Phospholipid turnover in the liver mitochondria of rats on a diet with a varying fat and protein ratio

Using the method of pulse introduction of labeled precursors the authors studied metabolism of rat liver mitochondrial phospholipids. The animals received high-protein diets (36% protein) containing 20% (diet II) and 36% (diet III) of fat as compared with the control (I) diet (18% protein and 20% fat). It appeared that the increase of protein in the diet (diet II) led to a reduction in the efficacy of 14C-palmitic acid incorporation into mitochondrial phospholipids, to a fall in the rate of metabolism of mitochondrial phospholipids and to a rise of their half-life within mitochondrial membranes, with the half-life of phospholipids labeled with 14C-palmitic acid in the fatty acid part being increased to a far greater degree as compared with that of phospholipids labeled with 3H-glycerin in the polar part of the molecules. However, in the presence of a high protein quota in the diet the fat/protein ratio agreed with the control level (diet III), whereas the metabolism of mitochondrial phospholipids remained close to the control values.     

Effect of hesperidin and naringin on the plasma lipid profile and plasma antioxidant activity in rats fed a cholesterol‐containing diet

The objective of this study was to compare the influence of hesperidin and naringin, the main flavonones of orange and grapefruit, on plasma lipid profile and antioxidant activity in rats fed a cholesterol‐containing diet. Sixty male Wistar rats were randomly divided into six groups of 10, named Control, Hesperidin, Naringin, Chol, Chol/Hesperidin and Chol/Naringin. The Control group was fed a basal diet (BD) and 1–2 mL of distilled water. To the BD of the other five groups were added 0.1–0.2 mg of hesperidin dissolved in 1–2 mL of distilled water (Hesperidin group), 0.46–0.92 mg of naringin in 1–2 mL of water (Naringin group), 1% of non‐oxidised cholesterol (NOC) and 1–2 mL of water (Chol), 1% of NOC and 0.1–0.2 mg of hesperidin in 1–2 mL of water (Chol/Hesperidin), 1% of NOC and 0.46–0.92 mg of naringin in 1–2 mL of water (Chol/Naringin). After 30 days of the experiment it was found that the diets supplemented with hesperidin and naringin increased the plasma antioxidant activity. In conclusion, diets supplemented with hesperidin and naringin significantly hindered the increase in plasma lipid levels caused by cholesterol feeding. Hesperidin and naringin, bioactive compounds of citrus fruits, are powerful plasma lipid lowering and plasma antioxidant activity increasing flavonones. Copyright © 2007 Society of Chemical Industry     

Effect of amaranth seeds in diet on oxidative status in plasma and selected tissues of high fructose-fed rats

The aim of this study was to assess the influence of amaranth seeds in different doses, under conditions of oxidative stress induced by dietary fructose, on antioxidant status of selected rat tissues, erythrocytes and plasma. Fructose administration caused oxidative stress that was manifested by the increase in plasma malondialdehyde and by the decrease in the enzymatic antioxidant activity. Co-administration of amaranth seeds influenced the oxidative stress, as was evidenced by decreasing malondialdehyde in plasma and changing the activities of antioxidant enzymes (erythrocyte superoxide dismutase, catalase, and plasma glutathione peroxidase). Our findings demonstrate that amaranth seeds can act as a moderate protective agent against fructose-induced changes. Our results suggest that the antioxidative system of plasma, heart and lungs is more efficient when amaranth seeds are present in the diet.     

亚麻籽饼对饲喂高脂日粮大鼠血浆中脂质及氧化应激改善作用的研究

研究了亚麻籽饼对饲喂高脂日粮大鼠血浆中血脂代谢和抗氧化能力的影响。将40只SD大鼠分成4组(n=10):正常组、高脂模型对照组、低剂量亚麻籽饼组(10%亚麻籽饼)、高剂量亚麻籽饼组(20%亚麻籽饼)。10周后处死SD大鼠,测定其血浆中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)的水平,同时测定血浆中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性以及还原型谷胱甘肽(GSH)、丙二醛(MDA)的含量。结果表明:亚麻籽饼可以显著降低SD大鼠血浆中TC、TG、LDL-C的水平,但对HDL-C无显著影响;亚麻籽饼可以提高SD大鼠血浆中GSH-Px、SOD、CAT的活性,同时增加GSH水平,降低MDA的含量。研究表明:亚麻籽饼可以改善饲喂高脂日粮对SD大鼠机体产生的不良影响,能够有效地提高抗氧化能力,缓解氧化应激和调节血脂代谢。     

