Oral administration of lipid oil-in-water emulsions performed with synthetic or protein-type emulsifiers differentially affects post-prandial triacylglycerolemia in rats

In this study, we compared the impact of administration of size-calibrated lipid emulsions prepared with either synthetic or natural emulsifiers on the post-absorptive plasma triacylglycerol responses in rats. We did this using four types of size-calibrated (10 mim diameter) and metastable (3 days) emulsions with 20% of an oleic acid-rich sunflower oil and 1% of either synthetic emulsifiers (Tween 80 or sodium 2-stearoyl-lactylate) or two proteins (β-lactoglobulin or sodium caseinate). An oral fat tolerance test was performed in fasted rats by oral administration of each of these formulations in continuous or emulsified forms. Kinetic parameters (AUC0-inf., AUC0-6h, Cmax, Tmax, and T1/2) for the description of the plasma triacylglycerol responses were calculated. AUC0-6h and AUC0-inf. calculated for the protein groups were significantly lower than those of the control and the synthetic groups. These lower values were associated with significant decreases in the Cmax, exacerbated by the emulsion form and with marked decreases in the Tmax as compared to the control group. T1/2 values were differentially affected by the lipid administration forms and by the nature of the emulsifiers. As compared with the control group, T1/2 was largely increased in the sodium stearoyl-2-lactylate group, but on the contrary, largely lowered in the casein group. We concluded that the use of proteins as natural emulsifiers in lipid emulsions decreased the magnitude of post-prandial triacylglycerolemia for the same amount of ingested lipids, when the emulsion size is controlled for. Proteins could be a promising alternative to the widespread use of synthetic emulsifiers in the food industry

Physiological effects of γ-linolenic acid and sesamin on hepatic fatty acid synthesis and oxidation.

Interrelated effects of γ-linolenic acid (GLA) and sesamin, a sesame lignan, on hepatic fatty acid synthesis and oxidation were examined. Rats were fed experimental diets supplemented with 0 or 2 g/kg sesamin (1:1 mixture of sesamin and episesamin) and containing 100 g/kg of palm oil (saturated fat), safflower oil rich in linoleic acid, or oil of evening primrose origin containing 43% GLA (GLA oil) for 18 days. In rats fed sesamin-free diets, GLA oil, compared with other oils, increased the activity and mRNA levels of various enzymes involved in fatty acid oxidation, except for some instances. Sesamin greatly increased these parameters, and the enhancing effects of sesamin on peroxisomal fatty acid oxidation rate and acyl-CoA oxidase, enoyl-CoA hydratase and acyl-CoA thioesterase activities were more exaggerated in rats fed GLA oil than in the animals fed other oils. The combination of sesamin and GLA oil also synergistically increased the mRNA levels of some peroxisomal fatty acid oxidation enzymes and of several enzymes involved in fatty acid metabolism located in other cell organelles. In the groups fed sesamin-free diets, GLA oil, compared with other oils, markedly reduced the activity and mRNA levels of various lipogenic enzymes. Sesamin reduced all these parameters, except for malic enzyme, in rats fed palm and safflower oils, but the effects were attenuated in the animals fed GLA oil. These changes by sesamin and fat type accompanied profound alterations in serum lipid levels. This may be ascribable to the changes in apolipoprotein-B-containing lipoproteins.

Safflower (Catharmus tinctorius L.) oil supplementation in overnourished rats during early neonatal development: effects on heart and liver function in the adult.

