Comparative acetylome analysis reveals the potential mechanism of high fat diet function in allergic disease

Modern technological lifestyles promote allergic diseases,especially food allergies.The underlying molecular mechanisms remain to be uncovered.Protein acetylation is one of the most important post-translational modifications,and it is involved in regulating multiple body metabolic processes.This study aimed to clarify the effects of a high-fat diet(HFD)on allergy risk and the underlying mechanisms.Four-week-old male C57 BL/6 J mice were randomly divided into two groups and fed a normal fat diet(NFD)or HFD for 24 weeks.Then,serum lipids were measured,and skeletal muscle was collected for acetylome analysis.Compared with the findings in the NFD group,HFD-fed mice were obese and hyperlipidemic.Acetylome analysis also revealed 32 differentially expressed proteins between the HFD and NFD groups.Among these,eight acetylated proteins were upregulated in the HFD group.In addition,13 and 11 proteins were acetylated only in the HFD group and NFD group,respectively.These proteins were mainly involved in regulating energy metabolism and mitochondrial function.This study provides information regarding the underlying molecular mechanisms by which HFD promotes allergy.

Modulating Effects of Chlorogenic Acid on Lipids and Glucose Metabolism and Expression of Hepatic Peroxisome Proliferator-activated Receptor-α in Golden Hamsters Fed on High Fat Diet

Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.

Effects of a high fat diet on intestinal microbiota and gastrointestinal diseases

Along with the rapid development of society, lifestyles and diets have gradually changed. Due to overwhelming material abundance, high fat, high sugar and high protein diets are common. Numerous studies have determined that diet and its impact on gut microbiota are closely related to obesity and metabolic diseases. Different dietary components affect gut microbiota, thus impacting gastrointestinal disease occurrence and development. A large number of related studies are progressing rapidly. Gut microbiota may be an important intermediate link, causing gastrointestinal diseases under the influence of changes in diet and genetic predisposition. To promote healthy gut microbiota and to prevent and cure gastrointestinal diseases, diets should be improved and supplemented with probiotics.

High fat diet feeding results in gender specific steatohepatitis and inflammasome activation

AIM: To develop an animal model that encompasses the different facets of non-alcoholic steatohepatitis (NASH), which has been a challenge.

High fat diet dysregulates microRNA-17-5p and triggers retinal inflammation:Role of endoplasmic-reticulum-stress

AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.

Characterization of inflammation and insulin resistance in high-fat diet-induced male C57BL/6J mouse model of obesity

Background: Animal models of diet-induced obesity(DIO) are commonly used in medical research for mimicking human diseases. There is no universal animal model, and careful evaluation of variety of factors needs to be considered when designing new experiments. Here, we investigated the effect of 9 weeks high-fat diet(HFD) intervention, providing 60% energy from fat, on parameters of inflammation and insulin resistance in male C57 BL/6 J mice.Methods: Six weeks old mice were initiated on regular diet(RD) or HFD providing 60 kcal energy from fat for 9 weeks. Fasting blood glucose levels were measured by glucometer, and fasting plasma levels of insulin and proinflammatory cytokines by Luminex assay. Insulin sensitivity was evaluated by using QUICKI and HOMA2 indexes.Results: HFD mice showed ~ 40% higher body weight and ~ 20% larger abdominal circumference, due to an increase in the white adipose tissue mass. Liver examination revealed increased size and higher hepatic lipid accumulation in livers from HFD mice compared to their RD counterparts. Animals from the HFD group were characterized with significantly higher presence of crown-like structures(CLS) in WAT and higher plasma levels of proinflammatory cytokines(TNF-α, IL-6, leptin, MCP-1, PAI-1, and resistin). HFD-fed mice also demonstrated impaired insulin sensitivity(lower QUICKI, higher HOMA-insulin resistance(HOMA-IR), and lower HOMA-percent sensitivity(HOMA-%S)) index values.Conclusion: Male C57 BL/6 J mice on 9 weeks HFD providing 60 kcal energy from fat display impaired insulin sensitivity and chronic inflammation, thus making this DIO mouse model appropriate for studies of early stages of obesity-related pathology.

