Effect of various dietary fats and proteins on serum cholesterol level in rats

A 60 day experiment on growing rats was performed to evaluate the effect of two protein sources (casein and soybean protein isolate) and four fats (olive oil, OO; evening primrose oil, EO; linseed oil, LO; and butter, B) on plasma lipoprotein fractions: total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C) and triacylglycerol (TAG) levels. The different protein and fat sources had no influence on body weight gain of rats. Fats had no significant effect on TC and LDL‐C. Significant differences were found only in HDL‐C. OO gave the lowest (43.3 mg dl^?1) and EO the highest (54.4 mg dl^?1) value. Proteins had a significant influence on all lipids analysed. Soybean protein caused higher TC (78.5 vs 67.9 mg dl^?1), HDL‐C and TAG levels but significantly lowered LDL‐C in the plasma of rats. These results suggest that protein has a stronger effect on cholesterol level than fat. © 2002 Society of Chemical Industry     

The probiotic role of Lactobacillus plantarum in reducing risks associated with cardiovascular disease

A novel strain of Lactobacillus plantarum DMDL 9010 (CGMCC No. 5172) was isolated from naturally fermented mustard. The potential cholesterol reduction effects of this strain were investigated using an in vivo model. The results showed that L. plantarum DMDL 9010 at a dose of 10⁹ cells per day significantly reduced (P ≤ 0.05) serum total cholesterol (TC), low‐density lipoprotein cholesterol content (LDL‐C) levels and atherosclerosis index (AI) by 23.03%, 28.00% and 34.03%, respectively, while L. plantarum DMDL 9010 did not exhibit a significant effect on reducing serum triglycerides (TG) and increasing the serum high‐density lipoprotein cholesterol content (HDL‐C) in experimental rats (P > 0.05). The morphological and pathological changes in the liver illustrated that L. plantarum DMDL 9010 protected the rats against hepatocyte steatosis. Additionally, a high dose of L. plantarum DMDL 9010 was shown to exhibit a positive cholesterol‐lowering effect through decreasing the liver cholesterol (?33.20%) and triglyceride (?40.86%) levels, and increasing significantly (P ≤ 0.05) faecal cholesterol (+31.07%) and bile acid excretion (+70.18%). The results demonstrated that L. plantarum DMDL 9010 acted in a dose‐dependent way to decrease serum and total hepatic cholesterol and triglyceride and enhance faecal excretion of bile acids. In conclusion, these findings suggest that L. plantarum DMDL 9010 has potential to be explored as a probiotic for hypercholesterolaemic preventive and therapeutic.     

Inhibitory effects of Hibiscus sabdariffa L extract on low‐density lipoprotein oxidation and anti‐hyperlipidemia in fructose‐fed and cholesterol‐fed rats

Hibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low‐density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid‐reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu²⁺‐mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high‐fructose diet (HFD) fed rats and serum cholesterol in high‐cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL‐cholesterol (LDL‐C) to HDL‐cholesterol (HDL‐C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD‐ or HCD‐fed rats. Copyright © 2004 Society of Chemical Industry     

LIPID-LOWERING EFFICACY OF PIPERINE FROM PIPER NIGRUM L. IN HIGH-FAT DIET AND ANTITHYROID DRUG-INDUCED HYPERCHOLESTEROLEMIC RATS

Male Wistar rats were divided into two groups: control diet group and high‐fat diet group (HFD). Both groups were divided into four subgroups, each consisted of 10 animals, and the diets were supplemented with the following ingredients for 10 weeks: (1) 1% carboxymethyl cellulose; (2) 10 mg carbimazole (CM)/kg body weight; (3) 10 mg CM + 40 mg piperine/kg body weight; and (4) 10 mg CM + 2 mg atorvastatin/kg body weight. Feeding HFD to rats significantly (P < 0.05) elevated plasma total cholesterol, triglycerides, phospholipids, free fatty acids, low‐density lipoprotein (LDL), very low‐density lipoprotein (VLDL) and the activity of 3‐hydroxy 3‐methyl glutaryl coenzyme A (HMG CoA) reductase in the liver, heart and aorta, while the activities of plasma and tissue lipoprotein lipase (LPL) and plasma lecithin cholesterol acyl transferase (LCAT) and high‐density lipoprotein were significantly (P < 0.05) lowered compared to control rats. Supplementing piperine with HFD significantly (P < 0.05) reduced the levels of plasma total cholesterol, LDL, VLDL tissue HMG CoA reductase and significantly (P < 0.05) elevated the levels of LPL and LCAT compared to rats that did not receive piperine. Fecal bile acids and neutral sterols were also elevated in HFD‐fed rats as compared to control animals, while simultaneous supplementation of piperine significantly (P < 0.05) enhanced further excretion of bile acids and neutral sterols. The results indicate that piperine can prevent the accumulation of plasma lipids and lipoproteins significantly by modulating the enzymes of lipid metabolism.     

