Diet, obesity and diabetes: a current update

Overview of the therapeutic efficacy of marine fish oil in managing obesity and associated metabolic disorders

In the present scenario, obesity is a challenging health problem and its prevalence along with comorbidities are on the rise around the world. Ingestion of fish becomes trendy in daily meals. Recent research has shown that marine fish oil (FO) (found in tuna, sardines, and mackerel) may offer an alternative method for reducing obesity and problems associated with it. Marine FO rich in long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) and long-chain omega-6 polyunsaturated fatty acids (LC n-6 PUFA) plays an important role in reducing abnormalities associated with the metabolic syndrome and has a variety of disease-fighting properties, including cardioprotective activity, anti-atherosclerotic, anti-obesity, anti-cancer, anti-inflammatory activity. Studies in rodents and humans have indicated that LC n-3 PUFA potentially elicit a number of effects which might be useful for reducing obesity, including suppression of appetite, improvements in circulation, enhanced fat oxidation, energy expenditure, and reduced fat deposition. This review discusses the interplay between inflammation and obesity, and their subsequent regulation via the beneficial role of marine FO, suggesting an alternative dietary strategy to ameliorate obesity and obesity-associated chronic diseases.

Association Between Serum Vitamin D Levels and Body Mass Index Status: A Cross-Sectional Study at King Khalid Hospital, Jeddah, Saudi Arabia, From 2019 to 2020

Introduction Low vitamin D levels have been associated more with overweight and obese people in previous studies. One of the possible explanations behind this association is the lipophilic property of vitamin D that causes the vitamin to deposit in adipose tissue and reduces the serum concentration of the vitamin, which still warrants further evaluation. Objective This study estimated the association between serum vitamin D levels and body mass index (BMI) among male patients in Jeddah, Saudi Arabia. Methods This is a cross-sectional study of male patients that was carried out in King Khalid Hospital, Jeddah, Saudi Arabia. Patients were included between October 2019 and November 2020. Results We concluded that almost half of the patients, 1,132 (48.3%), had adequate vitamin D, followed by 773 (33%) with vitamin D inadequacy, and only 288 (12.3%) had vitamin D deficiency. There was a significant relationship between age and vitamin D levels; younger people had lower vitamin D levels compared to older people (p<0.001). It was found that there was no significant relationship between BMI categories and vitamin D levels (p>0.05). Conclusion According to the findings of the current study, there was no discernible relationship between serum vitamin D levels and BMI. However, there was a substantial correlation between age and vitamin D levels, with younger age groups having lower amounts than older individuals. Future studies should adopt a prospective design encompassing multiple centers and preferably include the risk factors for developing vitamin D deficiency, such as sun exposure, dietary habits, comorbidities, etc. Such studies can provide a more accurate assessment of the association between BMI and vitamin D levels.

Fucoxanthin: A Promising Phytochemical on Diverse Pharmacological Targets

Fucoxanthin (FX) is a special carotenoid having an allenic bond in its structure. FX is extracted from a variety of algae and edible seaweeds. It has been proved to contain numerous health benefits and preventive effects against diseases like diabetes, obesity, liver cirrhosis, malignant cancer, etc. Thus, FX can be used as a potent source of both pharmacological and nutritional ingredient to prevent infectious diseases. In this review, we gathered the information regarding the current findings on antimicrobial, antioxidant, anti-inflammatory, skin protective, anti-obesity, antidiabetic, hepatoprotective, and other properties of FX including its bioavailability and stability characteristics. This review aims to assist further biochemical studies in order to develop further pharmaceutical assets and nutritional products in combination with FX and its various metabolites.

Inhibition of γ-secretase in adipocytes leads to altered IL-6 secretion and adipose inflammation

Adipocyte-mediated inflammatory signalling has been proposed to alter adipose physiology in obesity and Type 2 diabetes mellitus. Novel targets for alteration of inflammatory signalling are needed to improve obesity-related outcomes. The γ-secretase enzyme complex has been suggested to play a role both in adipocyte function as well as in immune regulation. We hypothesized that adipocyte-specific γ-secretase inhibition could alter the inflammatory makeup of adipose tissue. We found that genetic blockade of γ-secretase in adipocytes leads to a decrease in EMR1 (F4/80) expression, as a marker of macrophage presence, in adipose tissue without changes in expression of markers of other inflammatory cell types. To explore the mechanism by which adipocytes can alter macrophage function in vitro, fully differentiated 3T3-L1 adipocytes were treated with a γ-secretase inhibitor in the presence of lipopolysaccharide (LPS) and transcription of IL6 and ccl2 (MCP1) were quantified. IL-6 expression and secretion were significantly inhibited by γ-secretase blockade, with little effect on MCP1. Preconditioned media from 3T3-L1 adipocytes treated with a γ-secretase inhibitor also alters macrophage activation but did not affect macrophage translocation in vitro. Therefore, γ-secretase inhibition in fully differentiated adipocytes can alter IL-6 signalling to macrophages, consistent with our hypothesis that that γ-secretase is involved in adipocyte-initiated inflammatory signalling cascades.

