High-fat Emulsion Research Articles

Antihyperlipidaemic and antioxidant effect of the total flavonoids in Selaginella tamariscina (Beauv.) Spring in diabetic mice

To investigate the antidiabetic, antihyperlipidaemic and antioxidant activity of total flavonoids in Selaginella tamariscina (Beauv.) Spring (TFST) in a mouse model of diabetes. Normal mice, mice fed with a high-fat emulsion diet and streptozotocin (STZ)-induced diabetic mice were treated with TFST for 6 weeks. Serum glucose, insulin and lipid, hepatic steatosis, production of the protein visfatin and antioxidant indices were evaluated. TFST significantly decreased the concentration of fasting blood glucose, total cholesterol, triglycerides and low-density-lipoprotein cholesterol, while it increased the levels of insulin and high-density-lipoprotein cholesterol in diabetic mice. TFST also improved the results of the oral glucose tolerance test to a certain degree. Furthermore, both the free fatty acid levels in the liver and hepatic steatosis were ameliorated by TFST treatment. These changes may be be associated with decreased production of visfatin. Administration of TFST also significantly decreased the levels of malondialdehyde, nitric oxide and inducible nitric oxide synthase and increased the content of glutathione and the activity of superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase in the liver. No change in blood glucose levels were observed in the normal mice treated with TFST. TFST showed an excellent effect in reducing the high blood glucose level but had no effect on normal blood glucose level. The antidiabetic activity of TFST could be explained by its antioxidant and antihyperlipidaemic activity, which finally elevated the insulin sensitivity of liver.

Intermittent access to sweet high-fat liquid induces increased palatability and motivation to consume in a rat model of binge consumption

Binge eating disorders are characterized by discrete episodes of rapid and excessive food consumption. In rats, giving intermittent access to sweet fat food mimics this aspect of binge eating. These models typically employ solid food; however, the total amount consumed depends on motivation, palatability and satiety, which are difficult to dissociate with solid food. In contrast, lick microstructure analysis can be used to dissociate these parameters when the ingestant is a liquid. Therefore, we developed a binge model using a liquid emulsion composed of corn oil, heavy cream and sugar. We show that rats given intermittent access to this high-fat emulsion develop binge-like behavior comparable to that previously observed with solid high-fat food. One feature of this behavior was a gradual escalation in consumption across 2.5weeks of intermittent access, which was not apparent in rats given lower-fat liquid on the same access schedule. Lick microstructure analysis suggests that this escalation was due at least in part to increases in both motivation to consume and palatability-driven consumption.

Role of Fat Feeding on the Diabetic Albino Rats

Aim of the work: The nutrition of developing countries are rapidly changed and associated with high incidence of obesity as well as the metabolic syndrome and type 2diabetes. There is an increased intake of high caloric foods rich in refined carbohydrates, fats and red animal proteins instead of low caloric foods rich in fibers and containing low fats. This study aimed at the evaluation of effect of animal fats on the diabetic rats. Material and methods: This study was performed on forty eight albino rats (their body weight was 190 ± 10 grams) divided equally into four groups. Two groups (III & IV) were given intravenous streptozotocin in a concentration of 60 mg /Kg. B.W. for three days in order to induce diabetes through the destruction of pancreatic islet beta cells. Non-diabetic rats (group I) were given the laboratory diet (LD) while the non-diabetic second group of rats received an emulsion rich in fat. Third group diabetic animals were fed on the laboratory diet (LD) while group IV diabetic rats were received high-fat (HF) emulsion in the same dosage as group II. C-peptide (ng/ml), blood glucose (mg/ dl), serum triglycerides (TG; mmol/l) and total cholesterol (TC; mmol/l) were assessed before the beginning of this experiment and also once every two weeks for four months in non-fasted diabetic and non diabetic counterparts. Moreover, kidneys and liver were examined histopathologically to detect fatty intracellular accumulation and any other changes.