Anti‐obesity effect of Liupao tea extract by modulating lipid metabolism and oxidative stress in high‐fat‐diet‐induced obese mice

Liupao tea (LPT) is traditional dark Chinese tea. The effect of LPT extract on high‐fat‐diet‐induced obese mice was investigated systematically. The results showed that LPT extract could reduce body weight and significantly alleviate liver damage and fat accumulation. LPT could also decrease the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (AKP), total cholesterol (TC), triglycerides (TG), and low‐density lipoprotein cholesterol (LDL‐C) and increase the level of high‐density lipoprotein cholesterol (HDL‐C) in the liver. It also decreased the serum levels of inflammatory cytokines, including tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), interleukin (IL)‐1β, and IL‐6 and increased the serum levels of anti‐inflammatory cytokines, including IL‐10 and IL‐4. Moreover, LPT improved the levels of total superoxide dismutase (T‐SOD), glutathione peroxidase (GSH‐Px), and catalase (CAT) and reduced the level of malondialdehyde (MDA) in the liver. Moreover, LPT could upregulate the mRNA and protein expressions of peroxisome proliferator‐activated receptor alpha (PPAR‐α), lipoprotein lipase (LPL), carnitine palmitoyltransferase 1(CPT1), and cholesterol 7 alpha‐hydroxylase (CYP7A1) and downregulate those of PPAR‐γ and CCAAT/enhancer‐binding protein alpha (C/EBP‐α) in the liver. It also increased the mRNA expression of copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), CAT, gamma‐glutamylcysteine synthetase 1 (GSH1), and GSH‐Px. The components of LPT extract include catechin, rutin, taxifolin, and astragalin, which possibly have a wide range of biological activities. In conclusion, our work verified that LPT extract possessed an anti‐obesity effect and alleviated obesity‐related symptoms, including lipid metabolism disorder, chronic low‐grade inflammation, and liver damage, by modulating lipid metabolism and oxidative stress.     

Hepatoprotective effects of almond oil against carbon tetrachloride induced liver injury in rats

This research aimed at evaluating the protective effects of almond oil against acute hepatic injury induced by carbon tetrachloride in rats. The study results showed that animals received almond oil prior to the administration of CCl₄ significantly decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities, and total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL) content, and increased serum high density lipoprotein (HDL) content. Whereas, pre-treatment with almond oil markedly increased rat hepatic superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) levels, and decreased the malondialdehyde (MDA) level. These results combined with liver histopathology demonstrated that almond oil has potent hepatoprotective effects, and could be developed as a functional food for the therapy and prevention of liver damage.     

Effects of highly purified sardine proteins on lipid peroxidation and reverse cholesterol transport in rats fed a cholesterol-rich diet

The effect of highly purified sardine proteins was compared with that of casein on serum and lipoproteins lipid peroxidation and reverse cholesterol transport. Lecithin:cholesterol acyltransferase (LCAT) activity, high density lipoproteins (HDL₂ and HDL₃) composition and serum lipid and lipoproteins peroxidation were determined in rats fed a cholesterol-rich diet. Hypercholesterolemic rats were divided into two groups fed diets enriched with cholesterol and containing 20% of highly purified sardine proteins (SPc) or casein (CASc) for 28 days. A control group was fed a standard diet (CAS). Compared with CAS and CASc, the thiobarbituric acid reactive substances (TBARS) concentrations of low density lipoprotein (LDL)–HDL₁ in SPc were 3.5- and 1.7-fold higher compared with casein diets. TBARS in HDL₂ and HDL₃ were, respectively, 2.3- and 1.6-fold lower in SPc compared with CASc. In SPc group, LCAT activity was higher compared to CASc and CAS (P < 0.05). Purified sardine proteins had no beneficial effects on LDL-cholesterol and lipid peroxidation. However, they reduced HDL oxidation and improved reverse cholesterol transport, in the hypercholesterolemic rat.     

