Hawthorn fruit is hypolipidemic in rabbits fed a high cholesterol diet.

The present study examined the hypolipidemic activity of hawthorn fruit. New Zealand white rabbits were fed one of three diets, a reference diet with no cholesterol added (NC), a high cholesterol diet (1 g/100 g, HC) and a HC diet supplemented with 2 g/100 g hawthorn fruit powder (HC-H). After 12 wk, serum total cholesterol (TC) and triacylglycerols (TG) were 23.4 and 22.2% lower, respectively, in the hawthorn fruit group compared with the HC rabbits (P < 0.05). Hawthorn supplementation led to 50.6% less cholesterol accumulation in aorta (P < 0.05) and 23-95% greater excretion of neutral and acidic sterols (P < 0.05). Supplementation of hawthorn fruit did not affect the activities of hepatic 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA-R) or cholesterol 7alpha-hydroxylase (CH) but it suppressed the activity of intestinal acyl CoA:cholesterol acyltransferase (ACAT, P < 0.05). The results suggest that the mechanism by which hawthorn fruit decreases serum cholesterol involves, at least in part, the inhibition of cholesterol absorption mediated by down-regulation of intestinal ACAT activity.     

Grape skin improves antioxidant capacity in rats fed a high fat diet

This study was conducted to investigate the effect of dietary grape skin on lipid peroxidation and antioxidant defense system in rats fed high fat diet. The Sprague-Dawley rats were fed either control (5% fat) diet or high fat (25% fat) diet which was based on AIN-93 diet for 2 weeks, and then they were grouped as control group (C), control + 5% grape skin group (CS), high-fat group (HF), high fat + 5% grape skin group (HFS) with 10 rats each and fed corresponding diets for 4 weeks. The hepatic thiobarbituric acid reacting substances (TBARS) were increased in high fat group as compared with control group, but reduced by grape skin. The serum total antioxidant status, and activities of hepatic catalase and superoxide dismutase, xanthine oxidase and glucose-6-phosphatase were increased by supplementation of grape skin. Glutathione peroxidase activity was significantly higher in CS group than in C group. Grape skin feeding tended to increase the concentration of total glutathione, especially in control group. The ratio of reduced glutathione to oxidized glutathione was lower in high fat groups than in control groups. The ratio was increased by dietary supplementation of grape skin in control group. These results suggest that dietary supplementation of grape skin would be effective on protection of oxidative damage by lipid peroxidation through improvement of antioxidant defense system in rats fed high fat diet as well as rats with low fat diet.     

Effects of capsaicin on lipid metabolism in rats fed a high fat diet

Effects of capsaicin, a pungent principle of hot red pepper, were studied in experiments using male rats fed a diet containing 30% lard. Capsaicin was supplemented at 0.014% of the diet. The level of serum triglyceride was lower when capsaicin was present in the diet than when it was not. Levels of serum cholesterol and pre-beta-lipoprotein were not affected by the supplementation of capsaicin. The perirenal adipose tissue weight was lower when capsaicin was present in the diet than when it was not. Hepatic enzyme activities of glucose-6-phosphate dehydrogenase and adipose lipoprotein lipase were lower in rats fed the 30% lard diet than in those fed a nonpurified diet. Activities of these two enzymes were higher when capsaicin was added to the diet than when it was not. Hepatic acetyl-CoA carboxylase, beta-hydroxyacyl-CoA dehydrogenase, and adipose hormone-sensitive lipase activities were not affected by capsaicin feeding. Lipid absorption was not affected by the supplementation of capsaicin. The perirenal adipose tissue weight and serum triglyceride were decreased as the level of capsaicin in the diet increased up to 0.021%. These results suggest that capsaicin stimulates lipid mobilization from adipose tissue and lowers the perirenal adipose tissue weight and serum triglyceride concentration in lard-fed rats.     

