Sunflower Oil Diet Research Articles

Effect on rat blood and aorta lipids of three edible oils (arachid, sunflower and primor) with low saturated fatty acid content.

Arachid, sunflower and primor oils, which are all poor in saturated fatty acids and differ, in particular, in their oleic, linoleic and linolenic acid content, were fed to rats throughout one short and one long experiment. In the short experiment (1 month), they were given a hyperlipidic diet (35% of total food weight) and in the long experiment (1 year) a normolipidic diet (6% of total food weight). The chief results observed were as follows. Diminished weight gain of rats ingesting sunflower oil in the long experiment when compared with the other two groups. Absence of significant differences in cholesterolemia, triglyceridemia and phospholipidemia, depending on the type of oil ingested. A significant rise in glycemia for rats absorbing sunflower oil in the short experiment, thus confirming our previous observations. A significant rise in blood urea in rats ingesting primor oil in the short experiment. A significant rise in proteinemia in rats absorbing primor oil in both experiments. Very similar fatty acid composition for serum triglycerides and free fatty acids, with a high linoleic acid content in animals absorbing sunflower oil (this only applied to the short experiment with a hyperlipidic diet). Identical fatty acid composition of serum phospholipids, which were also rich in stearic acid and to a lesser extent in arachidonic acid (this applied to all diets and experiments). Identical fatty acid composition of serum cholesterol esters, also rich in arachidonic acid, for all diets and experiments. Very similar fatty acid composition for aorta triglycerides and free fatty acids which, like the corresponding serum fractions, also had a high linoleic acid content in the sunflower oil group, in the short experiment (animals on a hyperlipidic diet). Identical fatty acid composition of aorta phospholipids whatever the diet or type of experiment. This composition is very similar that of serum phospholipids (i.e. particularly rich in stearic acid and fairly rich in arachidonic acid). A fatty acid composition for aorta cholesterol esters completely different from that of serum cholesterol esters, the first being rich in palmitoleate and laurate; the nature of this difference depends on the oil ingested, since palmitoleate was chiefly found in rats absorbing primor oil, and laurate in animals on the sunflower oil diet.

Effect of dietary fat saturation on acylcoenzyme A: cholesterol acyltransferase activity of Ehrlich cell microsomes

Ehrlich cells grown in mice fed coconut oil diets (highly saturated) contain about twice as much cholesteryl ester as those grown in mice fed sunflower oil diets (highly polyunsaturated). Acylcoenzyme A: cholesterol acyltransferase (ACAT) activity was 30-100% higher in microsomes prepared from the cells grown on coconut oil (M(c)) than in those prepared from the cells grown on sunflower oil (M(s)). Increased ACAT activity was noted in M(c) with either [1-(14)C]palmitoyl CoA or [1,2-(3)H]cholesterol as the labeled substrate. This occurred at all acyl CoA concentrations tested and, in the [1,2-(3)H]cholesterol assay, with palmitoyl, oleoyl, or linoleoyl CoA as the substrate. The pH optimum for ACAT activity was the same with M(c) and M(s), pH 7.0. ACAT activity obeyed Michaelis-Menten kinetics at palmitoyl CoA concentrations between 1 and 10 micro M. Substrate inhibition occurred at higher concentrations. Kinetic analysis with [1-(14)C]palmitoyl CoA as the substrate indicated that the apparent K(m) for M(c) was 33% smaller than for M(s). There was no difference, however, in apparent V(max) values. The cholesterol and phospholipid contents of M(c) and M(s) were similar, but their fatty acid compositions differed considerably. M(c) contained 2.7 times more monoenoic fatty acid and only half as much polyenoic fatty acid as M(s). Our results indicate that dietary modification of the microsomal fatty acid composition is associated with alterations in the activity of ACAT, an enzyme that is tightly bound to the microsomes. These changes in ACAT activity may be partly responsible for the differences in cholesteryl ester contents of Ehrlich cells grown in mice fed the coconut and sunflower oil diets.

Modification of the fatty acid composition of L1210 murine leukemia cells.

AbstractWe have compared the effect of diets containing 16% sunflower seed oil (polyunsaturated fat‐rich) or 16% coconut oil (saturated fat‐rich) fed for 3–7 weeks on the composition of L1210 murine leukemia cells which were transplanted into the peritoneal cavity during the final week of feeding. The L1210 phospholipids of mice fed the sunflower oil diet contained 43% polyenoic fatty acids and an average of 1.5 double bonds per fatty acid molecule as compared to only 25% polyenoic fatty acids and 1.2 double bonds in the coconut oil group. In contrast, the cells from the sunflower oil group contained only 13% monoenoic fatty acids as compared to 33% in those from the coconut oil group. When compared to phospholipids of tumors from mice who were fed a commercial mouse chow, cells grown on sunflower oil had an 18% increase in polyenoic fatty acids and those grown on coconut oil a 31% decrease. The greatest changes occurred in the proportion of oleate and linoleate. There was only a small difference in the percentage of saturated fatty acids and in the mean fatty acid chain length among the tumor cells from animals on the experimental diets. The changes in the fatty acid composition of the L1210 cell neutral lipids and the lipids of the ascites fluid were similar to those observed in the phospholipids. A majority of the changes had occurred after 5 weeks of feeding the special diet. These results indicated that the fatty acid saturation of tumor cell phospholipids can be altered appreciably. The changes in fatty acid composition were not associated with any change in the sterol/phospholipid ratio of the cells. Therefore, our results suggest that it may be possible to alter the physical properties and function of a tumor cell membrane by dietary modification of its phospholipid composition.

