HF-fed Rats Research Articles

Prebiotic Potential of Goji Berry (Lycium barbarum) in Improving Intestinal Integrity and Inflammatory Profiles via Modification of the Gut Microbiota in High-Fat Diet-Fed Rats.

Background: Imbalances in gut microbiota and subsequent destabilization of intestinal barrier equilibrium have been related to the evolution of metabolic disorders. Goji berries (Lycium barbarum; GB) and their fermented counterpart (FGB) have been identified for their prebiotic capacity in managing intestinal barrier functions and inflammatory profiles Consequently, this research was designed to investigate the effects of supplementing GB and FGB on intestinal integrity, inflammation, and changes in the composition of gut microbiota in high-fat (HF)-fed rats. Materials and Methods: Thirty-two male Sprague-Dawley rats (6 weeks old, 8 per group) were divided into four categories based on their weight and provided with either respective diets over a 6-week period: low-fat (LF; 10% of calories from fat), HF (45% of calories from fat), and HF diets supplemented with either GB or FGB at a 2% (w/w). Results: Supplementation of GB and FGB resulted in compositional changes in the gut microbiota, denoted by a distinct abundance of Faecalibacterium prausnitzii with GB and Akkermansia muciniphila species with FGB, which have been linked to ameliorated obesity phenotypes and metabolic parameters. These alterations were correlated with enhancements in gut barrier integrity, thereby protecting against local and systemic inflammation induced by a HF diet. Supplementation with GB and FGB also mitigated lipopolysaccharide-induced inflammation through inhibition of its downstream pathway. Conclusion: These findings indicate that both GB and FGB supplementation can improve gut barrier function and inflammatory profiles in HF-fed rats via modulation of the microbial composition of the gut, supporting the potential application of GB and FGB in improving gut barrier function and managing inflammation amid metabolic challenges.

Dietary supplementation with L-leucine reduces nitric oxide synthesis by endothelial cells of rats.

This study tested the hypothesis that elevated L-leucine concentrations in plasma reduce nitric oxide (NO) synthesis by endothelial cells (ECs) and affect adiposity in obese rats. Beginning at four weeks of age, male Sprague-Dawley rats were fed a casein-based low-fat (LF) or high-fat (HF) diet for 15 weeks. Thereafter, rats in the LF and HF groups were assigned randomly into one of two subgroups (n = 8/subgroup) and received drinking water containing either 1.02% L-alanine (isonitrogenous control) or 1.5% L-leucine for 12 weeks. The energy expenditure of the rats was determined at weeks 0, 6, and 11 of the supplementation period. At the end of the study, an oral glucose tolerance test was performed on all the rats immediately before being euthanized for the collection of tissues. HF feeding reduced (P < 0.001) NO synthesis in ECs by 21% and whole-body insulin sensitivity by 19% but increased (P < 0.001) glutamine:fructose-6-phosphate transaminase (GFAT) activity in ECs by 42%. Oral administration of L-leucine decreased (P < 0.05) NO synthesis in ECs by 14%, increased (P < 0.05) GFAT activity in ECs by 35%, and reduced (P < 0.05) whole-body insulin sensitivity by 14% in rats fed the LF diet but had no effect (P > 0.05) on these variables in rats fed the HF diet. L-Leucine supplementation did not affect (P > 0.05) weight gain, tissue masses (including white adipose tissue, brown adipose tissue, and skeletal muscle), or antioxidative capacity (indicated by ratios of glutathione/glutathione disulfide) in LF- or HF-fed rats and did not worsen (P > 0.05) adiposity, whole-body insulin sensitivity, or metabolic profiles in the plasma of obese rats. These results indicate that high concentrations of L-leucine promote glucosamine synthesis and impair NO production by ECs, possibly contributing to an increased risk of cardiovascular disease in diet-induced obese rats.

