High-refined Carbohydrate-containing Diet Research Articles

Protective Effect of Virgin Coconut Oil on Osteopenia Induced by High Refined Carbohydrate-Containing Diet in Mice.

Background: Obesity leads to chronic low-grade inflammation, promoting detrimental effects on bone. The consumption of virgin coconut oil (VCO) is associated with benefits related to meta-inflammation. We evaluated the effect of VCO supplementation on osteopenia promoted by diet-induced obesity in mice. Methods: Male BALB/c mice were fed a control (C) or highly refined carbohydrate-containing (HC) diet for eight weeks. After that, the HC diet group was supplemented with three doses of VCO for four weeks. Results: The HC diet increased the adiposity and leptin levels associated with augmented systemic inflammatory cells improved with VCO supplementation. The HC diet reduced the trabecular bone in the tibia, lumbar vertebrae, distal and proximal femur, as well as the bone mineral density of the femur and alveolar bone. The VCO supplementation reverted bone osteopenia by increasing the trabecular bone in different sites and improving femur and alveolar bone microarchitecture. Although the reduced number of osteoblasts in the alveolar bone of the HC diet group was not significantly enhanced by VCO supplementation, the reduced Alp expression in the HC diet group was enhanced in the VCO group. These beneficial effects were associated with lowering the Rankl/Opg ratio. Conclusion: VCO supplementation might be an effective strategy to attenuate bone osteopenic effects induced by obesity.

High-refined carbohydrate diet consumption induces neuroinflammation and anxiety-like behavior in mice

Consumption of poor nutrients diets is associated with fat tissue expansion and with a central and peripheral low-grade inflammation. In this sense, the microglial cells in the central nervous system are activated and release pro-inflammatory cytokines that up-regulate the inducible nitric oxide synthase (iNOS), promoting Nitric Oxide (NO) production. The excess of NO has been proposed to facilitate anxious states in humans and rodents. We evaluated whether consumption of a high-refined carbohydrate-containing diet (HC) in mice induced anxiety-like behavior in the Novelty Suppressed Feeding Test (NFST) trough facilitation of NO, in the prefrontal cortex (PFC) and hippocampus (HIP). We also verified if HC diet induces activation of microglial cells, alterations in cytokine and leptin levels in such regions. Male BALB/c mice received a standard diet or a HC diet for 3 days or 12 weeks. The chronic consumption of HC diet, but not acute, induced an anxiogenic-like effect in the NSF test and an increase in the nitrite levels in the PFC and HIP. The preferential iNOS inhibitor, aminoguanidine (50 mg/kg, i.p.), attenuated such effects. Moreover, microglial cells in the HIP and PFC were activated after chronic consumption of HC diet. Finally, the expression of iNOS in the PFC and TNF, IL6 and leptin levels in HIP were higher in chronically HC fed mice. Taken together, our data reinforce the notion that diets containing high-refined carbohydrate facilitate anxiety-like behavior, mainly after a long period of consumption. The mechanisms involve, at least in part, the augmentation of neuroinflammatory processes in brain areas responsible for anxiety control.

SOCS2 modulates adipose tissue inflammation and expansion in mice

IntroductionObesity is usually triggered by a nutrient overload that favors adipocyte hypertrophy and increases the number of pro-inflammatory cells and mediators into adipose tissue. These mediators may be regulated by suppressors of cytokine signaling (SOCS), such as SOCS2, which is involved in the regulation of the inflammatory response of many diseases, but its role in obesity is not yet known. We aimed to investigate the role of SOCS2 in metabolic and inflammatory dysfunction induced by a high-refined carbohydrate-containing diet (HC). Material and methodsMale C57BL/6 wild type (WT) and SOCS2 deficient (SOCS2−/−) mice were fed chow or an HC diet for 8 weeks. ResultsIn general, SOCS2 deficient mice, independent of the diet, showed higher adipose tissue mass compared with their WT counterparts that were associated with decreased lipogenesis rate in adipose tissue, lipolysis in adipocyte culture and energy expenditure. An anti-inflammatory profile was observed in adipose tissue of SOCS2−/− by reduced secretion of cytokines, such as TNF and IL-6, and increased M2-like macrophages and regulatory T cells compared with WT mice. Also, SOCS2 deficiency reduced the differentiation/expansion of pro-inflammatory cells in the spleen but increased Th2 and Treg cells compared with their WT counterparts. ConclusionThe SOCS2 protein is an important modulator of obesity that regulates the metabolic pathways related to adipocyte size. Additionally, SOCS2 is an inflammatory regulator that appears to be essential for controlling the release of cytokines and the differentiation/recruitment of cells into adipose tissue during the development of obesity.