Polyphenols and obesity prevention: critical insights on molecular regulation, bioavailability and dose in preclinical and clinical settings

Obesity represents one of the most important public health challenges of the 21st century and is characterized by a multifactorial etiology in which environmental, behavioral, metabolic, and genetic factors work together. Despite the rapid increase in prevalence of obesity in the last decades, especially in children, it remains a preventable disease. To battle obesity a multisector approach promoting healthier lifestyle in terms of physical activity and nutrition is needed. Specifically, biologically active dietary compounds, as polyphenols, are able to modulate the expression of genes involved in the development and progression of obesity and its comorbidities as demonstrated by multiple studies using different obesity models. However, human studies focusing on the transcriptomic modulation by polyphenols in obese patients are still limited and do not often recapitulate the results obtained in preclinical setting likely due to the underestimation of some variables such as bioavailability, dose and form (native vs. metabolized) of polyphenols used. The aim of this review is to summarize the state-of-art of nutrigenomic in vitro, in vivo and ex vivo studies as well as clinical trials based on dietary polyphenols to fight obesity. We also critical discuss the variables to be considered to fill the gap between preclinical and clinical settings.

In Vitro Antidiabetic and Antiobesity Activities of Traditional Kochujang and Doenjang and Their Components

In this study we investigated the antidiabetic and antiobesity effects of aqueous ethanol extracts of traditional kochujang and doenjang. The average α-glucosidase inhibitory activity and adipogenesis inhibitory activity for the kochujang samples were 29.6% and 20.8%, respectively, while those of the doenjang samples were 46.3% and 11.6%, respectively. Therefore, antidiabetic activity is high in doenjang and antiobesity activity is high in kochujang. Kochujang and doenjang components responsible for suppressing the functional effects were investigated by metabolomic analysis. For kochujang, p-coumaric acid, N6,N6,N6-trimethyllysine, threonine, and methionine positively correlated with inhibition of adipogenesis activity, whereas for doenjang, betaine and betaine aldehyde were thought to be responsible for the antidiabetic effects. As p-coumaric acid and betaine were the most probable candidates with functional effects, these two compounds were selected for further analysis. Inhibition of adipogenesis was shown to be 14.0±1.85% for betaine chloride and 38.3±3.27% for p-coumaric acid, suggesting that p-coumaric acid is more effective than betaine against obesity. However, betaine exhibited higher α-glucosidase inhibitory activity than p-coumaric acid. Our results suggest that both kochujang and doenjang can be used against diabetes and obesity. However, clinical trials are necessary to support these results.

RNA-seq analysis of the transcriptome of the liver of cynomolgus monkeys with type 2 diabetes

Genetic and environmental factors such as high-fat diet are involved in the development of type 2 diabetes mellitus (T2DM). Cynomolgus monkey shares similar genetic makeup, tissue structures, physiology and metabolic function to human. This study aimed to establish T2DM model in cynomolgus monkey and compare expression profiles of hepatic genes and their associated pathways in normal cynomolgus monkeys and those with T2DM. We employed RNA-seq technique and identified 1451 differentially expressed genes (DEGs) with a false discovery rate (FDR) of 0.1% between normal and T2DM animals. KEGG pathway analysis revealed that DEGs were associated with 12 KEGG pathways (P < 0.05). Two of these pathways were associated with metabolism and five were related to immunity. Unexpected, we found ECM-receptor interaction pathway. In conclusion, our data suggest that three major pathways may be implicated in the development of T2DM, including steroid biosynthesis, immune response and ECM. Further characterization of these pathways may provide new targets for the prevention and therapy of T2DM.

Antidiabetic and antiobesity effects of SGLT2 inhibitor ipragliflozin in type 2 diabetic mice fed sugar solution

Obesity due to excessive calorie intake is a known aggravating factor contributing to the development and progression of type 2 diabetes. Recently, excessive intake of sugar-sweetened beverages has presented challenges in stemming the tide of obesity. Here, we investigated the possible effects of sugar solution intake on the antidiabetic effects of sodium-glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin in type 2 diabetic mice that were fed ordinary drinking water, water + glucose solution, or water + sucrose solution. Under all feeding conditions, all mice exhibited type 2 diabetic symptoms, including hyperglycemia, hyperinsulinemia, and obesity; ipragliflozin subsequently improved these symptoms through increases in urinary glucose excretion. Effective dose of and response to ipragliflozin for diabetes improvement did not significantly differ by feeding condition. Further, under all feeding conditions, ipragliflozin administration resulted in significantly increased intake of both water and sugar solutions in association with increased urine volume resulting from increased urinary glucose excretion. In sugar solution-fed diabetic mice, ipragliflozin administration tended to slightly increase the proportion of sugar solution intake in total drinking volume, although not significantly so. In addition, ipragliflozin significantly decreased calorie balance, as calculated using calorie intake from food and sugar solution and calorie excretion via urinary glucose excretion. Our observation that the antidiabetic and antiobesity effects of the SGLT2 inhibitor ipragliflozin were not greatly affected by sugar solution intake in type 2 diabetic mice suggests that, in a clinical setting, ipragliflozin will remain an effective treatment for type 2 diabetic patients with excessive intake of carbohydrates.

Serum metabolomics reveals the mechanistic role of functional foods and exercise for obesity management in rats

Obesity is one of the independent risk factors for several health problems, leading to metabolic perturbations and for which analytical approaches i.e., "metabolomics" is needed to monitor the underlying metabolic changes. In this study, obesity associated changes were assessed via serum metabolites analysis of obese rats fed on high fat diet. Obese rats were subsequently treated with different functional foods used for obesity management including pomegranate, grapefruit, and red cabbage in parallel to swimming exercise. Serum samples were analyzed using gas chromatography-mass spectrometry (GC-MS) followed by multivariate data analysis to classify samples and determine if such treatments can help revert obesity related metabolic changes back to normal status. Results led to the identification of several novel metabolites biomarkers for obesity related to lipids, amino acids and central tricarboxylic acid (TCA) pathways. Distinct variations in metabolite levels were recorded in obese rats compared to normal ones including l-aspartic, l-alanine, l-glutamine, l-glycine, phenylethanolamine, α-aminobutyric acid and β-hydroxybutyric acid. Metabolomics approach developed herein provides novel insight onto the metabolic disturbances associated with obesity, which will assist in future drug design that can help mitigate against such changes.