Comparison of lipoprotein fractionation by sequential density gradient ultracentrifugation with precipitation or fast phase liquid chromatography

Lipoprotein fractions, i.e. very low density (VLDL, ρ=0.93−1.019), low density (LDL, ρ=1.019−1.063), and high density lipoprotein (HDL, ρ=1.063−1.21) were separated by sequential gradient density ultracentrifugation (SDGU) and their cholesterol values were determined and compared with values determined by fast phase liquid chromatography (FPLC) or HDL cholesterol by phosphotungstic acid-MgCl₂ (PTMg) precipitation in hamsters fed diets containing various levels of cholesterol. The correlation coefficient (r) for LDL between the SDGU and FPLC methods in plasma from hamsters fed 0–3% cholesterol diets was 0.21–0.51, n=45. The FPLC method over estimated (+45%) LDL and the HDL values were under estimated (−18%). The agreement between FPLC and SDGU methods was also evaluated by plotting mean values against the differences between the values obtained by the two methods. FPLC method overestimated LDL 22–49% (mean 36%) and HDL was underestimated 14–27% (mean 20%). This was significant systematic bias with the FPLC method in VLDL, LDL and HDL values with the level of cholesterol in the diet. As FPLC is a fast method, it could be used in intervention type experiments to monitor the progress, however final results may need validation for research studies with the SDGU method. HDL determined by the SDGU method and phosphotungstic acid MgCl₂ precipitation in hamsters (n=26) fed 0.25% cholesterol diets was represented by two significantly different (P⩽0.05) divergent lines when a regression fitted model and a one-to-one relationship model by the two methods were plotted. The data suggest that in hamsters fed either no added cholesterol or cholesterol-containing diets, lipoprotein fractions determined by the precipitation method or by FPLC need to be validated against a SDGU for critical samples.     

Effect of administration of fermented milk containing whey protein concentrate to rats and healthy men on serum lipids and blood pressure

The effect of fermented milk supplemented with whey protein concentrate on the serum lipid level of rats was investigated. The serum total cholesterol level for the group fed fermented milk with both Lactobacillus casei TMC0409 and Streptococcus thermophilus TMC 1543 was significantly lower than that of the control group (P<0.05) in rats. Furthermore, the effect of the longterm intake of this fermented milk on the serum lipid level of twenty healthy adult men was investigated. During the 8-wk study, the volunteers consumed 200 ml of fermented milk or placebo in the morning and evening. Blood samples were drawn for analysis three times, just before taking the experimental diet, and after 4 wk and 8 wk of consumption. After 8 wk, the high density lipoprotein cholesterol level for the fermented milk group showed a significant rise after 4 wk (P<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The triglyceride level for the fermented milk group lowered significantly after 4 wk (<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The atherogenic index [(total cholesterol - high density lipoprotein cholesterol)/high-density lipoprotein cholesterol] for the fermented milk group decreased significantly from 4.24 to 3.52 (P<0.05). The systolic blood pressure lowered significantly by the intake of fermented milk (P<0.05) On the other hand, such effect was not observed in the placebo group (P>0.05). These results indicate potential of the development of fermented milk with multiple therapeutic effects.     

Dietetic and hypocholesterolaemic action of black soy peptide in dietary obese rats

To investigate the effect of peptides from black soy (rat's eye) bean (Rhynchosia volubilis Lour.) on weight gain and lipid composition, Sprague–Dawley male rats were fed either a black soy peptide (BSP; 2, 6 or 10% of energy)‐containing diet or a casein control diet (20% of energy) enriched with 36% fat and 1% cholesterol for 28 days. Compared with the casein group, the BSP groups showed significant attenuation of body, liver and epididymal adipose tissue weight gains (P < 0.05). Moreover, rats that consumed BSP had a lower total cholesterol concentration and low‐density lipoprotein/high‐density lipoprotein (LDL/HDL) ratio in serum and a lower level of hepatic triglycerides as well as higher excretion of faeces compared with those fed only casein (P < 0.05). Molecular weights of peptides from black soy were mainly below 10 kDa, and Arg/Lys and Gly/Met ratios in BSP were five and three times of those in casein respectively. It is concluded that BSP can be a potent nutraceutical component for anti‐obesity and hypolipidaemic benefits. Copyright © 2007 Society of Chemical Industry     

