Modulation of the regression of atherosclerosis in the hamster by dietary lipids: comparison of coconut oil and olive oil (original) (raw)
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Metabolites
The relationship between milk fat intake (because of its high saturated fatty acid content) and the risk of suffering from cardiovascular diseases remains controversial. Thus, Golden Syrian hamsters were fed two types of fat—sheep milk fat that was rich in rumenic (cis9,trans11-18:2) and vaccenic (trans11-18:1) acids and olive oil—and two doses (a high- or normal-fat diet) for 14 weeks, and markers of lipid metabolism and atherosclerosis evolution were analyzed. The results revealed that the type and percentage of fat affected most plasma biochemical parameters related to lipid metabolism, while only the expression of five (CD36, SR-B1, ACAT, LDLR, and HMG-CoAR) of the studied lipid-metabolism-related genes was affected by these factors. According to aortic histology, when ingested in excess, both fats caused a similar increase in the thickness of fatty streaks, but the high-milk-fat-based diet caused a more atherogenic plasma profile. The compositions of the fats that were used, th...
Atherosclerosis, 2002
In this study we report the effects of sunflower, virgin olive and fish oils on the progression of aortic lesions. A total of 24 male New Zealand rabbits (six per each group) were fed for 50 days on a diet containing 3% lard and 1.3% cholesterol, to induce atherosclerosis. An atherogenic control group (A) was killed after this period and three groups were fed for an additional period of 30 days with a diet composed of (1.75 g of supplemented oil and 98.25 of standard chow): sunflower oil (S), virgin olive oil (O) and fish oil (F). A control group (n =6) was fed with a standard chow diet for 80 days. LDL lipid composition and histological analysis of aortic atherosclerotic lesions were assayed. The atherogenic diet caused a significant increase of cholesterol levels in LDL and aorta tissue. Cholesterol ester content rose significantly in the aortic arch of groups S, O and F. Fatty streaks were found in all aortic sections, although only group S showed a significant progression of the lesion compared with group A. We conclude that the replacement of a high cholesterol-saturated fat diet by another cholesterol free-unsaturated fat diet does not regress atherosclerosis in rabbit. However, sunflower oil provokes a significant progression in lesion development, whereas diet enrichment with extra virgin olive oil and, to a lesser extent, fish oil, stops this progression.
UK Journal of Pharmaceutical Biosciences, 2015
The aim of this study was to analyze the effect of virgin coconut oil (VCO) on high lipid diet (HLD) and high carbohydrate diet (HCD) induced atherosclerosis in male Wistar rats. Spectrophotometer was used to determine the lipid parameters by enzymatic endpoint method. The plasma total cholesterol (TC), triglyceride (TG) and high-density lipoprotein (HDL) levels were measured using commercial enzymatic kits. The results showed that feeding with normal and VCO diet significantly decrease (p<0.05) body weight when compared to the control group rats. Body weight and lipid profile were estimated after 8 weeks of treatment. VCO showed a significant (p<0.05) reduction in TC, TG, Low density lipoprotein (LDL), Very low density lipoprotein (VLDL) levels and significant (p<0.05) increase in HDL in HCD /HLD group rats. There was significant decrease in atherogenic index (AI) (p<0.05) of all VCO treated groups when compared to the Control group. Hence, there was increase in the per...
The Journal of nutrition, 2004
There is growing evidence that dietary fatty acids and/or dietary cholesterol could have a direct role on inflammatory diseases such as atherosclerosis. F(1)B Golden Syrian hamsters (Mesocricetus auratus), in 2 groups of 72, were fed for 10 wk a semipurified diet containing either 20 g/100 g hydrogenated coconut oil without cholesterol or cocoa butter (20 g/100 g) with cholesterol (0.15 g/100 g). After the 10-wk treatment period, plasma was collected from food-deprived hamsters (16 h) for plasma lipid measurements. Hamsters were then ranked according to their plasma VLDL and LDL cholesterol (non-HDL-C) concentrations with 1.86 mmol/L as the cut-off point between low (Low; n = 36) and medium (Med; n = 36) concentrations for each treatment. Hamsters in the Low and Medium groups fed cholesterol (Low-chol) had significantly lower plasma total cholesterol (TC) concentrations than hamsters in the Low group fed coconut oil (Low-CO). However, this difference for the Medium group was reflect...