Effect of diet on animal performance, lipid composition of subcutaneous adipose and liver tissue of beef cattle

Two trials were carried out with Brahman beef cattle to study animal performance and carcass characteristics as well as fatty acid composition of subcutaneous adipose and hepatic tissue, as influence by length of grain feeding period or a pasturing regimen. In trial 1, steers were allotted to three feedlot finishing periods (76, 104 and 146 days) after being backgrounded on pasture. Steers fed 76 days had greater average daily gains (P < 0·05) than steers fed 146 and 104 days, respectively. Carcasses of steers slaughtered after 146 days on feed had higher (P < 0·05) marbling scores, quality grades, fat over ribeye, quality yield and per cent kidney, pelvic and heart (KPH) fat than steers fed for 104 and 76 days. The proprortions of certain fatty acid of subcutaneous fat and liver tissue were influenced by the length of grain feeding. There was a marked increased in the proportion of oleic acid in both tissues as the steers remained longer in the feedlot and a higher percentage of total saturated fatty acids at 76 days than at the other two times. Quantitative separation of hepatic lipid classes by the Iatroscan revealed that phosphatidylcholine and phosphatidylethanolamine were the main components of the phospholipids. Presents as minor components were cardiolipin and sphingomyelin. No differences (P > 0.·05) in these individual subclasses of liver lipids or in triglycerides were observed between the feedlot groups. Liver polyunsaturated fatty acids (PUFA) were higher (P < 0·001) at 104 than 76 days. In trial 2, steers fed a concentrate diet gained faster (P < 0·05) than the pasture group after 138 days. Marbling scores, yield grade, quality grade, fat over ribeye and per cent KPH were higher (P < 0·01) for the concentrate group while fat color scores were higher (P < 0·01) for the pasture group. Liver fatty acid analysis of summed ω6 PUFAs of triglyceride, phosphatidylcholine, phosphatidylethanolamine were higher for the feedlot than the pasture group. Linoleic acid was higher (P < 0·05) in the TG and PC liver subclass of the feedlot animals while higher (P < 0·05) linolenic acid occurred in the pasture group.     

Effects of a high fat diet on long-chain fatty acids composition in rats serum and liver

A reliable and sensitive technique had presented to monitor the content of long-chain fatty acids (LCFAs) in biological materials. The purpose of this study was to report a method for separation and quantification of LCFAs by capillary gas chromatography (GC) with better recovery. With this method, we detected some changes of LCFAs in the serum and liver of rat fed with high fat diet. The result showed that the levels of C22:0, C22:6, C26:0 of serum of the high fat group were higher than that of the control group (P < 0.01); and the levels of C22:6, C26:0 of liver of the high fat group were higher than that of the control group (P < 0.01), but the levels of C22:0 and C24:0 of liver of the high fat group were lower than that of the control group (P < 0.01). It indicated that a high fat diet had an adverse effect upon normal metabolism.     

Effects of diet supplementation with cactus pear seeds and oil on serum and liver lipid parameters in rats

The purpose of this investigation was to evaluate the effects of diets enriched with cactus pear oil (CPO) or seeds (CPS) on serum and liver lipid parameters compared to those of adult rats submitted to a standard diet. Male rats were divided into three groups, the first group represented control group, fed with standard diet, the second group was fed with control diet supplemented with CPO (2.5%, wt/wt) and the third group fed control diet supplemented with CPS (33%, wt/wt), for nine weeks. Feed intake and body weight of rats were measured every two days. Organ weights were determined at the end of treatment; cholesterol, HDL and triglycerides levels were determined by enzymatic methods. Liver and serum lipid extracts were analysed for their fatty acid composition for the three groups of rats. No differences in pancreas, kidney or liver weights were observed in the CPS diet whereas the CPO diet induced a significant increase in liver and pancreas weights. The tested diets significantly decreased the atherogenic index compared to the control diet, whereas serum cholesterol level was only reduced by the supplementation with CPO diet. No variations in serum lipids were observed among the groups, whereas liver lipids showed slight variations. Accordingly, these results indicated that the supplementation with CPO or CPS could be effective in decreasing the atherogenic risk factors in rats.     

