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     

Fish protein decreases serum cholesterol in rats by inhibition of cholesterol and bile acid absorption

Fish protein has been shown to decrease serum cholesterol content by inhibiting absorption of cholesterol and bile acid in laboratory animals, though the mechanism underlying this effect is not yet fully understood. The purpose of this study was to elucidate the mechanism underlying the inhibition of cholesterol and bile acid absorption following fish protein intake. Male Wistar rats were divided into 2 dietary groups of 7 rats each, 1 group receiving a diet consisting of 20% casein and the other receiving a diet consisting of 10% casein and 10% fish protein. Both experimental diets also contained 0.5% cholesterol and 0.1% sodium cholate. After the rats had been on their respective diets for 4 wk, their serum and liver cholesterol contents and fecal cholesterol, bile acid, and nitrogen excretion contents were measured. Fish protein consumption decreased serum and liver cholesterol content and increased fecal cholesterol and bile acid excretion and simultaneously increased fecal nitrogen excretion. In addition, fish protein hydrolyzate prepared by in vitro digestion had lower micellar solubility of cholesterol and higher binding capacity for bile acids compared with casein hydrolyzate. These results suggest that the hypocholesterolemic effect of fish protein is mediated by increased fecal cholesterol and bile acid excretion, which is due to the digestion products of fish protein having reduced micellar solubility of cholesterol and increased bile acid binding capacity.     

The correlation between serum total cholesterol and some trace elements in serum,liver and heart of rats fed high cholesterol diet

The work indicates the link between the serum cholesterol, atherosclerosis and certain metal metabolism. 122 adult albino rats were used in this study and classified into 5 groups: Control group, 29 rats fed the stock diet; group I, 32 rats fed the stock diet with 1 % cholesterol for 6 weeks; group II, 36 rats fed the stock diet with 1 % cholesterol for 8 weeks; group III_A, 17 rats fed the stock diet and 0.2 ml oil/day orally for 8 weeks and group III_B, 18 rats fed the stock diet and 0.2 ml oil with cholesterol daily (50 mg cholesterol/1 ml oil) for 8 weeks. The results obtained showed that: 1. A positive correlation was found between serum total cholesterol and serum copper, cadmium and Cd/Zn ratio, whereas a negative correlation occurred between serum total cholesterol and serum Zinc and Zn/Cu ratio. 2. A positive correlation was found between serum total cholesterol and cadmium, Zn/Cu and Cd/Zn ratio in liver. On the other hand, a negative correlation occurred between serum total cholesterol and copper in liver. 3. A positive correlation was found between serum total cholesterol and Zn/Cu ratio in heart which was negative in heart copper, cadmium and Cd/Zn ratio. Histopathological examination of liver sections of animals treated with cholesterol revealed the presence of mild degree of fatty change, while the kidney tissues showed glomerular lesion in the form of obliteration of Bowman's capsule with increased cellularity inside, beside degenerated tubules and interstitial fibrosis.     

The correlation between serum total cholesterol and some trace elements in serum, liver and heart of rats fed high cholesterol diet.

The work indicates the link between the serum cholesterol, atherosclerosis and certain metal metabolism. 122 adult albino rats were used in this study and classified into 5 groups: Control group, 29 rats fed the stock diet; group I, 32 rats fed the stock diet with 1% cholesterol for 6 weeks; group II, 36 rats fed the stock diet with 1% cholesterol for 8 weeks; group IIIA, 17 rats fed the stock diet and 0.2 ml oil/day orally for 8 weeks and group IIIB, 18 rats fed the stock diet and 0.2 ml oil with cholesterol daily (50 mg cholesterol/1 ml oil) for 8 weeks. The results obtained showed that: 1. A positive correlation was found between serum total cholesterol and serum copper, cadmium and Cd/Zn ratio, whereas a negative correlation occurred between serum total cholesterol and serum Zinc and Zn/Cu ratio. 2. A positive correlation was found between serum total cholesterol and cadmium, Zn/Cu and Cd/Zn ratio in liver. On the other hand, a negative correlation occurred between serum total cholesterol and copper in liver. 3. A positive correlation was found between serum total cholesterol and Zn/Cu ratio in heart which was negative in heart copper, cadmium and Cd/Zn ratio. Histopathological examination of liver sections of animals treated with cholesterol revealed the presence of mild degree of fatty change, while the kidney tissues showed glomerular lesion in the form of obliteration of Bowman's capsule with increased cellularity inside, beside degenerated tubules and interstitial fibrosis.     