Mulberry anthocyanin extract regulates glucose metabolism by promotion of glycogen synthesis and reduction of gluconeogenesis in human HepG2 cells

Mulberry has been demonstrated to possess important biological activities such as antioxidation and antiinflammation. However, research on the ability of mulberry for diabetes improvement mainly focuses on the leaves and less on the fruit. This study showed that a mulberry anthocyanin extract (MAE) had a significant effect on increasing the glucose consumption in HepG2 cells. The MAE enhanced the glycogen content and suppressed levels of glucose production. The enzyme activities of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) were decreased in HepG2 cells after MAE treatment due to PPARγ coactivator 1α (PGC-1α) and forkhead box protein O1 (FOXO1) inhibition. Moreover, the phosphorylation of protein kinase B (AKT) and glycogen synthase kinase-3β (GSK-3β) was increased by the MAE, leading to an expression enhancement of glycogen synthase 2 (GYS2). And this effect was blocked by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002. In summary, our results suggested that the MAE regulates glucose metabolism by activating the PI3K/AKT pathway that relates to glycogen synthesis as well as through the inhibition of key molecules that promote gluconeogenesis.

Adipocyte-specific blockade of gamma-secretase, but not inhibition of Notch activity, reduces adipose insulin sensitivity

Objective

As the obesity pandemic continues to expand, novel molecular targets to reduce obesity-related insulin resistance and Type 2 Diabetes (T2D) continue to be needed. We have recently shown that obesity is associated with reactivated liver Notch signaling, which, in turn, increases hepatic insulin resistance, opening up therapeutic avenues for Notch inhibitors to be repurposed for T2D. Herein, we tested the systemic effects of γ-secretase inhibitors (GSIs), which prevent endogenous Notch activation, and confirmed these effects through creation and characterization of two different adipocyte-specific Notch loss-of-function mouse models through genetic ablation of the Notch transcriptional effector Rbp-Jk (A-Rbpj) and the obligate γ-secretase component Nicastrin (A-Nicastrin).

Methods

Glucose homeostasis and both local adipose and systemic insulin sensitivity were examined in GSI-treated, A-Rbpj and A-Nicastrin mice, as well as vehicle-treated or control littermates, with complementary in vitro studies in primary hepatocytes and 3T3-L1 adipocytes.

Results

GSI-treatment increases hepatic insulin sensitivity in obese mice but leads to reciprocal lowering of adipose glucose disposal. While A-Rbpj mice show normal body weight, adipose development and mass and unchanged adipose insulin sensitivity as control littermates, A-Nicastrin mice are relatively insulin-resistant, mirroring the GSI effect on adipose insulin action.

Conclusions

Notch signaling is dispensable for normal adipocyte function, but adipocyte-specific γ-secretase blockade reduces adipose insulin sensitivity, suggesting that specific Notch inhibitors would be preferable to GSIs for application in T2D.

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γ-secretase inhibitors (GSIs) are non-specific inhibitors of Notch signaling.

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GSI-treatment of obese mice increases hepatic, but lowers adipose insulin sensitivity.

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Adipocyte-specific Notch inhibition does not affect adipose mass or glucose homeostasis.

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Adipocyte-specific γ-secretase blockade reduces adipose insulin sensitivity.

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Specific Notch inhibitors may be preferable to GSIs for treatment of Type 2 Diabetes.

The effect of physical activity on serum IL-6 and vaspin levels in late elementary school children

[Purpose]

This study investigates the effects of physical activity on serum IL-6 and vaspin in late elementary school children.

[Methods]

Those who (n = 220) completed the 7-day physical activity monitoring underwent a second round of measurements including body fat, serum glucose and insulin, and serum IL-6 and vaspin. One way ANOVAs followed by LSD post hoc tests were used to test for significant differences in dependent variables across incremental physical activity levels at p=0.05. Multivariate stepwise linear regression analyses were used to determine significant predictors for serum IL-6 and vaspin levels at p=0.05.

[Results]

The results showed significant inverse linear trends for body fat parameters across incremental physical activity levels (from low to high); the lower the body fat, the higher the physical activity levels. On the other hand, there were no significant linear trends for insulin resistance markers or dietary intake across incremental physical activity levels. Multiple stepwise linear regression analyses were used to determine significant predictors for individual variations in serum IL-6 and vaspin in the study population. We found that body mass index (p=0.002) and low- and moderate-intensity physical activities (p=0.002 and p=0.0045, respectively) were significant determinants of serum IL-6. In addition, low- and moderate-intensity physical activities (p=0.01 & p=0.022, respectively) were significant determinants of serum vaspin levels in this study population.

[Conclusion]

In summary, the findings of the current study suggest that promotion of physical activity along with a healthy diet should be key components of lifestyle interventions to improve serum cytokine profiles associated with insulin resistance syndrome in late elementary school children.

