Novel Plant Growth Inhibitors and an Insect Antifeedant from Chrysanthemum coronarium (Japanese Name: Shungiku)

The effect of overnight fasting on the dietary protein-dependent change in the fatty acid composition of tissue lipids was studied in rats fed with casein or soybean protein (20%) diets containing 5 or 2% corn oil. The activity of the Δ6-desaturase of liver microsomes, a key enzyme of linoleate metabolism to arachidonate, was depressed significantly by overnight fasting, and the protein effect disappeared, irrespective of the level of dietary fat. The proportion of linoleate in liver phosphatidylcholine was decreased, whereas that of arachidonate was increased after overnight fasting in rats fed with a low fat diet, resulting in an elevation of the linoleate desaturation index. Although the effect of fasting became obscure on a high fat diet, the protein effects were maintained even after fasting. A similar trend was also observed in various lipid fractions. Thus, the effect of dietary protein on the polyunsaturated fatty acid profile was not modulated by overnight fasting, particularly when a minimal amount of linoleic acid was supplied.     

Regulation of guinea pig hepatic acyl-coa:cholesterol acyltransferase activity by dietary fat saturation and cholesterol

We measured the interactive effects of dietary cholesterol and fat on the regulation of hepatic acyl-CoA:cholesterol acyltransferase (ACAT) activity and its relationship to hepatic microsomal lipid composition in guinea pigs fed 15 g/100 g (w/w) fat diets (corn oil, olive oil, or lard) with 0.01, 0.08, 0.17, or 0.33 g/100 g (w/w) added cholesterol. Guinea pigs exhibited a dose dependent increase in hepatic microsomal ACAT activity, with increasing levels of cholesterol intake (P < 0.001) in all dietary fat groups. Animals fed monounsaturated olive oil had the highest hepatic ACAT activity with the exception of the 0.33 g/100 g cholesterol diet (P < 0.001). There were no differences in ACAT activity with intake of polyunsaturated corn oil or saturated lard. Dietary cholesterol resulted in increased microsomal free cholesterol (FC) concentrations in a dose dependent manner but had no effects on microsomal phosphatidylcholine (PC) concentrations. Guinea pigs fed olive oil generally had the highest microsomal FC/PC molar ratios, and hepatic ACAT activities correlated significantly with this parameter. After modification of the lipid compositions of the microsomes from guinea pigs fed the 12 test diets with FC/PC liposome treatment, microsomal ACAT activities remained significantly related to the microsomal FC/PC molar ratios, and dietary fat type did not affect this correlation. Our findings do not support the hypothesis that the stimulation of hepatic ACAT activity with cholesterol intake is enhanced by polyunsaturated fat intake. The data demonstrate that although dietary fat type and cholesterol amount have differential effects on hepatic ACAT activity, substrate availability, expressed as microsomal FC/PC molar ratio, is a major regulator of hepatic microsomal ACAT activity.     

Effect of egg cholesterol and dietary fats on plasma lipids, lipoproteins, and apoproteins of normal women consuming natural diets