Purple potato flake reduces serum lipid profile in rats fed a cholesterol-rich diet

The effect of purple potato flake on cholesterol metabolism was investigated in rats fed a high-cholesterol diet. The hypocholesterolemic action of dietary purple potato flake might be related with caecal fermentation and steroid excretion due to the phosphorus and polyphenols including anthocyanin.     

Influence of qualitatively different fats on the level of cholesterol and phospholipids in the blood serum and liver on rats in choline-protein insufficiency]

The effect of lard and sunflower oil making part of a cirrhogenic ration with a high content of fat and deficient protein and choline on the level of total and esterified cholesterol and phospholipids in the blood serum and liver was studied. The experiments lasted for 150 and 210-240 days. Changes in the level of cholesterol and phospholipids in the blood serum and liver of the rats were noted to occur from the first days of developing fat dystrophy (fatty degeneration) of the liver, these changes gaining in intensity with lengthening of the test periods and progressive development of the pathological process. The quality of the fat influenced the extent of the upset cholesterol and phospholipids metabolism, since the saturated fat which accelerated and intensified the development of lipohepatosis and cirrhosis caused a significantly greater accumulation of the cholesterol ethers in the liver and reduction of these ethers, as well as of phospholipids in the serum. An addition of choline to the rations prevented the development of lipohepatosis, but failed to avert upsets of the lipids metabolism.     

The effect of leaf protein concentrate from red clover on plasma cholesterol level in rats

The effect of native and defatted leaf protein concentrate (LPC) from red clover on plasma cholesterol level in rats was studied. Fat-free casein was used as a control protein. The native LPC contained 212 g kg^?1 of ether extract and oleic acid (C_{18: 1}) was its main fatty acid. LPC protein was relatively poor in sulphur-containing amino acids. Each protein studied was given to rats with or without soya bean oil. It was found that total cholesterol level in plasma of rats fed with the oil-containing diets was higher than that of rats fed with the oil-free diets. Original fat present in the native LPC though rich in unsaturated fatty acids had no hypocholesterolaemic effect. LPC was hypocholesterolaemic compared with casein in diets not containing added soya bean oil, although the difference did not reach statistical significance.     

Influence of garlic on serum cholesterol,serum triglycerides,serum total lipids and serum glucose in human subjects

Human subjects were used for a garlic experiment. The subjects were given a fat-rich diet for 7 days and on the 8th day the fasting blood was analyzed for serum cholesterol, serum triglycerides, serum total lipids and serum glucose. The human subjects were then given a fat-rich diet with 40 g of garlic for 7 days and on the 15th day the fasting blood was analyzed for the above investigations. On a fat-rich diet the serum cholesterol, serum triglycerides and serum total lipids were significantly increased as compared to normally fed diet. When 40 g of garlic was substituted in fat-rich diet for 7 days, the garlic significantly reduced the serum cholesterol and serum triglycerides.     

自然发酵豆酱中降胆固醇乳酸菌的筛选鉴定及对大鼠血清胆固醇的影响

采用不同培养基从分离自自然发酵豆酱样品中的285株乳酸菌种中分离筛选出3株能够耐受人工胃肠环境,具有降胆固醇作用的乳酸菌,编号分别为DQ17-2、DD1-1、KY1-1,对胆固醇的去除率分别为34. 56%、27. 12%和29. 20%,最后通过形态学观察、生理生化试验、16S r DNA序列鉴定法确定3株乳酸菌均为植物乳杆菌。将菌株DQ17-2重新命名为植物乳杆菌WW(L. plantarum WW),为了进一步验证其在体内的降胆固醇作用,将32只5周龄雄性SD大鼠随机分为4组:普通对照组(A)、高脂模型组(B)、脱脂乳对照组(C)、菌液干预组(D)。饲喂12周后,采血,测定血清总胆固醇(totalcholesterol,TC)、高密度脂蛋白胆固醇(highdensity lipoprotein-cholesterol,HDL-C)、低密度脂蛋白胆固醇(lowdensity lipoprotein-cholesterol,LDL-C)、甘油三酯(triglyceride,TG)含量。结果表明,饲喂12周后成功构建高脂模型,与B组和C组相比,D组血清TC、TG、LDL-C含量明显降低(P 0. 05),HDL-C含量明显升高(P 0. 05)。该实验筛选出一株在体内外均具有降胆固醇作用的L. plantarum WW,为今后降胆固醇产品的研发提供原料与依据。     

