High Fat With High Sucrose Diet Leads to Obesity and Induces Myodegeneration

Consumption of sucrose-water rewires macronutrient uptake and utilization mechanisms in a tissue specific manner

Consumption of sugar-sweetened beverages (SSBs) have been linked to metabolic dysfunction, obesity, diabetes and enhanced risk of cardiovascular diseases across all age-groups globally. Decades of work that have provided insights into pathophysiological manifestations of sucrose overfeeding have employed paradigms that rarely mimic human consumption of SSBs. Thus, our understanding of multiorgan cross-talk and molecular and/or cellular mechanisms, which operate across scales and drive physiological derangement is still poor. By employing a paradigm of sucrose water feeding in mice that closely resembles chronic SSB consumption in humans (10% sucrose in water), we have unraveled hitherto unknown tissue-specific mechanistic underpinnings, which contribute towards perturbed physiology. Our findings illustrate that systemic impaired glucose homeostasis, mediated by hepatic gluconeogenesis and insulin resistance, does not involve altered gene expression programs in the liver. We have discovered the pivotal role of the small intestine, which in conjunction with liver and muscles, drives dyshomeostasis. Importantly, we have uncovered rewiring of molecular mechanisms in the proximal intestine that is either causal or consequential to systemic ill-effects of chronic sucrose water consumption including dysfunction of liver and muscle mitochondria. Tissue-specific molecular signatures, which we have unveiled as the primary outcome, clearly indicate that inefficient utilization of glucose is exacerbated by enhanced uptake by the gut. Besides providing systems-wide mechanistic insights, we propose that consumption of SSBs causes intestinal 'molecular addiction' for deregulated absorption of hexose-sugars, and drives diseases such as diabetes and obesity.

Paternal Cyanidin-3-O-Glucoside Diet Improved High-Fat, High-Fructose Diet-Induced Intergenerational Inheritance in Male Offspring's Susceptibility to High-Fat Diet-Induced Testicular and Sperm Damage

High-fructose and high-fat diet (HFHFD) has been associated with impaired spermatogenesis, leading to decreased sperm quality and increased male infertility, with similar effects observed in offspring. Cyanidin-3-O-glucoside (C3G), a recognized food antioxidant, has shown promise in protecting in male reproduction and modulating epigenetic modifications. However, its potential role in ameliorating intergenerational inheritance induced by HFHFD remains underexplored. In this study, we investigated the effects of paternal HFHFD on reproductive injury of offspring and the protective effect of C3G. Paternal mice were subjected to 12 weeks of HFHFD induction and C3G treatment was conducted for 8 weeks. Offspring obtained via in vitro fertilization were fed either a normal diet (ND) or high-fat diet (HFD). Our findings indicate that while the paternal HFHFD did not result in observable reproductive impairments in paternal mice, it did affect offspring testicular function through intergenerational inheritance, rendering them more susceptible to testicular damage and reduced sperm counts when exposed to an HFD. Notably, C3G intervention significantly mitigated these effects, suggesting its potential as a therapeutic compound for alleviating the impact of paternal intergenerational inheritance on male fertility resulting from HFHFD. These results underscore the importance of further exploring the mechanisms underlying intergenerational inheritance and the potential of interventions such as C3G in mitigating its effects, with implications for both basic research and clinical practice.

Periodic protein-restricted diets extend the lifespan of high-fat diet-induced Drosophila melanogaster males

Research has shown that sustained protein restriction can improve the effects of a high-fat diet on health and extend lifespan. However, long-term adherence to a protein-restricted diet is challenging. Therefore, we used a fly model to investigate whether periodic protein restriction (PPR) could also mitigate the potential adverse effects of a high-fat diet and extend healthy lifespan. Our study results showed that PPR reduced body weight, lipid levels, and oxidative stress induced by a high-fat diet in flies and significantly extended the healthy lifespan of male flies. Lipid metabolism and transcriptome results revealed that the common differences between the PPR group and the control group and high-fat group showed a significant decrease in palmitic acid in the PPR group; the enriched common differential pathways Toll and Imd were significantly inhibited in the PPR group. Further analysis indicated a significant positive correlation between palmitic acid levels and gene expression in the Toll and Imd pathways. This suggests that PPR effectively improves fruit fly lipid metabolism, reduces palmitic acid levels, and thereby suppresses the Toll and Imd pathways to extend the healthy lifespan of flies. Our study provides a theoretical basis for the long-term effects of PPR on health and offers a new dietary adjustment option for maintaining health in the long term.

Effect of Isoflavone on Muscle Atrophy in Ovariectomized Mice

BACKGROUND

Sarcopenia, characterized by muscle mass decline due to aging or other causes, is exacerbated by decreased estrogen levels after menopause in women. Isoflavones, a class of flavonoids acting on estrogen receptors, may have beneficial effects on metabolic disorders. We examined these effects in ovariectomized mice fed a high-fat, high-sucrose diet (HFHSD).

METHODS

At 7 weeks old, female C57BL6/J mice (18-20 g, n = 12) underwent bilateral ovariectomy (OVX), and were then fed a high-fat, high-sucrose diet starting at 8 weeks of age. Half of the mice received isoflavone water (0.1%). Metabolic analyses, including glucose and insulin tolerance tests, were conducted. Muscle analysis involved grip strength assays, next-generation sequencing, quantitative RT-PCR, and western blotting of skeletal muscle after euthanizing the mice at 14 weeks old. Additionally, 16S rRNA gene sequence analysis of the gut microbiota was performed.

RESULTS

The results demonstrated that isoflavone administration did not affect body weight, glucose tolerance, or lipid metabolism. In contrast, isoflavone-treated mice had higher grip strength. Gene expression analysis of the soleus muscle revealed decreased Trim63 expression, and western blotting showed inactivation of muscle-specific RING finger protein 1 in isoflavone-treated mice. Gut microbiota analysis indicated higher Bacteroidetes and lower Firmicutes abundance in the isoflavone group, along with increased microbiota diversity. Gene sets related to TNF-α signaling via NF-κB and unfolded protein response were negatively associated with isoflavones.

CONCLUSIONS

Isoflavone intake alters gut microbiota and increases muscle strength, suggesting a potential role in improving sarcopenia in menopausal women.

Daidzein Inhibits Muscle Atrophy by Suppressing Inflammatory Cytokine- and Muscle Atrophy-Related Gene Expression

BACKGROUND

Sarcopenic obesity, which is associated with a poorer prognosis than that of sarcopenia alone, may be positively affected by soy isoflavones, known inhibitors of muscle atrophy. Herein, we hypothesize that these compounds may prevent sarcopenic obesity by upregulating the gut metabolites with anti-inflammatory effects.

METHODS

To explore the effects of soy isoflavones on sarcopenic obesity and its mechanisms, we employed both in vivo and in vitro experiments. Mice were fed a high-fat, high-sucrose diet with or without soy isoflavone supplementation. Additionally, the mouse C2C12 myotube cells were treated with palmitic acid and daidzein in vitro.