The effects of the extract of oolong tea and its metabolites from Andraca theae in high fat diet induced obese Wistar rat

Obesity is a critical health issue worldwide.For a long time,the concept of drinking tea for health and pleasure is widely accepted.The strain of Andraca theae lives on the tea leaf and the bioactivity of its metabolites in the feces is unknown yet.Thus,the objective of this study was to investigate whether the extract of tea(Taiwan Tea Experiment Station No.12(TE))and its metabolites from Andraca theae(TME)could prevent obesity in the high fat diet-induced obese rats.Our results showed that TE had higher concentrations of epigallocatechin gallate(EGCG)and caffeine than that from TME.TE significantly decreased abdominal adipose tissue,especially epididymal fat via increasing preadipocyte factor 1(Pref-1),SRY(sex determining region Y)-box 9(SOX-9)and decreasing peroxisome proliferator-activated receptorγ(PPARγ),CCAAT/enhancer binding protein(C/EBP)β,C/EBPαand C/EBPβprotein expression.Taken together,these results suggest that the content of tea polyphenols in TE play an important role for alleviating abdominal fat.

Chlorogenic Acid Maintains Glucose Homeostasis through Modulating the Expression of SGLT-1,GLUT-2,and PLG in Different Intestinal Segments of Sprague-Dawley Rats Fed a High-Fat Diet

Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.

Effects of alkaline-electrolyzed and hydrogen-rich water,in a high-fat-diet nonalcoholic fatty liver disease mouse model

AIM To identify the effect of hydrogen-rich water(HRW) and electrolyzed-alkaline water(EAW) on high-fat-induced non-alcoholic fatty acid disease in mice.METHODS Mice were divided into four groups:(1) Regular diet(RD)/regular water(RW);(2) high-fat diet(HFD)/RW;(3) RD/EAW; and(4) HFD/EAW. Weight and body composition were measured. After twelve weeks, animals were sacrificed, and livers were processed for histology and reverse-transcriptase polymerase chain reaction. A similar experiment was performed using HRW to determine the influence and importance of molecular hydrogen(H2) in EAW. Finally, we compared the response of hepatocytes isolated from mice drinking HRW or RW to palmitate overload.RESULTS EAW had several properties important to the study:(1) pH = 11;(2) oxidation-reduction potential of-495 mV; and(3) H2 = 0.2 mg/L. However, in contrast to other studies, there were no differences between the groups drinking EAW or RW in either the RD or HFD groups. We hypothesized that the null result was due to low H2 concentrations. Therefore, we evaluated the effects of RW and low and high HRW concentrations(L-HRW = 0.3 mg H2/L and H-HRW = 0.8 mg H2/L, respectively) in mice fed an HFD. Compared to RW and L-HRW, H-HRW resulted in a lower increase in fat mass(46% vs 61%), an increase in lean body mass(42% vs 28%), and a decrease in hepatic lipid accumulation(P < 0.01). Lastly, exposure of hepatocytes isolated from mice drinking H-HRW to palmitate overload demonstrated a protective effect from H2 by reducing hepatocyte lipid accumulation in comparison to mice drinking regular water.CONCLUSION H2 is the therapeutic agent in electrolyzed-alkaline water and attenuates HFD-induced nonalcoholic fatty liver disease in mice.

Telmisartan prevents high-fat diet-induced hypertension and decreases perirenal fat in rats