Modification of the ehrlich ascites tumor cell nuclear lipids

The fatty acid composition of Ehrlich ascites tumor cell nuclei was different when the tumor-bearing mice were fed diets rich in either coconut or sunflower oil. When coconut oil was fed, the monoenoic fatty acid content of many of the nuclear lipids was increased and their polyenoic fatty acid content was reduced as compared with the sunflower oil diet. By contrast, only small changes were produced in the saturated fatty acid contents of the nuclear lipids. The nuclear membrane choline phospholipid, ethanolamine phospholipid and combined serine phospholipid plus inositol phospholipid fractions exhibited statistically significant changes in fatty acid composition, but the sphingomyelins were not altered appreciably by dietary lipid modification. The fatty acid composition of the small quantity of phospholipids associated with the chromatin was much more resistant to diet-induced modification. Except for sphingomyelin, the fatty acid composition of the chromatin phospholipids was different from that of the corresponding nuclear membrane phospholipids, containing much larger amounts of fatty acids having less than 16 carbon atoms. The fatty acid compositions of the nuclear triacylglycerols and cholesterol esters, which were associated almost entirely with the chromatin, were modified by the dietary lipid modifications. There were no changes in the DNA, RNA or lipid content of these nuclei. Therefore, this experimental system can be used to prepare mammalian nuclei that differ appreciably only in their fatty acyl composition.

Effect of dietary fats on pentobarbitone‐induced sleeping times and hepatic microsomal cytochrome P‐450 in rats

Female Wistar-derived rats were fed diets containing either sunflowerseed oil or tallow for 4 weeks. Rats fed the sunflowerseed oil diet had longer pentobarbitone-induced sleeping times and lower concentrations of hepatic microsomal cytochrome P-450 than rats fed the tallow diet. The addition of pentobarbitone to the drinking water of rats caused approximately 2-fold increases in the concentrations of hepatic microsomal cytochrome P-450 but did not alter the relative effect of the diets.

Alteration of the fatty acid composition of ehrlich ascites tumor cell lipids

The fatty acid composition of Ehrlich ascites tumor lipids was altered markedly in vivo by changing the type of fat fed to the tumor-bearing mice. As compared with regular chow, large differences were produced in polar and neutral lipid fatty acyl groups when the tumor cells were grown in mice fed coconut oil, sunflower oil or fat deficient diets. Subcellular membrane fractions obtained from these cells exhibited similar variations in fatty acyl composition. This experimental system provides large quantities of malignant cells for study of the relationships between membrane lipid structure and function.

Effects of Feeding Medium Chain Triglycerides to Rats for 13 Weeks

Three-week-old male Wistar rats, when maintained for 13 weeks on diets containing 19.3 wt% even or odd medium chain triglycerides (MCT) admixed with 4.9 wt% sunflowerseed oil (SFO), consumed comparable amounts of food in comparison with rats fed 24.2 wt% SFO. The growth of rats fed even MCT was better than those fed odd MCT but it was comparable to the growth of rats kept on SFO diet. Excretion of ketones in urine during the entire experimental period was observed in both MCT groups but more rats in the odd MCT group had ketonuria, which was probably why the blood alkali reserve in this latter group was lower. The data on total protein and albumin in plasma and glutamine oxaloacetic acid transaminase in urine indicated no metabolic derangement. The hematological data were also within physiological limits in the three groups. The histopathological study of the kidneys and liver of the MCT groups revealed no degenerative changes which might explain an increase in their relative weights. The other organs displayed no abnormalities.

Digestibility, efficiency and other metabolic effects of dietary rapeseed oil in rats.

Rats were fed diets containing 60 cal% rapeseed oil (RSO) or sunflowerseed oil (SSO) for periods up to 64 weeks. When the animals were allowed to eat <i>ad libitum, </i>the food consumption in the RSO group was significantly lower than in the SSO group. It was shown that the RSO diet is less readily digested than the SSO diet. This is due solely to the lower digestion coefficient of the RSO and of its erucic acid fraction in particular, which can be explained by its chain length. The digestion coefficient of the non-fat calories is equal in both groups. The digestion capacity is not a limiting factor in RSO digestion. The absorbed erucic acid is almost totally metabolized. Rats fed a RSO-containing diet utilize the digested calories less efficiently than animals offered an SSO diet. Moreover, their oxygen consumption and water-vapour release are higher. It is assumed that the lower efficiency of the RSO diet is caused by a slightly uncoupled oxidative phosphorylation and a greater heat increment.