Participation of antioxidant and cholinergic system in protective effect of naringenin against type-2 diabetes-induced memory dysfunction in rats

Naringenin is a flavone flavonoid possessing antidiabetic, antioxidant and memory improving effects. Therefore, we studied the influence of naringenin against type-2 diabetes-induced memory dysfunction in rats. Type-2 diabetes was induced by high-fat diet and high-fat emulsion for two weeks and a low dose of streptozotocin (35mg/kg). The memory deficit was assessed by using a novel object recognition paradigm. The changes in oxidative markers and cholinesterase (ChE) levels were evaluated in the hippocampal region. After confirmation of diabetes, naringenin (50mg/kg) treatment was given to animals as a preventive and in another set of experiments naringenin (25 and 50mg/kg) or pioglitazone (5mg/kg) or donepezil (3mg/kg) treatments were started after long-standing diabetes (4weeks after confirmation). Both the treatment schedules show significant protection and improvement in cognitive behavior against diabetes-induced memory dysfunction and biochemical changes. Also, treatment with pioglitazone and donepezil improved memory performance in rats. Naringenin was found to decrease oxidative stress by depleting elevated lipid peroxide and nitric oxide and elevating reduced glutathione levels. Cholinergic function was improved by naringenin through the inhibition of elevated ChE activity. In conclusion, the present study suggests that naringenin acts as an antioxidant and ChE inhibitor against type-2 diabetes-induced memory dysfunction.

Hypolipidemic Effects of Andrographolide and Neoandrographolide in Mice and Rats

Andrographolide (AND) and neoandrographolide (NEO) are the diterpenoids from the Andrographis paniculata (Acanthaceae). It is reported the diterpenoids exhibit a wide spectrum of biological activities. The aim of this study was to investigate the hypolipidemic effect of AND and NEO in hyperlipidemic mice induced by 75% yolk emulsion and in hyperlipidemic rats induced by high fat emulsion, respectively. The results showed that the levels of triglyceride, total cholesterol (TC) and low-density lipoprotein cholesterol were reduced by AND and NEO in a dose-dependent tendency in mice. Compared with the model group, the plasma TC levels of experimental groups with AND and NEO at 100 mg/kg dosage decreased by 23.9 and 20.2% in rats, respectively (P < 0.05). It was also found that the plasma aspartate transaminase and alanine transaminase levels were significantly decreased by feeding with AND and NEO in rats, compared with positive group (simvastatin) (P < 0.01). Otherwise, AND and NEO could protect the cardiovascular due to down-regulation of iNOS expression and up-regulation of eNOS expression. In conclusion, AND and NEO have potent hypolipidemic effects and protect the cardiovascular without significant liver damage.

The effect of isosteviol on hyperglycemia and dyslipidemia induced by lipotoxicity in rats fed with high-fat emulsion

Aims The aim of present study was to investigate the effects of isosteviol on hyperglycemia and hyperlipidemia in rats fed with high-fat emulsion (HFE). Main methods Hyperglycemia and hyperlipidemia in rats was induced by daily ingestion of HFE for 14 days. Isosteviol (0.2, 1.0, or 5.0 mg/kg/day) was orally administered for 7 days, with rosiglitazone maleate (5.0 mg/kg/day) used as the positive control. The levels of fasting serum glucose (FSG), fasting serum insulin (FSI), total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), and low density lipoprotein (LDL) in serum were assayed. Intravenous glucose tolerance test (IVGTT) was performed with serum glucose and insulin levels monitored. The effect of the supplement of palmitate in HFE on the activity of isosteviol was investigated. Ultrastructural changes in islet β-cells and peroxisome proliferator-activated receptor α (PPARα) mRNA expression profile were determined. Key findings FSG, FSI, TC and LDL levels and insulin resistance index (IRI) were decreased and HDL level was increased by all doses of isosteviol. During IVGTT, serum glucose levels were decreased by isosteviol and no significant differences were observed in insulin release between isosteviol-treated and control groups. The effects of isosteviol were attenuated by palmitate. Damage to pancreatic islet cells was partially attenuated, and expression profile of hepatic PPARα mRNA was enhanced by isosteviol. Significance Antihyperglycemic effects of isosteviol could enhance utilization of glucose in the periphery and reduce β-cell damage induced by dyslipidemia. Modulating-lipidemic effects of isosteviol might be related to the potential enhancement of liver PPARα mRNA expression.