RESULTS

The isoflavone considerably reduced muscle atrophy and the expression of the muscle atrophy genes in the treated group compared to the control group (Fbxo32, p = 0.0012; Trim63, p < 0.0001; Foxo1, p < 0.0001; Tnfa, p = 0.1343). Elevated levels of daidzein were found in the muscles and feces of the experimental group compared to the control group (feces, p = 0.0122; muscle, p = 0.0020). The real-time PCR results demonstrated that the daidzein decreased the expression of the palmitate-induced inflammation and muscle atrophy genes in the C2C12 myotube cells (Tnfa, p = 0.0201; Il6, p = 0.0008; Fbxo32, p < 0.0001; Hdac4, p = 0.0002; Trim63, p = 0.0114; Foxo1, p < 0.0001). Additionally, it reduced the palmitate-induced protein expression related to the muscle atrophy in the C2C12 myotube cells (Foxo1, p = 0.0078; MuRF1, p = 0.0119).

CONCLUSIONS

The daidzein suppressed inflammatory cytokine- and muscle atrophy-related gene expression in the C2C12 myotubes, thereby inhibiting muscle atrophy.

Experimental investigation for nonalcoholic fatty pancreas management using probiotics

BACKGROUND

Nonalcoholic fatty pancreatitis (NAFP) presents a pressing challenge within the domain of metabolic disorders, necessitating further exploration to unveil its molecular intricacies and discover effective treatments. Our focus was to delve into the potential therapeutic impact of ZBiotic, a specially engineered strain of probiotic B. subtilis, in managing NAFP by targeting specific genes linked with necroptosis and the TNF signaling pathway, including TNF, ZBP1, HSPA1B, and MAPK3, along with their upstream epigenetic regulator, miR-5192, identified through bioinformatics.

METHODS

Rats were subjected to either a standard or high-fat, high-sucrose diet (HFHS) for eight weeks. Subsequently, they were divided into groups: NAFP model, and two additional groups receiving daily doses of ZBiotic (0.5 ml and 1 ml/kg), and the original B. subtilis strain group (1 ml/kg) for four weeks, alongside the HFHS diet.

RESULTS

ZBiotic exhibited remarkable efficacy in modulating gene expression, leading to the downregulation of miR-5192 and its target mRNAs (p < 0.001). Treatment resulted in the reversal of fibrosis, inflammation, and insulin resistance, evidenced by reductions in body weight, serum amylase, and lipase levels (p < 0.001), and decreased percentages of Caspase and Nuclear Factor Kappa-positive cells in pancreatic sections (p < 0.01). Notably, high-dose ZBiotic displayed superior efficacy compared to the original B. subtilis strain, highlighting its potential in mitigating NAFP progression by regulating pivotal pancreatic genes.

CONCLUSION

ZBiotic holds promise in curbing NAFP advancement, curbing fibrosis and inflammation while alleviating metabolic and pathological irregularities observed in the NAFP animal model. This impact was intricately linked to the modulation of necroptosis/TNF-mediated pathway-related signatures.

Textural, rheological, melting properties, particle size distribution, and NMR relaxometry of cocoa hazelnut spread with inulin-stevia addition as sugar replacer

This study investigated the influence of substituting 60, 80, and 100% of the sugar in traditional cocoa hazelnut paste (control) formulation with inulin-stevia (90:10, w/w) mixture on textural and rheological characteristics, melting behavior, water activity (aw), particle size distribution (PSD), and color. Textural, rheological, melting properties, and color of samples were analyzed after 1, 2, and 3 months of storage at 11°C. Nuclear magnetic resonance (NMR) relaxometry experiments were also performed to understand the interaction of new ingredients with oil. Replacement of sugar with inulin-stevia gave darker color, reduced Casson yield stress, and changed the textural parameters and melting profile of the samples depending on the level but did not create a remarkable effect on PSD and Casson plastic viscosity. Increasing inulin-stevia content yielded lower aw and higher T2a values indicating decreased mobility of water. Complete removal of sugar caused low spreadability. The results showed that an 80% replacement level yielded a product with similar textural parameters and fat-melting mouth feeling compared to control sample. Cocoa hazelnut spreads prepared with inulin and stevia showed good textural stability during storage.

Accelerated Aging Induced by an Unhealthy High-Fat Diet: Initial Evidence for the Role of Nrf2 Deficiency and Impaired Stress Resilience in Cellular Senescence

High-fat diets (HFDs) have pervaded modern dietary habits, characterized by their excessive saturated fat content and low nutritional value. Epidemiological studies have compellingly linked HFD consumption to obesity and the development of type 2 diabetes mellitus. Moreover, the synergistic interplay of HFD, obesity, and diabetes expedites the aging process and prematurely fosters age-related diseases. However, the underlying mechanisms driving these associations remain enigmatic. One of the most conspicuous hallmarks of aging is the accumulation of highly inflammatory senescent cells, with mounting evidence implicating increased cellular senescence in the pathogenesis of age-related diseases. Our hypothesis posits that HFD consumption amplifies senescence burden across multiple organs. To scrutinize this hypothesis, we subjected mice to a 6-month HFD regimen, assessing senescence biomarker expression in the liver, white adipose tissue, and the brain. Aging is intrinsically linked to impaired cellular stress resilience, driven by dysfunction in Nrf2-mediated cytoprotective pathways that safeguard cells against oxidative stress-induced senescence. To ascertain whether Nrf2-mediated pathways shield against senescence induction in response to HFD consumption, we explored senescence burden in a novel model of aging: Nrf2-deficient (Nrf2+/-) mice, emulating the aging phenotype. Our initial findings unveiled significant Nrf2 dysfunction in Nrf2+/- mice, mirroring aging-related alterations. HFD led to substantial obesity, hyperglycemia, and impaired insulin sensitivity in both Nrf2+/- and Nrf2+/+ mice. In control mice, HFD primarily heightened senescence burden in white adipose tissue, evidenced by increased Cdkn2a senescence biomarker expression. In Nrf2+/- mice, HFD elicited a significant surge in senescence burden across the liver, white adipose tissue, and the brain. We postulate that HFD-induced augmentation of senescence burden may be a pivotal contributor to accelerated organismal aging and the premature onset of age-related diseases.

Differential effects of fish-oil and cocoa-butter based high-fat/high-sucrose diets on endocrine pancreas morphology and function in mice

INTRODUCTION

A high-fat/high-sucrose diet leads to adverse metabolic changes that affect insulin sensitivity, function, and secretion. The source of fat in the diet might inhibit or increase this adverse effect. Fish oil and cocoa butter are a significant part of our diets. Yet comparisons of these commonly used fat sources with high sucrose on pancreas morphology and function are not made. This study investigated the comparative effects of a fish oil-based high-fat/high-sucrose diet (Fish-HFDS) versus a cocoa butter-based high-fat/high-sucrose diet (Cocoa-HFDS) on endocrine pancreas morphology and function in mice.