Hypolipidaemic and hypoglycaemic effects of total flavonoids from seed residues of Hippophae rhamnoides L. in mice fed a high-fat diet

BACKGROUND: The present study was designed to investigate the hypolipidaemic and hypoglycaemic effects of total flavonoids from seed residues of Hippophae rhamnoides L. (FSH) in a high‐fat diet fed mouse model. Consumption of a high‐fat diet (HFD) for 4 weeks caused a significant rise of serum total cholesterol in mice. These hypercholesterolaemic mice then were orally administrated with different doses of FSH (50, 100 and 150 mg kg^?1 body weight) and simvastatin (20 mg kg^?1 body weight) for another 12 weeks under continuous HFD feeding. RESULTS: FSH administration markedly reduced total mouse body, liver, and epididymal fat pad weights. Serum total cholesterol and low density of lipoprotein‐cholesterol levels were also significantly decreased by FSH treatment. Additionally, FSH significantly lowered total cholesterol and triglyceride concentrations in liver, and the results were corroborated by transmission electron microscope findings. The rise in serum glucose was significantly suppressed by FSH treatment while improving impaired glucose tolerance. CONCLUSION: These results suggest that FSH possesses hypolipidaemic and hypoglycaemic properties in mice fed a high‐fat diet and could be developed as a supplement in healthcare foods and drugs. Copyright © 2011 Society of Chemical Industry     

哈萨克族传统发酵乳酪的乳清对实验性动脉粥样硬化大鼠的作用

观察哈萨克族传统发酵乳酪的乳清(简称乳酪乳清)对实验性动脉粥样硬化大鼠的作用。健康SD大鼠40只随机分为5组:正常组(n=8),髙脂模型组(n=8),阳性对照组(n=8)及给药组(n=16)。通过高脂饮食4周及内皮损伤建立动脉粥样硬化大鼠模型,给予哈萨克族传统发酵乳酪的乳清(大、小剂量组)及阳性对照药辛伐他汀3周后,分别测定肝指数(肝重/体重)、血脂、肝脂、C-反应蛋白等指标,并对大鼠冠状动脉,主动脉病理形态学进行观察。结果表明,乳酪乳清0.5mg/100g和1mg/100g组及辛伐他汀组(0.5mg/100g)降低动脉粥样硬化大鼠血清胆固醇(TC)分别为30.9%(P<0.01)及19%(P<0.05)。低密度脂蛋白胆固醇(LDL-C)分别降低17.3%(P<0.05)及31.3%(P<0.01)。模型组与给药组和辛伐他组相比,C反应蛋白显著降低(P<0.01)。病理切片结果表明,乳酪乳清能明显减轻大鼠动脉粥样硬化性损伤。结论:乳酪乳清0.5mg/100g组和1mg/100g组均具有调血脂作用,提示乳酪乳清具有显著抗大鼠实验性动脉粥样硬化作用。     

Properties of nanopowdered chitosan and its cholesterol lowering effect in rats

This study was carried out to compare the properties of nanopowdered chitosan (NPC) to commercially powdered chitosan (CPC) and examine the effect of NPC on serum and liver cholesterol lowering in rats. Twentyfour male rats of Sprague-Dawley strain were blocked into 3 groups and were raised for 8 weeks. High cholesterol diet, 2% CPC, or 2% NPC were given to 3 groups. NPC reduced total cholesterol by 46.6% and CPC reduced it by 18.6%. NPC also significantly reduced low density lipoprotein (LDL)-cholesterol by 55.7%, while CPC reduced by 36.8%. High density lipoprotein (HDL)-cholesterol content was increased more with NPC by 16.5% than with CPC by 9.6%. Triacylglycerol content was also decreased significantly by 42.8% with NPC, while reduced by 22.5% with CPC. The present study indicated that NPC feeding reduced total and LDL-cholesterol and triacylglycerol contents and increased HDL-cholesterol content.     

