High-fat Rats Research Articles

Co-treatment of Astragaloside IV with Vitamin D in Diabetic Peripheral Neuropathic Rats: Protective Effects and Potential Mechanisms.

The potential mechanism underlying the protective effect of Astragaloside IV (AS-IV) co-treatment with 1, 25-dihydroxy-vitamin D (Vit-D) on neuropathy in diabetic high-fat rats was investigated. The rat diabetic hyperlipidemia (DH) model was established via streptozotocin and a high-fat diet (HFD). After co-treatment (of AS-IV and Vit-D at respective doses of 50 mg/kg via oral gavage and 30000 IU/kg via intramuscular injection), blood glucose levels, markers of inflammation and oxidative stress, as well as apoptosis and histopathology were evaluated with appropriate techniques. Co-treatment could effectively reduce blood glucose levels substantially (p< 0.01), improve weight loss, and decrease oral glucose tolerance. Reduced respective sensory and motor nerve conduction velocities in rats were substantially improved (p<0.01) after co-treatment. Also, we observed obvious improvement in DH-induced injured nerve fiber myelin structure and other organ pathologies in co-treated rats. Besides, we observed up-regulated expressions of peroxisomal-proliferator activated receptor-alpha (PPAR-α) and Vit-D receptors (VDR) (p< 0.01) through the western blotting technique. Using the same technique, we also discovered reduced levels of interleukin (IL)1 beta, IL-6, and tumor necrosis factor-alpha, coupled with increased IL-10 and superoxide dismutase levels (p< 0.01). Importantly, co-treatment could effectively exert antioxidative and anti-inflammatory effects. Also, co-treatment resulted in the up-regulation of PPAR-α and VDR expressions, inhibition of the renin-angiotensin-aldosterone system, and promotion of β-cell sensitivity to insulin. The combined application of AS-IV and Vit-D exhibited health effects such as anti-oxidation, regulation of inflammatory factors, and promotion of cell repair, which may be considered as the mechanisms underlying treatment of diabetic peripheral neuropathy and improvement in biochemical indicators.

Stigmasterol and gastrodin, two major components of banxia-baizhu-tianma decoction, alleviated the excessive phlegm-dampness hypertension by reducing lipid accumulation

Ethnopharmacological relevanceBanxia baizhu tianma decoction (BBTD) originated from the Qing Dynasty Chinese medicine book “Medical Xinwu”, which has a clinical application history of more than 300 years. It's a classic prescription for expelling phlegm, extinguishing wind, strengthening the spleen (traditional Chinese medicine, ie, TCM, refers to the spleen channel) and dissipating excessive fluid based on TCM theory. BBTD is particularly effective in the treatment of excessive phlegm-dampness hypertension. However, the precise pharmacological effect of each herb of BBTD on hypertension treatment is not yet fully understood. Aim of the studyTo investigate the pharmacological effects of each herb in BBTD on hypertension treatment and to explore the mechanisms behind them. Materials and methodsA high-fat-diet fed animal model was developed to evaluate the efficacy of different groups of drugs in BBTD for the treatment of hypertension. Untargeted metabolism was used to detect the metabolic changes after modeling and drug intervention. Then, Stigmasterol (STI) and gastrodin (GAS), major components of Pinellia Ternate Makino and Gastrodia elata Blume, were selected for treatment on HepG2 cell steatosis model. Real-time quantitative polymerase chain reaction and Western blotting were used to detect changes of corresponding gene and protein after drug intervention to explore the exam anti-hyperlipidemia mechanism of STI and GAS combination. ResultsThe weight gain, elevated blood pressure and increased blood lipids induced by high-fat-diet were significantly decreased (p < 0.05) after each prescription medicine intervention in a dose-dependent manner. In addition, 28 differential metabolites (DMs) were detected after modeling and were regulated to normal at varying degrees after each drug group treatment. In addition, eight of the 28 DMs were significantly different from the model group after the full prescription drug intervention, primarily related to four metabolic pathways, while only two metabolites were significantly different from the model group after the unprincipled drug intervention, related to one metabolic pathway. In HepG2 hyperlipidemia cell model, STI, GAS and their combination significantly decreased TC, TG levels and lipid accumulation (p < 0.05), and decreased sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD1) and their protein expressions (p < 0.05), increased adenosine monophosphate-activated protein kinase (AMPK) and it's protein expression (p < 0.05). The two drugs work better in combination than alone. ConclusionBBTD has been shown to be effective in reducing lipid accumulation in a high-fat rat model, as well as in restoring the model-induced abnormal metabolites to normal levels in a dose-dependent manner. Pinellia ternata Makino and Gastrodia elata Blume, the main components of BBTD, may regulate lipid metabolism through fatty acid biosynthesis, arginine and proline metabolism. Their main active agents, STI and GAS, effectively reduce lipid accumulation and lipid content in cells and regulate the expression levels of genes and proteins associated with lipid metabolism. These results suggest that BBTD may regulate lipid metabolism via AMPK/SREBP-1c pathway.