Oligofructose improves small intestinal lipid-sensing mechanisms via alterations to the small intestinal microbiota

BackgroundUpper small intestinal dietary lipids activate a gut-brain axis regulating energy homeostasis. The prebiotic, oligofructose (OFS) improves body weight and adiposity during metabolic dysregulation but the exact mechanisms remain unknown. This study examines whether alterations to the small intestinal microbiota following OFS treatment improve small intestinal lipid-sensing to regulate food intake in high fat (HF)-fed rats.ResultsIn rats fed a HF diet for 4 weeks, OFS supplementation decreased food intake and meal size within 2 days, and reduced body weight and adiposity after 6 weeks. Acute (3 day) OFS treatment restored small intestinal lipid-induced satiation during HF-feeding, and was associated with increased small intestinal CD36 expression, portal GLP-1 levels and hindbrain neuronal activation following a small intestinal lipid infusion. Transplant of the small intestinal microbiota from acute OFS treated donors into HF-fed rats also restored lipid-sensing mechanisms to lower food intake. 16S rRNA gene sequencing revealed that both long and short-term OFS altered the small intestinal microbiota, increasing Bifidobacterium relative abundance. Small intestinal administration of Bifidobacterium pseudolongum to HF-fed rats improved small intestinal lipid-sensing to decrease food intake.ConclusionOFS supplementation rapidly modulates the small intestinal gut microbiota, which mediates improvements in small intestinal lipid sensing mechanisms that control food intake to improve energy homeostasis.7qHK-ay1HXaqfvyHrZSPZbVideo

1617-P: Small Intestinal Protein Sensing Mechanism in Feeding and Glucose Regulation

Protein activates small intestinal calcium sensing receptor (CaSR) and/or peptide transporter 1 (PepT1) to increase GLP-1, but the role in glucose and feeding regulation remains elusive. We performed intravenous glucose tolerance test and refeeding studies and infused 8% (w/v) casein hydrolysate into the upper small intestine (USI) or ileum of male rats. We found that USI casein vs. saline infusion increased glucose tolerance in chow (p&amp;lt;0.01) and HF-fed rats (p&amp;lt;0.05) and suppressed feeding in chow (p&amp;lt;0.01) but not HF rats. We inhibited CaSR via injecting lentivirus expressing shRNA of CaSR into the USI (reduced expression by ~40%) and CaSR knockdown negated casein to increase glucose tolerance but not to lower feeding (p&amp;lt;0.01). Instead, viral-mediated PepT1 knockdown by ~50% negated casein to lower feeding as similar to previously reported for glucose control. Thus, CaSR and PepT1 are required for casein in the USI to increase glucose tolerance, while PepT1 but not CaSR mediates casein to lower feeding, in chow rats. The differential role of PepT1 vs CaSR may explain why HF disrupts casein to regulate feeding but not glucose tolerance as HF inhibited PepT1 expression (p&amp;lt;0.05) but increased CaSR expression (p&amp;lt;0.05) in the USI. Ileal casein vs saline infusion increased glucose tolerance (p&amp;lt;0.01) and lowered feeding (p&amp;lt;0.01). Ileal CaSR inhibition negated casein vs saline to increase glucose tolerance and lower feeding, whereas ileal PepT1 inhibition failed to do so, indicating that ileal casein regulates glucose tolerance and food intake via PepT1-independent but CaSR-dependent pathways in chow rats. HF feeding inhibited ileal CaSR expression by ~60% (p&amp;lt;0.05) in association with a disruption in ileal casein action on feeding but surprisingly not on glucose control (p&amp;lt;0.01), suggesting that ileal casein could even regulate glucose tolerance independent of CaSR. In sum, we discover differential role of CaSR vs. PepT1 in the USI and ileum that alter feeding and glucose regulatory abilities of protein sensing. Disclosure D.Barros: None. R.J.W.Li: None. Y.Lim: None. S.Zhang: None. R.Kuah: None. A.Gao: None. T.K.Lam: None. Funding Canadian Institutes of Health Research (PJT183901)

Hypoabsorptive surgeries cause limb-dependent changes in the gut endocannabinoidome and microbiome in association with beneficial metabolic effects.

To determine whether the metabolic benefits of hypoabsorptive surgeries are associated with changes in the gut endocannabinoidome (eCBome) and microbiome. Biliopancreatic diversion with duodenal switch (BPD-DS) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) were performed in diet-induced obese (DIO) male Wistar rats. Control groups fed a high-fat diet (HF) included sham-operated (SHAM HF) and SHAM HF-pair-weighed to BPD-DS (SHAM HF-PW). Body weight, fat mass gain, fecal energy loss, HOMA-IR, and gut-secreted hormone levels were measured. The levels of eCBome lipid mediators and prostaglandins were quantified in different intestinal segments by LC-MS/MS, while expression levels of genes encoding eCBome metabolic enzymes and receptors were determined by RT-qPCR. Metataxonomic (16S rRNA) analysis was performed on residual distal jejunum, proximal jejunum, and ileum contents. BPD-DS and SADI-S reduced fat gain and HOMA-IR, while increasing glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) levels in HF-fed rats. Both surgeries induced potent limb-dependent alterations in eCBome mediators and in gut microbial ecology. In response to BPD-DS and SADI-S, changes in gut microbiota were significantly correlated with those of eCBome mediators. Principal component analyses revealed connections between PYY, N-oleoylethanolamine (OEA), N-linoleoylethanolamine (LEA), Clostridium, and Enterobacteriaceae_g_2 in the proximal and distal jejunum and in the ileum. BPD-DS and SADI-S caused limb-dependent changes in the gut eCBome and microbiome. The present results indicate that these variables could significantly influence the beneficial metabolic outcome of hypoabsorptive bariatric surgeries.