Carthamus tinctorius L. (common name: safflower) is an herb whose extracted oil (safflower oil) has been employed in both alternative and conventional medicine in the treatment of disease. Overnutrition during early postnatal life can increase the lifetime risk of obesity and metabolic syndrome. Here we investigate the effect of safflower oil supplementation given during a critical early developmental stage on the eventual occurrence of metabolic disease in overnourished rats. Groups of overnourished or adequately nourished rats were randomly assigned into 2 additional groups for supplementation with either safflower oil (SF) or vehicle for 7 to 30 days. Murinometric data and weights were examined. Serum was collected for measurement of glucose, cholesterol, high-density lipoprotein cholesterol, and triglycerides. Heart and liver oxidative status were also measured. Overnutrition for 7-30 days induced a significant increase in body weight and in values for abdominal circumference, thoracic circumference, body length, and body mass index. SF supplementation did not attenuate the effect of overnutrition on any of these parameters. In addition, overnutrition increased levels of glucose, triglycerides, and very low-density lipid compared with normal controls, but SF supplementation had no effect on these parameters. Measures of oxidative status in heart or liver were not influenced by overnutrition. However, oxidative measures were altered by SF supplementation in both of these organs. The present study reveals that nutritional manipulation during early development induces detrimental effects on metabolism in the adult that are not ameliorated by supplemental SF.

Maternal exposure to fish oil primes offspring to harbor intestinal pathobionts associated with altered immune cell balance.

Our previous studies revealed that offspring from rat dams fed fish oil (at 8% and 18% energy), developed impaired intestinal barriers sensitizing the colon to exacerbated injury later in life. To discern the mechanism, we hypothesized that in utero exposure to fish oil, rich in n-3 polyunsaturated fatty acid (PUFA), caused abnormal intestinal reparative responses to mucosal injury through differences in intestinal microbiota and the presence of naïve immune cells. To identify such mechanisms, gut microbes and naïve immune cells were compared between rat pups born to dams fed either n-6 PUFA, n-3 PUFA or breeder chow. Maternal exposure to either of the PUFA rich diets altered the development of the intestinal microbiota with an overall reduction in microbial density. Using qPCR, we found that each type of PUFA differentially altered the major gut phyla; fish oil increased Bacteroidetes and safflower oil increased Firmicutes. Both PUFA diets reduced microbes known to dominate the infant gut like Enterobacteriaceae and Bifidobacteria spp. when compared to the chow group. Uniquely, maternal fish oil diets resulted in offspring showing blooms of opportunistic pathogens like Bilophila wadsworthia, Enterococcus faecium and Bacteroides fragilis in their gut microbiota. As well, fish oil groups showed a reduction in colonic CD8+ T cells, CD4+ Foxp3+ T cells and arginase+ M2 macrophages. In conclusion, fish oil supplementation in pharmacological excess, at 18% by energy as shown in this study, provides an example where excess dosing in utero can prime offspring to harbor intestinal pathobionts and alter immune cell homeostasis.

Alternative lipid emulsions in the critically ill: a systematic review of the evidence.

PURPOSE: Parenteral lipid emulsions (LEs) are commonly rich in long-chain triglycerides derived from soybean oil (SO). SO-containing emulsions may promote systemic inflammation and therefore may adversely affect clinical outcomes. We hypothesized that alternative oil-based LEs (SO-sparing strategies) may improve clinical outcomes in critically ill adult patients compared to products containing SO emulsion only. The purpose of this systematic review was to evaluate the effect of parenteral SO-sparing strategies on clinical outcomes in intensive care unit (ICU) patients. METHODS: We searched computerized databases from 1980 to 2013. We included randomized controlled trials (RCTs) conducted in critically ill adult patients that evaluated SO-sparing strategies versus SO-based LEs in the context of parenteral nutrition. RESULTS: A total of 12 RCTs met the inclusion criteria. When the results of these RCTs were statistically aggregated, SO-sparing strategies were associated with clinically important reductions in mortality (risk ratio, RR 0.83; 95 % confidence intervals, CI 0.62, 1.11; P = 0.20), in duration of ventilation (weighted mean difference, WMD -2.57; 95 % CI -5.51, 0.37; P = 0.09), and in ICU length of stay (LOS) (WMD -2.31; 95 % CI -5.28, 0.66; P = 0.13) but none of these differences were statistically significant. SO-sparing strategies had no effect on infectious complications (RR 1.13; 95 % CI 0.87, 1.46; P = 0.35). CONCLUSION: Alternative oil-based LEs may be associated with clinically important reductions in mortality, duration of ventilation, and ICU LOS but lack of statistical precision precludes any clinical recommendations at this time. Further research is warranted to confirm these potential positive treatment effects.