Ginger (Zingiber officinale Rosc.) Ameliorated Metabolic and Inflammatory Dysfunction Induced by High-Refined Carbohydrate-Containing Diet in Mice.

This study aimed to evaluate the effects and the mechanisms of ginger extract intake in the adiposity gain, metabolic and inflammatory disturbances induced by a high-refined carbohydrate (HC) diet in mice. Ginger extract at doses of 200, 600, and 1800 mg/kg was supplemented in the daily food of obese Balb/c mice during an 8-week experiment. Our findings indicate that consumption of high doses of ginger extracts prevents the increase of adiposity induced by HC diet, improves lipid profile, and promotes decrease of inflammatory markers in mice. We showed that ginger addition to HC diet leads to decrease in the recruitment of cells visualized in vivo in the microvasculature of adipose tissue, decrease of inflammatory cytokines, and increase of adiponectin serum levels. These results indicate that the consumption of ginger decreases the negative metabolic consequences induced by HC diet.

Virgin coconut oil is effective to treat metabolic and inflammatory dysfunction induced by high refined carbohydrate-containing diet in mice

The global rise in obesity rates is alarming since this condition is associated with chronic low-grade inflammation and secondary comorbidities as glucose intolerance, cardiovascular disease and liver damage. Therefore, a lot of dietary approaches are proposed to prevent and to treat obesity and its associated disorders. Virgin coconut oil (VCO) is well known as a functional food due to its significant amounts of medium-chain triglycerides. This study aimed to evaluate the effect of VCO on adiposity, metabolic and inflammatory dysfunctions induced by a high-refined carbohydrate-containing (HC) diet in mice. Male BALB/c mice were divided into two groups and fed with control (C) or HC diet to induce obesity for eight weeks. At the 9th week mice fed with HC diet were randomly regrouped into four groups, and were kept this way until the 12th week, as following: (i) HC diet alone or HC diet supplemented with three different VCO doses (ii) 1000 mg/kg, (iii) 3000 mg/kg and (iv) 9000 mg/kg. Regardless of the concentration used, VCO supplementation promoted lower adiposity and also improvement in glucose tolerance, lower serum glucose and lipid levels and decreased hepatic steatosis. Moreover, VCO intake induced a lower inflammatory response due to decreased number of leukocytes and TNF-α and IL-6 concentrations in adipose tissue, as well as reduced counts of total leukocytes, mononuclear and polymorphonuclear circulating cells. Our data showed that VCO can be considered as an interesting potential dietary approach to attenuate obesity and its metabolic and inflammatory alterations.

A high-refined carbohydrate diet facilitates compulsive-like behavior in mice through the nitric oxide pathway

Obesity is characterized by abnormal adipose tissue expansion and is associated with chronic inflammation. Obesity itself may induce several comorbidities, including psychiatric disorders. It has been previously demonstrated that proinflammatory cytokines are able to up-regulate inducible nitric oxide synthase (iNOS) and nitric oxide (NO) release, which both have a role in compulsive related behaviors. ObjectiveTo evaluate whether acute or chronic consumption of a high-refined carbohydrate-containing (HC) diet will modify burying-behavior in the Marble Burying Test (MBT) through augmentation of NO signaling in the striatum, a brain region related to the reward system. Further, we also verified the effects of chronic consumption of a HC diet on the reinforcing effects induced by cocaine in the Conditioned Place Preference (CPP) test. MethodsMale BALB/c mice received a standard diet (control diet) or a HC diet for 3 days or 12 weeks. ResultsAn increase in burying behavior occurred in the MBT after chronic consumption of a HC diet that was associated with an increase of nitrite levels in the striatum. The pre-treatment with Aminoguanidine (50 mg/kg), a preferential inhibitor of iNOS, prevented such alterations. Additionally, a chronic HC diet also induced a higher expression of iNOS in this region and higher glutamate release from striatal synaptosomes. Neither statistical differences were observed in the expression levels of the neuronal isoform of NOS nor in microglia number and activation. Finally, the reinforcing effects induced by cocaine (15 mg/kg, i.p.) during the expression of the conditioned response in the CPP test were not different between the chronically HC diet fed mice and the control group. However, HC diet-feeding mice presented impairment of cocaine-preference extinction. ConclusionAltogether, our results suggest that the chronic consumption of a HC diet induces compulsive-like behavior through a mechanism possibly associated with NO activation in the striatum.