Voluntary physical activity in early life attenuates markers of fatty liver disease in adult male rats fed a high-fat diet.

Paediatric fatty liver disease (FLD) can develop into steatohepatitis, cirrhosis and hepatocellular carcinoma in adulthood. We assessed if early life physical exercise reduced the effects of high-fat (HF) diet-induced steatosis. Male HF-fed rats with access to a running wheel from weaning until day (D)60 (early exercise) or from D67 to D120 (late exercise) were compared with control HF- or chow-fed groups with no wheel. At D63 and D120, liver histopathology (Kleiner score), type I collagen and plasma enzymes were assessed. At D63, early life activity significantly reduced histopathology scores (total, portal inflammation, steatosis, ballooning, but not lobular inflammation or fibrosis) and the number of rats affected. At D120, HF control scores were higher than in chow-fed controls, but the effect of activity was selective: early exercise reduced portal inflammation, steatosis, ballooning and fibrosis, but late activity affected only portal inflammation and ballooning. The chow-fed portal inflammation score was significantly less than all HF groups, but lobular inflammation was lower in the HF control group only. The fibrosis score in the HF early exercise and control chow group were lower than in the late exercise and sedentary HF groups, indicating that early life exercise was more effective than when activity was introduced later in life. Plasma biomarkers showed minor between-group differences. The retained effect on liver histopathology rat at D120 after only early life exposure activity suggests that timing of introduction of exercise is critical in reducing FLD scores and prevalence in children, young adults and possibly into adulthood.

Effect of chitosan on cardio-metabolic risk factors induced by high fat diet in rats

PurposeThis study aims to scrutinize the efficacy of chitosan (CT) on cardio-lipotoxic responses elicited by a high-fat diet (HF).Design/methodology/approachThirty-six male Wistar rats were distributed across six groups (n = 6): normal diet (ND), HF, ND-5%CT, HF-1%CT, HF-3%CT and HF-5%CT, for seven weeks. Blood and cardiac tissues were processed for biochemical, immunohistochemical and histopathological analyses.FindingsIngestion of HF induced hyperlipidaemia and lipid accumulation, leading to increased body and heart weight by 70.5% (p < 0.0001) and 124% (p = 0.0021), respectively, compared to ND-groups. Cardiac damage markers (creatine kinase, lactate dehydrogenase and malondialdehyde) were higher in the HF-group compared to control rats. Also, atherogenic and coronary risk indices were significantly elevated by 155% (p = 0.0044) and 174% (p = 0.0008), respectively, compared to control rats. Rats fed HF had significantly reduced cardiac antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and elevated expression of NF-κB-p65 and p53 (p < 0.0001) in the cardiac tissues. Histology revealed lipid inclusions in the cardiac tissues of HF-groups. CT (1%–5%) prevented hyperlipidaemia, lipid accumulation, oxidative stress and cardiac damage in HF-fed rats, while greatly improving the histology of the cardiac tissues in HF-fed rats in a dose-dependent manner.Originality/valueTo the best of the authors’ knowledge, this is the first report of the effects of CT against cardio-lipotoxicity elicited by HF diet ingestion. The findings suggest that CT may present a safe therapeutic alternative for managing complications arising from cardio-lipotoxicity.