中国楤木粗多糖对糖尿病大鼠的降血糖作用

目的：研究中国楤木粗多糖（Aralia chinensis polysaccharide,ACP）对糖尿病大鼠的降血糖作用。方法：采用四氧嘧啶（alloxan,ALX）诱导建立糖尿病大鼠模型,并随机将Sprague-Dawley（SD）大鼠分为正常对照组,糖尿病模型组,ACP高、中、低剂量组,二甲双胍组。连续灌胃给药28 d,测定ACP对糖尿病大鼠空腹血糖（fasting blood glucose,FBG）、糖化血红蛋白（glycosylated hemoglobin A1c,HbA1c）、总胆固醇（totalcholesterol,TC）、甘油三酯（triglyceride,TG）、高密度脂蛋白（high density lipoprotein,HDL）、低密度脂蛋白（low density lipoprotein,LDL）水平的影响。结果：ACP能够有效降低糖尿病大鼠的FBG、HbA1c、TC、TG水平,提高HDL水平。结论：ACP能够显著降低糖尿病大鼠血糖水平,有效调节糖尿病大鼠血脂代谢紊乱。     

Hypocholesterolaemic and antioxidant effects of Glycyrrhiza glabra (Linn) in rats

The hypocholesterolaemic and antioxidant effects of Glycyrrhiza glabra (GG) root powder were examined in hypercholesterolaemic male albino rats. A 4-week administration of GG root powder (5 and 10 gm% in diet) to hypercholesterolaemic rats resulted in significant reduction in plasma, hepatic total lipids, cholesterol, triglycerides and plasma low-density lipoprotein and VLDL-cholesterol accompanied by significant increases in HDL-cholesterol levels. Furthermore, significant increases in fecal cholesterol, neutral sterols and bile acid excretion along with an increase in hepatic HMG-CoA reductase activity and bile acid production were observed in these animals. The root powder administration to hypercholesterolaemic rats also decreased hepatic lipid peroxidation with a concomitant increase in superoxide dismutase (SOD) and catalase activities and total ascorbic acid content. Thus, the hypocholesterolaemic and antioxidant effects of GG root appeared to be mediated via (i) accelerated cholesterol, neutral sterol and bile acid elimination through fecal matter with an increased hepatic bile acid production and (ii) improving the activities of hepatic SOD, catalase and increasing the ascorbic acid content. The normo-cholesterolaemic animals when fed with GG root powder at 10 gm% level, registered a significant decline in plasma lipid profiles and an increase in HDL-cholesterol content. The antioxidant status of these animals also was improved upon treatment.     

Phytochemical,Toxicological, Biochemical and Haematological Studies on Avocado (Persea americana) in Experimental Animals

The avocado tree belongs to the family lauraceae and is classified as Persea americana. The analysis of the fruits extract revealed the presence of considerable amounts of vitamins A, B₂, C, K, folic acid, lutein, zeaxanthin, coenzyme Q₁₀ and beta-carotene. When administered to wistar rats for acute toxicity studies, the animals did not exhibit any sign of toxicity even when large doses were given. The maximum tolerable dose (MTD) was therefore determined to be ≥ 10 g/kg body weight. The extract was found to significantly decrease (p < 0.05) the activity of liver and heart enzymes in the treated animals when compared with the control. The extract decreased total cholesterol (TC) by 37.97%, triglycerides by 37.87%, very low density lipoproteins(VLDL) by 47,41%, low density lipoproteins(LDL) by 59.57%, and at the same time increased high density lipoprotein (HDL) by 3.64%. The extract also decreased the prothrombin time (PT) and the partial prothrombo plastin time with kaolin (PTTK). These results are discussed with regard to the preventive and possible curative values of this extract as a potential inhibitor of cardiovascular diseases and in the regulation of blood clotting time due to its significant vitamin K content.     