TNF and IL-18 cytokines may regulate liver fat storage under homeostasis conditions.

The inflammation induced by obesogenic diets is associated with deposition of fat in the liver. On the other hand, anti-inflammatory and immunosuppressive therapies may impact in body fat storage and in liver lipid dynamics. It is important to study specific inflammatory mediators in this context, since their role on hepatic damage is not fully clarified. This study aimed to evaluate the role of interleukin (IL)-18 and tumor necrosis factor (TNF) receptor in liver dysfunction induced by diet. Male C57BL/6 wild-type (WT), IL-18, and TNF receptor 1 knockout mice (IL-18-/- and TNFR1-/-) were divided according to the experimental diets: chow diet or a high-refined carbohydrate-containing diet. Alanine aminotransferase was quantified by colorimetric analysis. Total fat content in the liver was determined by Folch methods. Levels of TNF, IL-6, IL-4, and IL-13 in liver samples were measured by ELISA assay. IL-18 and TNFR knockout mice fed with chow diet showed higher liver triglycerides deposition than WT mice fed with the same diet (WT: 131.9 ± 24.5; IL-18-/-: 239.4 ± 38.12*; TNF-/-: 179.6 ± 50.45*; *P < 0.01). Furthermore, these animals also showed a worse liver histopathological score and lower levels of TNF, IL-6, IL-4, and IL-13 in the liver. Interestingly, treatment with a high-carbohydrate diet did not exacerbate liver damage in IL-18-/- and TNFR1-/- mice. Our data suggest that IL-18 and TNF may be involved on hepatic homeostasis mainly in a context of a healthy diet.

Immunologic and metabolic effects of high-refined carbohydrate-containing diet in food allergic mice

ObjectiveAllergic mice show a reduction in body weight and adiposity with a higher inflammatory response in the adipose tissue similar to obese fat tissue. This study aimed to evaluate whether the low-grade inflammatory milieu of mice with diet-induced mild obesity interferes with the allergic response induced by ovalbumin (OVA). MethodsBALB/c mice were divided into four groups: 1) non-allergic (OVA−) mice fed chow diet, 2) allergic (OVA+) mice fed chow diet, 3) OVA− mice fed high-refined carbohydrate-containing (HC) diet, and 4) OVA+ mice fed HC diet. After 5 wk, allergic groups were sensitized with OVA and received a booster 14 d later. All groups received an oral OVA challenge 7 d after the booster. ResultsAllergic groups showed increased serum levels of total IgE, anti-OVA IgE, and IgG1; a high disease activity index score; aversion to OVA; and increased intestinal eosinophil infiltration. Non-allergic mild-obese mice also showed aversion to OVA and an increased number of eosinophils in the proximal jejunum. After the allergic challenge, OVA+ mice fed chow diet showed weight loss and lower adiposity in several adipose tissue depots. OVA+ mice fed HC diet showed a loss of fat mass only in the mesenteric adipose tissue. Furthermore, increased levels of TNF, IL-6, and IL-10 were observed in this tissue. ConclusionsOur data show that mild-obese allergic mice do not present severe pathologic features of food allergy similar to those exhibited by lean allergic mice. Mild obesity promoted by HC diet ingestion causes important intestinal disorders that appear to modulate the inflammatory response during the antigen challenge.

Platelet-activating factor modulates fat storage in the liver induced by a high-refined carbohydrate-containing diet

Hepatic diseases are comorbidities caused by obesity and are influenced by diet composition. The aim of this study was to evaluate the kinetics of metabolic and inflammatory liver dysfunction induced by a high-refined carbohydrate-containing (HC) diet and to determine how platelet-activating factor (PAF) modulates the liver lipid content of mice. BALB/c mice were fed a chow or HC diet for the following experimental periods: 1 and 3 days, 1, 2, 4, 6, 8, 10 and 12 weeks. Wild-type (WT) and PAF receptor-deficient (PAFR−/−) mice were fed the same diets for 8 weeks. Mice fed with HC diet showed higher triglycerides and cholesterol levels, fibrosis and inflammation in the liver. The number of neutrophils migrating into the liver was also increased in mice fed with HC diet. However, transaminase levels did not change. PAFR−/− mice fed with HC diet showed more steatosis, oxidative stress and higher transaminases levels associated with lower inflammation than WT mice. The consumption of HC diet altered the metabolic and inflammatory response in the liver and was worse in PAFR−/− mice. We suggest that PAF regulates liver lipid content and dyslipidemia, protecting the mice from lipotoxicity and liver damage.