Docosahexaenoic acid synthesis from alpha-linolenic acid is inhibited by diets high in polyunsaturated fatty acids.

The conversion of the plant-derived omega-3 (n-3) α-linolenic acid (ALA, 18:3n-3) to the long-chain eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) can be increased by ALA sufficient diets compared to ALA deficient diets. Diets containing ALA above an optimal level result in no further increase in DHA levels in animals and humans. The present study evaluates means of maximizing plasma DHA accumulation by systematically varying both linoleic acid (LA, 18:2n-6) and ALA dietary level. Weanling rats were fed one of 54 diets for three weeks. The diets varied in the percentage of energy (en%) of LA (0.07-17.1 en%) and ALA (0.02-12.1 en%) by manipulating both the fat content and the balance of vegetable oils. The peak of plasma phospholipid DHA (>8% total fatty acids) was attained as a result of feeding a narrow dietary range of 1-3 en% ALA and 1-2 en% LA but was suppressed to basal levels (∼2% total fatty acids) at dietary intakes of total polyunsaturated fatty acids (PUFA) above 3 en%. We conclude it is possible to enhance the DHA status of rats fed diets containing ALA as the only source of n-3 fatty acids but only when the level of dietary PUFA is low (<3 en%).

Formulation, stability, and administration of parenteral nutrition with new lipid emulsions.

Intravenous lipid emulsions (IVLE) are an important source of energy and essential fatty acids and their incorporation into pediatric and adult parenteral nutrition (PN) regimens has revolutionized nutrition therapy. However, their clinical use has not been without risk, and will continue to remain so because of the intravenous route of administration. Pharmaceutical and microbiological concerns are centered around the methods of compounding all-in-one (AIO) admixtures, but these can be largely minimized with today's technologies and advanced understanding of aseptic principles. Modern lipid products, based on olive, coconut, and/or fish oils, have demonstrable formulation and clinical benefits over traditional soybean and safflower IVLE and, when combined in the new multi-chamber bags, can also offer improvements in stability and safety. This review outlines the rationale for different lipid formulations in PN admixtures, reviews the factors influencing stability and efficacy of lipid-based AIO regimens and evaluates some technologies for minimizing peroxidation and maximizing stability of AIO admixtures.

Fish oil prevents sucrose-induced fatty liver but exacerbates high-safflower oil-induced fatty liver in ddy mice.

UNLABELLED: Diets high in sucrose/fructose or fat can result in hepatic steatosis (fatty liver). We analyzed the effects of dietary fish oil on fatty liver induced by sucrose, safflower oil, and butter in ddY mice. In experiment I, mice were fed a high-starch diet [70 energy% (en%) starch] plus 20% (wt/wt) sucrose in the drinking water or fed a high-safflower oil diet (60 en%) for 11 weeks. As a control, mice were fed a high-starch diet with drinking water. Fish oil (10 en%) was either supplemented or not. Mice supplemented with sucrose or fed safflower oil showed a 1.7-fold or 2.2-fold increased liver triglyceride content, respectively, compared with that of control mice. Fish oil completely prevented sucrose-induced fatty liver, whereas it exacerbated safflower oil-induced fatty liver. Sucrose increased SREBP-1c and target gene messenger RNAs (mRNAs), and fish oil completely inhibited these increases. In experiment II, mice were fed a high-safflower oil or a high-butter diet, with or without fish oil supplementation. Fish oil exacerbated safflower oil-induced fatty liver but did not affect butter-induced fatty liver. Fish oil increased expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and target CD36 mRNA in safflower oil-fed mice. These increases were not observed in sucrose-supplemented or butter-fed mice. CONCLUSION: The effects of dietary fish oil on fatty liver differ according to the cause of fatty liver; fish oil prevents sucrose-induced fatty liver but exacerbates safflower oil-induced fatty liver. The exacerbation of fatty liver may be due, at least in part, to increased expression of liver PPARgamma.