Camel milk protein hydrosylate alleviates hepatic steatosis and hypertension in high fructose-fed rats

Context Camel milk is used in traditional medicine to treat diabetes mellitus hypertension and other metabolic disorders. Objective This study evaluated the antisteatotic and antihypertensive effects of camel milk protein hydrolysate (CMH) in high fructose (HF)-fed rats and compared it with the effects afforded by the intact camel milk protein extract (ICM). Materials and methods Adult male Wistar rats were divided into 6 groups (n = 8 each) as 1) control, 2) ICM (1000 mg/kg), 3) CMH (1000 mg/kg), 4) HF (15% in drinking water), 5) HF (15%) + ICM (1000 mg/kg), and 6) HF (15%) + CMH (1000 mg/kg). All treatments were given orally for 21 weeks, daily. Results Both ICM and CMH reduced fasting glucose and insulin levels, serum and hepatic levels of cholesterol and triglycerides, and serum levels of ALT and AST, angiotensin II, ACE, endothelin-1, and uric acid in HF-fed rats. In addition, both ICM and CMH reduced hepatic fat deposition in the hepatocytes and reduced hepatocyte damage. This was associated with an increase in the hepatic activity of AMPK, higher PPARα mRNA, reduced expression of fructokinase C, SREBP1, SREBP2, fatty acid synthase, and HMG-CoA-reductase. Both treatments lowered systolic and diastolic blood pressure. However, the effects of CMH on all these parameters were greater as compared to ICM. Discussion and conclusions The findings of this study encourage the use of CMH in a large-scale population and clinical studies to treat metabolic steatosis and hypertension.

Resistance Exercise Training Improves Metabolic and Inflammatory Control in Adipose and Muscle Tissues in Mice Fed a High-Fat Diet.

This study investigates whether ladder climbing (LC), as a model of resistance exercise, can reverse whole-body and skeletal muscle deleterious metabolic and inflammatory effects of high-fat (HF) diet-induced obesity in mice. To accomplish this, Swiss mice were fed for 17 weeks either standard chow (SC) or an HF diet and then randomly assigned to remain sedentary or to undergo 8 weeks of LC training with progressive increases in resistance weight. Prior to beginning the exercise intervention, HF-fed animals displayed a 47% increase in body weight (BW) and impaired ability to clear blood glucose during an insulin tolerance test (ITT) when compared to SC animals. However, 8 weeks of LC significantly reduced BW, adipocyte size, as well as glycemia under fasting and during the ITT in HF-fed rats. LC also increased the phosphorylation of AktSer473 and AMPKThr172 and reduced tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL1-β) contents in the quadriceps muscles of HF-fed mice. Additionally, LC reduced the gene expression of inflammatory markers and attenuated HF-diet-induced NADPH oxidase subunit gp91phox in skeletal muscles. LC training was effective in reducing adiposity and the content of inflammatory mediators in skeletal muscle and improved whole-body glycemic control in mice fed an HF diet.

High Hydrostatic Pressure Extract of Mulberry Leaf Attenuated Obesity-Induced Inflammation in Rats.

Low-grade inflammation might be a link between obesity and obesity-associated metabolic dysfunction, including diabetes, hepatic steatosis, and other health complications. This study investigated whether the supplementation of high hydrostatic pressure extract of mulberry (Morus alba L.) leaves (HML) to obese rats could counteract obesity-related inflammation. Three-week-old male Sprague-Dawley rats were separated into three groups as follows: (a) a normal diet, (b) 45% high-fat (HF) diet, and HF diet containing 0.4% HML (c) or 0.8% HML (d) (IACUC No. 17-033). After 14 weeks of HML supplementation, adipose tissue mass, mRNA expression of adipogenic genes, such as aP2, peroxisome proliferator-activated receptor γ (PPARγ), and sterol regulatory element binding protein 1c (SREBP1c), and macrophage recruitment were significantly decreased in HF-fed obese rats. Serum concentrations of nitric oxide and mRNA levels of arginase1 (Arg1), CD11c, and inducible nitric oxide synthase (iNOS) involved in adipose tissue macrophage M1 polarization were also significantly reduced by HML. Moreover, HML alleviated the serum and hepatic lipid profiles and reduced hepatic lipogenic gene expression of acetyl-CoA carboxylase (ACC), cluster of differentiation 36 (CD36), CPT1, fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD1), and SREBP1c, and inflammation-associated genes, including IL1β, interleukin 6 (IL6), and tumor necrosis factor α (TNFα). Serum IL6 and TNFα levels were remarkedly suppressed in the 0.8% HML group. These results suggested that the favorable effect of HML on obesity-associated inflammation might be related in part to the decrease in adipose tissue and hepatic fat deposition and inflammation.