Lipoprotein lipase activity and chylomicron clearance in rats fed a high fat diet

The relationships of tissue and plasma lipoprotein lipase (LPL) activities to tissue uptake and plasma clearance of 14C-labeled chylomicron-triglyceride (14C-CM-TG) were studied in female rats fed isoenergetic and isonitrogenous control (12% kJ from fat) or high fat diets (72% kJ from fat) for 8 wk. Animals fed the high-fat diet had higher levels of fasting plasma triglycerides and lower LPL activities in heart, renal adipose tissue and post-heparin plasma. Changes in LPL activities of skeletal muscles varied among muscles with higher values in the soleus and plantaris (32-61%) and no differences in the gastrocnemius. The lower LPL activity in renal adipose tissue was associated with lower uptake of fatty acids from 14C-CM-TG by adipose. Fatty-acid uptake from labeled TG was not associated with tissue LPL activity in other tissues. Clearance of 14C-CM-TG from plasma and the half-lives of 14C-CM-TG were similar in both dietary groups. These data indicate that tissue and plasma LPL activities are not a direct index of uptake of fatty acids by tissues or clearance of chylomicron triglycerides.     

茶多酚对代谢综合征大鼠血管通透性影响

目的探讨绿茶多酚对高脂膳食诱导代谢综合征大鼠血管通透性升高的干预效果。方法雄性wist-ar大鼠随机分为正常对照、高脂对照、茶多酚低、中、高剂量干预组,断乳后开始给予高脂饮食,达到成年体重后进行茶多酚干预,持续30周,测定大鼠体重、脂肪系数、血糖、血脂水平,采用伊文思蓝注射法测定大鼠血管通透性,硝酸根还原酶法测定大鼠血清一氧化氮(NO)水平,采用试剂盒测定内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)活性,制作血管冷冻切片,采用二氢乙啶荧光探针检测其活性氧分子(ROS)水平。结果与对照组(0.16±0.007)μg/mg比较,高脂组大鼠血管通透性(0.19±0.006)μg/mg明显升高,与高脂组比较,低、中、高茶多酚组大鼠血管通透性[(0.16±0.004)、(0.14±0.010)、(0.15±0.010)μg/mg]明显降低;茶多酚组ROS水平明显低于高脂组;与高脂组比较,茶多酚明显上调eNOS活性,而下调iNOS活性。结论绿茶多酚对代谢综合征大鼠血管通透性升高具有保护作用,其保护效应可能与减轻氧化损伤有关。     

Lipid composition of liver plasma membranes isolated from rats fed a high glucose or a high fat diet.

Several plasma membrane associated functions have been shown to differ in rats fed a high lard, carbohydrate free diet (L rats) from those observed in preparations from rats fed a high glucose, fat free diet (G rats). To explore the possibility that differences in the lipid components of the plasma membranes might contribute to these functional changes, groups of rats were fed each diet for 5 days and the lipids of their plasma membranes were separated and analyzed. The major differences found were a greater cholesterol content in the plasma membranes from L rats compared to those of G rats (12.2 +/- 2.20 versus 7.8 +/- 1.40 mg/100 mg membrane protein) and more than twice as much phosphatidyl serine and phosphadidyl inositol in the plasma membranes of the former group. Of several variations in fatty acid distribution found in the phospholipid and neutral lipid fractions, the most notable quantitatively were an increase in phospholipid oleic acid (18:1) and a decrease in phospholipid stearic acid (18:0) in L rat plasma membranes. Whether these changes are related to altered membrane function is not known.     

The effects of black garlic (Allium satvium) extracts on lipid metabolism in rats fed a high fat diet

BACKGROUD/OBEJECTIVESThe mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet.MATERIALS/METHODSThirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined.RESULTSSignificant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group.CONCLUSIONSConsumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.     

Patterns of lipogenesis in laying hens fed a high fat diet containing safflower oil

Lipogenesis by liver and ovarian tissue in vitro, incorporation of lipids synthesized de novo into the egg yolk in ovo, and the fatty acid composition of liver and yolk triglycerides were studied in laying hens fed a low fat control diet or 30% safflower oil diet for 3 wk. The study was conducted to determine if reduced triglyceride synthesis and the fatty acid composition of dietary fat could account for the changes in the fatty acid composition of liver and egg yolk triglyceride from safflower oil feeding. Triglyceride synthesis was reduced by safflower oil feeding. Relative distribution of labeled carbon into liver triglycerides and phospholipids was also reduced. In vivo incorporation of labeled carbon from [1-14C]acetate into egg yolk triglycerides and phospholipids closely paralleled that in liver slices, suggesting that the liver controls the pattern of lipid incorporation into yolk. The fatty acid composition of liver and yolk triglycerides was markedly altered by safflower oil feeding. The changes in fatty acid composition of yolk triglycerides could not be accounted for by the reduction in triglyceride synthesis and the fatty acid composition of safflower oil.     