We sought to investigate the effects of telmisartan on high-fat diet-induced hypertension and to explore the possible underlying mechanisms. Rats receiving high-fat diet were randomly divided into two groups, the tel- misartan group （n = 9） and the high-fat diet group （n = 10）. The control group consisted of age-matched rats on a regular diet （n = 10）. At the end of the treatment, the body weight, blood pressure, insulin sensitivity and serum adiponectin levels of all rats were examined, and their visceral fat was extracted and weighed. Our results showed that telmisartan improved insulin resistance and dyslipidemia and increased serum adiponectin levels. Telmisar- tan also lowered both systolic blood pressure and diastolic blood pressure, and decreased the accumulation of perirenal fat associated with high-fat diet. Furthermore, telmisartan increased adiponectin mRNA expression in the perirenal fat. Correlation analysis showed that both systolic blood pressure and diastolic blood pressure were positively correlated with perirenal fat. These effects of telmisartan may be mediated through decreases in perirenal fat and contributed to the improvement of perirenal fat function. Our findings suggested a strong link between perirenal fat and high-fat diet-induced hypertension, and identified telmisartan as a potential drug for the treatment of obesity-related hypertension.

Negative effects of long-term feeding of high-grain diets to lactating goats on milk fat production and composition by regulating gene expression and DNA methylation in the mammary gland

Background： It is well known that feeding a high concentrate（HC） diet to lactating ruminants likely induces subacute ruminal acidosis（SARA） and leads to a decrease in milk fat production. However, the effects of feeding a HC diet for long periods on milk fatty acids composition and the mechanism behind the decline of milk fat still remains poorly understood. The aim of this study was to investigate the impact of feeding a HC diet to lactating dairy goats on milk fat yield and fatty acids composition with an emphasis on the mechanisms underlying the milk fat depression. Seventeen mid-lactating dairy goats were randomly allocated to three groups. The control treatment was fed a low-concentrate diet（35% concentrate, n = 5, LC） and there were two high-concentrate treatments（65% concentrate, HC）, one fed a high concentrate diet for a long period（19 wks, n = 7, HL）; one fed a high concentrate diet for a short period of time（4 wk, n = 5, HS）. Milk fat production and fatty acids profiles were measured. In order to investigate the mechanisms underlying the changes in milk fat production and composition,the gene expression involved in lipid metabolism and DNA methylation in the mammary gland were also analyzed.Results： Milk production was increased by feeding the HC diet in the HS and HL groups compared with the LC diet（P 〈 0.01）, while the percentage of milk fat was lower in the HL（P 〈 0.05） but not in the HS group. The total amount of saturated fatty acids（SFA） in the milk was not changed by feeding the HC diet, whereas the levels of unsaturated fatty acids（UFA） and monounsaturated fatty acids（MUFA） were markedly decreased in the HL group compared with the LC group（P 〈 0.05）. Among these fatty acids, the concentrations of C15：0（P 〈 0.01）, C17：0（P 〈 0.01）, C17：1（P 〈 0.01）, C18：1 n-9 c（P 〈 0.05）, C18：3 n-3 r（P 〈 0.01） and C20：0（P 〈 0.01） were markedly lower in the HL group, and the concentrations of C20：0（P 〈 0.05） and C18：3 n-3 r（P 〈 0.01） were lower in the HS group compared with the LC group. However, the concentrations of C18：2 n-6 c（P 〈 0.05） and C20：4 n-6（P 〈 0.05） in the milk fat were higher in the HS group. Real-time PCR results showed that the m RNA expression of the genes involved in milk fat production in the mammary gland was generally decreased in the HL and HS groups compared with the LC group. Among these genes, ACSL1, ACSS1 ＆ 2, ACACA, FAS, SCD, FADS2, and SREBP1 were downregulated in the mammary gland of the HL group（P 〈 0.05）, and the expressions of ACSS2, ACACA, and FADS2 m RNA were markedly decreased in the HS goats compared with the LC group（P 〈 0.05）. In contrast to the gene expression, the level of DNA methylation in the promoter regions of the ACACA and SCD genes was increased in the HL group compared with the LC group（P 〈 0.05）. The levels of ACSL1 protein expression and FAS enzyme activity were also decreased in the mammary gland of the HL compared with the LC group（P 〈 0.05）.Conclusions： Long-term feeding of a HC diet to lactating goats induced milk fat depression and FAs profile shift with lower MUFAs but higher SFAs. A general down-regulation of the gene expression involved in the milk fat production and a higher DNA methylation in the mammary gland may contribute to the decrease in milk fat production in goats fed a HC diet for long time periods.

