, on bone quality and bone biomechanical properties as well as the redox state of bone marrow in rats fed a fructose rich diet (FRD), an experimental model to mimic human metabolic syndrome. NAR blocked the enhancement in the number of osteoclasts and adipocytes and the decrease in the number of osteocytes and osteocalcin (+) cells caused by FRD. The trabecular number was significantly higher in the FRD+NAR group. FRD induced a decrease in femoral trabecular and cortical bone mineral density, which was blocked by NAR. The fracture and ultimate loads were also decreased by the FRD and FRD+NAR groups. NAR increased the number of nodes to terminal trabecula, the number of nodes to node trabecula, the number of nodes, and the number of nodes with two terminals, and decreased the Dist (mean size of branches) value. Bone marrow catalase activity was decreased by the FRD, an effect prevented by NAR. In conclusion, FRD produces detrimental effects on long bones, which are associated with oxidative stress in bone marrow. Most of these changes are avoided by NAR through its antioxidant properties and promotion of bone formation. Novelty bullets: • Fructose rich diet produces detrimental effects on long bones, which are associated with oxidative stress in bone marrow. • Most of these changes are avoided by Naringin through its antioxidant properties and promotion of bone formation.

Development of a Method for Quantitation of Glyceraldehyde in Various Body Compartments of Rodents and Humans

There is limited information available about the physiological content of glyceraldehyde, a precursor of toxic advanced glycation end products. The conventional derivatization method for aldoses using 1-phenyl-3-methyl-5-pyrazolone did not allow reproducible quantification of glyceraldehyde due to the instability of glyceraldehyde compared to other aldoses. We optimized the derivatization condition to achieve high and reproducible recovery of derivatives for liquid chromatography tandem mass spectrometry quantification. Based on the stability of glyceraldehyde during sample preparation and high recovery of spiked standard, the present method provides reproducible quantification of glyceraldehyde in the body. The glyceraldehyde contents in fasting conditions in the rodent liver (mice: 50.0 ± 3.9 nmol/g; rats: 35.5 ± 4.9 nmol/g) were higher than those in plasma (9.4 ± 1.7 and 7.2 ± 1.2 nmol/mL). The liver glyceraldehyde levels significantly increased after food consumption (p < 0.05) but remained constant in the plasma. High fat diet feeding significantly increased plasma glyceraldehyde levels in mice (p < 0.005). In healthy human volunteers, the plasma glyceraldehyde levels remained unchanged after the consumption of steamed rice. In patients with type 2 diabetes, the plasma glyceraldehyde level was positively correlated with the plasma glucose level (r = 0.84; p < 0.0001).

The Controversial Role of Adiponectin in Appetite Regulation of Animals

Eating disorders and obesity are important health problems with a widespread global epidemic. Adiponectin (AdipoQ), the most abundant adipokine in the plasma, plays important roles in the regulation of energy homeostasis, glucose metabolism and lipid metabolism. Plasma adiponectin concentration is negatively associated with obesity and binge eating disorder. There is a growing interest in the appetite regulation function of adiponectin. However, the effect of AdipoQ on feeding behavior is controversial and closely related to nutritional status and food composition. In this review, we summarize the literatures about the discovery, structure, tissue distribution, receptors and regulation of nutritional status, and focus on the biological function of adiponectin in the regulation of food intake in the central and peripheral system.

Metabolic programming in offspring of mice fed fructose during pregnancy and lactation

Fructose (C6H12O6), also known as levulose, is a hexose. Chronic consumption of fructose may be associated with increased intrahepatic fat concentration and the development of insulin resistance as well as an increase in the prevalence of nonalcoholic fatty liver disease and hyperlipidemia during pregnancy. Despite the existence of many studies regarding the consumption of fructose in pregnancy, its effects on fetuses have not yet been fully elucidated. Therefore, the objective of this study was to evaluate the genetic and biochemical effects in offspring (male and female) of female mice treated with fructose during pregnancy and lactation. Pairs of 60-day-old Swiss mice were used and divided into three groups; negative control and fructose, 10%/l and 20%/l doses of fructose groups. After offspring birth, the animals were divided into six groups: P1 and P2 (males and females), water; P3 and P4 (males and females) fructose 10%/l; and P5 and P6 (males and females) fructose 20%/l. At 30 days of age, the animals were euthanized for genetic and biochemical assessments. Female and male offspring from both dosage groups demonstrated genotoxicity (evaluated through comet assay) and oxidative stress (evaluated through nitrite concentration, sulfhydril content and superoxide dismutase activity) in peripheral and brain tissues. In addition, they showed nutritional and metabolic changes due to the increase in food consumption, hyperglycemia, hyperlipidemia, and metabolic syndrome. Therefore, it is suggested that high consumption of fructose by pregnant female is harmful to their offspring. Thus, it is important to carry out further studies and make pregnant women aware of excessive fructose consumption during this period.

A review on the fruit components affecting uric acid level and their underlying mechanisms

Uric acid (UA) is produced in the liver and excreted through the kidneys and intestines. If UA is overproduced or its excretion reduces, the concentration of UA increases, leading to hyperuricemia and gout. The high concentration of UA is also related to cardiovascular disease, hypertension, obesity, and other diseases. Fruits are healthy foods. However, fruits contain fructose and small amounts of purine, and the product of their metabolism is UA. Therefore, theoretically, eating fruits will increase the concentration of serum UA. Fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In addition to the UA synthesized by fructose and purine metabolism, the mechanisms by which other components affect the concentration of serum UA can be summarized as follows: (a) inhibiting xanthine oxidase; (b) reducing reabsorption of UA; and (c) improving the excretion of UA. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations, and explained their mechanisms for the first time, which references for patients with hyperuricemia to take fruits. PRACTICAL APPLICATIONS: With the rising prevalence, hyperuricemia and gout have become public health problems that endanger our daily life. The key to the treatment of hyperuricemia is to control the level of serum UA within the normal range. Fruits are healthy foods. However, fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations. We also explained their mechanisms, which references for patients with hyperuricemia to take fruits.