奥曲肽对高脂饲料诱导的肥胖大鼠肝脏糖异生的影响

目的探讨生长抑素(SST)类似物奥曲肽对高脂饲料诱导的肥胖大鼠肝脏糖异生的影响。方法雄性SD大鼠随机分为正常对照组(n=16)和高脂饲料组(n=40),分别喂以普通饲料与高脂饲料。饲养24周后,从高脂饲料组中选出肥胖大鼠,分成肥胖组(n=16)和奥曲肽干预组(n=16)。奥曲肽干预组大鼠连续8 d皮下注射奥曲肽,剂量为每12 h 40 mg/kg BW。实验结束后测定大鼠的身长、体重、空腹血糖、血脂、血胰岛素及血浆生长抑素水平,计算Lee’s指数和HOMA指数。RTPCR测定葡萄糖-6-磷酸酶(G6pase)、磷酸烯醇式丙酮酸羧激酶(Pepck)和叉头框家族转录因子1(Foxo1)mRNA表达水平。蛋白质免疫印迹法测定Foxo1在核蛋白和胞浆蛋白中的表达。结果肥胖组大鼠体重、空腹血糖、血脂、血胰岛素水平及HOMA指数较正常对照组大鼠显著升高;与肥胖组大鼠比较,奥曲肽干预组大鼠上述指标均下降。肥胖组大鼠血浆SST水平较正常对照组大鼠有降低的趋势(P>0.05),奥曲肽干预组大鼠血浆SST水平较肥胖组大鼠显著升高(P<0.05)。肥胖组大鼠肝脏G6pase、Pepck及Foxo1 mRNA表达水平及肝细胞核内与胞浆中Foxo1蛋白表达水平的比值较正常对照组均显著增加(P<0.01),而奥曲肽干预组大鼠则较肥胖组大鼠显著下降(P<0.01)。结论奥曲肽可改善高脂饲料诱导的肥胖大鼠异常增强的肝脏糖异生作用,其作用机制可能与降低Foxo1的活性和表达,抑制肝脏G6pase及Pepck的转录有关。     

Less body fat accumulation in rats fed a safflower oil diet than in rats fed a beef tallow diet

The effects on body fat accumulation of long-term feeding of high fat diets of differing fatty acid composition were studied in rats. The rats were meal-fed isoenergetic diets based on safflower oil or beef tallow for 4 mo. Each diet was freshly prepared every day throughout the experimental period. Oxygen consumption and carbon dioxide production for 6 h after meals were measured between the 50th and 54th d of the experimental period. Oxygen consumption for 3 h after meals was significantly greater in the safflower oil diet group than in the beef tallow diet group, indicating greater diet-induced thermogenesis in the former group. From the assessment of respiratory quotient, the fat oxidation rate was also higher in the former. After the experimental period (4 mo), body fat accumulation was significantly less in the rats fed safflower oil. This difference was, at least in part, ascribed to increased diet-induced thermogenesis and fat oxidation. Serum triacylglycerol level was markedly lower in the rats fed safflower oil than in those fed beef tallow. The lipoprotein lipase activities in heart and soleus muscle after meals appeared to be higher in the former than in the latter. These results suggest that the consumption of the safflower oil diet increased lipoprotein lipase activity in heart and skeletal muscle, resulting in the elevation of fat oxidation rate and the depression of serum triacylglycerol level.     