Salvia miltiorrhiza extract may exert an anti-obesity effect in rats with high-fat diet-induced obesity by modulating gut microbiome and lipid metabolism

BACKGROUND Studies have shown that a high-fat diet(HFD) can alter gut microbiota(GM)homeostasis and participate in lipid metabolism disorders associated with obesity.Therefore, regulating the construction of GM with the balance of lipid metabolism has become essential for treating obesity. Salvia miltiorrhiza extract(Sal), a common traditional Chinese medicine, has been proven effective against atherosclerosis, hyperlipidemia, obesity, and other dyslipidemia-related diseases.AIM To investigate the anti-obesity effects of Sal in rats with HFD-induced obesity, and explore the underlying mechanism by focusing on GM and lipid metabolism.METHODS Obesity was induced in rats with an HFD for 7 wk, and Sal(0.675 g/1.35 g/2.70g/kg/d) was administered to treat obese rats for 8 wk. The therapeutic effect was evaluated by body weight, body fat index, waistline, and serum lipid level. Lipid factors(cAMP, PKA, and HSL) in liver and fat homogenates were analyzed by ELISA. The effect of Sal on GM and lipid metabolism was assessed by 16S rRNAbased microbiota analysis and untargeted lipidomic analysis(LC-MS/MS),respectively.RESULTS Sal treatment markedly reduced weight, body fat index, serum triglycerides(TG), total cholesterol(TC), low-density lipoprotein, glucose, free fatty acid, hepatic lipid accumulation, and adipocyte vacuolation, and increased serum high-density lipoprotein(HDL-C) in rats with HFD-induced obesity. These effects were associated with increased concentrations of lipid factors such as c AMP, PKA, and HSL in the liver and adipose tissues, enhanced gut integrity, and improved lipid metabolism. GM analysis revealed that Sal could reverse HFD-induced dysbacteriosis by promoting the abundance of Actinobacteriota and Proteobacteria, and decreasing the growth of Firmicutes and Desulfobacterita. Furthermore, LC-MS/MS analysis indicated that Sal decreased TGs(TG18:2/18:2/20:4, TG16:0/18:2/22:6), DGs(DG14:0/22:6, DG22:6/22:6), CL(18:2/18:1/18:1/20:0), and increased ceramides(Cers;Cer d16:0/21:0, Cer d16:1/24:1),(O-acyl)-ω-hydroxy fatty acids(OAHFAs;OAHFA18:0/14:0) in the feces of rats. Spearman’s correlation analysis further indicated that TGs, DGs, and CL were negatively related to the abundance of Facklamia and Dubosiella, and positively correlated with Blautia and Quinella, while OAHFAs and Cers were the opposite.CONCLUSION Sal has an anti-obesity effect by regulating the GM and lipid metabolism.

Prolonged high-fat-diet feeding promotes non-alcoholic fatty liver disease and alters gut microbiota in mice

BACKGROUND Non-alcoholic fatty liver disease (NAFLD) has become an epidemic largely due to the worldwide increase in obesity. While lifestyle modifications and pharmacotherapies have been used to alleviate NAFLD, successful treatment options are limited. One of the main barriers to finding safe and effective drugs for long-term use in NAFLD is the fast initiation and progression of disease in the available preclinical models. Therefore, we are in need of preclinical models that (1) mimic the human manifestation of NAFLD and (2) have a longer progression time to allow for the design of superior treatments. AIM To characterize a model of prolonged high-fat diet (HFD) feeding for investigation of the long-term progression of NAFLD. METHODS In this study, we utilized prolonged HFD feeding to examine NAFLD features in C57BL/6 male mice. We fed mice with a HFD (60% fat, 20% protein, and 20% carbohydrate) for 80 wk to promote obesity (Old-HFD group, n = 18). A low-fat diet (LFD)(14% fat, 32% protein, and 54% carbohydrate) was administered for the same duration to age-matched mice (Old-LFD group, n = 15). An additional group of mice was maintained on the LFD (Young-LFD, n = 20) for a shorter duration (6 wk) to distinguish between age-dependent and age-independent effects. Liver, colon, adipose tissue, and feces were collected for histological and molecular assessments.RESULTS Prolonged HFD feeding led to obesity and insulin resistance. Histological analysis in the liver of HFD mice demonstrated steatosis, cell injury, portal and lobular inflammation and fibrosis. In addition, molecular analysis for markers of endoplasmic reticulum stress established that the liver tissue of HFD mice have increased phosphorylated Jnk and CHOP. Lastly, we evaluated the gut microbial composition of Old-LFD and Old-HFD. We observed that prolonged HFD feeding in mice increased the relative abundance of the Firmicutes phylum. At the genus level, we observed a significant increase in the abundance of Adercreutzia, Coprococcus, Dorea, and Ruminococcus and decreased relative abundance of Turicibacter and Anaeroplasma in HFD mice. CONCLUSION Overall, these data suggest that chronic HFD consumption in mice can mimic pathophysiological and some microbial events observed in NAFLD patients.