Lack of platelet‐activating factor receptor protects mice against diet‐induced adipose inflammation and insulin‐resistance despite fat pad expansion

The role of platelet-activating factor (PAF) on diet-induced inflammatory and metabolic dysfunction is unknown. The effects of diet-induced metabolic and inflammatory dysfunction in mice with deletion of the PAF receptor (PAFR(-/-) ) were evaluated in this study. Wild-type and PAFR(-/-) mice were fed chow (WT-C and PAFR(-/-) -C) or high-refined carbohydrate-containing diet (WT-HC and PAFR(-/-) -HC). PAFR(-/-) - RESULTS: HC mice gained more weight and adiposity than PAFR(-/-) -C and WT-HC mice. Lipogenesis increased and hormone-sensitive lipase expression decreased in PAFR(-/-) -HC compared to WT-HC mice. WT-HC mice had impaired glucose tolerance and insulin sensitivity compared to WT-C mice. In contrast, glucose tolerance and insulin sensitivity in PAFR(-/-) -HC mice were similar to that of lean littermates. PAFR(-/-) -HC mice expressed significantly more peroxisome proliferator-activator receptor gamma (PPARγ) than PAFR(-/-) -C and WT-C mice. Resistin increased in WT-HC mice compared to WT-C mice. However, the levels of resistin were 35% lower in PAFR(-/-) -HC mice than WT-HC mice. PAFR(-/-) presented with less HC diet-induced adipose tissue inflammation than WT mice. Adipocytes isolated from PAFR(-/-) mice incubated in media containing normal or high levels of glucose secreted less interleukin-6 and tumor necrosis factor alpha and presented lower rate of lipolysis than WT mice. PAFR deficiency resulted in less inflammation in adipose tissue and improvement in glucose homeostasis when fed the HC diet. The higher adiposity observed in PAFR(-/-) mice fed HC diet could be owing to the maintenance of insulin sensitivity, decreased adipocyte lipolysis rate, high lipogenesis and PPARγ expression, and lower inflammatory milieu in adipose tissue.

Acute and sustained inflammation and metabolic dysfunction induced by high refined carbohydrate‐containing diet in mice

The effects of high-refined carbohydrate-containing diet (HC) on inflammatory parameters and metabolic disarrangement of adipose tissue are poorly understood. The aim of this study was to evaluate the timing and progression of metabolic and inflammatory dysfunction induced by HC diet in mice. BALB/c mice were fed chow or HC diet for 1 and 3 days, 1, 2, 4, 6, 8, 10, and 12 weeks. Animals given HC diet exhibited acute and sustained increase in visceral adiposity, glucose intolerance, low insulin sensitivity, hyperlipemia, acute increase in mRNA expression of ACC, LPL, PPARγ, SREBP-1, and ChREBP and altered circulating levels of adiponectin, resistin, and leptin. There was leucocyte rolling and adhesion on adipose tissue microvessels already at 3 days and until 8 weeks of HC diet. Adipose tissue of mice had increased number of macrophages (M1 and M2), lymphocytes (CD8+ and CD4+ Foxp3+), and neutrophils (GR1+) already at 3 days after initiation of HC diet. Overall, concentration of cytokines and chemokines, TNF-α, IL-6, IL-10, TGF-β1, CCL2, and CXCL1, in adipose tissue was elevated throughout the experimental period. Levels of IL-10 and TGF-β1 tended to reach baseline levels at 12 weeks of HC diet. We describe a novel murine model of fat pad expansion induced by HC diet that is characterized by early onset and sustained adipose tissue inflammation and metabolic disarrangement. The acute inflammatory response in adipose tissue occurs very early and is sustained, suggesting that adipose tissue inflammation is a homeostatic mechanism to regulate nutrient overload and adipose expansion.