Effect of excess dietary manganese on lipid composition of calf blood plasma, heart, and liver.

Preruminant calves were fed milk replacer containing control (40 ppm) or two high concentrations (200 and 1000 ppm) of Mn to assess the effect of excessive Mn intakes on plasma, heart, and liver lipids. The two higher Mn intakes had no effect on lipid classes in liver and heart, except for elevated triglycerides in liver and lower sphingomyelin in heart (for 1000 ppm of Mn). At 1000 ppm of Mn intake, but not at 200 ppm, marked increases occurred in plasma total lipids, phosphatidylcholine, cholesterol, cholesterol esters, sphingomyelin, and triglycerides. The highest intake altered the essential fatty acid composition of liver phosphatidylcholine. Linoleic and linolenic acids were increased, but arachidonic and eicosapentaenoic acids were decreased, suggesting that very high excess of Mn interfered with hepatic desaturation and elongation of the essential fatty acids. Thus, high Mn intake (200 ppm) caused relatively few tissue lipid changes, whereas very high intake (1000 ppm) markedly increased plasma lipid classes and apparently interfered with essential fatty acid metabolism in liver.     

Effect of total fasting on testicular lipid fractions in rats]

Rats weighing 290 g each were fasting for 12 days with no changes occurring in the weight of the testicles, total lipids, phospholipids, di- and triglycerides content therein. The cholesterol ethers level increased by 53 per cent and in the composition of di- and triglycerides and the cholesterol ethers the relative content of high-molecular polyunsaturated fatty acids was going up, while the fatty acids composition of the phospholipids remained the same.     

The influence of panthotenic acid mitochondrial oxidation and oxidative phosphorylation in liver of rats with alimentary obesity

Alimentary obesity induced by the long-term feeding of rats by high-fat diet results the reducing of rate and efficiency of oxidative phosphorylation in liver mitochondria when NAD-dependent substrates are used. The treatment of the obese rats with panthotenic acid derivatives (phosphopantotenate, panthetin, panthenol) enhanced oxidative phosphorylation of pyruvate and fatty acid carnitine esters. Among investigated compounds panthenol activated respiratory control and phosphorylation rate more effectively. Moreover, panthenol, but not phosphopanthotenate nor panthetine, increased the activity of carnitine palmitoyltransferase 1 that confirms the preferable usage of fatty acids for mitochondrial oxidation under the influence of this compound.     

Effect of a linseed diet on lipid composition, lipid peroxidation and consumer evaluation of French fresh and cooked pork meats

Twenty castrated pigs [(Large-White × Landrace) × (Pietrain)] (52.9 ± 5.1 kg initial body weight) were fed a control or a linseed diet containing 4.2% of extruded linseed. Animals were slaughtered at 106.6 ± 3.7 kg live weight. There was no effect of diet on pig performance. Feeding the linseed diet increased the contents of n−3 polyunsaturated fatty acids (PUFA) in chops (raw and cooked), chitterlings sausages, country style pâté, garlic sausages, liver pâté, and smoked belly. However, docosahexaenoic acid (DHA) level was not affected by the linseed diet. The linseed diet produced a robust decrease in the n−6/n−3 and linoleic acid (LA)/α-linolenic acid (ALA) ratios (<4). Feeding pigs with a high n−3 PUFA diet led to a decrease in the oxidative stability of chops, in contrast to smoked bellies for which thiobarbituric acid-reactive substances (TBARS) values were not affected by the diet. However, there was no deleterious effect on consumer overall appreciation of the meat.     

Effects of sanshoamides and capsaicinoids on plasma and liver lipid metabolism in hyperlipidemic rats

Food Science and Biotechnology - The objective of this study was to determine the effects of sanshoamides and capsaiciniods on plasma and liver lipid levels and the mRNA expression levels of key...     

Milk from cows fed a diet with a high forage:concentrate ratio improves inflammatory state,oxidative stress,and mitochondrial function in rats

Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism.     