Studying the possibility of using olive oil and its active components together with atorvastatin in the treatment of biochemical parameters and iron deposition in heart tissue with lung histopathology conditions induced by hypercholesterolemia in male rod

Background Hyperlipidemia is one of the leading causes of the inflammatory response due to damage to the lung tissue, and the antioxidant activity of olive oil and hydroxytyrosol curbs these disorders. Therefore, the current study aimed to investigate the effect of Hydroxytyrosol (HXT) and Olive Oil (OO) on increased levels of Adiponectin, decreased Tumor Necrosis Factor Alpha (TNF-α) and Interleukin 6 (IL-6) in blood serum with the improvement of histological lung disorders in experimental hyperlipidemia in male Sprague Dawley rats and an assessment of outcomes with atorvastatin. Method Thirty albino male rats were used in this study, divided into six groups of approximately identical weight. The initial group received a typical diet devoid of cholesterol. The two groups were fed a diet including 2% cholesterol for the length of the experiment for eight weeks, and the 3rd, 4th, 5th, and 6th teams were placed on a two-week high-cholesterol diet. They were given a dose of (OO) extract just, (HXT) just, (OO) extract + (HXT), and a drug. Atorvastatin (ATOR), consecutively, from the third week to the eighth week of the experiment. Results The results of the study showed a significant decrease (P≤0.05) in the concentration of Adiponectin and a significant increase in the concentration of TNF-α and IL-6 in the blood serum, In addition to a rise in the scale of malondialdehyde (MDA), iron deposition, lower rates in the level of glutathione (GSH), and the activity of the catalase (CAT) enzyme in heart tissue; additionally, numerous lung histopathological disorders, that also comprised damage to the alveolar (DA) and damage to the alveolar sacs (DAS), Thickening Vessels (TV), Thickening Bronchioles (TB), Fibrosis (Fi), Inflammatory Infiltration (II), Congestions (CON), Hemorrhage (H), Degeneration (D), necrosis (N) and karyolysis (KL) in the group with hyperlipidemia food contrasted to the group of healthy controls. Whereas the teams of high-fat rats, which were also gavage by (OO) extract just, (HXT) just, (OO) extract + (HXT), and (ATOR) drug demonstrated an enhancement in each of the factors above, as (OO) extract + (HXT) outperformed all treatments. Conclusions As a result, we conclude the present study that hyperlipidemia causes a significant lowering in the concentration of adiponectin and a significant rise in the concentration of TNF-α and IL-6 in serum from the blood, In addition to lower rates in the scale of MDA, iron deposition, lower rates in the level of GSH, and the activity of the CAT enzyme in heart tissue, as well as many histological disorders in the lung, and that mixing olive oil extract and hydroxytyrosol plays an essential role in Inhibition of adverse consequences of hypercholesterolemia.

Mechanism of VPS26 gene promoting implant osseointegration through Wnt/β-catenin pathway in hyperlipidemia rats