Serum lipid concentrations and mean life span are modulated by dietary polyunsaturated fatty acids in the senescence-accelerated mouse.

The senescence-accelerated mouse (SAMP8) is an animal model used in studies of aging. This study was undertaken to investigate the effects of dietary PUFA on longevity (Experiment 1) and serum lipid concentrations (Experiment 2) in SAMP8 mice. Male mice were fed either an (n-3) PUFA-rich (9 g/100 g perilla oil) or an (n-6) PUFA-rich (9 g/100 g safflower oil) diet beginning at 6 wk of age. Experiment 1: The groups did not differ in body weight gain, but those fed perilla oil had significantly lower scores of senescence relative to those fed safflower oil (P<0.05). The mean life span of mice fed perilla oil was 357+/-21 d and of those fed safflower oil, 426+/-24 d (P<0.05). Pathological studies revealed that the incidence of tumors was significantly lower in the perilla oil group than in the safflower oil group (P<0.05). Approximately half the mice fed perilla oil had died after 10 mo, and the direct causes closely connected with death could not be specified. Experiment 2: The serum total cholesterol, HDL cholesterol, triglyceride and phospholipid concentrations were significantly lower in the perilla oil group than in the safflower oil group (P<0.01). A marked decrease of serum HDL cholesterol and apolipoprotein A-II (ApoA-II)concentrations in advanced age were observed in the mice fed perilla oil (P<0.01). Ten-month-old mice fed perilla oil had a significantly greater ratio of apolipoprotein A-I (ApoA-I) to ApoA-II than those fed safflower oil. Separation of HDL subfractions revealed that the smaller HDL species were much more abundant than the larger HDL species in both dietary oil groups. These findings suggest that dietary (n-3) and (n-6) PUFA differ in their effects on serum lipid metabolism which may modulate the mean life span of SAMP8 mice fed each dietary oil.

Lack of promotion of colon carcinogenesis by high-oleic safflower oil.

BACKGROUND: The nonpromoting effect of olive oil on colon carcinogenesis has been attributed to its high oleic acid content, whereas a positive association of monounsaturated fat in beef tallow with colon tumors has been reported. The effect of constituents other than fatty acids could not be neglected in these experiments. In order to minimize the effects of minor constituents in the oils, the authors compared conventional safflower oil with oil from a mutant strain of safflower that is rich in oleic acid. METHODS: ICR mice were treated with 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight every week for 12 weeks) and then were fed either a high-fat diet (23.5% by weight), containing safflower oil (HF-LA) or high-oleic safflower oil (HF-OA), or a low-fat diet (5% by weight), containing safflower oil (LF-LA) or high-oleic safflower oil (LF-OA). The test diets were continued until termination of the experiment at 30 weeks after the first administration of DMH. Fatty acid composition of colon phospholipids was determined by gas-liquid chromatography-mass spectrometry. RESULTS: Tumor multiplicity in animals fed the HF-OA diet was indistinguishable from that in animals fed LF-LA or LF-OA. In contrast, animals fed the HF-LA diet had a significantly higher incidence of colon tumors (mostly adenocarcinomas) than the other groups. Fatty acid profiles of colon phospholipids reflected those of the diet. Animals fed a HF-LA diet showed a marked decrease of nervonic acid (C24:1, n-9) in the colon sphingomyelin. CONCLUSIONS: These data indicate that oleic acid does not enhance DMH-induced colon carcinogenesis in mice, even when they are fed a high-fat diet.

Dietary fish oil delays puberty in female rats.