Effect of grape seed oil supplementation on plasma lipid profiles in rats

The purpose of the study was to investigate the comparative effects of feeding of grape seed oil (GSO), soybean oil (SO), and lard on plasma lipid profile in rats. Lard fed diets increased body weight gain in rats and resulted in negative effects on lipoprotein metabolism. However, the GSO fed rats had a significant reduction in total cholesterol (TC, 60.6 mg/dL), low density lipoprotein cholesterol (LDLC, 16.8 mg/dL), and atherogenic index (AI, 0.9), and the ratio of high density lipoprotein cholesterol (HDLC) to TC (0.5) was significantly higher than those of SO and lard groups. These data suggest that GSO supplementation has significant health benefits through favorable alterations in plasma lipid profiles compared to SO and lard fed rats. GSO may be good dietary oil and may provide health benefits in hyperlipidemia and related complications.     

普洱茶对酒精性脂肪肝大鼠抗氧化应激作用的研究

为探讨普洱茶（熟茶）对酒精性脂肪肝大鼠抗氧化应激作用的影响,将Wistar大鼠随机分为阴性、阳性、药物对照组、普洱茶低、中、高剂量组,60d后牺牲试验大鼠,测定大鼠肝组织细胞色素P4502E1（CYP2E1）、胰岛素样生长因子1（IGF-1）基因表达情况、大鼠肝组织中氧自由基（ROS）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-PX）活性及丙二醛（MDA）含量、大鼠血清胰岛素（INS）、游离脂肪酸（FFA）、甘油三酯（TG）水平。结果表明:与阳性对照组比较,高剂量组大鼠肝组织CYP2E1基因表达显著降低（p<0.05）;高剂量组大鼠肝组织IGF-1基因表达、GSH-PX活性及中、高剂量组SOD活性显著升高（p<0.05）;高剂量组大鼠肝组织中MDA含量及中、高剂量组大鼠ROS活性,低、中、高剂量组大鼠血清INS活力、TG含量,中、高剂量组大鼠血清FFA含量均显著降低（p<0.05,p<0.01）。说明普洱茶对酒精性脂肪肝大鼠具有抗氧化应激的作用。      

Effect of fish oil and sunflower oil on rumen fermentation characteristics and fatty acid composition of digesta in ewes fed a high concentrate diet

Studies in ruminants have shown that supplementing the diet with a mixture of fish oil (FO) and sunflower oil (SO) enhances the concentration of cis-9, trans-11 conjugated linoleic acid (CLA), 20:5 n-3, and 22:6 n-3 in milk because of alterations in ruminal biohydrogenation, but the intermediates formed under these conditions are not well characterized. Five ewes fitted with rumen cannula and fed a high concentrate diet were used to examine the effect of a mixture (30 g/kg of DM) of FO and SO (1:2, wt/wt) on temporal changes in rumen fermentation characteristics and the relative abundance of biohydrogenation intermediates in ruminal digesta collected after 0, 3, and 10 d on diet. Appearance and identification of biohydrogenation intermediates was determined based on complementary gas-liquid chromatography and Ag+-HPLC analysis of fatty acid methyl esters and gas chromatography-mass spectrometry analysis of corresponding 4,4-dimethyloxazoline derivatives. Inclusion of FO and SO in the diet had no effect on rumen pH, volatile fatty acid concentrations, or nutrient digestion, but altered the fatty acid composition of ruminal digesta, changes that were characterized by time-dependent decreases in 18:0 and 18:2 n-6 and the accumulation of trans 16:1, trans 18:1, 10-O-18:0, and trans 18:2. Lipid supplements enhanced the proportion of 20:5 n-3 and 22:6 n-3 in digesta and resulted in numerical increases in cis-9, trans-11 conjugated linoleic acid concentrations, but decreased the relative abundance of trans-10, cis-12 conjugated linoleic acid. Furthermore, detailed analysis revealed the appearance of several unique 20:1, 20:2, 22:1, 22:3, and 22:4 products in ruminal digesta that accumulated over time, providing the first indications of 20 and 22 carbon fatty acid intermediates formed during the biohydrogenation of long-chain unsaturated fatty acids in sheep. In conclusion, FO and SO in a high concentrate diet caused a time-dependent inhibition of the complete biohydrogenation of 16 and 18 carbon unsaturated fatty acids, and resulted in the accumulation of trans 16:1, trans 18:1, and trans 18:2, 20, and 22 carbon metabolites in ruminal digesta of sheep, with no evidence of a shift in ruminal biohydrogenation pathways toward trans-10 18:1 formation.