METHODS

C57BL/6 male mice (n=12) were randomly assigned to dietary intervention either Fish-HFDS (n=6) or Cocoa-HFDS (n=6) for 22 weeks. Intraperitoneal glucose and insulin tolerance tests (IP-GTT and IP-ITT) were performed after 20-21 weeks of dietary intervention. Plasma concentrations of c-peptide, insulin, glucagon, GLP-1, and leptin were measured by Milliplex kit. Pancreatic tissues were collected for immunohistochemistry to measure islet number and composition. Tissues were multi-labelled with antibodies against insulin and glucagon, also including expression on Pdx1-positive cells.

RESULTS AND DISCUSSION

Fish-HFDS-fed mice showed significantly reduced food intake and body weight gain compared to Cocoa-HFDS-fed mice. Fish-HFDS group had lower fasting blood glucose concentration and area under the curve (AUC) for both GTT and ITT. Plasma c-peptide, insulin, glucagon, and GLP-1 concentrations were increased in the Fish-HFDS group. Interestingly, mice fed the Fish-HFDS diet displayed higher plasma leptin concentration. Histochemical analysis revealed a significant increase in endocrine pancreas β-cells and islet numbers in mice fed Fish-HFDS compared to the Cocoa-HFDS group. Taken together, these findings suggest that in a high-fat/high-sucrose dietary setting, the source of the fat, especially fish oil, can ameliorate the effect of sucrose on glucose homeostasis and endocrine pancreas morphology and function.

Miso, fermented soybean paste, suppresses high-fat/high-sucrose diet-induced muscle atrophy in mice

This study investigated the effects of miso, a traditional fermented soybean food in Japan, on muscle mass atrophy. Eight week old male C57BL/6J mice were fed high fat/high sucrose diet with or without miso for 12 weeks. A miso diet increased soleus muscle weights (p<0.05) and reduced intraperitoneal glucose tolerance and insulin tolerance (p<0.05). The miso diet downregulated the Tnfα and Ccl2 expression, related to inflammation, and Trim63 and Fbxo32 expression, related to muscle atrophy, in the soleus muscle (p<0.05). The miso diet increased short-chain fatty acids levels, including acetic, propanoic, and butanoic acids, in the feces, serum, and soleus muscle (p<0.05). According to the LEfSe analysis, the miso diet increased family Prevotellaceae, family Christensenellaceae, family Dehalobacterium, family Desulfitibacter; family Deferribacteraceae, order Deferribacterales, class Deferribacteres; and family Gemmatimonadaceae, order Gemmatimonadetes, and class Gemmatimonadales, whereas the miso diet decreased family Microbacteriaceae, order Micrococcales, class Actinobacteria, and family Lactobacillaceae. Miso suppressed high fat/high sucrose diet induced impaired glucose tolerance, low muscle strength, and muscle atrophy by improving dysbiosis and increasing short-chain fatty acids production and provides new insights into the preventive effects of fermented foods on sarcopenia.

Alpha-ketoglutarate partially alleviates effects of high-fat high-fructose diet in mouse muscle

Consumption of high-calorie diets leads to excessive accumulation of storage lipids in adipose tissue. Metabolic changes occur not only in adipose tissue but in other tissues, too, such as liver, heart, muscle, and brain. This study aimed to explore the effects of high-fat high-fructose diet (HFFD) alone and in the combination with alpha-ketoglutarate (AKG), a well-known cellular metabolite, on energy metabolism in the skeletal muscle of C57BL/6J mice. Five-month-old male mice were divided into four groups - the control one fed a standard diet (10 % kcal fat), HFFD group fed a high-fat high-fructose diet (45 % kcal fat, 15 % kcal fructose), AKG group fed a standard diet with 1 % sodium AKG in drinking water, and HFFD + AKG group fed HFFD and water with 1 % sodium AKG. The dietary regimens lasted 8 weeks. Mice fed HFFD had higher levels of storage triacylglycerides, lower levels of glycogen, and total water-soluble protein, and higher activities of key glycolytic enzymes, namely hexokinase, phosphofructokinase, and pyruvate kinase, as compared with the control group. The results suggest that muscles of HFFD mice may suffer from lipotoxicity. In HFFD + AKG mice, levels of the metabolites and activities of glycolytic enzymes did not differ from the respective values in the control group, except for the activity of pyruvate kinase, which was significantly lower in HFFD + AKG group compared with the control. Thus, metabolic changes in mouse skeletal muscles, caused by HFFD, were alleviated by AKG, indicating a protective role of AKG regarding lipotoxicity.

Different Effects of High-Fat/High-Sucrose and High-Fructose Diets on Advanced Glycation End-Product Accumulation and on Mitochondrial Involvement in Heart and Skeletal Muscle in Mice

Diets with an elevated content of fat, sucrose, or fructose are recognized models of diet-induced metabolic alterations, since they induce metabolic derangements, oxidative stress, and chronic low-grade inflammation associated with local and systemic accumulation of advanced glycation end-products (AGEs). This study used four-week-old C57BL/6 male mice, randomly assigned to three experimental dietary regimens: standard diet (SD), high-fat high-sucrose diet (HFHS), or high fructose diet (HFr), administered for 12 weeks. Plasma, heart, and tibialis anterior (TA) skeletal muscle were assayed for markers of metabolic conditions, inflammation, presence of AGEs, and mitochondrial involvement. The HFHS diet induced a tissue-specific differential response featuring (1) a remarkable adaptation of the heart to HFHS-induced heavy oxidative stress, demonstrated by an increased presence of AGEs and reduced mitochondrial biogenesis, and efficaciously counteracted by a conspicuous increase in mitochondrial fission and PRXIII expression; (2) the absence of TA adaptation to HFHS, revealed by a heavy reduction in mitochondrial biogenesis, not counteracted by an increase in fission and PRXIII expression. HFr-induced mild oxidative stress elicited tissue-specific responses, featuring (1) a decrease in mitochondrial biogenesis in the heart, likely counteracted by a tendency for increased fission and (2) a mild reduction in mitochondrial biogenesis in TA, likely counteracted by a tendency for increased fusion, showing the adaptability of both tissues to the diet.

Oxidative stress: roles in skeletal muscle atrophy

Oxidative stress, inflammation, mitochondrial dysfunction, reduced protein synthesis, and increased proteolysis are all critical factors in the process of muscle atrophy. In particular, oxidative stress is the key factor that triggers skeletal muscle atrophy. It is activated in the early stages of muscle atrophy and can be regulated by various factors. The mechanisms of oxidative stress in the development of muscle atrophy have not been completely elucidated. This review provides an overview of the sources of oxidative stress in skeletal muscle and the correlation of oxidative stress with inflammation, mitochondrial dysfunction, autophagy, protein synthesis, proteolysis, and muscle regeneration in muscle atrophy. Additionally, the role of oxidative stress in skeletal muscle atrophy caused by several pathological conditions, including denervation, unloading, chronic inflammatory diseases (diabetes mellitus, chronic kidney disease, chronic heart failure, and chronic obstructive pulmonary disease), sarcopenia, hereditary neuromuscular diseases (spinal muscular atrophy, amyotrophic lateral sclerosis, and Duchenne muscular dystrophy), and cancer cachexia, have been discussed. Finally, this review proposes the alleviation oxidative stress using antioxidants, Chinese herbal extracts, stem cell and extracellular vesicles as a promising therapeutic strategy for muscle atrophy. This review will aid in the development of novel therapeutic strategies and drugs for muscle atrophy.