Authorea
Aim: High plasma cholesterol levels, mainly LDL is a widely recognized major risk factor for Coronary Heart Disease(CHD). According to the epidemiologic studies findings, people from the Mediterranean countries, have lower CHD rates than other countries, in these countries the usual diet is high in olive oil. The present study compares the effects of cholesterol-enriched diet with or without adding olive oil on serum Lipoproteins, lipid peroxidation, and atherosclerosis development. Methods: Twenty Dutch male rabbits were categorized into four groups (one group as Control, and others as Experimental). They received one of Standard (I), Olive oil rich (II), Cholesterol-rich (III), and Cholesterol + Olive oil (IV) diet for Twelve weeks. Fasting blood samples from the heart were collected at the beginning, and the end of the experimental period. Results: Means of serum lipids were not significantly different at the beginning of the experimental period. After intervention, significant differences were showen in total cholesterol, HDL-C, triglyceride and MDA between groups. The comparison of III and the IV groups showed a higher mean of MDA in group III (P< 0.001). Any aortic lesion was not observed at I and II groups. Aortic lesions in IV group showed a significantly lower degree than group III (p=0.02). Conclusions: These findings showed the preventive effect of olive oil against atherosclerosis development which is independent of plasma lipoprotein effect, and suggested that probably olive oil acts on arteries directly. What's already known about this topic? * Some previous studies showed the beneficial effects of olive oil. * Studies regarding the effect of olive oil on atherosclerosis development in rabbits are limited. What does this article add? • This study is the first investigation that was designed to evaluate the effect of olive oil on serum lipoproteins, lipid peroxidation, and atherosclerosis development in rabbits. • The present study indicated the preventive effect of olive oil against atherosclerosis development which is independent of plasma lipoprotein effect, and suggested that probably olive oil acts on arteries directly.
Dietary fats and cholesterol supplementation effects on aortic and lipid response in rats
The Journal of Nutritional Biochemistry
The experiment was designed to elucidate the effects of feeding four dietary oils (corn, hazelnut, olive, and fish), and cholesterol supplementation on plasma, liver lipids, and aortic smooth muscle response to drugs. Male Sprague Dawley rats were fed semipurified diets containing one of the above oils (15% wt/wt), either with or without cholesterol supplementation (1% wt/wt), for 20 days. Hazelnut oil-fed rats showed the highest plasma total cholesterol level, while animals fed fish oil exhibited the lowest plasma total and high density lipoprotein cholesterol concentrations. Hepatic cholesterol content was not affected by dietary oils. Liver lipids increased when dietary cholesterol was added to any of the oils used. Acetylcholine pD2 was elevated in fish oil- and hazelnut oil-fed rats, but rats fed all dietary oils showed maximal relaxation. Cholesterol supplementation reduced aortic maximal relaxation caused by acetylcholine. These results indicate that the type of dietary oil a...
British Journal of Nutrition, 2003
We have compared lipoprotein metabolism in, and susceptibility to atherosclerosis of, two strains of male Golden Syrian hamster, the Bio F1B hybrid and the dominant spot normal inbred (DSNI) strain. When fed a normal low-fat diet containing approximately 40 g fat and 0·3 g cholestero/g, triacylglycerol-rich lipoprotein (chylomicron+VLDL) and HDL-cholesterol were significantly higher (P<0·001) in Bio F1B hamsters than DSNI hamsters. When this diet was supplemented with 150 g coconut oil and either 0·5 or 5·0 g cholestero/g, significant differences were seen in response. In particular, the high-cholesterol diet produced significantly greater increases in plasma cholesterol and triacylglycerol in the Bio F1B compared with the DSNI animals (P=0·002 and P<0·001 for cholesterol and triacylglycerol, respectively). This was particularly dramatic in non-fasting animals, suggesting an accumulation of chylomicrons. In a second experiment, animals were fed 150 g coconut oi/g and 5·0 g cho...