Nine normal women, 22 to 37 years old, consumed controlled quantities of natural foods to test their responses to dietary cholesterol and saturated fat. All diets contained, as percentage of calories, 14% protein, 31% fat, and 55% carbohydrate. The main sources of polyunsaturated and saturated fats were corn oil and lard, respectively, and egg yolk was used for cholesterol supplementation. All subjects participated in four diet protocols of 15 days duration, and each diet period was separated by 3 weeks without diet control. The first diet (corn) was based on corn oil, had a polyunsaturated to saturated fat ratio (P/S) of 2.14, and contained 130 mg of cholesterol. The second diet (corn+) was identical to the first but contained a total of 875 mg of cholesterol. The third diet (lard) was based on lard, had a P/S ratio of 0.64, and contained 130 mg of cholesterol. The fourth diet (lard+) was identical to the third, but contained 875 mg of cholesterol per day. Changes of the plasma lipid, lipoprotein and apoprotein parameters relative to the corn diet were as follows: the corn+ diet significantly increased total plasma cholesterol, HDL-cholesterol, LDL-cholesterol, and apoB levels; the lard diet significantly increased total cholesterol, HDL-cholesterol, and apoB; and the lard+ diet significantly increased the total cholesterol, HDL-cholesterol, LDL-cholesterol, and apoA-I and apoB levels. There were no significant variations in VLDL-cholesterol, triglyceride, or apoE levels with these diets. The diets affected both the number of lipoprotein particles as well as the composition of LDL and HDL. Compared to the corn diet, cholesterol and saturated fat each increased the number of LDL particles by 17% and 9%, respectively, and the cholesterol per particle by 9%. The combination of saturated fat and cholesterol increased particle number by 18% and particle size by 24%. Switching from lard+ to lard, corn+, or corn diets reduced LDL-cholesterol of the group by 18%, 11%, and 28%, respectively, while a large inter-individual variability was noted. In summary, dietary fat and cholesterol affect lipid and lipoprotein levels as well as the particle number and chemical composition of both LDL and HDL. There is, however, considerable inter-individual heterogeneity in response to diet.     

Effects of protein type and concentration on development and reproduction of the German cockroach, Blattella germanica

Nymphal development and adult female reproduction were examined in the German cockroach, Blattella germanica, using a defined artificial diet in which the type of protein was varied. Milk proteins, including casein, supported development poorly compared to meat and plant proteins. Soybean protein supported development better than all other highly purified proteins including vitamin-free casein which is commonly used in artificial diets. Last instar females fed the soybean-based diet eclosed earlier at higher eclosion weights, developed their oocytes at a faster rate and experienced higher fecundity than females fed a vitamin-free casein-based diet. Last instar females exhibited different dose-response patterns on diets containing soybean isolate or vitamin-free casein. However, at all concentrations soybean protein was superior to casein in supporting development. The results of a food utilization study during the last instar revealed that consumption rates varied between females fed the soybean and casein based diets. However, approximate digestibility, efficiency of conversion of digested food and the efficiency of conversion of ingested food did not vary significantly between the two dietary treatments. Differential development of females fed the two diets was attributed to differences in stage-specific consumption rates and the poorer quality of casein as a source of protein for development in this species.     

Reproduction response of Chinese mitten-handed crab (Eriocheir sinensis) fed different sources of dietary lipid

The effect of feeding three semi-purified diets containing different lipid sources (anchovy oil, soybean oil and pork lard) on fecundity, hatchability and egg fatty acid composition of Chinese mitten-handed crab (Eriocheir sinensis) broodstock was compared with a fresh clam diet in a 6-month feeding trial. Broodstock crabs fed the diet containing pork lard showed poor fecundity and low hatchability. Crabs fed the diet containing soybean oil showed improved fecundity; however, no significant improvement in hatchability was observed. Broodstock fed the diet containing anchovy oil showed the highest fecundity and egg hatchability. Eggs from broodstock fed anchovy oil as sole dietary lipid had a higher n-3 polyunsaturated fatty acid (PUFA) content (33.3%) compared with those of crabs fed diets with soybean oil (20.1%) and pork lard (16.3%) as lipid sources. The results indicate a close correlation between: (1) the 20:5n-3 content of the egg lipid and fecundity; (2) the 22:6n-3 content and hatchability; and (3) fecundity, hatchability and n-3/n-6 fatty acid ratio. The results also suggest that each of these n-3 HUFAs may play different and specific roles in crab reproduction and that either must be adequate in the broodstock diet.     

Reduction of cholesterol absorption by dietary oleinate and fish oil in African green monkeys.