Polyphenols-rich extracts from walnut green husk prevent non-alcoholic fatty liver disease, vascular endothelial dysfunction and colon tissue damage in rats induced by high-fat diet

This study is aims to evaluate the beneficial effects of polyphenols-rich extracts from walnut green husk (WGHP) on the prevention of obesity, nonalcoholic fatty liver disease (NAFLD), vascular endothelial dysfunction and colon tissue damage in rats fed high fat diet for 8 weeks. HPLC analysis showed that epicatechin, rutin and caffeic acid are the main components of WGHP. Administration of WGHP to HF-fed rats effectively prevented abnormal body weight gain, lipid metabolism disorder, oxidative stress and inflammation. Biochemical analysis and histopathological observation consistently confirmed the protective effects of WGHP on NAFLD, vascular endothelial dysfunction and colon tissue damage in rats caused by HF. In addition, 16S RNA sequencing results showed that WGHP reduced the Firmicutes/Bacteroidetes ratio in HF-fed rats and reversed the relative abundance of Ruminococcaceae-UCG-014 and Fusicatenibacter. These results suggest that WGHP may serve as a nutritional agent for protecting liver, cardiovascular and colon tissue in HF-fed rats.

Distinct mechanisms involving diacylglycerol, ceramides, and inflammation underlie insulin resistance in oxidative and glycolytic muscles from high fat-fed rats

This study investigated whether oxidative and glycolytic rat skeletal muscles respond differently to a high-fat (HF) sucrose-enriched diet with respect to diacylglycerol (DAG) and ceramides accumulation, protein kinase C (PKC) activation, glucose metabolism, and the expression of inflammatory genes. HF diet (8 weeks) suppressed insulin-stimulated glycogen synthesis and glucose oxidation in soleus (Sol), extensor digitorum longus (EDL) and epitrochlearis (Epit) muscles. However, DAG and ceramides levels increased in Sol and EDL, but not in Epit muscles of HF-fed rats. Additionally, membrane-bound PKC-delta and PKC-theta increased in Sol and EDL, whereas in Epit muscles both PKC isoforms were reduced by HF diet. In Epit muscles, HF diet also increased the expression of tumor necrosis factor-α (TNF-α) receptors (CD40 and FAS), toll-like receptor 4 (TLR4), and nuclear factor kappa light polypeptide gene enhancer in B cells (NF-kB), whereas in Sol and EDL muscles the expression of these inflammatory genes remained unchanged upon HF feeding. In conclusion, HF diet caused DAG and ceramides accumulation, PKC activation, and the induction of inflammatory pathways in a fiber type-specific manner. These findings help explain why oxidative and glycolytic muscles similarly develop insulin resistance, despite major differences in their metabolic characteristics and responsiveness to dietary lipid abundance.

Hepatic Energy Metabolism Underlying Differential Lipidomic Responses to High-Carbohydrate and High-Fat Diets in Male Wistar Rats

BackgroundLow-carbohydrate diets are suggested to exert metabolic benefits by reducing circulating triacylglycerol (TG) concentrations, possibly by enhancing mitochondrial activity. ObjectiveWe aimed to elucidate mechanisms by which dietary carbohydrate and fat differentially affect hepatic and circulating TG, and how these mechanisms relate to fatty acid composition. MethodsSix-week-old, ∼300 g male Wistar rats were fed a high-carbohydrate, low-fat [HC; 61.3% of energy (E%) carbohydrate] or a low-carbohydrate, high-fat (HF; 63.5 E% fat) diet for 4 wk. Parameters of lipid metabolism and mitochondrial function were measured in plasma and liver, with fatty acid composition (GC), high-energy phosphates (HPLC), carnitine metabolites (HPLC-MS/MS), and hepatic gene expression (qPCR) as main outcomes. ResultsIn HC-fed rats, plasma TG was double and hepatic TG 27% of that in HF-fed rats. The proportion of oleic acid (18:1n–9) was 60% higher after HF vs. HC feeding while the proportion of palmitoleic acid (16:1n–7) and vaccenic acid (18:1n–7), and estimated activities of stearoyl-CoA desaturase, SCD-16 (16:1n–7/16:0), and de novo lipogenesis (16:0/18:2n–6) were 1.5–7.5-fold in HC vs. HF-fed rats. Accordingly, hepatic expression of fatty acid synthase (Fasn) and acetyl-CoA carboxylase (Acaca/Acc) was strongly upregulated after HC feeding, accompanied with 8-fold higher FAS activity and doubled ACC activity. There were no differences in expression of liver-specific biomarkers of mitochondrial biogenesis and activity (Cytc, Tfam, Cpt1, Cpt2, Ucp2, Hmgcs2); concentrations of ATP, AMP, and energy charge; plasma carnitine/acylcarnitine metabolites; or peroxisomal fatty acid oxidation. ConclusionsIn male Wistar rats, dietary carbohydrate was converted into specific fatty acids via hepatic lipogenesis, contributing to higher plasma TG and total fatty acids compared with high-fat feeding. In contrast, the high-fat, low-carbohydrate feeding increased hepatic fatty acid content, without affecting hepatic mitochondrial fatty acid oxidation.