Correlation Analysis Between Gene Expression Profile of Rat Liver Tissues and High-Fat Emulsion-Induced Nonalcoholic Fatty Liver

Nonalcoholic fatty liver disease (NAFLD) is caused by fat metabolism disorders and thereby abnormal or excessive accumulation of fat in hepatocytes, and characterized by steatosis, inflammation, fibrosis, apoptosis or necrosis. This study was carried out to explore the correlation between gene expression profiles of rat livers and the occurrence and progression of NAFLD at the transcriptional level. A rat model of nonalcoholic steatohepatitis (NASH) was established by feeding male rats with high-fat emulsion via gavage, and Rat Genome 230 2.0 Array was used to detect gene expression profiles of liver tissues obtained from male rats following 0, 2, 4, and 6weeks of high-fat emulsion feeding. Methods of bioinformatics and systems biology were applied to analyze the correlation between gene expression changes and physiological activities involved in NAFLD. In total, 93 function-known genes, including 36 up-regulated and 57 down-regulated, differed significantly in expression compared to those of control rats, and 18 physiological activities were closely related to NAFLD. Especially, the activity of cell differentiation was decreased during the whole process of NAFLD, and the activities of inflammation response, stimulus response, cell migration and adhesion were attenuated in the second, fourth and sixth week, respectively. In the fourth and sixth weeks, lipid metabolism and cell apoptosis were augmented, and the former might be associated with the enhanced expression of plin, acsl6, scd2, elovl3, etc. These data provide useful information on the global gene expression changes due to high-fat emulsion feeding and bring important insights into the mechanisms of NAFLD.

Hypolipidemic effects of chitosan nanoparticles in hyperlipidemia rats induced by high fat diet

The aim of this study was to investigate the hypolipidemic effects of chitosan nanoparticles(CTS-NP) preparations with ionotropic gelation, rotary evaporation, and spray-drying technique. Male SD (Sprague–Dawley) rats were separated into five groups, a normal diet group, a high fat emulsions group, a CTS control group and CTS-NP groups treated with two different doses of CTS-NP. The nanoparticles were spherical in shape and had a smooth surface. The size range of the nanoparticles was between 500 and 1000 nm. The apparent serum lipid and plasma viscosity in CTS-NP group was significantly lower than that in the CTS group, as well as the serum superoxide dismutate (SOD) levels was increased. Although no significant difference in adipose tissue was found among the groups, the rats fed on CTS-NP had lower relative liver weight and body weight when compared with those fed on normal diet. This study was the first report of the effects of CTS-NP in the hyperlipidemia rats, and suggests that the CTS-NP could be used for the treatment of hyperlipidemia.

Lipid-Lowering mechanisms of grape seed extract (Vitis vinifera L) and its antihyperlidemic activity

Grape seed extract (GSE) has been targeted to promote beneficial health effects, especially the prevention of obesity and hyperlipidemia. In present study, we investigated the mechanisms of GSE on inhibition of lipid digestion and absorption. GSE significantly inhibited pancreatic lipase and cholesterol esterase in dose-dependent manner with the IC50 values of 3.71 ± 0.03 and 27.27 ± 4.12 mg/mL, respectively. In addition, GSE also inhibited the formation of cholesterol micelles, and bound to bile acid. The oral administration of GSE significantly decreased serum triglyceride and cholesterol in rat fed high fat emulsion through inhibition of lipid digestion and absorption. GSE may be a feasible therapeutic strategy for prevention and treatment of patients with hyperlipidemia and obesity. Key words: Grape seed extract, bile acid binding, cholesterol micellization, pancreatic cholesterol esterase, pancreatic lipase, mechanisms.