A novel rat model of sarcopenic obesity based on aging and high-fat diet consumption

Sarcopenic obesity (SO) is defined as a combination of obesity and sarcopenia, leading to serious health consequences. However, a lack of suitable animal models has hampered research into this disorder. 12-month-old Sprague-Dawley rats were given a high fat content (HFD, SO group) or standard diet (DC groups) for 28 weeks (until 20 months of age). In addition, 2-month-old rats were fed a standard diet as an age control (YC group) until they reached 10 months of age. At the end of the intervention, quadriceps development in the rats was monitored using magnetic resonance examinations and MR spectroscopy. Age-related changes in muscle mass and strength, histopathology, HFD-induced adiposity, and metabolic disturbances were compared between the three groups. Comparing with DC group, rats of SO (20 months, and fed by high-fat diet) exhibited a more prominent loss of muscle mass and strength, a more pronounced decline in myofibre number, IFM, increase in myocyte apoptosis accompanied with increased visceral fat, remarkable glycolipid metabolic disorders, and insulin resistance. However, DC group rats (20 months with standard diet) only showed a decline in quadriceps cross-sectional area/body weight, forelimb grip strength, myofibre cross-sectional area and number, and intermyofibrillar mitochondria number (IFM), increased myocyte apoptosis, without significant metabolic disorder compared with YC group rats. After verifying, SO animal model was successfully set up by HFD induced obesity concomitant with aging-related sarcopenia.

Prevalence and Mechanisms of Skeletal Muscle Atrophy in Metabolic Conditions

Skeletal muscle atrophy is prevalent in a myriad of pathological conditions, such as diabetes, denervation, long-term immobility, malnutrition, sarcopenia, obesity, Alzheimer's disease, and cachexia. This is a critically important topic that has significance in the health of the current society, particularly older adults. The most damaging effect of muscle atrophy is the decreased quality of life from functional disability, increased risk of fractures, decreased basal metabolic rate, and reduced bone mineral density. Most skeletal muscle in humans contains slow oxidative, fast oxidative, and fast glycolytic muscle fiber types. Depending on the pathological condition, either oxidative or glycolytic muscle type may be affected to a greater extent. This review article discusses the prevalence of skeletal muscle atrophy and several mechanisms, with an emphasis on high-fat, high-sugar diet patterns, obesity, and diabetes, but including other conditions such as sarcopenia, Alzheimer's disease, cancer cachexia, and heart failure.

A mixture of four dietary fibres ameliorates adiposity and improves metabolic profile and intestinal health in cafeteria-fed obese rats: an integrative multi-omics approach

The aim of this study was to assess the effects of a mixture of four dietary fibers on obese rats. Four groups of male Wistar rats were fed with either standard chow (STD) or cafeteria diet (CAF) and were orally supplemented with either fibre mixture (2 g kg-1 of body weight) (STD+F or CAF+F groups) or vehicle (STD+VH or CAF+VH groups). We studied a wide number of biometric, biochemical, transcriptomic, metagenomic and metabolomic variables and applied an integrative multivariate approach based on multiple factor analysis and Pearson's correlation analysis. A significant reduction in body weight, adiposity, HbA1c and HDL-cholesterol serum levels, and colon MPO activity was observed, whereas cecal weight and small intestine length:weight ratio were significantly increased in F-treated groups compared to control animals. CAF+F rats displayed a significant enhancement in energy expenditure, fat oxidation and fresh stool weight, and a significant reduction in adiponectin and LPS serum levels, compared to control group. Animals in STD+F group showed reduced serum LDL-cholesterol levels and a significant reduction in total cholesterol levels in the liver compared to STF+VH group. The intervention effect was reflected at the metabolomic (i.e., production of short-chain fatty acids, phenolic acids, and amino acids), metagenomic (i.e., modulation of Ruminococcus and Lactobacillus genus) and transcriptomic (i.e., expression of tight junctions and proteolysis) levels. Altogether, our integrative multi-omics approach highlights the potential of supplementation with a mixture of fibers to ameliorate the impairments triggered by obesity in terms of adiposity, metabolic profile, and intestinal health.

High-refined carbohydrate diet alters different metabolic functions in female rats

A diet containing refined carbohydrate (HCD) caused obesity and white adipose tissue (WAT) abnormalities, but it is unclear if HCD is linked with other metabolic dysfunctions in female models. Thus, we assessed whether HCD results in WAT, pancreas, liver, skeletal muscle (SM) and thyroid (TH) abnormalities in female rats. Female rats were fed with HCD for 15 days and metabolic morphophysiology, inflammation, oxidative stress (OS), and fibrosis markers were assessed. HCD rats presented large adipocytes, hyperleptinemia, and WAT OS. HCD caused irregular glucose metabolism, low insulin levels, and large pancreatic isle. Granulomas, reduced glycogen, and OS were observed in HCD livers. HCD caused hypertrophy and increased in glycogen in SM. HCD caused irregular TH morphophysiology, reduced colloid area and high T3 levels. In all selected tissues, inflammation and fibrosis were observed in HCD rats. Collectively, these data suggest that the HCD impairs metabolic function linked with irregularities in WAT, pancreas, liver, SM and TH in female rats.

Naringin Ameliorates Skeletal Muscle Atrophy and Improves Insulin Resistance in High-Fat-Diet-Induced Insulin Resistance in Obese Rats

Obesity causes progressive lipid accumulation and insulin resistance within muscle cells and affects skeletal muscle fibres and muscle mass that demonstrates atrophy and dysfunction. This study investigated the effects of naringin on the metabolic processes of skeletal muscle in obese rats. Male Sprague Dawley rats were divided into five groups: the control group with normal diet and the obese groups, which were induced with a high-fat diet (HFD) for the first 4 weeks and then treated with 40 mg/kg of simvastatin and 50 and 100 mg/kg of naringin from week 4 to 8. The naringin-treated group showed reduced body weight, biochemical parameters, and the mRNA expressions of protein degradation. Moreover, increased levels of antioxidant enzymes, glycogen, glucose uptake, the expression of the insulin receptor substrate 1 (IRS-1), the glucose transporter type 4 (GLUT4), and the mRNA expressions of protein synthesis led to improved muscle mass in the naringin-treated groups. The in vitro part showed the inhibitory effects of naringin on digestive enzymes related to lipid and glucose homeostasis. This study demonstrates the potential benefits of naringin as a supplement for treating muscle abnormalities in obese rats by modulating the antioxidative status, regulating protein metabolism, and improved insulin resistance in skeletal muscle of HFD-induced insulin resistance in obese rats.

Lipomodulatory and anti-oxidative stress effects of a polyherbal formulation based on garlic and avocado seed extracts on high fat high sucrose diet fed rats

Objective

To determine antioxidant potentials of Allium sativum and Persea americana seeds extracts and three formulation-based extracts in vitro, and to evaluate the effects of the best formulation on oxidative stress and dyslipidemia on rats fed with high fat and high sucrose diet (HFHSD).