Objective: To investigate the mechanism of VPS26 effect on osteogenesis and adipogenesis differentiation of rat bone marrow mesenchymal stem cells (BMSC) in high fat environment, and to explore the effect of VPS26 on implants osseointegration of high fat rats and ectopic osteogenesis in nude mice. Methods: BMSC were cultured under normal osteogenic induction (osteogenic group) and high-fat osteogenic induction (high-fat group).High-fat group was transfected with VPS26 enhancer and inhibitor, and the expression levels of osteogenesis related genes and adipogenesis related genes were examined. Osteogenesis and adipogenesis of BMSC were detected by alkaline phosphatase (ALP) staining and oil red O staining after 7 and 14 days of induction.In osteogenic group,the binding of VPS26 to β-catenin was detected by immunofluorescence staining and immunoprecipitation, and dual luciferase reporter assay (TOP Flash) was used to analyze the TOP/FOP ratio. Eighteen male 12-week hyperlipidemic Wista rats (160-200 g) were implanted with implants, and six in each group were injected with VPS26 overexpression lentivirus (LV-VPS26 group), negative control lentivirus (LV-nc group) and saline (blank control group).Micro-CT analysis , HE and oil red O staining were used to evaluate the osseointegration of the implants and lipid droplets formation of the femur samples. Twenty female 6-week nude mice (30-40 g) were divided into five groups and subcutaneously implanted with osteogenic BMSC non-transfected and transfected LV-VPS26, LV-nc, shVPS26, and shscr lentivirus on the back. Samples were used to observe ectopic osteogenesis. Results: The mRNA expression levels of ALP in the high-fat group BMSC after overexpression of VPS26 (1.56±0.09) were significantly higher than those of the negative control (1.01±0.03) (t=10.09, P<0.001), while those of peroxisome proliferator-activated receptor-γ (PPAR-γ) (t=6.44, P<0.001) and fatty acid-binding protein4 (FABP4) (t=10.01, P<0.001) were lower than those of the negative control. Western blotting results showed that compared with the negative control, protein expression of ALP and Runt-related transcription gene 2 was enhanced in the high-fat group BMSC after overexpression of VPS26 while PPAR-γ and FABP4 were inhibited. ALP activity of BMSC in the high-fat group was stronger after overexpression of VPS26, and the formation of lipid droplets was weaker than that in negative control. The results of immunofluorescence, immunoprecipitation and dual luciferase reporter assays showed co-localization and interaction of VPS26 with β-catenin and a significant 43.10% increase in the TOP/FOP ratio (t=-3.17, P=0.034). VPS26 overexpression enhanced osseointegration and decreased the number of lipid droplets in high-fat rat and enhanced ectopic osteogenesis of nude mice. Conclusions: VPS26 activated osteogenesis differentiation and inhibited adipogenic differentiation of BMSCs through Wnt/β-catenin pathway, promoting osseointegration of high-fat rat implants and ectopic osteogenesis of nude mice.

A glucose-sensing mechanism with glucose transporter 1 and pyruvate kinase in the area postrema regulates hepatic glucose production in rats

The area postrema (AP) of the brain is exposed to circulating metabolites and hormones. However, whether AP detects glucose changes to exert biological responses remains unknown. Its neighboring nuclei, the nucleus tractus solitarius (NTS), responds to acute glucose infusion by inhibiting hepatic glucose production, but the mechanism also remains elusive. Herein, we characterized AP and NTS glucose-sensing mechanisms. Infusion of glucose into the AP, like the NTS, of chow rats suppressed glucose production during the pancreatic (basal insulin)-euglycemic clamps. Glucose transporter 1 or pyruvate kinase lentiviral-mediated knockdown in the AP negated AP glucose infusion to lower glucose production, while the glucoregulatory effect of NTS glucose infusion was also negated by knocking down glucose transporter 1 or pyruvate kinase in the NTS. Furthermore, we determined that high-fat (HF) feeding disrupts glucose infusion to lower glucose production in association with a modest reduction in the expression of glucose transporter 1, but not pyruvate kinase, in the AP and NTS. However, pyruvate dehydrogenase activator dichloroacetate infusion into the AP or NTS that enhanced downstream pyruvate metabolism and recapitulated the glucoregulatory effect of glucose in chow rats still failed to lower glucose production in HF rats. We discovered that a glucose transporter 1- and pyruvate kinase-dependent glucose-sensing mechanism in the AP (as well as the NTS) lowers glucose production in chow rats and that HF disrupts the glucose-sensing mechanism that is downstream of pyruvate metabolism in the AP and NTS. These findings highlight the role of AP and NTS in mediating glucose to regulate hepatic glucose production.

Does oestradiol treatment alleviate obesity-induced oxidative stress in the male liver?