Obesity: interactions of genome and nutrients intake

Obesity has become one of the major public health problems all over the world. Recent novel eras of research are opening for the effective management of obesity though gene and nutrient intake interactions because the causes of obesity are complex and multifactorial. Through GWASs (genome-wide association studies) and genetic variations (SNPs, single nucleotide polymorphisms), as the genetic factors are likely to determine individuals’ obesity predisposition. The understanding of genetic approaches in nutritional sciences is referred as “nutrigenomics”. Nutrigenomics explores the interaction between genetic factors and dietary nutrient intake on various disease phenotypes such as obesity. Therefore, this novel approach might suggest a solution for the effective prevention and treatment of obesity through individual genetic profiles and help improve health conditions.

Extract of Ginkgo Biloba Ameliorates Streptozotocin-Induced Type 1 Diabetes Mellitus and High-Fat Diet-Induced Type 2 Diabetes Mellitus in Mice

Diabetes mellitus (DM) is caused by either destruction of pancreatic β-cells (type 1 DM) or unresponsiveness to insulin (type 2 DM). Conventional therapies for diabetes mellitus have been developed but still needs improvement. Many diabetic patients have complemented conventional therapy with alternative methods including oral supplementation of natural products. In this study, we assessed whether Ginkgo biloba extract (EGb) 761 could provide beneficial effects in the streptozotocin-induced type 1 DM and high-fat diet-induced type 2 DM murine model system. For the type 1 DM model, streptozotocin-induced mice were orally administered EGb 761 for 10 days prior to streptozotocin injection and then again administered EGb 761 for an additional 10 days. Streptozotocin-treated mice administered EGb 761 exhibited lower blood triglyceride levels, lower blood glucose levels and higher blood insulin levels compared to streptozotocin-treated mice. Furthermore, liver LPL and liver PPAR-α were increased whereas IL-1β and TNF-α were decreased in streptozotocin-injected mice treated with EGb 761 compared to mice injected with streptozotocin alone. For the type 2 DM model, mice were given high-fat diet for 60 days and then orally administered EGb 761 every other day for 80 days. We found that mice given a high-fat diet and EGb 761 showed decreased blood triglyceride levels, increased liver LPL, increased liver PPAR-α and decreased body weight compared to mice given high-fat diet alone. These results suggest that EGb 761 can exert protective effects in both type 1 and type 2 DM murine models.

Roles of physical activity and cardiorespiratory fitness on sex difference in insulin resistance in late elementary years

PURPOSE

Little is known about the potential role of lifestyle factors in sex differences in insulin resistance in late elementary school children.

METHODS

In this cross-sectional study, we compared sex differences in Tanner scales, body fat, physical activity (PA) and fitness, and insulin resistance markers in elementary school children (boys, n = 69 and girls, n = 81) aged 12-13 years. Body composition was assessed with a standardized protocol. Cardiorespiratory fitness was measured as oxygen consumption during an incremental treadmill exercise. Fasting blood samples were collected for blood chemistry assays including lipids, glucose, insulin and homeostasis model assessment for insulin resistance (HOMA-IR), leptin, and adiponectin. Daily PA was measured with an accelerometer for 7 consecutive days, and they were classified as low-, moderate-, and vigorous-PA. Independent t-tests were used to compare mean differences in the measured variables between boys and girls. There were significant sex differences in Tanner scales, body mass index, percent body fat, and waist circumference (WC).

RESULTS

Girls had significantly higher values in Tanner scales (p < 0.001) and percent body fat (p < 0.001) than boys. Boys had significantly higher values in body mass index (p = 0.019) and waist circumference (p < 0.001) than girls. Boys also had significantly higher values in VO2max (p < 0.001) and low (p < 0.001), moderate (p < 0.001), and vigorous (p < 0.001) PAs. With respect to metabolic risk factors, girls had significantly higher serum levels of triglycerides (p = 0.005), insulin (p < 0.001), and HOMA-IR (p < 0.001) and significantly lower high-density lipoprotein cholesterol (p = 0.015) than boys.

CONCLUSION

In summary, the current findings of the study showed that the increased risk for insulin resistance in girls over boys is associated with higher Tanner scale and percent body fat in conjunction with poor cardiorespiratory fitness and physical inactivity, suggesting that exercise intervention to promote physical activity and fitness is imperative for general health promotion of school children, with a special focus on girls.

Preventive medicine and the traditional concept of living in balance

Chronic diseases such as arthritis, heart disease and type 2 diabetes are becoming much more common. The cost of maintaining patients inflicted with these diseases increases yearly. These diseases were less common prior to 1970. This paper will consider several questions. How do toxic lifestyles contribute to these chronic diseases What is preventive medicine How can traditional healing help educate people about disease prevention What is the traditional concept of balance and how is it important in modern medicine The dangers of obesity are discussed in terms of inflammatory adipokine and inflammatory fat production. Mechanisms of disease causation or promotion are reviewed for heart disease, type 2 diabetes, arthritis and cancer. A preventive medicine approach to preventing or perhaps curing these diseases is given which involves treating toxic lifestyles and encouraging people to live in balance. The traditional concept of balance is explained in traditional Chinese medicine terms and in scientific terms. Yin and yang are cold and hot but can also be seen as agonist and antagonist. In addition, yin and yang can be seen as rest and exercise. When yin and yang are in balance, chi flows in the body. Chi is the flow of extracellular and intracellular signaling compounds and processes in the body. When the body is in balance, it can heal itself. The traditional concept of balance should be taught as a central principle of preventive medicine.