To determine whether diets enriched in monounsaturated or n-3 fatty acids cause a reduction in cholesterol absorption relative to those more enriched in saturated fatty acids, we measured cholesterol absorption in 18 African green monkeys fed diets enriched in lard, oleinate (oleic acid-rich safflower oil), or fish oil at two levels of dietary cholesterol (0.05 vs. 0.77 mg/kcal). All animals were initially challenged with the lard, high cholesterol diet to ascertain their responsiveness to dietary cholesterol. Based on the results of this challenge, low versus high responders were equally distributed in assignation to the low (n = 6) and high (n = 12) cholesterol regimens. Within each level of dietary cholesterol animals consumed all three dietary fats in random sequences during three experimental phases each lasting 9-12 months with a monkey chow washout period between each phase, so that each animal served as its own control. During each dietary phase measurements of plasma lipids and cholesterol absorption were performed. The animals fed the higher versus lower level of dietary cholesterol had significantly higher plasma total cholesterol and low density lipoprotein (LDL) cholesterol concentrations and lower percentage cholesterol absorption; high density lipoprotein (HDL) cholesterol levels were not affected by the level of dietary cholesterol. Dietary fish oil resulted in a 20-30% reduction (P less than 0.01) in total plasma and LDL cholesterol and a 30-40% reduction (P less than 0.01) in HDL cholesterol concentrations compared to lard and oleinate regardless of the level of dietary cholesterol. At the high level of cholesterol intake, the oleinate and fish oil diets resulted in significantly lower percentage cholesterol absorption compared to the lard fat diet (35 +/- 2%, 34 +/- 3%, 41 +/- 4%, respectively). At the lower level of dietary cholesterol, percentage cholesterol absorption values were higher than those at the high cholesterol intake (45-52% vs. 34-41%) but were not affected by the type of dietary fat. There was a significant positive correlation between plasma LDL cholesterol concentrations and percentage cholesterol absorption for the oleinate and lard diets at the high level of dietary cholesterol and a significant inverse association between plasma HDL cholesterol and percentage cholesterol absorption. We conclude that the type of dietary fat can influence cholesterol absorption in African green monkeys and that oleinate and fish oil reduce cholesterol absorption relative to lard when a high amount of cholesterol (0.77 mg/kcal) is present in the diet.     

Combined effects of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) in rats

The interaction of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) was studied in male rats fed diets containing casein (CAS) or soy protein (SOY) as a protein source with low fat (LF, 6.0% soybean oil) or high fat (HF, 13.0% soybean oil) combinations for 4 weeks. CLA was added at the 1.0% level to all diets. The weight of perirenal adipose tissue tended to be lower in the SOY groups than in the corresponding CAS groups, and the difference between the LF diets was significant. The weight of epididymal adipose tissue showed a similar but insignificant trend. The weight of brown adipose tissue was heaviest on the SOY-HF diet and lowest on two CAS diets, the SOY-LF diet being intermediate. The concentration of serum leptin was lowest on the SOY-LF diet and was significantly lower than that of the corresponding CAS group, but this difference disappeared when the dietary fat level increased. The serum cholesterol-lowering activity of SOY in relation to CAS was reproduced even when CLA was given. Thus the body fat-reducing activity of CLA was most marked when rats were fed the SOY-LF diet. Although the CAS-HF diet increased body fat deposition, the magnitude of the reduction by lowering dietary fat level was more marked than in the case of SOY. These results indicate a complicated interaction of dietary manipulations with the body fat-reducing effect of CLA, but the combination of CLA with the SOY-LF diet appears to be an appropriate approach.     