Walnut green husk polysaccharides prevent obesity, chronic inflammatory responses, nonalcoholic fatty liver disease and colonic tissue damage in high-fat diet fed rats

High-fat (HF) diets cause obesity, gut microbial dysbiosis and associated disorders and inflammatory bowel disease (IBD) due to increased intestinal permeability, which is an important reason for chronic inflammation and oxidative stress. This study was to investigate the effects and mechanism by which walnut green husk polysaccharides (WGHP) prevents obesity, oxidative stress, inflammation, liver and colon damage in HF diet induced rats. We found that WGHP alleviated HF-induced abnormal weight gain, disordered lipid metabolism, inflammation, oxidative stress, colonic tissue injury and up-regulate the expression level of colonic tight junction protein in the rats. Besides, the administration of WGHP promoted browning of iWAT and thermogenesis in BAT of HF-fed rats, and improved gut microbiota dysbiosis by increasing the bacterial diversity and reducing the relative abundance of potential pathogenic bacteria in the colon of the rats. Furthermore, WGHP consumption not only increased the SCFAs content but also improved the relative abundance of Prevotellaceae and Allobaculum in the gut of rats. Our results suggest that the protective effect of WGHP on metabolic inflammation caused by HF may be due to the regulation of gut microbiota and SCFAs.

Effect of mitoquinone on liver metabolism and steatosis in obese and diabetic rats.

Previous work by ourselves and others showed that mitoquinone (mitoQ) reduced oxidative damage and prevented hepatic fat accumulation in mice made obese with high‐fat (HF) feeding. Here we extended these studies to examine the effect of mitoQ on parameters affecting liver function in rats treated with HF to induce obesity and in rats treated with HF plus streptozotocin (STZ) to model a severe form of type 2 diabetes. In prior reported work, we found that mitoQ significantly improved glycemia based on glucose tolerance data in HF rats but not in the diabetic rats. Here we found only non‐significant reductions in insulin and glucose measured in the fed state at sacrifice in the HF mice treated with mitoQ. Metabolomic data showed that mitoQ altered several hepatic metabolic pathways in HF‐fed obese rats toward those observed in control normal chow‐fed non‐obese rats. However, mitoQ had little effect on pathways observed in the diabetic rats, wherein diabetes itself induced marked pathway aberrations. MitoQ did not alter respiration or membrane potential in isolated liver mitochondria. MitoQ reduced liver fat and liver hydroperoxide levels but did not improve liver function as marked by circulating levels of aspartate and alanine aminotransferase (ALT). In summary, our results for HF‐fed rats are consistent with past findings in HF‐fed mice indicating decreased liver lipid hydroperoxides (LPO) and improved glycemia. However, in contrast to the HF obese mice, mitoQ did not improve glycemia or reset perturbed metabolic pathways in the diabetic rats.

Supplementation of branched-chain amino acids decreases fat accumulation in the liver through intestinal microbiota-mediated production of acetic acid

Non-alcoholic fatty liver disease (NAFLD) is a significant problem because its prevalence is increasing worldwide. Recent animal studies have identified gut microbiota as a potentially important player in the pathogenesis of NAFLD. Previously, we reported that the administration of branched-chain amino acids (BCAAs) reduces hepatic fat accumulation in experimental animal models. This study aimed to clarify how changes in the intestinal microbial flora following the administration of BCAAs affect a high-fat diet (HF)-induced fat accumulation in the liver. We examined whether the administration of BCAAs alters the development of hepatic fat accumulation as well as intestinal microbial flora. The oral administration of BCAAs (3% kcal) induced a significant increase in Ruminococcus flavefaciens (R. flavefaciens) and portal acetic acid levels, and it reduced hepatic fat accumulation in HF-fed rats. In addition, BCAAs reduced the expression of the lipogenesis-related genes FAS and ACC in the liver. Furthermore, we observed that R. flavefaciens is essential for promoting a BCAA-induced reduction in hepatic fat accumulation. These data suggest that BCAA treatment induces the proliferation of intestinal flora including R. flavefaciens and that portal acetic acid synthesized from intestinal flora improves NAFLD by downregulating the expression of FAS and ACC in the liver.