Effects of SGLT2 selective inhibitor ipragliflozin on hyperglycemia, hyperlipidemia, hepatic steatosis, oxidative stress, inflammation, and obesity in type 2 diabetic mice

The sodium-glucose cotransporter 2 (SGLT2) is responsible for most glucose reabsorption in the kidney and has been proposed as a novel therapeutic target for the treatment of type 2 diabetes. In the present study, the therapeutic effects of SGLT2 selective inhibitor ipragliflozin were examined in high-fat diet and streptozotocin-nicotinamide-induced type 2 diabetic mice which exhibit impaired insulin secretion, insulin resistance, hyperlipidemia, hepatic steatosis, and obesity. Single administration of ipragliflozin dose-dependently increased urinary glucose excretion, reduced blood glucose and plasma insulin levels, and improved glucose intolerance. Four-week repeated administration of ipragliflozin improved not only glucose tolerance, hyperglycemia, and hyperinsulinemia but also impaired insulin secretion, hyperlipidemia, hepatic steatosis, and obesity with a concomitant increase in urinary glucose excretion. In addition, ipragliflozin reduced plasma and liver levels of oxidative stress biomarkers (thiobarbituric acid reactive substances and protein carbonyl) and inflammatory markers (interleukin 6, tumor necrosis factor α, monocyte chemotactic protein-1, and c-reactive protein), and improved liver injury as assessed by plasma levels of aminotransferases. These results demonstrate that SGLT2 selective inhibitor ipragliflozin improves not only hyperglycemia but also diabetes/obesity-associated metabolic abnormalities in type 2 diabetic mice and suggest that ipragliflozin may be useful in treating type 2 diabetes with metabolic syndrome.

Paprika Pigments Attenuate Obesity-Induced Inflammation in 3T3-L1 Adipocytes

Obesity is related to various diseases, such as diabetes, hyperlipidemia, and hypertension. Adipocytokine, which is released from adipocyte cells, affects insulin resistance and blood lipid level disorders. Further, adipocytokine is related to chronic inflammation in obesity condition adipocyte cells. Paprika pigments (PPs) contain large amounts of capsanthin and capsorubin. These carotenoids affect the liver and improve lipid disorders of the blood. However, how these carotenoids affect adipocyte cells remains unknown. Present study examined the effects of PP on adipocytokine secretion, which is related to improvement of metabolic syndrome. In addition, suppressive effects of PP on chronic inflammation in adipocyte cells were analyzed using 3T3-L1 adipocyte cells and macrophage cell coculture experiments. PP promoted 3T3-L1 adipocyte cells differentiation upregulated adiponectin mRNA expression and secretion. Further, coculture of adipocyte and macrophage cells treated with PP showed suppressed interleukin-6 (IL-6), tumor necrosis factor- α (TNF- α ), monocyte chemotactic protein-1 (MCP-1), and resistin mRNA expression, similarly to treatment with troglitazone, which is a PPAR γ ligand medicine. Conclusion. These results suggest that PP ameliorates chronic inflammation in adipocytes caused by obesity. PP adjusts adipocytokine secretion and might, therefore, affect antimetabolic syndrome diseases.

Analysis of hepatic gene expression profile in a spontaneous mouse model of type 2 diabetes under a high sucrose diet

Both genetic factors and diabetogenic environmental factors, such as a high-sucrose diet (HSD), are involved in the development of type 2 diabetes. In this study, the Nagoya-Shibata-Yasuda (NSY) mouse, an animal model of type 2 diabetes and C3H mice used as controls, were fed a HSD, a high-fat diet (HFD) or a regular diet (RD) from weaning. In C3H mice, HFD significantly increased body weight gain, but maintained glucose tolerance. In contrast, in NSY mice, HSD resulted in increased body weight gain and liver steatosis and increased glucose intolerance to a greater extent than HFD. Furthermore, we performed DNA microarray analysis to detect differences in hepatic gene expression levels in both strains under HSD. We then performed RT-PCR analysis on selected genes to evaluate basal expression level under RD and changes under HSD conditions. HSD-fed NSY, but not C3H mice, exhibited increased hepatic expression levels of Pparg2, an isoform of Pparg as well as G0s2, a target of Pparg, which are known to be adipocyte-specific genes. Compared to RD-fed C3H mice, hepatic expression levels of Kat2b (transcriptional regulation), Hsd3b5 (steroid hormone metabolism) and Cyp7b1 (bile acid metabolism) were initially lower in RD-fed NSY mice, and were further decreased in HSD-fed NSY mice. Expression of Metallothionein (Mt1) and Metallothionein 2 (Mt2) was significantly lower in NSY mice compared to C3H mice, irrespective of dietary condition. These data suggest that elucidation of this heterogeneity in response to HSD might contribute to further understanding of the gene-environment interactions leading to diabetes in humans.

Differential effects of low-dose resveratrol on adiposity and hepatic steatosis in diet-induced obese mice

Consumption of a high-fat diet (HFD) enriched in saturated fat induces excessive weight gain due to adiposity, which can lead to metabolic complications, as well as increased risk of fatty liver disease and CVD. The present study investigated the underlying mechanism and dose-response effects of resveratrol (RV) on obesity, hepatic steatosis and dyslipidaemia in mice fed a HFD. Male C57BL/6J mice were fed a normal diet or a HFD (20 % fat, w/w) combined with 0·005 or 0·02 % (w/w) RV for 10 weeks. As expected, mice fed a HFD developed obesity, as shown by increased body weight gain, visceral fat, hepatic fat and plasma cholesterol. RV significantly reduced visceral fat and plasma NEFA. In the liver of HFD-fed mice, RV significantly reduced TAG and cholesterol, as well as lipid droplet number and size. A low dose of RV (0·005 %) appeared to be more effective than a higher dose of RV (0·02 %) for suppressing adiposity and hepatic steatosis development with a significant decrease in body weight gain, plasma TAG and total cholesterol levels. These changes were seemingly attributable to a suppression of the fatty acid (FA) synthase, glucose-6-phosphate dehydrogenase, and phosphatidate phosphohydrolase and/or an activation of FA oxidation in the liver and epididymal adipose tissue. In conclusion, daily consumption of a low dose of RV is effective for protecting against diet-induced obesity, hepatic steatosis and dyslipidaemia in HFD-fed mice.