Potential protective effects of a traditional Chinese herb, Litsea coreana Levl., on liver fibrosis in rats

It was found that total flavonoids from Litsea coreana Levl. (TFLC), which is a traditional Chinese medicine, had a preventive effect against hepatic steatosis in our previous study. This study was designed to evaluate whether TFLC could improve liver fibrosis in rats. The liver fibrosis model rats were treated with composite factors of high-fat emulsion (10 ml/kg) via gavage accompanied by a subcutaneous injection of low-dose CCl(4). Thirty rats were given composite factors plus TFLC (100, 200, 400 mg/kg), respectively, for 8 weeks. The results showed that TFLC (200 and 400 mg/kg) treatment significantly reduced the elevation of liver index (liver weight/body weight) and spleen index (spleen weight/body weight), alanine transaminase, aspartate aminotransferase, hyaluronic acid, laminin, procollagen III N-terminal peptide, procollagenase IV and hydroxyproline. In addition, TFLC treatment improved the morphologic changes of hepatic fibrosis, suppressed expression of alpha-smooth muscle actin, collagen I, transforming growth factor (TGF)-beta1 and TGFbeta receptor (TGFbetaR)1, and increased peroxisome proliferator-activated receptor-gamma expression in the liver of hepatic fibrosis rats. In conclusion, TFLC is able to ameliorate liver injury and protect rats from liver fibrosis. This process may be related to inhibiting the expression of transforming growth factor-beta1 and increasing the expression of peroxisome proliferator-activated receptor-gamma.

Hexarelin suppresses high lipid diet and vitamin D 3-induced atherosclerosis in the rat

Growth hormone-releasing peptides (GHRP) and ghrelin are synthetic and natural ligands of growth hormone secretagogue receptor (GHSR) respectively and are shown to exert protective actions on cardiac dysfunction. Because ghrelin has been reported to inhibit proinflammatory responses in human endothelium and GHSR has been identified in blood vessels, we hypothesized that GHRP could alleviate the development of atherosclerosis (As). Atherosclearosis was induced by a short period (4 days) of vitamin D 3 and chronic (three months) intragastric feeding of high fat emulsion (containing 0.5% propylthiouracil) in adult SD rats. Some As rats received chronic hexarelin (a variant of GHRP) injection (SC BID, 30 days) and normal rats received placebo as control. Significant atherosclerosis developed in animals fed with the emulsion. Serum total cholesterol and LDL-c increased, and HDL-c and aortic nitric oxide (NO) decreased significantly in As group. Hexarelin suppressed the formation of atherosclerotic plaques and neointima, partially reversed serum HDL-c/LDL-c ratio and increased the levels of serum NO and aortic mRNAs of eNOS, GHSR and CD36 in As rats. Hexarelin also decreased [ 3H]-TdR incorporation in cultured vascular smooth muscle cell (VSMC) and calcium sedimentation in aortic wall. Furthermore, foam cell formation induced by ox-LDL was decreased by hexarelin. In conclusion, hexarelin suppresses high lipid diet and vitamin D3-induced atherosclerosis in rats, possibly through upregulating HDL-c/LDL-c ratio, vascular NO production and downregulating the VSMC proliferation, aortic calcium sedimentation and foam cell formation. These novel anti-atherosclerotic actions of hexarelin suggest that the peptide might have a clinical potential in treating atherosclerosis.

Congruence subgroups of Hecke groups

This study is to investigate the effect of diet and gene on blood-fat trait of the individual mouse. One hundred and twenty mice were fed with high fat emulsion for 4 weeks. Then the genotypes of Glut-4 were analyzed by PCR-SSCP to investigate the effect on blood-fat traits and some organ performance of mice. After fed with high fat emulsion for 4 weeks, 98 mice suffered from hyperlipidemia, while 22 mice did not. And a T/A mutation was found in 188 targeted fragments we amplified at 8,521 site, and association analysis showed that the mice carried BB genotype had higher TC, TG and LW/BW level than those of the mice with AA genotype (P < 0.05). Different Glut-4 genotypes show different sensitivities to high fat emulsion on mice.