The liver is an organ in which many oxidative processes occur and represents an important target of oxidative stress (OxS). Under physiological conditions of normal mitochondrial homeostasis, hepatocytes effectively remove reactive oxygen species (ROS) by enabling metabolic adaptations and through the antioxidant defence system mechanisms. However, obesity-induced lipid accumulation in the hepatocytes causes significantly elevated production of ROS, reduces oxidative capacity, and increases oxidative stress (OxS). In men, compared with premenopausal women, the development of insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) in obesity are more prevalent, where oestradiol (E2), the most potent female sex steroid, is proposed as the main culprit. Exogenous oestradiol (E2) administration exerts beneficial effects on antioxidant properties, restores total plasma antioxidant capacity and decreases biomarkers of OxS in ovariectomized animal models. Thus, we hypothesized that E2 treatment in states of obesity could have beneficial effects againstOxS in the obese male's liver. We assumed that E2 could directly affect the level of OxS by increasing the level/activity of the AOS enzymes, particularly SOD1, SOD2, GPx, and CAT, in obese males' livers. In addition, we assumed that the level of malondialdehyde (MDA) and protein carbonyl content (PCC) in obese males' livers would be reduced after E2 treatment as a result of E2 inhibitory effect on lipid peroxidation and protein oxidation, respectively. To test our hypothesis, we used the liver of a high-fat (HF) diet-fed male Wistar rats as an animal model of obesity, treated with E2 intraperitoneally (40 μg/kg). Preliminary results from this study support our hypothesis that E2 increases liver protein expression of AOS enzymes: SOD1, GPx, and CAT, in control and HF male rats compared with their respective controls. The protein level of SOD2 and CAT activity was increased in HF treated with E2 compared with non-treated HF rats. Moreover, as we expected, E2 administration significantly decreased the MDA level in both E2-treated groups compared to their controls, while the PCC level was significantly decreased in HF treated group compared with untreated HF rats. In conclusion, the preliminary results we obtained in this study indicate that E2 administration can effectively inhibit the OxS-related processes in the liver in HF diet-induced obesity by increasing AOS enzymes levels and CAT activity, and also by decreasing levels of MDA and PCC. A consequence of our hypothesis is that treatment with E2 may be an innovative way to improve obesity-related liver disease prevention and healing.

The capsaicinoid nonivamide suppresses the inflammatory response and attenuates the progression of steatosis in a NAFLD-rat model.

Nonalcoholic fatty liver disease (NAFLD) is relatively associated with comorbidities in obesity and metabolic inflammation. Low-grade inflammation following the high-fat diet (HFD)-induced NAFLD can promote the development of nonalcoholic steatohepatitis (NASH) through particularly liver-resident immune cell recruitment and hepatic nuclear factor kappa B (NF-κB) pathway. Therefore, inflammatory intervention may contribute to NASH reduction. Pelargonic acid vanillylamide (PAVA) or nonivamide is one of the pungent capsaicinoids of Capsicum species and has been found in chili peppers. Our previous study demonstrated that PAVA improved hepatic function, decreased oxidative stress and reduced apoptotic cell death but the insight role of PAVA on NAFLD is still unclear. Thus, this study aimed to investigate the underlying anti-inflammatory mechanism of PAVA in an NAFLD-rat model. Male Sprague Dawley rats were fed with normal diet or HFD for 16 weeks. Then high-fat rats were given vehicle or PAVA (1 mg/kg/day) for another 4 weeks. We found that PAVA alleviated hepatic inflammation associated with the reducing toll-like receptor 4/NF-κB pathway, showing significantly lower recruitment of cluster of differentiation 44. PAVA also maintained activity of insulin signaling pathway, and attenuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome formation. NAFLD progresses to NASH through transforming growth factor (TGF-β1), and also recovery to simple stage followed by PAVA suppresses pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, interleukin-6, and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway. Therefore, our findings suggest that PAVA provides a novel therapeutic approach for NAFLD and slows the progression to NASH.

Resistant starch from black rice, Oryza sativa L. var. ameliorates renal inflammation, fibrosis and injury in insulin resistant rats.