Design flaws in randomized, placebo controlled, double blind clinical trials

The hypothesis in drug clinical trials is that the drug is better than a placebo in patients suffering from a disease. The unstated assumption is that the drug cures the disease or is a powerful treatment for the disease. This is an incorrect assumption. Drugs do not cure or treat diseases. The body heals itself; drugs promote this ability of the body to heal itself. Placebos are assumed to be inactive; however, placebos can also promote the ability of the body to heal itself. Placebos are actually treatments that can stimulate endogenous healing mechanisms. The possible place of placebos in health management is controversial. Clinical trial design should be altered. The hypothesis of clinical trials should be that the drug speeds up or improves the healing of the patient, putting patient healing as the first objective. Placebos should not be used as controls but could be tested as drugs in their own right. The control in clinical trials should be no treatment. Alternatively, new drugs could be compared to existing drugs in clinical trials.

Association between ESR1 rs1884051 polymorphism and dietary total energy and plant protein intake on obesity in Korean men

ESR1 has been listed in the Human Obesity Gene Map as candidate gene associated with obesity. Thus, in this study, we investigated the effect of the ESR1 rs1884051 polymorphism on obesity-related variables, together with their modulations by dietary intake in Korean men. The obesity-related variables and dietary intake of 3,039 Korean men aged 40-59 years from KoGES database were analyzed. Body weight (P = 0.007), BMI (P = 0.003), waist-hip ratio (= 0.011), fat body mass (P = 0.010), and body fat percentage (P = 0.040) were significantly lower in subjects with the minor T allele of ESR1 rs1884051 than in subjects carrying the C allele. Moreover, the rs1884051 T allele was associated with a decreased risk of obesity prevalence (P = 0.040). Among the subjects whose total energy intake was below the median, carrier of the minor T allele of ESR1 rs1884051 had a lower BMI (P = 0.003) when compared with subjects carrying the C allele. In addition, among subjects whose plant protein intake was above the median, carrier of the minor T allele of ESR1 rs1884051 had a lower BMI (P = 0.044) compared with subjects carrying the C allele. Our findings demonstrate that there is a significant association between the ESR1 rs1884051 variant and obesity-related variables and this association can be potentially modified by dietary energy and plant protein intake.

Differential effects of powdered whole soy milk and its hydrolysate on antiobesity and antihyperlipidemic response to high-fat treatment in C57BL/6N mice

This study was performed to investigate the beneficial effects of powdered whole soy milk and its hydrolysate, compared to the processed soy milk and its hydrolysate, on the alteration of lipid metabolism and their possible effects on antiobesity in C57BL/6N mice fed a high-fat and -cholesterol diet. The mice were divided into a control group (20% casein) and four test groups for 5 weeks: soy milk (SM, 20% soy milk protein), soy milk hydrolysate (SMH, 20% hydrolyzed soy milk protein), whole soy milk (WSM, 20% whole soy milk protein), and whole soy milk hydrolysate (WSMH, 20% whole soy milk hydrolysate protein). The body weight and adipose tissue weights were significantly lowered in SMH, WSM, and WSMH groups compared to the control group despite providing an isoenergetic diet. Plasma lipid concentrations and hepatic fatty acid synthase (FAS) and glucose-6-phosphate dehydrogenase (G6PD) activities were significantly lowered in all soy milk groups; however, the hepatic lipid contents and malic enzyme (ME) activity were only significantly lowered in the WSM and WSMH groups, compared to the control group. Data suggest that powdered WSM or WSMH appears to be more beneficial than SM or SMH in overall antiobesity and antihyperlipidemic properties following in the order WSMH/WSM, SMH, SM, and casein.

EGT1442, a potent and selective SGLT2 inhibitor, attenuates blood glucose and HbA(1c) levels in db/db mice and prolongs the survival of stroke-prone rats

Sodium glucose co-transporter 2 (SGLT2) is a renal type III integral membrane protein that co-transports sodium and glucose from filtrate to epithelium in the proximal tubule. Human subjects with homozygous or compound heterozygous mutations in SLC5A2 exhibit glucosuria without hypoglycemia or other obvious morbidity, suggesting that blockade of SGLT2 has the potential to promote normalization of blood glucose without hypoglycemia in the setting of type 2 diabetes. This report presents the in vitro and in vivo pharmacological activities of EGT1442, a recently discovered SGLT2 inhibitor in the C-aryl glucoside class. The inhibitory effects of EGT1442 for human SGLT1 and SGLT2 were evaluated in an AMG uptake assay and the in vivo efficacy of treatment with EGT1442 was investigated in rats and dogs after a single dose and in db/db mice after chronic administration. The effect of EGT1442 on median survival of SHRSP rats was also evaluated. The IC(50) values for EGT1442 against human SGLT1 and SGLT2 are 5.6μM and 2nM, respectively. In normal rats and dogs a saturable urinary glucose excretion was produced with an ED(50) of 0.38 and 0.09mg/kg, respectively. Following chronic administration to db/db mice, EGT1442 dose-dependently reduced HbA(1c) and blood glucose concentration without affecting body mass or insulin level. Additionally, EGT1442 significantly prolonged the median survival of SHRSP rats. EGT1442 showed favorable properties both in vitro and in vivo and could be beneficial to the management of type 2 diabetic patients.