Eicosanoid synthesis and ornithine decarboxylase activity in mammary tumors of rats fed varying levels and types of N-3 and/or N-6 fatty acids

Virgin female Sprague-Dawley rats (50 days of age) were administered a single intragastric 10 mg dose of 7,12-dimethylbenz(a) anthracene (DMBA). Three weeks later they were placed on diets containing either 20% corn oil (CO), 20% primrose oil (PO), 20% black currant seed oil (BCO), 20% borage oil (BO), 15% menhaden oil plus 5% corn oil (15% MO + 5% CO), 10% menhaden oil plus 10% corn oil (10% MO + 10% CO), 5% menhaden oil plus 15% corn oil (5% MO + 15% CO) or 10% menhaden oil plus 10% borage oil (10% MO + 10% BO). Incidences of mammary tumors at 16 weeks post-DMBA were 80% in rats fed the CO diet, 84% in rats fed PO diet, 67% in rats fed BCO diet, 88% in rats fed BO diet, 60% in rats fed 15% MO + 5% CO diet, 67% in rats fed 10% MO + 10% CO diet, 83% in rats fed 5% MO + 15% CO diet, and 92% in rats fed 10% MO + 10% BO diet. Tumor multiplicity was lowest in PO-fed rats and highest in BO-fed rats. The tumor burden per tumor-bearing rat was lowest in rats fed the 15% MO + 5% CO, and 10% MO + 10% CO, diets and highest in those fed 20% BCO diet. Although body weight at 16 weeks post DMBA was not significantly different among the dietary groups, food intake was significantly greater in rats fed a diet containing 20% BO, or 5% MO + 15% CO.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of the effectiveness of soy protein isolate and fish oil for reducing the severity of retinoid-induced hypertriglyceridemia

The effectiveness of soy protein isolate (SPI) to reduce the severity of retinoid-induced hypertriglyceridemia has been demonstrated in the rat, but not in human subjects. Because fish oil has been demonstrated to be effective at lowering serum triglyceride concentration in human subjects undergoing retinoid therapy, a study was conducted to compare the ability of SPI with that of fish oil to reduce the severity of retinoid-induced hypertriglyceridemia in the rat. Male Fischer 344 rats, n=8/group, were fed one of four isonitrogenous, isoenergetic diets, consisting of a control diet containing 24% casein +20% corn oil (C), and three 13-cis retinoic acid (13cRA)-supplemented diets containing 24% casein +20% corn oil (R), 24% SPI +20% corn oil (SR), and 24% casein +15% fish oil and 5% corn oil (FR). There was no effect of diet on food intake or final body weight. Serum triglyceride concentration for group R was higher (P<0.001) than for groups C, SR, and FR (7.20 vs. 2.50, 2.84, and 2.02 mmol/L, respectively); values for groups SR and FR did not differ for this parameter. The serum concentration of 13cRA for group R did not differ from that for groups SR and FR. Thus, SPI was as effective as fish oil in reducing the severity of retinoid-induced hypertriglyceridemia in an animal model, suggesting that it may be effective for this purpose in human subjects.     

Effects of dietary polyunsaturated fatty acid on platelet aggregation in rats

In the present study, we changed the fatty acid profile in blood and platelet membranes by dietary manipulation, and examined the effect on platelet aggregation in rats. Fifty-five rats were divided into five groups and fed for 56 days with 1% cholesterol and different types of fatty acid-rich diets: basal, lard, lard + fish oil, soybean oil, and soybean oil + fish oil. a decrease in serum arachidonic acid (20:4, omega-6, AA) and an increase in serum eicosapentaenoic acid (20:5, omega-3, EPA) were found in all experimental dietary groups fed with refined fish oil. Similar changes in the polyunsaturated fatty acids were also found in the platelet membrane phospholipids. Platelet aggregation, quantitated by the slope and height of the aggregation curve induced by different concentrations of ADP in a platelet aggregometer, was inhibited in all groups fed with refined fish oil. This inhibition of platelet aggregation may be related to an increase in the ratio of EPA and AA in the platelet membrane phospholipids after dietary manipulation. The differences in the platelet aggregation and thromboxane B2 (TXB2) concentration between the lard and the lard + fish oil groups were more profound than that between the soybean oil and the soybean oil + fish oil group. However, the malondialdehyde (MDA) concentration revealed no significant differences between the five groups.     