It has recently been reported that black rice (BR) extract has anti-obesity, anti-diabetic, and anti-osteoporosis effects. It has been shown to reduce obese-related kidney dysfunction in animal models. This study aimed to investigate the effect of resistant starch from BR (RS) on renal inflammation, oxidative stress, and apoptosis in obese insulin resistant rats. Male Wistar rats were divided into six groups: normal diet (ND), ND treated with 150 mg of RS (NDRS150), high-fat (HF) diet, HF treated with 100 and 150 mg of RS (HFRS100), (HFRS150), and HF treated with metformin as a positive control. Insulin resistance was shown in the HF rats by glucose intolerance, increased insulin, total area under the curve of glucose and homeostasis model assessment of insulin resistance and dyslipidemia. The resulting metabolic disturbance in the HF rats caused renal inflammation, fibrosis and apoptosis progressing to kidney injury and dysfunction. Prebiotic RS including anthocyanin from BR at doses of 100 and 150 mg ameliorated insulin resistance, dyslipidemia and liver injury. Treatment with RS reduced TGF-β fibrotic and apoptotic pathways by inhibition of NF-κB and inflammatory cytokines which potentially restore kidney damage and dysfunction. In conclusion, prebiotic RS from BR ameliorated obesity induced renal injury and dysfunction by attenuating inflammatory, fibrotic, and apoptotic pathways in insulin resistant rats induced by HF.

A high fat diet does not stimulate blood pressure dependence on chemerin in the Sprague-Dawley rat

The adipokine chemerin is a candidate for connecting obesity to hypertension. Study objectiveTo test the hypothesis that a high fat (HF) diet stimulates dependence on chemerin for blood pressure regulation. DesignBlood pressure in male Sprague Dawley rats fed a control (10 % fat) or HF (60 % fat) diet from weaning was measured using radiotelemetry. Antisense oligonucleotides (ASOs), administered after 17 weeks of feeding, were used to abolish chemerin production. ResultsThe HF diet did not increase blood pressure (mm Hg; control = 117.0 ± 2.5; HF = 122.0 ± 2.2). An ASO against chemerin (dosed 1×/week, 4 weeks) similarly reduced blood pressure in the control (−14.0 ± 2.7 mmHg) and HF rat (−12.4 ± 2.3). Chemerin mRNA was abolished in the liver and fats (primary producers of chemerin) from rats given the ASO chemerin vs control. ConclusionA HF diet alone is insufficient to stimulate the dependence of blood pressure in the rat on chemerin.

Sex Differences in Diurnal Sodium Handling During Diet-Induced Obesity in Rats.

Emerging evidence over the past several years suggests that diurnal control of sodium excretion is sex dependent and involves the renal endothelin system. Given recent awareness of disruptions of circadian function in obesity, we determined whether diet-induced obesity impairs renal handling of an acute salt load at different times of day and whether this varies by sex and is associated with renal endothelin dysfunction. Male and female Sprague-Dawley rats were placed on a high-fat diet for 8 weeks before assessing renal sodium handling and blood pressure. Male, but not female, rats on high fat had a significantly reduced natriuretic response to acute NaCl injection at the beginning of their active period that was associated with lower endothelin 1 (ET-1) excretion, lower ET-1 mRNA expression in the cortex and outer medulla as well as lower ETB receptor expression in the outer medulla of the high-fat rats. Obese males also had significantly higher blood pressure (telemetry) that was exacerbated by adding high salt to the diet during the last 2 weeks. While female rats developed hypertension with a high-fat diet, they were not salt sensitive and ET-1 excretion was unchanged. These data identify diet-induced obesity as a sex-specific disruptive factor for maintaining proper sodium handling. Although high-fat diets induce hypertension in both sexes, these data reveal that males are at greater risk of salt-dependent hypertension and further suggest that females have more redundant systems that can be productive against salt-sensitive hypertension in at least some circumstances.

1358-P: Small Intestinal Casein Sensing Regulates Food Intake and Glucose Tolerance in Rats