Proteomic analysis for antiobesity potential of capsaicin on white adipose tissue in rats fed with a high fat diet

It is well recognized that capsaicin increases thermogenesis through enhancement of catecholamine secretion from the adrenal medulla. In the present study of the antiobesity effect of capsaicin, rats (5-week old) received capsaicin (10 mg/kg) along with a high-fat diet (HFD). In comparison with saline-treated rats, body weight of those in the capsaicin-treated group decreased by 8%. We performed differential proteomic analysis using two-dimensional electrophoresis (2-DE) combined with MALDI-TOF mass spectrometry to elucidate the molecular action of capsaicin on the antiobesity effect in epididymal white adipose tissue (WAT). Protein mapping of WAT homogenates using 2-DE revealed significant alterations to a number of proteins: 10 spots were significantly up-regulated and 10 spots were remarkably down-regulated in HFD fed rats treated with capsaicin. Among them, significant down-regulation of heat shock protein 27 (Hsp27) and Steap3 protein, as well as up-regulation of olfactory receptor (Olr1434) in obese WAT was reported for the first time in association with obesity. Most of the identified proteins are associated with lipid metabolism and redox regulation, in which levels of vimentin, peroxiredoxin, and NAD(P)H:quinone oxidoreductase 1 (NQO1) were significantly reduced (>2-fold), whereas aldo-keto reductase, flavoprotein increased with capsaicin treatment. These data demonstrate that thermogenesis and lipid metabolism related proteins were markedly altered upon capsaicin treatment in WAT, suggesting that capsaicin may be a useful phytochemical for attenuation of obesity.

Evidence for three novel QTLs for adiposity on chromosome 2 with epistatic interactions: the NHLBI Family Heart Study

We sought to identify quantitative trait loci (QTLs) by genome-wide linkage analysis for BMI and waist circumference (WC) exploring various strategies to address heterogeneity including covariate adjustments and complex models based on epistatic components of variance. Because cholesterol-lowering drugs and diabetes medications may affect adiposity and risk of coronary heart disease, we excluded subjects medicated for hypercholesterolemia and hyperglycemia. The evidence of linkage increased on 2p25 (BMI: lod = 1.59 vs. 2.43, WC: lod = 1.32 vs. 2.26). Because environmental and/or genetic components could mask the effect of a specific locus, we investigated further whether a QTL could influence adiposity independently of lipid pathway and dietary habits. Strong evidence of linkage on 2p25 (BMI: lod = 4.31; WC: lod = 4.23) was found using Willet's dietary factors and lipid profile together with age and sex in adjustment. It suggests that lipid profile and dietary habits are confounding factors for detecting a 2p25 QTL for adiposity. Because evidence of linkage has been previously detected for BMI on 7q34 and 13q14 in National Heart, Lung, and Blood Institute Family Heart Study (NHLBI FHS), and for diabetes on 15q13, we investigated epistasis between chromosome 2 and these loci. Significant epistatic interactions were found between QTLs 2p25 and 7q34, 2q37 and 7q34, 2q31 and 13q14, and 2q31-q36 and 15q13. These results suggest multiple pathways and factors involving genetic and environmental effects influencing adiposity. By taking some of these known factors into account, we clarified our linkage evidence of a QTL on 2p25 influencing BMI and WC. The 2p25, 2q24-q31, and 2q36-q37 showed evidence of epistatic interaction with 7q34, 13q14, and 15q13.

Basal metabolic rate is decreased in women with polycystic ovary syndrome and biochemical hyperandrogenemia and is associated with insulin resistance

OBJECTIVE

To evaluate basal metabolic rate (BMR) in women with PCOS and to determine its association with insulin resistance (IR).

DESIGN

Prospective assessment of BMR in women with PCOS.

SETTING

Outpatient clinic of the Division of Reproductive Endocrinology.

PATIENT(S)

The study included 91 Greek women with PCOS and biochemical hyperandrogenemia, with mean age 24.03 +/- 0.55 years and mean body mass index (BMI) 26.67 +/- 0.69 kg/m(2), and 48 matched regularly menstruating women, with mean age 26.33 +/- 0.93 years and mean BMI 23.35 +/- 0.85 kg/m(2), as control subjects.

INTERVENTION(S)

Assessment of BMR by indirect calorimetry, IR by HOMA and QUICKI indices, fasting insulin, and fasting glucose/insulin ratio.

MAIN OUTCOME MEASURE(S)

Reduced BMR in PCOS with or without IR.

RESULT(S)

Adjusted BMR was 1,868 +/- 41 kcal/day in the control group, 1,445.57 +/- 76 in all PCOS women, 1,590 +/- 130 in PCOS women without IR and 1,116 +/- 106 in PCOS women with IR. Adjusted BMR showed a statistically significant difference between women with PCOS and control subjects, with lowest values in the group of PCOS women with IR, even after adjusting all groups for age and BMI.