Improved endothelial dysfunction by Cynanchum wilfordii in apolipoprotein E(-/-) mice fed a high fat/cholesterol diet

Cynanchum wilfordii is used in traditional Chinese medicine with almost all parts of this plant considered beneficial for various vascular diseases. This study was performed to evaluate the effect of an ethanol extract of C. wilfordii (ECW) on vascular dysfunction in apolipoprotein E (apoE)(-/-) mice fed with high fat/cholesterol diets (HFCDs). The apoE(-/-) mice were fed HFCD consisting of 7.5% cocoa butter and 1.25% cholesterol, with or without 100 or 200?mg/day/kg ECW. Chronic ECW treatment significantly lessened the level of low-density lipoprotein (P<.05) and elevated that of high-density lipoprotein-cholesterol (P<.01). Chronic ECW treatment normalized the HFCD-induced increase in systolic blood pressure, maintained smooth and soft intimal endothelial layers, and decreased intima-media thickness in aortic sections of HFCD-fed apoE(-/-) mice. ECW significantly restored the diet-induced decrease in vasorelaxation response to acetylcholine; however, the response to sodium nitroprusside did not change. ECW clearly restored the HFCD-induced reduction in endothelial nitric oxide synthase expression levels in aortic tissue, leading to decreased vascular inflammation through an inhibition of cellular adhesion molecules such as E-selectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1 as well as endothelin-1 (ET-1) expression. In conclusion, ECW ameliorates endothelial dysfunction via improvement of the nitric oxide/cyclic GMP signaling pathway in a diet/genetic model of hyperlipidemia. ECW also substantially inhibited the development of atherosclerosis, possibly by inhibiting ET-1, cell adhesion molecules, and lesion formation, suggesting a vascular protective role for this herb in the treatment and prevention of atherosclerotic vascular disease.     

Green tea aqueous extract reduces visceral fat and decreases protein availability in rats fed with a high-fat diet

Green tea is associated with beneficial health effects mainly because of its body fat-reducing and hypocholesterolemic activities, but an effective dose without pronounced influence on protein availability is unknown. The objective of this study was to examine the hypothesis that green tea aqueous extract (GTAE) depending on dose improves cardiovascular risk indicators such as body weight, visceral fat content, and atherogenic index of plasma and does not have unfavorable effect on protein availability in rats fed with a high-fat diet. The rats fed with a high-fat diet enriched with 1.1 and 2.0% GTAE for 8 weeks had significantly (P < .05) lower atherogenic index (in both groups, about 14.3%). Only administration of 2.0% GTAE significantly (P < .05) decreased body weight gain (5.6%) and prevented visceral fat accumulation (17.8%) in rats. However, considerably (P < .05), reduction in the digestion of protein (but not fat) was observed in both GTAE groups (1.1% GTAE: 82.6% ± 1.8%; 2.0% GTAE: 84.3% ± 0.8%) when compared to the control (93.3% ± 1.5%). It was concluded that GTAE may have preventive effects on the accumulation of visceral fat but only in higher doses. Although both doses improved cardiovascular risk indicators, they, in addition, significantly inhibited protein digestion.     

Angiogenesis in the New Zealand obese mouse model fed with high fat diet

Background  

Obesity and its complications lead to vascular injury, atherosclerosis, diabetes and pathological angiogenesis. One of the models to study the obesity and its entanglements is the New Zealand Obese mice model. Aim of this study was to check the effect of high fat diet on changes in biochemical parameters as well as on process of angiogenesis in NZO mice.     

Protonated nanostructured aluminosilicate (NSAS) reduces plasma cholesterol concentrations and atherosclerotic lesions in Apolipoprotein E deficient mice fed a high cholesterol and high fat diet

The aim of this work was to assess the effect of chronic administration of protonated nanostructured aluminosilicate (NSAS) on the plasma cholesterol levels and development of atherosclerotic lesions in Apolipoprotein (ApoE) deficient mice fed a high cholesterol and high fat diet. Apolipoprotein E (ApoE) deficient mice were divided into the following treatment groups: protonated NSAS 1.4% (w/w), untreated control and 2% (w/w) stigmastanol mixed with high-cholesterol/high-fat diet. Animals were treated for 12 weeks, blood samples were withdrawn every 4 weeks for determination of plasma cholesterol and triglyceride levels. At the end of the study the aortic roots were harvested for assessment of atherosclerotic lesions. NSAS at 1.4% (w/w) and stigmastanol at 2% (w/w) treatment groups showed significant decreases in plasma cholesterol concentrations at all time points relative to the control animals. The lesion sum area in 1.4% (w/w) NSAS and 2% (w/w) stigmastanol groups were significantly less from the control animals. In conclusion, in this study, the effectiveness of chronic administration of protonated NSAS material in the reduction of plasma cholesterol levels and decrease in development of atherosclerotic lesions was demonstrated in Apo-E deficient mice model.     