Methods

Aqueous extracts of Allium sativum, Persia. americana and three formulations were mixed at various portions (A. s/P. a; w/w): F (1:1), F (3: 1), and F(1:3). They were then tested for their antioxidant potentials in vitro using FRAP, DPPH and NO radicals to identify the best formulation. Four hundred (400) mg/kg b.w. of formulation F(1:1) were administered once daily for 21 days to rats previously fed with HFHSD for 8 weeks. Standard diet, vitamin E, and Atorvastatin were used as controls. After 21 days, body weight, blood glucose, lipid markers, activities of transaminases and markers of the antioxidant systems were assessed.

Results

The Formulation F(1:1) showed the best in vitro activity with IC₅₀ values of 6.5 and 2.23 mg/mL respectively for FRAP and DPPH- radical scavenging capacity. HFHSD caused a depletion of antioxidants associated with an increase of pro-oxidants and all the lipid markers except HDL-c Treatment with F(1:1) significantly increased TAC, SOD, and catalase activities, while MDA, protein carbonyls, and NO levels decreased (p < 0.05). Formulation F(1:1) decreased triglycerides (119.88 ± 4.25 mg/dL) and LDL-c (3.78 ± 0.66 mg/dL) levels and significantly increased the HDL-c level: (108.07 ± 6.29 mg/mL). Furthermore, Formulation F(1:1) significantly caused weight loss (2.31%), reduced blood glucose levels (27.38%) and ALT activity.

Conclusion

The formulation F(1:1) could be a good candidate for the prevention and treatment of oxidative stress, dyslipidemia and features of metabolic syndrome.

A High-Fat Diet Induces Muscle Mitochondrial Dysfunction and Impairs Swimming Capacity in Zebrafish: A New Model of Sarcopenic Obesity

Obesity is a highly prevalent disease that can induce metabolic syndrome and is associated with a greater risk of muscular atrophy. Mitochondria play central roles in regulating the physiological metabolism of skeletal muscle; however, whether a decreased mitochondrial function is associated with impaired muscle function is unclear. In this study, we evaluated the effects of a high-fat diet on muscle mitochondrial function in a zebrafish model of sarcopenic obesity (SOB). In SOB zebrafish, a significant decrease in exercise capacity and skeletal muscle fiber cross-sectional area was detected, accompanied by high expression of the atrophy-related markers Atrogin-1 and muscle RING-finger protein-1. Zebrafish with SOB exhibited inhibition of mitochondrial biogenesis and fatty acid oxidation as well as disruption of mitochondrial fusion and fission in atrophic muscle. Thus, our findings showed that muscle atrophy was associated with SOB-induced mitochondrial dysfunction. Overall, these results showed that the SOB zebrafish model established in this study may provide new insights into the development of therapeutic strategies to manage mitochondria-related muscular atrophy.

Resveratrol Blunts Mitochondrial Loss in Slow and Mixed Skeletal Muscle Phenotypes of Non-Human Primates following a Long-Term High Fat/Sugar Diet

Mitochondrial biogenesis and destruction in skeletal muscle are coordinated by distinct signaling pathways that are influenced by internal and exogenous variables including, but not limited to, muscle phenotype, physical activity, dietary composition, or drug administration. Previously we found that long-term resveratrol administration (up to 480 mg/day) ameliorates the slow-to-fast phenotypic shift in soleus muscles and promotes the expression in slow myosin heavy chain in the mixed plantaris muscle of non-human primates consuming a high fat/sugar (HFS) diet. Here, we expand on these earlier findings by examining whether mitochondrial content and the markers that dictate their biogenesis and mitophagy/autophagy are similarly affected by HFS and/or influenced by resveratrol while consuming this diet (HFSR). Compared to controls (n = 9), there was a ∼20-25% decrease in mitochondrial content in HFS (n = 8) muscles as reflected in the COX2- and CYTB-to-GAPDH ratios using PCR analysis, which was blunted by resveratrol in HFSR (n = 7) soleus and, to a lesser degree, in plantaris muscles. A ∼1.5 and 3-fold increase in Rev-erb-α protein was detected in HFSR soleus and plantaris muscles compared to controls, respectively. Unlike in HFSR animals, HFS soleus and plantaris muscles exhibited a ∼2-fold elevation in phosphor-AMPKα (Thr172). HFS soleus muscles had elevated phosphorylated-to-total TANK binding protein-1 (TBK1) ratio suggesting an enhancement in mito/autophagic events. Taken together, resveratrol appears to blunt mitochondrial losses with a high fat/sugar diet by tempering mito/autophagy rather than promoting mitochondrial biogenesis, suggesting that the quantity of daily resveratrol supplement ingested and/or its long-term consumption are important considerations.Supplemental data for this article is available online at http://dx.doi.org/ .

Heart failure in diabetes

Heart failure and cardiovascular disorders represent the leading cause of death in diabetic patients. Here we present a systematic review of the main mechanisms underlying the development of diabetic cardiomyopathy. We also provide an excursus on the relative contribution of cardiomyocytes, fibroblasts, endothelial and smooth muscle cells to the pathophysiology of heart failure in diabetes. After having described the preclinical tools currently available to dissect the mechanisms of this complex disease, we conclude with a section on the most recent updates of the literature on clinical management.

Untargeted Metabolomic Characteristics of Skeletal Muscle Dysfunction in Rabbits Induced by a High Fat Diet

Simple Summary

In the present study, we performed an untargeted metabolomic analysis of skeletal muscle of rabbits and found that the skeletal muscle of rabbits fed a high-fat diet is rich in many metabolites, most of which are associated with type 2 diabetes and metabolic syndrome. In this paper, the mechanism of action of these metabolites in skeletal muscle and the metabolic pathways that interfere with the normal operation mechanism of the body are described and presented in the form of charts. Finally, we found that skeletal muscle-rich phospholipids, long-chain carnitine, histidine, carnosine, and tetrahydrocortisone may be potential markers for type 2 diabetes and metabolic syndrome, and may serve as potential therapeutic targets for related diseases in the future.