High protein diet reduces food intake and improves glucose homeostasis in rodents and humans with obesity and diabetes, but the mechanistic site (s) of action remain unclear. Small intestinal lipid and glucose sensing regulates energy and glucose homeostasis, but the metabolic role of gut protein sensing remains elusive. In this study, we infused 8% casein hydrolysate as protein source into the upper small intestine (USI) and performed fasting-refeeding studies. We found that USI casein infusion (1.28 kcal/min) suppressed food intake up to 6h in chow but not high fat (HF) - fed rats (chow USI: sal 47±2 vs. cas 36±2 kcal, n=18, p&amp;lt;0.01. HF USI: sal 39±3 vs. cas 40±3 kcal, n=11) . Interestingly, we discovered USI casein infusion instead improved intravenous glucose tolerance effectively in both chow and HF rats (AUC, chow USI: sal 1152±112 vs. cas 850.2±37, n=7, p&amp;lt;0.05. HF USI: sal 1172±54 vs. cas 758.3±42 kcal, n=9, p&amp;lt;0.05) . Next, we evaluated whether small intestinal calcium sensing receptor (CaSR) mediates protein sensing and first discovered that CaSR was expressed in the small intestine with higher expression in the ileum vs. USI (USI 1.0±0.1 vs. ileum 5.8±1, n=8, p&amp;lt;0.01) . Next, we inhibited CaSR with CaSR inhibitor NPS2143 (56 µM) and found that its USI co-infusion with casein prevented the effects on glucose tolerance in both chow and HF rats. Finally, we injected lentivirus expressing shRNA of CaSR or mismatch sequence into the USI and CaSR expression was reduced by ˜40% (n=6, p&amp;lt;0.001) . Importantly, USI casein effect in both chow and HF rats on glucose tolerance were lost (chow: MM cas 799.2±51 vs. LV-CaSR cas 1069±64, n=6, p&amp;lt;0.01; HF: MM cas 771.8±20 vs. LV-CaSR + cas 1240±89, n=4, p&amp;lt;0.05) . In summary, these data illustrate that USI protein sensing increases glucose tolerance in chow and HF rats via CaSR, and lowers feeding in chow but not HF rats. Future studies are needed to dissect the metabolic role of CaSR not only for USI but also ileal protein sensing in energy balance and glucose homeostasis in obesity and diabetes. Disclosure R.J.W.Li: None. D.Barros: None. Y.Lim: None. S.Zhang: None. A.Gao: None. T.K.Lam: None.

Effect of artemisinin on improving islet function in rats fed with maternal high-fat diet

Background Maternal high-fat diet (HFD) is a detrimental factor in developing glucose intolerance, obesity, and islet dysfunction. However, the effect of artemisinin on maternal HFD and whether it is related to the alterations of islet function is seldom studied since artemisinin treatments not only attenuate insulin resistance (IR) and restore islet ß cell function in Diabetes mellitus type 2. Methods Female rats were randomly fed a HFD (45% kcal from fat), HFD + artemisinin, or a regular chow diet (RCD) before pregnancy and during gestation. Glucose metabolism and the β cell phenotypes were assessed. Results Maternal HFD increased islet load in female rats, proliferation of pancreatic β cells, increased insulinogen, and decreased insulin secretion response to high glucose stimulation with delayed insulin release, increased fasting glucose, and glucose area under the curve compared with the general diet group. HFD inhibited expression of Foxo1 and PAX6 in female rats. Under the effect of both HFD and pregnancy, islet load was further increased, insulinogen was further increased, and fasting insulin level and fasting glucose were higher than RCD fed general-pregnancy group. ALDH1a3 transdifferentiation and PAX6, Foxo1, and PDX1 expression were increased in islets of high-fat pregnant rats. When adding artemisinin in HFD treated pregnant rats, islet function was significantly improved. Conclusions Intervention with artemisinin in maternal HFD resulted in reduced islet size, decreased number of β-cells and improved islet microcirculation, insulin processing shear process, decreased insulinogen/insulin ratio, and restored islet function through increased expression of PC1/3.

Eight weeks consumption of high-fat diet promotes Mesenteric fat deposition when compared to other rat diets

Metabolic syndrome is a grouping of several medical conditions plaguing the modern world today. Excessive visceral fat is strongly associated with abdominal obesity which is one of the characteristics of metabolic syndrome. In general, an unbalanced, rich diet plays an important role in the proliferation of adipocytes. Our aim is to observe which diet contributes to the deposition of visceral fat such as the mesenteric fat. For eight weeks, thirty-five Sprague Dawley rats were divided into five groups and were fed five different types of diets. The five diets are normal rat chow, high sugar, high starch, high protein and high fat rat (palm oil-based) feed formula. Besides the formularized rat feeds, the rats were given tap water ad libitum. The result showed high fat diet promotes mesenteric fat proliferation when compared to other rat feed formula. Present study showed that high-fat diet promotes mesenteric fat proliferation when compared to other diets.

The beneficial effects of exercise on glucose and lipid metabolism during statin therapy is partially mediated by changes of the intestinal flora.