Marine oils contain eicosapentaenoic acid, a fatty acid that competes for cyclooxygenase and reduces the synthesis of dienoic prostanoids including prostaglandin E2 (PGE2). Since PGE2 plays an important role in the estrogen-stimulated release of hypothalamic GnRH on proestrus, it was postulated that a diet containing fish oil would delay first ovulation through inhibitory effects on GnRH release. Thirty, 22-day-old female Sprague-Dawley rats were fed a diet containing fish oil ad libitum. Controls were pair-fed an identical diet with the substitution of safflower oil as the dietary fat. All rats were killed on the morning of first metestrus after vaginal opening and the display of an estrous smear(s). Fish oil feeding did not affect growth as indicated by the lack of an observed effect on body weights or femur lengths. On the other hand, pituitary, ovarian, and uterine weights were significantly lower in the rats fed fish oil (p < 0.001). The age at first estrus of the rats fed fish oil was significantly increased compared with the controls (42.9 +/- 1.0 vs. 36.1 +/- 0.3 days; p < 0.001), whereas the number of rats with corpora lutea (CL), as well as the number of CL per ovary (2.3 +/- 0.4 vs 4.8 +/- 0.6 for controls; p < 0.001) was significantly reduced by fish oil feeding. GnRH concentration in the preoptic area/hypothalamus was significantly increased in the fish oil-fed rats (21.4 +/- 4.0 pg/mg vs. 7.6 +/- 2.2 pg/mg for controls; p < 0.01); radioimmunoassable hypothalamic PGE2 was concomitantly reduced (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Correction of linoleic acid deficiency in cystic fibrosis.

To identify evidence of essential fatty acid deficiency, we screened 64 patients with cystic fibrosis by analyzing total lipid extracts from plasma. Forty-three had an abnormal linoleate (18:2) level (less than 26%). Thirteen deficient patients (aged 10-24 yr) ingested for 1 yr 7% of their total calories as linoleate derived from a daily supplement of Microlipid. Five deficient patients (aged 10-37 yr) served as controls. Plasma and erythrocyte fatty acid composition were monitored by gas chromatography of total lipid extracts seven times during the twelve month period. Prostaglandins E2 and F2 alpha and their 15 keto 13, 14 dihydrometabolite, 6-keto F1 alpha, and thromboxane B2 were measured by radioimmunoassay. Sweat tests, oxygen saturation, growth indices, clinical severity scores, compliance, and possible side effects from taking Microlipid were followed. Results showed that oral supplementation with Microlipid can significantly increase plasma and erythrocytes % 18:2. One compliant patient died during the study and had normal tissue 18:2 levels. Nine of 13 patients gained more weight while taking Microlipid than in the previous year. No significant changes in sweat electrolytes, clinical scores, or oxygen saturation were found during the study year. Prostaglandin metabolites prostaglandin E2 showed an upward trend in supplemented patients, compared to controls. Prostaglandin F2 alpha remained unchanged over 1 yr but showed a trend significantly downward over the final 6 months in supplemented patients. We conclude that linoleate deficiency can be corrected with daily Microlipid supplements and that correction may alter prostaglandin metabolism.

Studies with a safflower oil emulsion in total parenteral nutrition.

The prevention of essential fatty acid deficiency and the provision of adequate amounts of energy are two major concerns in total parenteral nutrition. Since earlier preparations of fat emulsion used to supplement the usual regimen of hypertonic glucose and amino acids have widely varying clinical acceptability, a new product, a safflower oil emulsion available in two concentrations (Liposyn), was evaluated. In four clinical trials the emulsion was used as a supplement to total parenteral nutrition. In five surgical patients 500 ml of the 10% emulsion infused every third day prevented or corrected essential fatty acid deficiency; however, in some cases in infusion every other day may be necessary. In 40 patients in severe catabolic states the emulsion provided 30% to 50% of the energy required daily: 10 patients received the 10% emulsion for 14 to 42 days, 9 patients received each emulsion in turn for 7 days, and 21 patient received the 20% emulsion for 14 to 28 days. All the patients survived and tolerated the lipid well; no adverse clinical effects were attributable to the lipid infusions. Transient mild, apparently clinically insignificant abnormalities in the results of one or more liver function tests and eosinophilia were observed in some patients. Thus, the safflower oil emulsion, at both concentrations, was safe and effective as a source of 30% to 50% of the energy required daily by seriously ill patients.