Abstract

Type 2 diabetes and metabolic syndrome caused by a high fat diet (HFD) have become public health problems worldwide. These diseases are characterized by the oxidation of skeletal muscle mitochondria and disruption of insulin resistance, but the mechanisms are not well understood. Therefore, this study aims to reveal how high-fat diet causes skeletal muscle metabolic disorders. In total, 16 weaned rabbits were randomly divided into two groups, one group was fed a standard normal diet (SND) and the other group was fed a high fat diet (HFD) for 5 weeks. At the end of the five-week experiment, skeletal muscle tissue samples were taken from each rabbit. Untargeted metabolomic analysis was performed using ultra-performance liquid chromatography combined with mass spectrometry (UHPLC-MS/MS). The results showed that high fat diet significantly altered the expression levels of phospholipids, LCACs, histidine, carnosine, and tetrahydrocorticosterone in skeletal muscle. Principal component analysis (PCA) and least squares discriminant analysis (PLS-DA) showed that, compared with the SND group, skeletal muscle metabolism in HFD group was significantly up-regulated. Among 43 skeletal muscle metabolites in the HFD group, phospholipids, LCACs, histidine, carnosine, and tetrahydrocorticosteroids were identified as biomarkers of skeletal muscle metabolic diseases, and may become potential physiological targets of related diseases in the future. Untargeted metabonomics analysis showed that high-fat diet altered the metabolism of phospholipids, carnitine, amino acids and steroids in skeletal muscle of rabbits. Notably, phospholipids, LCACs, histidine, carnopeptide, and tetrahydrocorticosteroids block the oxidative capacity of mitochondria and disrupt the oxidative capacity of glucose and the fatty acid-glucose cycle in rabbit skeletal muscle.

Cardiometabolic Syndrome: An Update on Available Mouse Models

Cardiometabolic syndrome (CMS), a disease entity characterized by abdominal obesity, insulin resistance (IR), hypertension, and hyperlipidemia, is a global epidemic with approximately 25% prevalence in adults globally. CMS is associated with increased risk for cardiovascular disease (CVD) and development of diabetes. Due to its multifactorial etiology, the development of several animal models to simulate CMS has contributed significantly to the elucidation of the disease pathophysiology and the design of therapies. In this review we aimed to present the most common mouse models used in the research of CMS. We found that CMS can be induced either by genetic manipulation, leading to dyslipidemia, lipodystrophy, obesity and IR, or obesity and hypertension, or by administration of specific diets and drugs. In the last decade, the ob/ob and db/db mice were the most common obesity and IR models, whereas Ldlr-/- and Apoe-/- were widely used to induce hyperlipidemia. These mice have been used either as a single transgenic or combined with a different background with or without diet treatment. High-fat diet with modifications is the preferred protocol, generally leading to increased body weight, hyperlipidemia, and IR. A plethora of genetically engineered mouse models, diets, drugs, or synthetic compounds that are available have advanced the understanding of CMS. However, each researcher should carefully select the most appropriate model and validate its consistency. It is important to consider the differences between strains of the same animal species, different animals, and most importantly differences to human when translating results.

Sargassum fusiforme together with turmeric extract and pomegranate peel extract alleviates obesity in high fat-fed C57BL/6J mice

Sargassum fusiforme, a nutritious edible brown alga, has been widely suggested to play an important role in the development of functional food because of its multiple biological activities. The aim of this study was to explore the anti-obesity effect of the combination of Sargassum fusiforme with extracts of fruit and vegetable by comparing the effects of Sargassum fusiforme (S), Sargassum fusiforme together with pomegranate peel extract (SP), Sargassum fusiforme together with turmeric extract (ST) and Sargassum fusiforme together with turmeric extract and pomegranate peel extract (C) on diet-induced obese C57BL/6J mice. Long-term consumption of a high-fat diet can lead to high levels of blood lipid, increase adipocyte size, and cause lipid metabolism dysfunction and gut microbiota dysbiosis. According to the results of the experiments, SP and ST were more effective in reducing lipid levels and fat accumulation than S; and, C exhibited the strongest efficacy compared with the other three supplements. ST and C also regulated adipocytokines and had significant effects on the gene expression of lipid metabolism. We also found that C alleviated the imbalance of intestinal flora caused by a high-fat diet to a certain extent. In conclusion, SP, ST and C have anti-obesity potentials, which can be used as alternative ingredients in the formula of functional food for obese people.

Effect of Long-Term Continuous Light Exposure and Western Diet on Adropin Expression, Lipid Metabolism, and Energy Homeostasis in Rats

Long-term continuous light exposure (CL) and western diet (WD) effects on Adropin expression, RORα, and Rev-erb-α nuclear receptors and energy homeostasis were studied in rats. Thirty-two male Wistar rats (250-290 g) were enrolled for 3 months in the following groups (n = 8/group): (a) Normal control group (NC), (b) CL group, (c) WD group, and (d) CL + WD group. Then, indirect calorimetry and food intake (FI) were measured. Finally, Adropin, hormone-sensitive lipase (HSL), adipocyte triglyceride lipase (ATGL), and free fatty acids (FFA) were measured. Additionally, the histopathology and gene expression of Enho, RORα, and Rev-erb-α genes were done. The CL alone elevated the Adropin plasma level and gene expression, increased RORα expression, and decreased the Rev-erb-α nuclear receptor expression mainly in the liver and kidney. Besides, CL increased the total energy expenditure (TEE) and decreased the respiratory quotient. WD alone or in combination with the CL reversed gene expression of Enho, RORα, and Rev-erb-α. Combined CL and WD increased the TEE, reduced the food intake, increased the ATGL, and reduced the Adropin level in addition to widespread degenerative changes in the liver, spleen, and renal tissues. The deleterious effects of CL and WD on energy homeostasis may include Adropin with the involvement of the RORα and Rev-erb-α nuclear receptors.

The effect of the high-fat diet supplemented with various forms of chromium on rats body composition, liver metabolism and organ histology Cr in liver metabolism and histology of selected organs

BACKGROUND

In the present study, we hypothesized that feeding rats a high-fat diet negatively affects liver metabolism and function and disturbs the histology of some internal organs. We also postulated that there is a form of chromium whose administration alleviates the negative effects of a high-fat diet in rats.

METHODS

To verify the hypotheses, we tested the effect of various forms of chrome (picolinate - Cr-Pic, Chromium(III)-methionine complex - Cr-Met, and chrome nanoparticles - Cr-NPs) applied in the recommended amount of 0.3 mg/kg of BW on growth parameters, body fat, liver metabolism and functional disorders, and histological parameters of selected internal organs in rats fed a standard (S) or high-fat diet (F). The experiment was conducted on 56 male outbred Wistar rats (Rattus norvegicus. Cmdb:WI) randomly divided into eight experimental groups. For eight weeks the rats received a standard or high-fat diet, without Cr or with Cr at 0.3 mg/kg diet in the form of Cr-Pic, Cr-Met or Cr-NPs.

RESULTS AND CONCLUSION

The use of a F diet disrupted the lipid-carbohydrate profile, worsened liver metabolism and function, reduced the expression of hepatic PPAR-α and leaded to negative changes in the histological image of internal organs - liver, kidneys and pancreas. The 8-week use of an chromium supplement in a F diet, regardless of the form used, did not improve the ratio of fat tissue to lean tissue, worsened liver function and negatively affected on the histological image of the liver, kidneys and pancreas. However, the most negative changes in lipid-carbohydrate metabolism and liver functioning were observed with CrNPs supplementation.