Long-Term Treatment with an Herbal Formula MCC Ameliorates Obesity-Associated Metabolic Dysfunction in High Fat Diet-Induced Obese Mice: A Comparative Study among MCC and Various Combinations of Its Constituents

Obesity has been found to be associated with increased incidence of various metabolic disorders. Anti-obesity interventions are therefore urgently needed. An earlier study has demonstrated that treatment with an herbal formula MCC, which comprises the fruit of Momordica charantia (MC), the pericarpium of Citri reticulate (CR) and L-carnitine (CA), reduced the weight gain in high fat diet (HFD)-fed mice. In the present study, we investigated the effect of long-term treatment with MCC (6 g/kg/day × 40 doses) and various combinations of its constituents in HFD-fed female ICR mice. Body weight change was monitored during the course of the experiment. Total and differential adiposity, plasma lipid contents, metabolic enzyme activities and mitochondrial coupling efficiency in skeletal muscle were measured. Glucose homeostasis was also assessed. Results showed that HFD increased the body weight, total and differential adiposity, and plasma lipid contents as well as impaired metabolic status in skeletal muscle and glucose homeostasis. MCC and all combinations of its constituents reduced the weight gain in HFD-fed mice, which was accompanied with an improvement on glucose homeostasis. While MC, CA and CR independently suppressed the HFD-induced weight gain in mice, MC seems to be the most effective in weight reduction, all of which correlated with the induction of mitochondrial uncoupling in skeletal muscle. Only CA and CR, but not MC, significantly reduced the total adiposity and visceral adiposity as well as plasma cholesterol level. However, the two component combinations, MC + CR and MC + CA, decreased the degree of visceral adiposity and plasma cholesterol level, respectively. MCC treatment at 1.5 g/kg (but not a higher dose of 6 g/kg) suppressed visceral adiposity and induced mitochondrial uncoupling in skeletal muscle in HFD-fed mice. The finding suggests that MCC may offer a promising prospect for ameliorating the diet-induced obesity and metabolic disorders in humans.

Monascus pilosus-fermented black soybean inhibits lipid accumulation in adipocytes and in high-fat diet-induced obese mice

Objective:To explore the anti-obesity effects and the mechanism of action of Monascus pilosus(M.pilosus)-fermented black soybean(MFBS)extracts(MFBSE)and MFBS powders(MFBSP)in adipocytes and high-fat diet(HFD)-induced obese mice,respectively.Methods:Black soybean was fermented with M.pilosus,and the main constituents in MFBS were analyzed by HPLC analysis.In vitro,MFBSE were examined for anti-adipogenic effects using Oil-Red O staining.In vivo,mice were fed a normal-fat diet(NFD)control,HFD control or HFD containing 1 g/kg MFBSP for 12 weeks,and then body weight gain and tissues weight measured.Real-time PCR and western blot assay were used to determine the mechanism of anti-adipogenic effects.Results:MFBSE inhibited lipid accumulation in 3T3-L1 adipocytes without exerting cell cytotoxicity.MFBSP treatment in HFD-fed mice significantly decreased the body weight gain compared with the HFD control mice.MFBSE and MFBSP treatment resulted in significantly lower mRNA levels of adipogenesis-related genes,such as peroxisome proliferator-activated receptorγ(PPARγ),fatty acid-binding protein 4(FABP4),and fatty acid synthase(FAS),in adipocytes and in white adipose tissue(WAT)of HFD-induced obese mice.Conclusions:These results suggest that the anti-obesity effects of MFBS are elicited by regulating the expression of adipogenesis-related genes in adipocytes and WAT of HFDinduced obese mice.