Oxidative stress and antioxidant status in mouse kidney: effects of dietary lipid and vitamin E plus iron

The purpose of this study was to determine the effects of dietary fat, vitamin E, and iron on oxidative damage and antioxidant status in kidneys of mice. Sixty 1-month-old male Swiss-Webster mice were fed a basal vitamin E-deficient diet that contained either 8% fish oil + 2% corn oil or 10% lard with or without 1 g all-rac-alpha-tocopherol acetate or 0.74 g ferric citrate per kilogram of diet for 4 weeks. Significantly (P < 0.05) higher levels of lipid peroxidation products, thiobarbituric acid reactants (TBAR), and conjugated dienes were found in the kidneys of mice fed with fish oil compared with mice fed lard irrespective of vitamin E status. Mice maintained on a vitamin E-deficient diet had significantly higher renal levels of TBAR, but not conjugated dienes, than the supplemented group. Fish oil fed mice receiving vitamin E supplementation had lower levels of alpha-tocopherol than did mice in the lard fed group. Significantly higher levels of ascorbic acid were also found in the kidneys of mice fed with fish oil than were found in mice fed lard. The levels of protein carbonyls and glutathione (GSH), and activities of catalase, superoxide dismutase, selenium (Se)-GSH peroxidase, and non-Se-GSH peroxidase were not significantly altered by dietary fat or vitamin E. Dietary iron had no significant effect on any of the oxidative stress and antioxidant indices measured. The results obtained provide experimental evidence for the pro-oxidant effect of high fish oil intake in mouse kidney and suggest that dietary lipids play a key role in determining cellular susceptibility to oxidative stress.     

High fat diet induced oxidative DNA damage estimated by 8-oxo-7,8-dihydro-2-deoxyguanosine excretion in rats

The role of dietary fats and energy in carcinogenesis has been partly related to oxidative damage to DNA. We have investigated the effect of dietary fat content and saturation on the urinary excretion of 8-oxo-7,8dihydro-2'-deoxyguanosine (8-oxodG) in male and female rats. Groups of Fischer F344 rats (n = 6-10) were fed control chow (3.4% fat) or diets containing 21.8% corn oil or 19.8% coconut oil + 2% corn oil for 12-15 weeks. At the end of the diet intervention period 24h urine was collected for determination of 8-oxodG by HPLC. In the male groups fed control, corn oil and coconut oil diet the excretion of 8-oxodG was 403+/-150, 932+/-198 and 954+/-367pmol/kg 24 h, respectively (p < 0.05). In the female groups fed control and corn oil diet the excretion of 8-oxodG was 752+/-80 and 2206+/-282 pmol/kg 24 h, respectively (p < 0.05). Calculated per whole animal the excretion was 137+/-51, 324+/-70 and 328+/-128 pmol/24 h in the control, corn and coconut oil male groups and 156+/-21 and 464+/-56 pmol/24 h in the control and corn oil female groups, respectively ( p < 0.05). Thus, per animal or per consumed energy there was much less difference in 8-oxodG excretion between the corresponding male and female groups and only significant difference between the high fat groups. There was a close correlation (r = 0.7; p < 0.05) between 8-oxodG excretion and the energy intake. The present study suggests that a high fat diet increases oxidative DNA modification substantially irrespective of the saturation level of the fat. Energy intake appears to be the major determinant of the rate of modification.     

Estimation of protein digestibility—IV. Digestive proteinases from the pyloric caeca of coho salmon (Oncorhynchus kisutch) fed diets containing soybean meal