Recent research has confirmed that moderate-intensity exercise affects the gut microbiome composition and improves cardiac function in an animal model after myocardial infarction (MI). However, few studies have investigated the effects of exercise on glucose and lipid metabolism in patients with coronary heart disease (CHD) receiving a statin treatment and successful percutaneous coronary intervention (PCI). Meanwhile, since statin therapy may lead to the risk of an increase in blood glucose level in CHD patients, we hypothesized that moderate-intensity exercise may be helpful for regulating glucose-lipid metabolism and stabilizing the blood glucose level in CHD patients. Therefore, to confirm our conjecture, we conducted a clinical retrospective study and animal experiment, respectively. The clinical study involved a total of 501 statin-treated patients with CHD after PCI. According to the study protocol, patients were divided into the following three groups: a non-exercise group, exercise at the recommended standard group, and exercise not at the recommended standard group. We found that qualified moderate-intensity exercise decreased blood glucose and lipid levels at follow-up at a mean of 2.2 years, and the incidence of new-onset diabetes showed a downward trend compared with the non-exercise and exercise not at the recommended standard groups. Furthermore, we used a high-fat rat model to explore an additional mechanism of the beneficial effects of exercise-based management on glucose-lipid metabolism apart from the known mechanism. We used 16S rRNA high-throughput sequencing technology to analyze the changes induced by exercise in the composition of intestinal flora in experimental rats. We found that rats that exercised with or without statin administration had lower plasma glucose and lipid levels and that these parameters were higher in the control and statin-treated rats that did not exercise. These results were consistent with the human study. The results from high-throughput sequencing of the intestinal flora of rats showed, to the best of our knowledge, that exercise leads to an increased relative abundance of Akkermansia muciniphila, which contributes to improved glucose and lipid metabolism. Based on our current results, we suggest that moderate-intensity exercise can improve glucose and lipid metabolism and prevent statin treatment-related side effects, such as hyperglycemia, in patients after PCI. Exercise could facilitate the applicability of statins for lower lipid levels. Exercise training also provides additional benefits, such as alteration of the gut microbiota, which contributes to improved glucose and lipid metabolism.

Periodontitis exacerbates the renal degenerative effects of obesity in rats.

Obesity and periodontitis are systemic subclinical inflammatory diseases with established negative renal effects. The aim of this animal study was to thoroughly investigate the possible effects of these two diseases on renal structure and function. Thirty-two male Sprague Dawley rats were divided into four groups: control (C), obesity (Ob), experimental periodontitis (Ep), and Ob+Ep. The first 16weeks of the experiment were aimed for the induction of obesity and the last 5weeks for the induction of periodontitis. Throughout the experimental period, the C and Ep groups were fed standard rat chow, while the Ob groups (Ob and Ob+Ep) were fed high-fat rat chow. Right after the establishment of obesity, periodontal tissue destruction was achieved by placing 3.0silk sutures in sub-paramarginal position around the cervices of mandibular right-left first molar teeth and preserving them for 5weeks. On the last day of the 22nd week, following blood collection, all rats were euthanized, and kidneys and mandibles were collected. Alveolar bone loss was measured on microcomputed tomographic slices. Histopathological evaluations (light microscopy, semi-quantitative analysis of renal corpuscle area, and immunohistochemical analysis of caspase-3 activity) were done on right kidneys and biochemical evaluations (malonyl-aldehyde [MDA], glutathione [GSH], total oxidant status [TOS], total antioxidant status [TAS], oxidative stress [OSI], tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], matrix metalloproteinase [MMP]-8, MMP-9, and cathepsin D [CtD] levels) were done on left kidneys. Renal functional status was evaluated with levels of serum creatinine, urea, and cystatin C. Periodontal bone loss was significantly higher in the Ep and Ob+Ep groups, compared with the C and Ob groups (p<.05). All parameters except TAS and GSH were highest in the Ob+Ep group, and the differences were statistically significant compared with the control group (p<.05). Although the mean TAS and GSH levels were lower in the Ob+Ep group than the other groups, the differences were not statistically significant (p>.05). While the atypical glomeruli score was significantly higher in the Ob+Ep group than in all other groups (p<.05), the acute tubular necrosis and histopathological scores were significantly different only compared with the control group (p<.05). This experimental study showed that the negative effects of the co-existence of periodontitis and obesity on inflammatory stress and apoptotic changes in the kidneys together with the functional parameters were significantly more severe, compared with the presence of one of these diseases alone. TNF-α could have a central role in the periodontitis and obesity-related structural and functional renal changes.