Characterization and acid-induced gelation of butter oil emulsions produced from heated whey protein dispersions

Whey protein isolate was dispersed at 4% or 8% (w/v) and heated at neutral pH to produce protein polymers. Butter oil, up to 20%, was homogenized in heated whey protein dispersions at pressure ranging from 10 to 120 MPa. Emulsion gelation was induced by acidification with glucono- δ-lactone. Whey protein polymers produced finely dispersed emulsions with fat droplet diameter ranging from 340 to 900 nm. Homogenization pressure was the main factor influencing droplet size. At low fat volume fraction, the emulsions exhibited Newtonian behaviour. As fat content increased, shear thinning behaviour developed as a result of depletion flocculation. Emulsion consistency index increased with protein and fat concentrations. Increasing homogenization pressure had no effect on Newtonian emulsions but promoted flocculation and significantly increased the consistency of high fat emulsions. Protein concentration was the main factor explaining emulsion gel hardness and syneresis. Syneresis decreased with increasing fat content in the gel.

High-fat emulsion-induced rat model of nonalcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is emerging as a common medical problem. Nonalcoholic steatohepatitis (NASH) is the critical turning point at which NAFLD progresses to more advanced stages such as hepatic fibrosis, cirrhosis and even hepatocellular carcinoma. However, the study of the pathogenic or therapeutic factors involved in NASH has been hampered by the absence of a suitable experimental model. The aim of the present work was to establish a high-fat emulsion-induced rat model of NASH. Male Sprague–Dawley rats were fed a high-fat emulsion via gavage for 6 weeks. Animals were examined for weight gain, serum and hepatic biochemistry, insulin sensitivity, hepatic malondialdehyde (MDA), superoxide dismutase (SOD) and tissue morphology, as well as cytochrome P-450 2E1 (CYP2E1) and peroxisome proliferator-activated receptor α (PPARα) expression in the liver. The results showed that rats treated with high-fat emulsion became obese, demonstrated abnormal aminotransferase activity, hyperlipoidemia, hyperinsulinemia, hyperglycemia and insulin resistance. The model rats exhibited an increased concentration of serum TNF-α, total cholesterol (TC), triglyceride (TG), MDA and reduced SOD levels in the liver. Immunoblot analysis showed that the expression of CYP2E1 was increased, whereas PPARα was reduced in the NASH model rat liver. Moreover, morphological evaluation revealed that hepatic steatosis, inflammation and mitochondrial lesions were also reproduced in this model. In conclusion, a practical and repeatable new rat model of steatohepatitis was established by feeding with high-fat emulsion via gavage. This model provides a valuable research tool and reproduces many of the clinical indices of human NASH.

Clinical Study on Early Venous Glucose-free Nutrition after Hepatolobectomy

Objective: A randomized trial was designed to study the optimal nutrition after hepatolobectomy. Methods: Thirty-two patients receiving hepatolobectomy were randomly divided into 2 groups: 16 patients in the experimental group receiving high dose fat emulsion and amino acids without glucose for 7 days after hepatolobectomy, and 16 patients in the control group receiving traditional intravenous nutrition. Postoperative changes in blood glucose, lipid, amino acids and total ketone bodies were compared between two groups. Results: Postoperative glucose and lipid levels remained normal in the experimental group, while the free amino acids levels and utilization of ketone bodies were significantly higher than in the control group. Conclusion: Intravenous injection of glucose-free nutrition after hepatolobectomy could not only supply sufficient calories, but also avoid metabolic disturbance due to intravenous injection of glucose.

Development of Wistar rat model of insulin resistance

To establish a simplified and reliable animal model of insulin resistance with low cost in Wistar rats. Wistar rats were treated with a high fat emulsion by ig for 10 d. Changes of the diets, drinking and body weight were monitored every day and insulin resistance was evaluated by hyperinsulinemic-euglycemic clamp techniques and short insulin tolerance test using capillary blood glucose. Morphologic changes of liver, fat, skeletal muscles, and pancreatic islets were assessed under light microscope. mRNA expressions of GLUT2 and alpha-glucosidase in small intestine epithelium, GLUT4 in skeletal muscles and Kir6.2 in beta cell of islets were determined by in situ hybridization. K(ITT) was smaller in treated animals (4.5+/-0.9) than in untreated control Wistar rats (6.8+/-1.5), and so was glucose injection rate. Both adipocyte hypertrophy and large pancreatic islets were seen in high fat fed rats, but no changes of skeletal muscles and livers were observed. mRNA levels of GLUT2, alpha-glucosidase in small intestinal epithelium and Kir6.2 mRNA in beta cells of islets increased, whereas that of GLUT4 in skeletal muscles decreased in high fat fed group compared with normal control group. An insulin resistance animal model in Wistar rats is established by ig special fat emulsion.