Effect of bee bread on some biochemical parameters and skeletal muscle histology of high-fat diet-induced obese Sprague-Dawley rats

The effect of bee bread (BB) on the biochemical parameters-body weights, calorie intake, Lee obesity indices, serum amylase, aspartate and alanine amino transferases, skeletal muscle activities of creatine kinase, superoxide dismutase, glutathione peroxidase, catalase, malondialdehyde, glutathione-S-transferase, total antioxidant activity, endogenous secretory receptor for advanced glycation end products (esRAGE), and muscle histology of high-fat diet (HFD) obese rats-was studied. Thirty-six male Sprague-Dawley rats were divided into six groups: Control: received rat feed and water (1 ml/kg); HFD: received HFD and water (1 ml/kg): BB or orlistat preventive: received HFD and BB (0.5 g/kg) or HFD and orlistat (10 mg/kg; weeks 1 to 12); BB or orlistat treated: received HFD and BB (0.5 g/kg) or HFD and orlistat (10 mg/kg; weeks 6 to 12), following obesity induction. At week 12, HFD group had altered (p < .05) levels of some biochemical parameters which were modulated by BB and corroborated by muscle histology. PRACTICAL APPLICATIONS: Obesity is a global health problem, which prevalence has continued to be on the increase due to changes in lifestyle and dietary behavior. Additionally, the approaches that currently are being used for the treatment of this disease have not been able to successfully reverse obesity and its associated complications. The current study which showed that bee bread prevented or attenuated obesity-induced muscular pathology, places bee bread in the spotlight as a functional food that could be useful in preventing or mitigating obesity-induced muscular pathology.

A Mitochondrial Approach to Cardiovascular Risk and Disease

BACKGROUND

Cardiovascular diseases (CVDs) are a leading risk factor for mortality worldwide and the number of CVDs victims is predicted to rise through 2030. While several external parameters (genetic, behavioral, environmental and physiological) contribute to cardiovascular morbidity and mortality; intrinsic metabolic and functional determinants such as insulin resistance, hyperglycemia, inflammation, high blood pressure and dyslipidemia are considered to be dominant factors.

METHODS

Pubmed searches were performed using different keywords related with mitochondria and cardiovascular disease and risk. In vitro, animal and human results were extracted from the hits obtained.

RESULTS

High cardiac energy demand is sustained by mitochondrial ATP production, and abnormal mitochondrial function has been associated with several lifestyle- and aging-related pathologies in the developed world such as diabetes, non-alcoholic fatty liver disease (NAFLD) and kidney diseases, that in turn can lead to cardiac injury. In order to delay cardiac mitochondrial dysfunction in the context of cardiovascular risk, regular physical activity has been shown to improve mitochondrial parameters and myocardial tolerance to ischemia-reperfusion (IR). Furthermore, pharmacological interventions can prevent the risk of CVDs. Therapeutic agents that can target mitochondria, decreasing ROS production and improve its function have been intensively researched. One example is the mitochondria-targeted antioxidant MitoQ10, which already showed beneficial effects in hypertensive rat models. Carvedilol or antidiabetic drugs also showed protective effects by preventing cardiac mitochondrial oxidative damage.

CONCLUSION

This review highlights the role of mitochondrial dysfunction in CVDs, also show-casing several approaches that act by improving mitochondrial function in the heart, contributing to decrease some of the risk factors associated with CVDs.

Resveratrol prevents sarcopenic obesity by reversing mitochondrial dysfunction and oxidative stress via the PKA/LKB1/AMPK pathway

Background: The concept of sarcopenic obesity refers to low muscle mass coupled with high adiposity in older adults. Sarcopenic obesity is a new medical challenge that imposes tremendous financial burdens on healthcare authorities worldwide. This study investigated the effects of resveratrol on high-fat diet-induced sarcopenic obesity in aged rats and palmitate acid-induced muscle atrophy in L6 myotubes and explored the underlying mechanisms.

Results: In vivo, resveratrol prevented muscle loss and myofiber size decrease, improved grip strength and abolished excessive fat accumulation. In vitro, resveratrol inhibited the palmitate acid-mediated reductions in myosin heavy chain content and myotube diameter. Moreover, resveratrol ameliorated mitochondrial dysfunction and oxidative stress, leading to an improvement in protein metabolism and contributing to the prevention of muscle atrophy. Furthermore, the protective effects of resveratrol on mitochondrial function, oxidative stress and muscle atrophy were abolished by PKA siRNA, LKB1 siRNA and AMPK siRNA transfection in vitro.

Conclusions: Resveratrol prevented high-fat diet-induced muscle atrophy in aged rats by reversing mitochondrial dysfunction and oxidative stress, which was partially mediated by the PKA/LKB1/AMPK pathway. These findings indicate that resveratrol might have potential uses for the prevention and treatment of sarcopenic obesity.

Precision Medicine in Lifestyle Medicine: The Way of the Future?

Precision medicine has captured the imagination of the medical community with visions of therapies precisely targeted to the specific individual's genetic, biological, social, and environmental profile. However, in practice it has become synonymous with genomic medicine. As such its successes have been limited, with poor predictive or clinical value for the majority of people. It adds little to lifestyle medicine, other than in establishing why a healthy lifestyle is effective in combatting chronic disease. The challenge of lifestyle medicine remains getting people to actually adopt, sustain, and naturalize a healthy lifestyle, and this will require an approach that treats the patient as a person with individual needs and providing them with suitable types of support. The future of lifestyle medicine is holistic and person-centered rather than technological.

Effect of Dietary Silk Peptide on Obesity, Hyperglycemia, and Skeletal Muscle Regeneration in High-Fat Diet-Fed Mice

Obesity is associated with excess body fat accumulation that can cause hyperglycemia and reduce skeletal muscle function and strength, which characterize the development of sarcopenic obesity. In this study, we aimed to determine the mechanism whereby acid-hydrolyzed silk peptide (SP) prevents high-fat diet (HFD)-induced obesity and whether it regulates glucose uptake and muscle differentiation using in vivo and in vitro approaches. Our findings demonstrate that SP inhibits body mass gain and the expression of adipogenic transcription factors in visceral adipose tissue (VAT). SP also had an anti-diabetic effect in VAT and skeletal muscle because it upregulated glucose transporter type 4 (GLUT4) and uncoupling protein 3 (UCP3) expression. Furthermore, SP reduced ubiquitin proteasome and promoted myoblast determination protein 1 (MyoD)/myogenic factor 4 (myogenin) expression, implying that it may have potential for the treatment of obesity-induced hyperglycemia and obesity-associated sarcopenia.

Modulation of the Liver Protein Carbonylome by the Combined Effect of Marine Omega-3 PUFAs and Grape Polyphenols Supplementation in Rats Fed an Obesogenic High Fat and High Sucrose Diet

Diet-induced obesity has been linked to metabolic disorders such as cardiovascular diseases andtype 2 diabetes. A factor linking diet to metabolic disorders is oxidative stress, which can damagebiomolecules, especially proteins. The present study was designed to investigate the effect of marineomega-3 polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid (EPA) and docosahexaenoic acid(DHA)) and their combination with grape seed polyphenols (GSE) on carbonyl-modified proteins fromplasma and liver in Wistar Kyoto rats fed an obesogenic diet, namely high-fat and high-sucrose (HFHS)diet. A proteomics approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labelling of proteincarbonyls, visualization of FTSC-labelled protein on 1-DE or 2-DE gels, and protein identification byMS/MS was used for the protein oxidation assessment. Results showed the efficiency of the combinationof both bioactive compounds in decreasing the total protein carbonylation induced by HFHS diet in bothplasma and liver. The analysis of carbonylated protein targets, also referred to as the 'carbonylome',revealed an individual response of liver proteins to supplements and a modulatory effect on specificmetabolic pathways and processes due to, at least in part, the control exerted by the supplements on theliver protein carbonylome. This investigation highlights the additive effect of dietary fish oils and grapeseed polyphenols in modulating in vivo oxidative damage of proteins induced by the consumption ofHFHS diets.