1946-P: Dapagliflozin Suppresses Adipose Fatty Acid Accumulation in Rats Fed on High-Fat Diet but Not on Normal Chow

SGLT2 inhibitor (SGLT2i) exerts not only on enhancement of glucose excretion but also on improvement of serum lipid profile via increase in lipid utilization as an energy source instead of glucose. That is, SGLT2i might affect the lipid storage. In the present study, we evaluated the effects of dapagliflozin (DAPA) on weight and fatty acid contents of adipose tissues. At 8 weeks of age, male rats were divided into four groups: (a) NC (n=6) fed on a standard laboratory chow (LC); (b) NC+DAPA (n=6) on the LC with 1 mg/kg/day DAPA administration; (c) HFD (n=6) on a high-fat diet (HF); (d) HFD+DAPA (n=6) on the HF with 1 mg/kg/day DAPA administration. After 7 weeks, we weighed epididymal (EPI), mesenteric (MES), retroperitoneal (RET), and inguinal subcutaneous (SUB) adipose tissues, and measured 21 adipose fatty-acid contents (μmol/g BW). As a result, adipose tissue weight in the examined four sites in HFD rats were significantly higher (P&amp;lt;0.01) than those, respectively, in NC rats. No significant differences were observed in weights of any adipose tissues or in their contents of fatty acids between the NC and NC+DAPA rats. In contrast, MES weight in HFD+DAPA rats was significantly lower (P&amp;lt;0.05) than that in the HFD rats. Contents of 1, 3, 2 and 1 saturated fatty acids (SFAs) in EPI, MES, RET and SUB, respectively, in the HFD+DAPA rats were significantly lower (P&amp;lt;0.05) than those, respectively, in the HFD rats. Contents of 3 and 2 monounsaturated fatty acids in MES and SUB, respectively, and contents of 2 and 1 polyunsaturated fatty acids in MES and RET, respectively, in the HFD+DAPA rats were significantly lower (P&amp;lt;0.05) than those, respectively, in the HFD rats. These results suggest that DAPA could reduce some SFAs in any adipose tissues in HF-fed rats, but not in LC-fed rats. The reduction might sometimes arise without concomitant decrease in tissue weight. In addition, DAPA might suppress accumulation of a wide range of fatty acids in MES of HF-fed rats in particular, probably due to their consumption. Disclosure D. Sato: None. J. Amarume: None. M. Yano: None. Y. Umehara: None. M. Kusunoki: Other Relationship; Self; Kaken Pharmaceutical Co., Ltd., Ono Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd. Z. Feng: None. T. Nakamura: Research Support; Self; AstraZeneca K.K., Ono Pharmaceutical Co., Ltd. Funding Ono Pharmaceutical Co., Ltd.; AstraZeneca K.K.

71-OR: Oligofructose Improves Small Intestinal Nutrient-Sensing Mechanisms via the Small Intestinal Microbiota

Manipulations to the microbiota may serve as a potential treatment for obesity. Oligofructose (OFS), a nondigestible carbohydrate, beneficially alters the distal gut microbiome and results in decreased food intake and bodyweight, although the exact mechanisms remain unknown. Despite the importance of small intestinal (SI) gut-brain nutrient feedback mechanisms in regulating food intake and energy homeostasis, no studies have directly examined whether OFS can improve SI gut-brain signaling, potentially via changes in the SI microbiota. Given recent evidence highlighting the importance of SI microbiota on regulating metabolic homeostasis, we tested the hypothesis that OFS specifically improves SI lipid-sensing mechanisms controlling food intake, via manipulation of SI microbiota. Before any significant changes in body weight are observed, acute (3d) treatment with OFS in high fat (HF)-fed rats results in a significant suppression of 2hr food intake following an intralipid or liquid meal SI infusion (6kcal) compared to HF alone, likely due to a restored gut to brain signal. OFS treatment also increased jejunal CD36 gene and protein expression, which is known to mediate lipid-induced release of GLP-1. As such, OFS-treated rats exhibited significantly increased portal GLP-1 levels and c-fos, a marker neuronal activation, in the NTS of the hindbrain following intralipid SI infusion, compared to HF-fed rats. Importantly, transplant of SI microbiota from 3d OFS HF-fed donors into HF-fed rats recapitulated these results, demonstrating the importance of OFS-induced SI microbiota changes in restoring nutrient-induced gut brain signaling. These results highlight the importance of the small intestinal microbiota in energy regulation and identify a potential role of the small intestine and small intestinal nutrient sensing in the beneficial effects of OFS. Disclosure S.N. Weninger: None. E. Beauchemin: None. A.I.L. Lane: None. R. Meyer: None. F. Duca: None. Funding Arizona Biomedical Research Commission (NIA17-7401)