The effect of pre-resection obesity on post-resection body composition after 75% small bowel resection in rats

In patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. Rats (CD IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. Preoperative body weight was 884 ± 95 versus 741 ± 75 g, and preoperative percent body fat was 35.8 ± 3.9 versus 24.9 ± 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% versus 5% decrease in high-fat versus low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. The high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.

The therapeutic effects of berberine plus sitagliptin in a rat model of fatty liver disease.

Objective(s):Fatty liver disease (FLD) is a disorder related to accumulation of excess fat within the hepatocytes. In this study, the effects of Berberine, a natural compound, and Sitagliptin as a DPP-4 inhibitor, were observed in a rat model of FLD.Materials and Methods:Forty male rats were divided into five groups (n=6) including the control group (normal food and water), high-fat group (high-fat diet (HF) for 6 weeks), Berberine group (HF with oral administration of Berberine at 150 mg/kg for 6 weeks), Sitagliptin group (HF with oral administration of Sitagliptin at 10 mg/kg for 6 weeks), and Berberine/ Sitagliptin group (HF diet within combination with oral administration of Berberine 75 mg/kg and Sitagliptin 5 mg/kg for 6 weeks). Animals were examined for weight gain, serum and hepatic biochemical parameters, tissue histology, expression of glucose transporter type 4 (GLUT4) mRNA, and protein expression of Adiponectin receptor2 (AdipoR2) and extracellular signal-regulated kinase (ERK) and phoERK.Results:The results showed that ALT, AST, lipid profile, insulin, glucose, MDA, and TNF-α were significantly improved in high-fat rats treated with Berberine/ Sitagliptin compared with HF and Sitagliptin, and Berberine alone groups. SOD and adiponectin levels in Berberine/ Sitagliptin group were also significantly increased compared with the other groups. Immunoblot analysis showed that the expression of pho-ERK/ERK was significantly decreased and expression of AdipoR2 significantly increased in the Berberine/ Sitagliptin group compared with other groups.Conclusion:Co-administration of Berberine and Sitagliptin is an effective therapeutic regimen for conditions associated with hyperlipidemia.

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.

Small intestinal taurochenodeoxycholic acid-FXR axis alters local nutrient-sensing glucoregulatory pathways in rats

ObjectiveThe mechanism of nutrient sensing in the upper small intestine (USI) and ileum that regulates glucose homeostasis remains elusive. Short-term high-fat (HF) feeding increases taurochenodeoxycholic acid (TCDCA; an agonist of farnesoid X receptor (FXR)) in the USI and ileum of rats, and the increase of TCDCA is prevented by transplantation of microbiota obtained from the USI of healthy donors into the USI of HF rats. However, whether changes of TCDCA-FXR axis in the USI and ileum alter nutrient sensing remains unknown. MethodsIntravenous glucose tolerance test was performed in rats that received USI or ileal infusion of nutrients (i.e., oleic acids or glucose) via catheters placed toward the lumen of USI and/or ileum, while mechanistic gain- and loss-of-function studies targeting the TCDCA-FXR axis or bile salt hydrolase activity in USI and ileum were performed. ResultsUSI or ileum infusion of nutrients increased glucose tolerance in healthy but not HF rats. Transplantation of healthy microbiome obtained from USI into the USI of HF rats restored nutrient sensing and inhibited FXR via a reduction of TCDCA in the USI and ileum. Further, inhibition of USI and ileal FXR enhanced nutrient sensing in HF rats, while inhibiting USI (but not ileal) bile salt hydrolase of HF rats transplanted with healthy microbiome activated FXR and disrupted nutrient sensing in the USI and ileum. ConclusionsWe reveal a TCDCA-FXR axis in both the USI and ileum that is necessary for the upper small intestinal microbiome to govern local nutrient-sensing glucoregulatory pathways in rats.

FXR in the dorsal vagal complex is sufficient and necessary for upper small intestinal microbiome-mediated changes of TCDCA to alter insulin action in rats

ObjectiveConjugated bile acids are metabolised by upper small intestinal microbiota, and serum levels of taurine-conjugated bile acids are elevated and correlated with insulin resistance in people with type 2 diabetes....