Effect of High-fat Diet on Cholesterol Metabolism in Rats and Its Association with Na^+/K^+-ATPase/Src/pERK Signaling Pathway

Summary： Abnormal cholesterol metabolism is associated with an elevated risk of developing athero- sclerosis, hypertension, and diabetes etc. Na＋/K＋-ATPase was found to regulate cholesterol synthesis, distribution and trafficking. This study aimed to examine the effect of high-fat diet on cholesterol me- tabolism in rats and the role of Na＋/K＋-ATPase/Src/ERK signaling pathway in the process. Forty male SD rats were evenly divided into high-fat diet group and control group at random. Animals in the former group were fed on high-fat diet for 12 weeks, and those fed on basic diet served as control. Blood lipids, including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesteral （LDL-C） levels, were detected at 3, 6 and 12 weeks. The ratio of cholesterol content in cytoplasm to that in cell membrane was detected in liver tissues. RT-PCR and Western blotting were used to measure the expression of lipid metabolism-associated genes （HMG-CoA reductase and SREBP-2） after 12-week high-fat diet. Na＋/K＋-ATPase/Src/ERK signaling path- way-related components （Na＋/K＋-ATPase ctl, Src-PY418 and pERK1/2） were also measured by West- ern blotting. The results showed that the serum TC, TG, and LDL-C levels were significantly higher in high-fat diet group than those in control group, while the HDL-C level was significantly lower in high-fat diet group at 6 weeks （P〈0.01）. High-fat diet led to an increase in the cholesterol content in the cytoplasm and cell membrane. The ratio of cholesterol content in cytoplasm to that in cell membrane was elevated over time. The expression of HMG-CoA reductase and SREBP-2 was significantly sup- pressed at mRNA and protein levels after 12-week high-fat diet （P〈0.05）. Moreover, high-fat diet pro- moted the expression of Na＋/K＋-ATPase α1 but suppressed the phosphorylation of Src-PY418 and ERK1/2 at 12 weeks （P〈0.05）. It was concluded that high-fat diet regulates cholesterol metabolism, and Na＋/K＋-ATPase signaling pathway is involved in the process possibly by regulating the expression of lipid metabolism-associated proteins HMG-CoA reductase and SREBP-2.

Energy restriction and exercise modulate angiopoietins and vascular endothelial growth factor expression in the cavernous tissue of high-fat diet-fed rats

The purpose of the current study was to evaluate the effect of a high-fat （HF） diet, energy restriction and exercise on the expression of vascular endothelial growth factor （VEGF）, angiopoietin （Ang） I and 2, and their receptors in rat corpus cavernosum （CC）. Male Wistar rats were fed adlibitum with an H F diet for 8 or 16 weeks. After 8 weeks of the H F diet, a group of rats was subjected to energy restriction with or without exercise for 8 weeks. Control animals had free access to standard diet for the same period. After euthanasia, blood was collected and the penises removed for immunofluorescence assays （VEGF, VEGF receptor （VEGFR） I and 2, Angl, Ang2 and Tie2） and semiquantification of VEGF, VEGFR 1, VEGFR2, Angl, Ang2, Tie2, endothelial nitric oxide synthase （eNOS） and Aktlphospho-Akt by Western blotting. HF diet-fed rats exhibited lower high-density lipoprotein cholesterol （HDL-c） levels, higher systolic blood pressure and an increased atherogenic index. A significant increase in Ang2 expression in the CC was verified and coupled to a decrease in VEGF and VEGFRs. The Akt pathway was activated by the HF diet. Energy restriction and exercise increased eNOS expression and restored most HF diet-induced modifications except for VEGFR2 expression. These results emphasize the role of diet on vascular function regulation, demonstrating that cavernous imbalance of VEGF/VEGFRs and Angs/Tie2 systems occurs before serum lipid changes and obesity onset, antedating structural atherosclerotic features.