Protonated nanostructured aluminosilicate (NSAS) reduces plasma cholesterol concentrations and atherosclerotic lesions in Apolipoprotein E deficient mice fed a high cholesterol and high fat diet

There is a predominance of small and dense LDL cholesterol particles in familial combined hyperlipidemia (FCH). The lipoprotein lipase gene could exert an influence in these circumstances. To study the relationship of pattern B LDL and lipids with N291S polymorphism of lipoprotein lipase (LPL) in FCH patients. Lipid profile, apolipoproteins, diameter of LDL and N291S polymorphism were determined in 93 patients with FCH and 286 individuals from the general population. FCH patients with N291S polymorphism showed a lower mean diameter of LDL. FCH patients with pattern B LDL showed higher concentrations of triglycerides, VLDLc, non-HDLc and apo B100 and lower levels of HDLc than those with pattern A. Of FCH patients with polymorphism 87.5% presented pattern B and 12.5% pattern A, while patients without polymorphism presented pattern A in 69.2% cases and pattern B in 30.8% cases, with differences being statistically significant (p < 0.004). The prevalence of this mutation in our FCH patients was 9.7%. The prevalence of N291S mutation in our FCH patients was similar to the 9.3% described in Dutch FCHL patients but clearly higher than the 2–5% described for other Caucasian populations. No polymorphism was found in our general population sample. FCH patients with phenotype B of LDL possessed an atherogenic lipid profile. The relationship between small and dense LDL and the presence of the N291S mutation may identify patients with high cardiovascular risk.     

Bitter melon (Momordica charantia) reduces adiposity,lowers serum insulin and normalizes glucose tolerance in rats fed a high fat diet

Bitter melon (BM) is known for its hypoglycemic effect but its effect on rats fed a hyperinsulinemic high fat diet has not been examined. In a dose-response (0.375, 0.75 and 1.5%) study, oral glucose tolerance was improved in rats fed a high fat (HF; 30%) diet supplemented with freeze-dried BM juice at a dose of 0.75% or higher (P < 0.05). At the highest dose, BM-supplemented rats had lower energy efficiency (P < 0.05) and tended (P = 0.10) to have less visceral fat mass. In a subsequent experiment, rats habitually fed a HF diet either continued to consume the diet or were switched to a HF+BM, low fat (LF; 7%) or LF+BM diet for 7 wk. BM was added at 0.75%. Final body weight and visceral fat mass of the two last-mentioned groups were similar to those of rats fed a LF diet for the entire duration. Rats switched to the HF+BM diet gained less weight and had less visceral fat than those fed the HF diet (P < 0.05). The addition of BM did not change apparent fat absorption. BM supplementation to the HF diet improved insulin resistance, lowered serum insulin and leptin but raised serum free fatty acid concentration (P < 0.05). This study reveals for the first time that BM reduces adiposity in rats fed a HF diet. BM appears to have multiple influences on glucose and lipid metabolism that strongly counteract the untoward effects of a high fat diet.     

Effect of Chlorella vulgaris on lipid metabolism in Wistar rats fed high fat diet

This study was performed to investigate effects of Chlorella vulgaris on lipid metabolism in rats fed high fat diet. Sixty 6-week-old male Wistar rats were divided into two groups; normal diet group and high fat diet group, then the rats in each group were further divided into three subgroups and fed 0%, 5% and 10% (w/w) chlorella-containing diets, respectively, and raised for 9 weeks. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity and total protein and albumin concentration were not different among groups. Serum total lipids and liver TG concentration were significantly lower in 5% and 10% chlorella groups than 0% chlorella group in high fat diet groups (p<0.05). Serum TG, serum total cholesterol, liver total lipid and liver total cholesterol concentrations were significantly lower in 10% chlorella groups than 0% chlorella group in high fat diet groups (p<0.05). Fecal total lipid, TG and total cholesterol excretions were significantly higher in 5% and 10% chlorella groups than 0% chlorella groups in normal diet and high fat diet groups, respectively (p<0.05). These results suggest that Chlorella vulgaris is effective for prevention of dyslipidemia which may be due to the modulation of lipid metabolism and increased fecal excretion of lipid.