Effects of trypsin inhibitor on plasma antioxidant activity and lipid levels in mice from sweet potato roots

BACKGROUND: Several inflammatory diseases are thought to be related to oxidative injury and reactive oxygen species have been proposed as important causative agents of heart disease and ageing. This study was designed to investigate the effects of sweet potato trypsin inhibitor (SPTI) on antioxidant enzymes, lipid peroxidation and lipid profiles in mice. RESULTS: Twenty mice were randomly divided into four groups and fed with TI (10, 50 and 100 mg kg^?1 BW) as treatment and with saline as a control in addition to regular diets. After 35 days, Trolox equivalent antioxidant capacity (TEAC), triglyceride (TG) and cholesterol levels in plasma and superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), thiobarbituric acid reactive substances (TBARS) in liver were measured. Serum from the group that had received the the highest oral dose of SPTI (100 mg kg^?1 BW) had the highest total antioxidant activity (expressed as 3.59 ± 0.237 mmol L^?1 TEAC). The SOD, catalase and GPx activity of SPTI groups were significantly increased compared with the control group. Malondialdehyde (MDA) was significantly lower in all experimental groups compared with the control one. No significant differences in the concentration of low‐density lipoprotein (LDL)‐cholesterol was found, but high density lipoprotein (HDL)‐cholesterol, triglyceride (TG) and total cholesterol tended to decrease. CONCLUSION: This study showed that the oral intake of SPTI in mice may trigger inflammatory responses which result in an increase in antioxidant enzyme activities, and a decrease in MDA, TG and total cholesterol, which are known risk factors of inflammatory and heart disease. Copyright © 2008 Society of Chemical Industry     

Characterisation of Lactobacillus fermentum SM-7 isolated from koumiss, a potential probiotic bacterium with cholesterol-lowering effects

BACKGROUND: Lactic acid bacteria (LAB) have been demonstrated to have cholesterol‐reducing effects in many studies. RESULTS: Lactobacillus fermentum SM‐7 screened from ten LAB strains isolated from koumiss, a fermented milk drink, reduced cholesterol by 66.8%. It also showed acid and bile tolerance as well as antimicrobial activity against pathogenic Escherchia coli and Staphylococcus aureus. Lactobacillus fermentum SM‐7 cells assimilated 61.5% and co‐precipitated and absorbed 38.5% of the cholesterol in the media. Co‐precipitation of cholesterol with cholic acid increased rapidly at pH levels below 6. In vivo experiments using L. fermentum SM‐7 on artificially induced hyperlipidaemial ICR mice significantly decreased serum total cholesterol and total triglyceride levels, low‐density lipoprotein cholesterol concentrations and atherogenic index (P < 0.01), while serum high‐density lipoprotein cholesterol concentrations did not increase significantly (P > 0.05). The body weight and liver weight/body weight ratio of SM‐7 groups were lower than those of mice on a high‐cholesterol diet that were not given lactobacilli. There was no bacterial translocation in the liver, spleen or kidney of experimental mice. CONCLUSION: The results suggested that L. fermentum SM‐7 is a potential probiotic bacterium with cholesterol‐lowering effects. Copyright © 2010 Society of Chemical Industry     

Choosing hamsters but not rats as a model for studying plasma cholesterol‐lowering activity of functional foods

Rats and hamsters are commonly used rodents to test the efficacy of cholesterol‐lowering functional foods. In general, a diet containing 1% cholesterol for rats whereas a diet containing 0.1% cholesterol for hamsters is used to induce the hypercholesterolemia. The present study was carried out to compare hamsters with rats as a hypercholesterolemia model. Golden Syrian hamsters and Sprague Dawley rats were randomly divided into four groups and fed one of the four diets containing 0–0.9% cholesterol. Results demonstrated that serum total cholesterol (TC) in hamsters was raised 73–81% higher than that in rats fed the same cholesterol diets. Unlike rats in which HDL‐C accounted very little for serum TC, the lipoprotein profile in hamsters was closer to that in humans. We investigated interaction of higher cholesterol diets with 3‐hydroxy‐3‐methylglutary‐CoA (HMG‐CoA) reductase, low‐density lipoprotein receptor (LDL‐R) and cholesterol‐7α‐hydroxylase (CYP7A1), sterol regulatory element binding protein‐2 (SREBP‐2), and liver X receptor (LXR‐α). Results showed hamsters and rats metabolized cholesterol differently. In view that hamsters synthesize and excrete cholesterol and bile acids in a manner similar to that in humans, it is concluded that hamsters but not rats shall be chosen as a model to study efficacy of cholesterol‐lowering functional foods.