Rheological changes during thermal processing of low-fat meat emulsions formulated with different texture-modifying ingredients

The rheological behaviour of high-fat (22%) and low-fat (8%) meat emulsions during thermal processing in the presence (3%) of various texture-modifying non-meat ingredients, namely maltodextrin, starch, wheat flour, egg white and apple fibre, was analysed. Rheological properties of emulsions were assessed using non-destructive measurements (thermal scanning rigidity monitor, TSRM). The lower the fat content, the lower were the rigidity values of meat emulsions throughout the temperature range studied. Emulsions made with maltodextrin proved less rigid. Addition of starch and egg white favoured the formation of more rigid structures in low-fat meat emulsions at temperatures over 55 °C. Low-fat meat batters containing wheat flour and apple fibre exhibited the highest rigidity values over the given temperature range. The presence of wheat flour caused variations in the modulus of rigidity at all stages of the thermal gelation process, very similar to those observed in high-fat emulsions.

29 Fatty acid utilization of MCT containing fat emulsion in newborn infants

Medium-chain triglycerides(MCT)are applied mainly in enteral nutrition of newborn infants. As results of oxidative utilization of MCT after parenteral application have' not yet been published, we investigated MCT oxidation in neonates using the 13C trioctanoin breath test. We carried out 16 breath tests on 11 newborn patients between the first and the thirty-fifth day of life. The patients were nourished with 1,0-6,7g/kg/day glucose i.v., 1,0-2,3g/kg/day 1-amino acids i.v., 1,0g/kg/day fat emulsion i.v. and 12-183ml/kg/day formula. They received parenterally 10mg/ kg 1-13C3 trioctanoin emulsified with Lipofundin MCT/LCT 10% R. The expired 13CO2 resulting from fat oxidation was determined by the use of a ratio-mass-spectrometer. The amount of 13C contained in the expired air gives the rate of the fatty acid oxidation. Within 8 hours between 31,6% and 89,6% of the applied tracer amount was oxidized. The fatty acid oxidation showed a significant negative correlation with simultaneous supply of carbohydrates (r=-O,95, p<0,001). The oxidation rates of MCT were about twice as high as those of long-chain triglycerides. Because of their high energetic level MCT-containing fat emulsions are, in principle, also suitable for parenteral nutrition of newborn infants. The oxidative MCT utilization, is apparently reduced by a high carbohydrate intake. Therefore, the simultaneous administration of carbohydrates must be considered during i.v.supply of MCT-containing fat emulsion. Further investigations are necessary before recommendation can be given for clinical application in neonates.

Pharmacological study on Panax ginseng C.A. Meyer. VII. Protective effect of red ginseng on infection. (1) On phagocytic activity of mouse reticuloendothelial system

The effect of methanol extractives from tea leaves on hypercholesterolemia was examined in animal models. It was found that orally administered (-)-epicatechin gallate and (-)-epigallocatechin gallate from tea leaves lowered the serum cholesterol level in mice fed a high fat emulsion. Quantitation of tissue cholesterol and examination of liver tissues in mice fed a high cholesterol diet revealed that these constituents also significantly lowered the amount of cholesterol crystallization. These results support the reputed effectiveness of tea use in hypercholesterolemia.

Effects of crude drugs on experimental hypercholesterolemia. I. Tea and its active principles

The effect of methanol extractives from tea leaves on hypercholesterolemia was examined in animal models. It was found that orally administered (—)-epicatechin gallate and (— )-epigallocatechin gallate from tea leaves lowered the serum cholesterol level in mice fed a high fat emulsion. Quantitation of tissue cholesterol and examination of liver tissues in mice fed a high cholesterol diet revealed that these constituents also significantly lowered the amount of cholesterol crystallization. These results support the reputed effectiveness of tea use in hypercholesterolemia.