Food deprivation during active phase induces skeletal muscle atrophy via IGF-1 reduction in mice

Skeletal muscle mass is largely influenced by nutritional status and physical activity. Although feeding at specific times of the day (time-restricted feeding, TRF) modulates obesity and other metabolic functions, its effects on skeletal muscles remain unclear. We explored the effects of feeding mice only during the inactive (daytime feeding, DF) or active (nighttime feeding, NF) phases for one week. Daytime feeding did not abolish the nocturnal activity rhythm, although total daily activity was reduced in these mice. Temporal expression of the circadian clock genes, Per2 and Rev-erbα, became synchronized to the feeding cycle in the liver, but not in skeletal muscle. Skeletal muscle mass, grip strength, and cross-sectional area were significantly lower in DF, than in NF mice, although DF increased body weight gain and lipid accumulation. Expression of the atrophy-related ubiquitin ligases, Atrogin-1 and Murf1 and the autophagy-related genes, Lc3b and Bnip3, was induced during the active phase in the gastrocnemius muscles of DF, compared with those of NF mice. Plasma IGF-1 concentrations and Igf-1 expression in the livers and gastrocnemius muscles during the active phase were lower in DF, than in NF mice. Furthermore, exogenous IGF-1 injection significantly suppressed DF-induced reduction in gastrocnemius muscle mass, which might at least partly explain the association between decreased plasma IGF-1 concentrations and reductions in the skeletal muscle mass of DF mice. These findings suggest that feeding only during the inactive phase reduces skeletal muscle mass via a decrease in plasma IGF-1 concentrations during the active phase.

Evaluating the Impact of Different Hypercaloric Diets on Weight Gain, Insulin Resistance, Glucose Intolerance, and its Comorbidities in Rats

Animal experimentation has a long history in the study of metabolic syndrome-related disorders. However, no consensus exists on the best models to study these syndromes. Knowing that different diets can precipitate different metabolic disease phenotypes, herein we characterized several hypercaloric rat models of obesity and type 2 diabetes, comparing each with a genetic model, with the aim of identifying the most appropriate model of metabolic disease. The effect of hypercaloric diets (high fat (HF), high sucrose (HSu), high fat plus high sucrose (HFHSu) and high fat plus streptozotocin (HF+STZ) during different exposure times (HF 3 weeks, HF 19 weeks, HSu 4 weeks, HSu 16 weeks, HFHSu 25 weeks, HF3 weeks + STZ) were compared with the Zucker fatty rat. Each model was evaluated for weight gain, fat mass, fasting plasma glucose, insulin and C-peptide, insulin sensitivity, glucose tolerance, lipid profile and liver lipid deposition, blood pressure, and autonomic nervous system function. All animal models presented with insulin resistance and dyslipidemia except the HF+STZ and HSu 4 weeks, which argues against the use of these models as metabolic syndrome models. Of the remaining animal models, a higher weight gain was exhibited by the Zucker fatty rat and wild type rats submitted to a HF diet for 19 weeks. We conclude that the latter model presents a phenotype most consistent with that observed in humans with metabolic disease, exhibiting the majority of the phenotypic features and comorbidities associated with type 2 diabetes in humans.

Effect of a Single Bout of Exercise on Autophagy Regulation in Skeletal Muscle of High-Fat High-Sucrose Diet-Fed Mice

Background

Autophagy maintains metabolic homeostasis of muscles, and its impairment may cause muscle dysfunction. Exercise can improve muscle dysfunction induced by long-term high-fat diet. This study aimed to explore the association of autophagy with impaired muscle dysfunction in obese conditions and investigate its relationship with exercise-induced muscle function improvement.

Methods

Male C57BL/6 mice (n=24) were randomly assigned to four groups: low-fat diet+plain water feeding sedentary (CON) group, low-fat diet+plain water feeding exercise (CON+EX) group, high-fat high-sucrose (HFHS) diet-fed sedentary group, and HFHS diet-fed exercise (HFHS+EX) group, and subjected to a single bout of exhaustive exercise.

Results

HFHS diet resulted in shorter hanging time, reduced grip force, and lower exhaustion time and distance, and decreased lean mass per body weight. Moreover, in the soleus, which is chosen as a representative red (oxidative) muscle, LC3II/LC3I ratio, P62, and Bnip3 levels were altered following the HFHS diet, and were negatively correlated with muscle performance parameters; exercise significantly decreased the LC3II/LC3 ratio while P62 increased with HFHS diet. Autophagy-related protein changes were not found in the white (glycolytic) gastrocnemius.

Conclusion

The study revealed that 20-week HFHS diet causes a significant increase in body weight and fat mass, along with a decrease in muscle function. Autophagy-related LC3 and P62 protein expression was negatively correlated with muscle function, and they were reduced when a single bout of exercise stimulated the soleus of obese mice. However, no change of autophagy-related proteins was seen in the gastrocnemius.

How Western Diet And Lifestyle Drive The Pandemic Of Obesity And Civilization Diseases

Westernized populations are plagued by a plethora of chronic non-infectious degenerative diseases, termed as "civilization diseases", like obesity, diabetes, cardiovascular diseases, cancer, autoimmune diseases, Alzheimer's disease and many more, diseases which are rare or virtually absent in hunter-gatherers and other non-westernized populations. There is a growing awareness that the cause of this amazing discrepancy lies in the profound changes in diet and lifestyle during recent human history. This paper shows that the transition from Paleolithic nutrition to Western diets, along with lack of corresponding genetic adaptations, cause significant distortions of the fine-tuned metabolism that has evolved over millions of years of human evolution in adaptation to Paleolithic diets. With the increasing spread of Western diet and lifestyle worldwide, overweight and civilization diseases are also rapidly increasing in developing countries. It is suggested that the diet-related key changes in the developmental process include an increased production of reactive oxygen species and oxidative stress, development of hyperinsulinemia and insulin resistance, low-grade inflammation and an abnormal activation of the sympathetic nervous system and the renin-angiotensin system, all of which play pivotal roles in the development of diseases of civilization. In addition, diet-related epigenetic changes and fetal programming play an important role. The suggested pathomechanism is also able to explain the well-known but not completely understood close relationship between obesity and the wide range of comorbidities, like type 2 diabetes mellitus, cardiovascular disease, etc., as diseases of the same etiopathology. Changing our lifestyle in accordance with our genetic makeup, including diet and physical activity, may help prevent or limit the development of these diseases.