Asia Pacific Journal of Clinical Nutrition, 2002
Several studies have reported on the effect of palm olein oil (PO; palmitic acid content ∼38%) incorporation into the diet on blood cholesterol concentration. Information on the effect of PO on atherosclerosis is, however, lacking. In vervet monkeys (Cercopithecus aethiops), low-density lipoprotein cholesterol (LDL-C) concentrations can be modulated by the type and amount of fat in the diet. The vervet is a proven model for both the type and composition of human atherosclerotic lesions. The aim of this study was to determine the effect of PO in a moderate-fat moderate-cholesterol diet (MFD) on plasma lipoproteins and the progression of atherosclerosis in a non-human primate model after 25.5 months of dietary exposure. Thirty adult male vervets, never exposed to a Western-type atherogenic diet, were stabilised on a MFD (28%E fat; 26 mg cholesterol/1000 kJ) with a polyunsaturated to saturated fatty acid (P/S) ratio of 0.4 for six weeks. Baseline LDL-C, high-density lipoprotein (HDL)-C and bodyweight were used to stratify the vervets into three comparable groups of 10 each. One group continued with the MFD in which 11.0%E was derived from lard (AF). In the other two groups, the AF was substituted isocalorically with either sunflower oil (SO) or PO. Plasma lipids were measured at 6-monthly intervals and atherosclerosis was assessed in the aorta and in five peripheral arteries after 25.5 months of dietary exposure. The frequency of atherosclerosis in peripheral arteries and aortas was low. PO, relative to SO and AF, significantly reduced the risk for developing early lesions in peripheral arteries (P = 0.0277 and P = 0.0038, respectively) and, relative to AF, in aortas (P = 0.0335). The cholesterolaemic effect of MFD-PO was not significantly different from MFD-SO and MFD-AF. However, at 24 months the plasma total cholesterol concentration with MFD-AF was significantly higher than with MFD-SO (P = 0.0256). It is confirmed that a MFD with PO is no different from AF or SO in its cholesterolaemic effect. The anti-atherogenic efficacy of a MFD with PO, relative to SO and AF, was demonstrated in a non-human primate model of atherogenesis.
Use of hamster as a model to study diet-induced atherosclerosis
Nutrition & Metabolism, 2010
Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apoB-100 and intestinal apoB-48 secretion, and uptake of the majority of LDL cholesterol via the LDL receptor pathway. Early work suggested hamsters fed high cholesterol and saturated fat diets responded similarly to humans in terms of lipoprotein metabolism and aortic lesion morphology. Recent work has not consistently replicated these findings. Reviewed was the literature related to controlled hamster feeding studies that assessed the effect of strain, background diet (non-purified, semipurified) and dietary perturbation (cholesterol and/or fat) on plasma lipoprotein profiles and atherosclerotic lesion formation. F1B hamsters fed a non-purified cholesterol/fat-supplemented diet had more atherogenic lipoprotein profiles (nHDL-C > HDL-C) than other hamster strains or hamsters fed cholesterol/fat-supplemented semi-purified diets. However, fat type; saturated (SFA), monounsaturated or n-6 polyunsaturated (PUFA) had less of an effect on plasma lipoprotein concentrations. Cholesterol-and fish oil-supplemented semi-purified diets yielded highly variable results when compared to SFA or n-6 PUFA, which were antithetical to responses observed in humans. Dietary cholesterol and fat resulted in inconsistent effects on aortic lipid accumulation. No hamster strain was reported to consistently develop lesions regardless of background diet, dietary cholesterol or dietary fat type amount. In conclusion, at this time the Golden-Syrian hamster does not appear to be a useful model to determine the mechanism(s) of diet-induced development of atherosclerotic lesions.
The Journal of Nutritional Biochemistry, 2005
Physically refined rice bran oil containing 2-4% nontriglyceride components as compared to other vegetable oils appears to be associated with lipid lowering and antiinflammatory properties in several rodent, primate and human models. These experiments were designed to investigate possible mechanisms for the hypocholesterolemic effect of the physically refined rice bran oil and to examine its effect on aortic fatty streak formation. In the first experiment, 30 hamsters were fed, for 8 weeks, chow-based diets plus 0.03% added cholesterol and 5% (wt/wt) coconut, canola, or physically refined rice bran oil (COCO, CANOLA or PRBO animal groups, respectively). Both plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in PRBO but not in CANOLA relative to COCO. PRBO also showed a significant 15-17% reduction in cholesterol absorption and significant 30% increase in neutral sterol (NS) excretion with no effect on bile acid (BA) excretion. Both CANOLA and PRBO showed a significant 300-500% increase in intestinal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and significant (N 25%) decrease in hepatic HMG-CoA reductase activities with respect to COCO. In a second experiment, 36 hamsters were fed chow-based diets with 0.05% added cholesterol, 10% coconut oil and 4% additional COCO, CANOLA or PRBO. Relative to COCO and CANOLA, plasma TC and LDL-C were significantly reduced in PRBO. Early atherosclerosis (fatty streak formation) was significantly reduced (48%) only in PRBO, relative to the other two. These results suggest that the lipid lowering found in PRBO is associated with decreased cholesterol absorption, but not hepatic cholesterol synthesis, and that the decrease in fatty streak formation with this oil may be associated with its nontriglyceride components not present in the other two diets.