Lagenaria siceraria fruit extract ameliorate fat amassment and serum TNF-αin high-fat diet-induced obese rats

Objective:To investigate the effects of ethanolic extract of Lagenaria siceraria fruit(ELSF) on fat amassment and serum TNF-αin high-fat diet-induced obese rats.Methods:The high fat diet induced obese rals were orally treated with orlistat(50 mg/kg) and ELSF(100,200.300 mg/kg/day) to the respective treatment groups.The body weight,lasting blood glucose level,lipid profile, serum levels of tumor necrosis factor-α(TNF-α) in rats were measured after 30 days of treatment adn compared to the obese control animals.Results:ELSF significantly(P 【 0.001) reduced the body weight gain,fasting blood glucose,total cholesterol,triglyceride,total protein and TNF-α.Conclusions:These encouraging findings suggest that Lagenaria siceraria has excellent pharmacological potential to prevent fat amassment.

Conditioned Place Preference Deficits in Adulthood Following High Fat and High Sugar Diet Intake in Pre- and Periadolescence: A Test of the Specificity Hypothesis

Obesity is linked to poorer cognitive performance, both of which may result from eating high-fat foods during development. In the present study, pre-and periadolescent (postnatal days 21 to 40) male rats were fed high fat (HF), high sugar (HS), or rodent chow (Chow) diets. After conditioning for 16 days with either Cheetos? (high-fat) or Froot Loops? (high-sugar) unconditioned stimuli (US) on one side of a conditioned place preference (CPP) apparatus, rats were tested on postnatal day 61 for a place preference. Chow rats preferred the US-paired side, but HF rats showed no preference. HS rats preferred the side paired with Cheetos? but not with Froot Loops?. In spite of these deficits, object recognition, a nonassociative learning task, was not impaired. These results show mixed support for the specificity hypothesis, which predicts that CPP deficits will be nutrient-specific. The results show for the first time that eating a HS diet leads to a nutrient-specific CPP deficit (for HS foods), whereas eating a HF diet leads to a general CPP deficit (for HS and HF foods).

Effects of Mogroside V on Glucose and Lipid Metabolism in High Fat Diet Mice

[Objectives]To explore the effects and mechanism of mogroside V(MV)on glucose and lipid metabolism in high-fat diet(HFD)mice.[Methods]The experiment fed mice with high-fat diet for 8 weeks,and 40 mice with successful modeling were randomly divided into normal group,model group,and MV dose group(100,200 mg/kg),with 10 mice in each group.From the ninth week,the MV dose group was given intragastric administration,and the normal group and the model group were given an equal volume of distilled water by intragastric administration for 6 weeks,then killed and blood samples and livers were collected.Serum triglycerides(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C),free fatty acids(FFA),Advanced glycation end products(AGE-P)-peptides(AGE-P)and glycosylated hemoglobin(HbA1c)content,and TG and hepatic glycogen content in liver were detected by biochemical method.Fasting blood glucose(FBG)was measured by glucose oxidase method.The fasting serum insulin(FINS)content was detected by enzyme-linked immunosorbent assay(ELISA),and the insulin resistance index(HOMA-IR)was calculated.Oil red O staining was used to observe the fat deposition in liver tissue.[Results]MV(100,200 mg/kg)dose groups could significantly down-regulate the contents of TC,TG,LDL-C,FBG,FINS,AGE-P and HbA1c and HOMA-IR,and up-regulate HDL-C and hepatic glycogen content and reduce the fat deposits.[Conclusions]The mechanism of MV regulating glucose and lipid metabolism in mice may be related to the regulation of insulin resistance.