Increased concentrations of liver cholesterol in rats fed lactulose

The disaccharide lactulose (beta-D-galactopyranosyl-(1-4)-D-fructofuranose) is thought to be poorly hydrolized by intestinal enzymes but is broken down by microorganisms in the colon. Thus lactulose shares with pectin similar characteristics. Lactulose is used in the food industry and in the treatment of constipation. There is preliminary evidence that dietary lactulose (5%, w/w) causes increased concentrations of serum and liver cholesterol in rats when compared with pectin. This paper describes dose-response relationships between dietary lactulose and cholesterol in either serum or liver.     

Effect of emotional and pain stress on the level of antioxidant vitamins in the blood serum of rats

The content of ascorbic acid and alpha-tocopherol was found to be decreased in the blood of rats which had suffered an emotional pain stress. Preadaptation of the animals to hypoxia did not change the level of ascorbic acid, but it was valuable with respect to alpha-tocopherol. The emotional pain stress in the presence of adaptation to hypoxia induced in the animals reduction of the blood levels of both vitamins similar to that in the controls. The synthetic antioxidant ionol diminished stress-induced hypovitaminosis of ascorbic acid and completely prevented reduction of alpha-tocopherol level in the blood of rats after the stress.     

Black raspberry extract can lower serum LDL cholesterol via modulation of gut microbial composition and serum bile acid profile in rats fed trimethylamine-N-oxide with a high-fat diet

Food Science and Biotechnology - Blood trimethylamine-N-oxide (TMAO) has been associated with cardiovascular disease. Black raspberry (Rubus occidentalis, BR) has been regarded to be beneficial for...     

Comparative study of resistant starch from minor millets on intestinal responses,blood glucose,serum cholesterol and triglycerides in rats

Native starch (NS) extracted from rice and five different minor millets, when subjected to five autoclaving and cooling cycles, contained higher amounts of resistant starch (RS) than NS. Both NS and treated starch (TS) were fed to groups of rats for 2 weeks. In rice and all the minor millets, rats fed with treated starch showed a six-fold (TS alone) or nearly 18-fold (TS with antibiotics) increase in faecal wet weight than rats fed with NS. Increase in faecal volumes paralleled increases in faecal weight. Rats fed with diet (both NS and TS) from Echinochloa frumentacea had the lowest blood glucose, serum cholesterol and triglycerides than the rice and other minor millets. ©1997 SCI     

Goat milk feeding causes an increase in biliary secretion of cholesterol and a decrease in plasma cholesterol levels in rats

The hypocholesterolemic effect of goat milk with respect to cow milk observed in a previous study led us to examine the influence of goat and cow milk in the diet on certain aspects of biliary physiology in normal rats. The fat content in all diets was 10% but the lipid quality was varied: the standard diet was based on virgin olive oil, and the other 2 diets included fat obtained from lyophilized cow milk and goat milk. We characterized the bile secretion, including biliary phospholipid, cholesterol, and bile acid outputs, the interrelation between bile acids and bile lipids, and the lithogenic index. The consumption of goat milk in the diet, compared with that of cow milk, caused an increase in the biliary secretion of cholesterol together with a decrease in plasma cholesterol concentration, whereas values for bile phospholipids, biliary acid concentrations, and the lithogenic index remained normal. Moreover, consumption of this type of milk decreased plasma triglyceride concentration and therefore had a positive effect, similar to that of olive oil (standard diet), on the lipid metabolism; hence, it may be recommended for consumption by the general population.     

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.     

Effects of pectin in the ration on cholesterol metabolism in rats]

Inclusion into the ration of 2.5 or 5% of apple pectin during 20 days did not significantly change the blood serum composition: cholesterol content decreased as compared to the control, the number of general bile acids increased. When apple pectin was added to the animals' ration containing egg powder, the amount of cholesterol excreted with feces increased depending on pectin content in the food.