Association between 12α-hydroxylated bile acids and hepatic steatosis in rats fed a high-fat diet

High-fat (HF) diet induces hepatic steatosis that is a risk factor for noncommunicable diseases such as obesity, type 2 diabetes and cardiovascular disease. Previously, we found that HF feeding in rats increases the excretion of fecal bile acids (BAs), specifically 12α-hydroxylated (12αOH) BAs. Although the liver is the metabolic center in our body, the association between hepatic steatosis and 12αOH BAs in HF-fed rats is unclear. Thus, we investigated extensively BA composition in HF-fed rats and evaluated the association between hepatic steatosis and 12αOH BAs. Acclimated male inbred WKAH/HkmSlc rats were divided into two groups and fed either control or HF diet for 8 weeks. Feeding HF diet increased hepatic triglyceride and total cholesterol concentrations, which correlated positively with 12αOH BAs concentrations but not with non-12αOH BAs in the feces, portal plasma and liver. Accompanied by the increase in 12αOH BAs, the rats fed HF diet showed increased fat absorption and higher mRNA expression of liver Cidea. The enhancement of 12αOH BA secretion may contribute to hepatic steatosis by the promotion of dietary fat absorption and hepatic Cidea mRNA expression. The increase in 12αOH BAs was associated with enhanced liver cholesterol 7α-hydroxylase (Cyp7a1) and sterol 12α-hydroxylase (Cyp8b1) mRNA expression. There was a significant increase in 7α-hydroxycholesterol, a precursor of BAs, in the liver of HF-fed rats. Altogether, these data suggest that the HF diet increases preferentially 12αOH BAs synthesis by utilizing the accumulated hepatic cholesterol and enhancing mRNA expression of Cyp7a1 and Cyp8b1 in the liver.

Repurposing Disulfiram as an Anti-Obesity Drug: Treating and Preventing Obesity in High-Fat-Fed Rats.

Background and ObjectivesA drug repurposing strategy is an approach for identifying new therapeutic uses for approved or investigational drugs. Thanks to the moderate cost of repurposing a drug compared to bringing new chemical entity to the market, drug repurposing is rapidly gaining ground. The aim of this work is to study the anti-obesity effect of disulfiram (DSF), an irreversible aldehyde dehydrogenase inhibitor approved by the Food and Drug Administration (FDA) to treat chronic alcoholism since 1951.MethodsThirty male Albino rats were randomly assigned to six groups. G1, the control group, was given a standard diet. G2, the positive control group, was given a high-fat diet (HFD). G3 was given an HFD, and DSF 50 mg/kg/day was administered orally from day one for six weeks. G4 was given an HFD, and DSF 200 mg/kg/day was administered orally from day one for six weeks. G5 was given an HFD for six weeks; then treatment started with 50 mg/kg/day DSF orally. G6 was given an HFD for six weeks; then treatment started with 200 mg/kg/day DSF orally for three weeks. The body weight, food consumption and blood glucose levels were monitored over the given time interval.ResultsBoth doses of DSF significantly limited the body weight gain caused by an HFD for the treated animals. HF-fed rats received 50 and 200 mg/kg/day of DSF had their body weight increased by 51.93 ± 7.89% and 20.88 ± 15.05% respectively, whereas the body weight of control animals increased by 93.1 ± 20.04%. DSF also significantly decreased the body weight of obese animals. At 50 and 200 mg/kg/day of DSF, HF-fed rats lost 16.74 ± 8.61% and 23.9 ± 3.93% respectively, as their untreated counterparts had their body weight increased by 11.85 ± 3.79% after three weeks of treatment, thus restoring a body weight matching those who received a standard diet.ConclusionFDA-approved disulfiram has a strong anti-obesity effect on HFD-fed rats.