CONCLUSION(S)

Women with PCOS, particularly those with IR, present a significantly decreased BMR.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Management of the metabolic syndrome and type 2 diabetes through lifestyle modification

Sustainable lifestyle modifications in diet and physical activity are the initial, and often the primary, component in the management of diabetes and the metabolic syndrome. An energy-prudent diet, coupled with moderate levels of physical activity, favorably affects several parameters of the metabolic syndrome and delays the onset of diabetic complications. Weight loss, albeit not an absolute prerequisite for improvement, is a major determinant and maximizes effectiveness. Adopting a healthy lifestyle pattern requires a series of long-term behavioral changes, but evidence to date indicates low long-term adherence to diet and physical activity recommendations. This calls for greater research and public health efforts focusing on strategies to facilitate behavior modification.

Remogliflozin etabonate, in a novel category of selective low-affinity sodium glucose cotransporter (SGLT2) inhibitors, exhibits antidiabetic efficacy in rodent models

The low-affinity sodium glucose cotransporter (SGLT2) plays an important role in renal glucose reabsorption and is a remarkable transporter as a molecular target for the treatment of diabetes. We have discovered remogliflozin etabonate, which is a novel category of selective SGLT2 inhibitors. Remogliflozin etabonate is a prodrug based on benzylpyrazole glucoside and is metabolized to its active form, remogliflozin, in the body. We identified remogliflozin to be a potent and highly selective SGLT2 inhibitor by examining COS-7 cells transiently expressing either high-affinity sodium glucose cotransporter (SGLT1) or SGLT2. Orally administered remogliflozin etabonate increased urinary glucose excretion in a dose-dependent manner in both mice and rats. By increasing urinary glucose excretion, remogliflozin etabonate inhibited the increase in plasma glucose after glucose loading without stimulating insulin secretion in normal rats. Remogliflozin etabonate also showed antihyperglycemic effects in both streptozotocin-induced diabetic rats in oral glucose tolerance and in db/db mice in the fed condition. Chronic treatment with remogliflozin etabonate reduced the levels of fasting plasma glucose and glycated hemoglobin, and it ameliorated glucosuria in db/db mice. In high-fat diet-fed Goto-Kakizaki rats, remogliflozin etabonate improved hyperglycemia, hyperinsulinemia, hypertriglyceridemia, and insulin resistance. This study demonstrates that treatment with remogliflozin etabonate exhibits antidiabetic efficacy in several rodent models and suggests that remogliflozin etabonate may be a new and useful drug for the treatment of diabetes.

Nutrigenomic analysis of diet-gene interactions on functional supplements for weight management

Recent advances in molecular biology combined with the wealth of information generated by the Human Genome Project have fostered the emergence of nutrigenomics, a new discipline in the field of nutritional research. Nutrigenomics may provide the strategies for the development of safe and effective dietary interventions against the obesity epidemic. According to the World Health Organization, more than 60% of the global disease burden will be attributed to chronic disorders associated with obesity by 2020. Meanwhile in the US, the prevalence of obesity has doubled in adults and tripled in children during the past three decades. In this regard, a number of natural dietary supplements and micronutrients have been studied for their potential in weight management. Among these supplements, (-)-hydroxycitric acid (HCA), a natural extract isolated from the dried fruit rind of Garcinia cambogia, and the micronutrient niacin-bound chromium(III) (NBC) have been shown to be safe and efficacious for weight loss. Utilizing cDNA microarrays, we demonstrated for the first time that HCA-supplementation altered the expression of genes involved in lipolytic and adipogenic pathways in adipocytes from obese women and up-regulated the expression of serotonin receptor gene in the abdominal fat of rats. Similarly, we showed that NBC-supplementation up-regulated the expression of myogenic genes while suppressed the expression of genes that are highly expressed in brown adipose tissue in diabetic obese mice. The potential biological mechanisms underlying the observed beneficial effects of these supplements as elucidated by the state-of-the-art nutrigenomic technologies will be systematically discussed in this review.

Dietary combination of fucoxanthin and fish oil attenuates the weight gain of white adipose tissue and decreases blood glucose in obese/diabetic KK-Ay mice

Fucoxanthin is a marine carotenoid found in edible brown seaweeds. We previously reported that dietary fucoxanthin attenuates the weight gain of white adipose tissue (WAT) of diabetic/obese KK- A(y) mice. In this study, to evaluate the antiobesity and antidiabetic effects of fucoxanthin and fish oil, we investigated the effect on the WAT weight, blood glucose, and insulin levels of KK- A(y) mice. Furthermore, the expression level of uncoupling protein 1 (UCP1) and adipokine mRNA in WAT were measured. After 4 weeks of feeding, 0.2% fucoxanthin in the diet markedly attenuated the gain of WAT weight in KK- A(y) mice with increasing UCP1 expression compared with the control mice. The WAT weight of the mice fed 0.1% fucoxanthin and 6.9% fish oil was also significantly lower than that of the mice fed fucoxanthin alone. In addition, 0.2% fucoxanthin markedly decreased the blood glucose and plasma insulin concentrations in KK- A(y) mice. The mice fed with the combination diet of 0.1% fucoxanthin and fish oil also showed improvements similar to that of 0.2% fucoxanthin. Leptin and tumor necrosis factor (TNFalpha) mRNA expression in WAT were significantly down-regulated by 0.2% fucoxanthin. These results suggest that dietary fucoxanthin decreases the blood glucose and plasma insulin concentration of KK- A(y) along with down-regulating TNFalpha mRNA. In addition, the combination of fucoxanthin and fish oil is more effective for attenuating the weight gain of WAT than feeding with fucoxanthin alone.