Protective effect of nicarbazin on nutritional encephalopathy in chicks.

Nutritional encephalopathy was induced in young chicks by vitamin E-deficient diets containing either 4% methyl esters of safflower oil or 10% thermally oxidized safflower oil. The coccidiostat nicarbazin (an equimolecular complex of 4,4'-dinitrocarbanilide and 2-hydroxy 4,6-dimethylpyrimidine) reduced the incidence of encephalopathy, but zoalene (3,5-dinitro-o-toluamide) and amprolium [1-(4-amino-2-n-propyl-5-pyrimidinylmethyl)-2-picolinium chloride hydrochloride] did not. Neither of the two components of nicarbazin affected the rate of development of encephalopathy when fed separately, but when included together in the diet, they reduced the incidence of the disease.

The effect of polyunsaturated fats on bile acid metabolism and cholelithiasis in squirrel monkeys.

Squirrel monkeys (Saimiri sciureus) were fed diets containing safflower oil, butter, or coconut oil and 1 mg cholesterol/cal for 15--17 mo to examine the effect of type of fat on cholelithiasis and bile acid metabolism. Controls were fed low cholesterol diets containing an isocaloric mixture of the three fats. Cholic acid fractional catabolic rate, pool size, chenodeoxycholic acid pool size, and total bile acid pool size and excretion rate were estimated using a modification of Lindstedt's isotopic turnover procedure. The animals fed the safflower oil diet had the highest incidence of cholelithiasis (9/10) when compared to those fed butter (3/7) and coconut oil (1/7). Animals consuming the low cholesterol control diet did not develop gallstones. The butter- and coconut oil-fed groups had significantly (p less than 0.05) expanded bile acid pools when compared to controls, and the butter-fed group had a significantly increased (p less than 0.05) cholic acid fractional catabolic rate. The safflower oil group had the smallest mean bile acid pool and the highest mean lithogenic index of the cholesterol-fed groups. It was concluded that the safflower oil-fed animals had a higher incidence of cholelithiasis than the butter group because, unlike the latter group, they did not compensate for a high cholesterol intake by stimulating bile acid synthesis. The animals consuming coconut oil apparently did not absorb cholesterol to the extent of the other groups and as a result their bile did not become saturated with cholesterol.

Effect of high-oleic and high-linoleic safflower oils on mammary tumors induced in rats by 7,12-dimethylbenz(alpha)anthracene.

A mutant safflower oil, rich in oleic acid, was used for a critical test of the hypothesis that polyunsaturated fats act as co-carcinogens. Weanling female rats were each given 5 mg of 7,12-dimethylbenz(alpha)anthracene. They were then pair-fed diets containing 20%, by weight, of conventional high-linoleic safflower oil; a mutant high-oleic safflower oil; or coconut oil. Half of each group received supplementary DL-alpha-tocopherol. Tumors were identified by two observers, by palpation. Data on incidence of tumors and on numbers of tumors per affected rat led to similar conclusions. At 16 weeks, there were significant differences when supplementary tocopherol was included in the diet: the group fed high-oleic safflower oil had more tumors than the group fed coconut oil. This difference was not seen in the absence of supplementary tocopherol. When the data for tocopherol-supplemented and unsupplemented subgroups were combined, the high-oleic safflower oil group had significantly more tumors than did the coconut oil group. The high-linoleic safflower oil group was not significantly different from either of the other groups. In all groups, histologic examination of the largest tumor in each rat revealed more benign tumors, mostly duct papillomas, than carcinomas.