The goal of this study was to better understand why dietary soybean products are poorly utilized by salmonids. The influence of dietary intake on coho salmon fingerling weight gain and specific properties of pyloric caeca enzymes was investigated. Fingerlings were fed diets containing heated or unheated soybean meal (SBM) or Promoveal™, as 15–25% herring meal replacer, for 8–12 weeks. Fish fed to apparent satiation with diets containing heated SBM replacer gained more weight than those fed unheated SBM at the same level. Fish increased in body weight at the same rate when fed restricted rations containing either 15% SBM replacer that was variously heated up to 20 min, 15% Promoveal™ replacer or the herring meal basal diet. After the experimental diets were fed, digestive proteinases were isolated from the pyloric caeca. Yield of pyloric caeca enzymes (PCE), recovery of trypsin in PCE, soybean trypsin inhibitor (SBTI) sensitivity of PCE trypsin, specific activity of PCE trypsin and in vitro casein digestibility by PCE were determined for each dietary group. Weight gain vs in vitro casein digestibility by PCE was linear for animals fed unheated SBM to apparent satiation (r² = 0.71, P < 0.1) but not for animals fed either heated SBM to apparent satiation or variously heated SBM as 15% replacer at restricted levels. Trypsin from fish fed diets with heated or unheated SBM, but not Promoveal™ replacer, was less sensitive to SBTI than fish fed no SBM. For fish fed diets with variously heated SBM as 15% replacer, the SBTI activity of the SBM and SBTI inhibition of PCE trypsin were inversely related (r² = 0.88, P < 0.05). The yield of PCE was higher for fish fed 25% of heated SBM replacer than it was for diet groups fed less SBM. The yield of PCE trypsin was higher from animals fed 25% heated SBM replacer than those fed diets with a lower percentage of heated SBM replacer. Feeding coho fingerlings rations with SBM replacer appears to promote physiological compensation of PCE. Heat stable and/or heat-activated factor(s) and SBTI appear to cause the compensation of salmon digestive proteinases from coho salmon fed diets with SBM.     

Effects of dietary lipid source on reproductive performance and tissue lipid levels of Nile tilapia Oreochromis niloticus (Linnaeus) broodstock

Nile tilapia were fed diets supplemented with one of the following lipid sources at 5% level: cod liver oil, corn oil, soybean oil, a coconut oil-based cooking oil or a combination of cod liver oil and corn oil (1 : 1). The control diet had no lipid supplement and tad fish meal as a sole protein source. A diet with soybean meal as a protein source was also tested. The number of females that spawned, spawning frequency, number of fry per spawning, and total fry production were increased at varying degrees by the supplemental lipid sources except for the cod liver oil. Fish fed the soybean oil diet tad the best overall reproductive performance over a 24-week period. Fish fed the cod liver oil diet had the highest weight gain but the poorest reproductive performance. The suplemental lipids significantly increased crude fat levels in the liver and ovaries. Both males and females Ld the cod liver oil diet had the highest levels of fat in the liver and muscle. The ratio of total n-6/n-3 fatty acid in the liver, ovaries and testes was influenced by the supplemental lipid sources. It was highest in fish fed either the soybean oil diet, the corn oil diet, or the soybean meal diet and lowest in fish fed the control diet or the cod liver oil diet.     

Effect of quality and quantity of dietary fat and dimethylhydrazine in colon carcinogenesis in rats.

The effect, quality, and quantity of dietary fat on colon tumor induction by DMH were studied in rats exposed to a given regimen for two generations prior to treatment with DMH. Animals fed a 20% corn oil or 20% lard and treated with DMH had a higher incidence of colonic tumors than did rats fed a 5% corn oil, 5% lard or Purina lab chow and treated similarly. The quality of fat had no major difference on the incidence of colonic tumors.     

Effect of fatty acid composition of dietary fat on energy balance and expenditure in hamsters

The comparative effects of feeding diets containing corn, olive, coconut, or menhaden fish oil on efficiency of energy deposition and on short term energy expenditure were examined in growing hamsters. Diets comprising oils mixed with laboratory diets at 10% oil w/w were fed ad libitum for 3 weeks. Animals fed laboratory diets were used as controls. Body composition was determined before and after the feeding period using 3H2O distribution space. Oxygen consumption was measured in each animal during the final week. Weight gains of groups fed corn and olive oil diets exceeded those of the group fed laboratory diet alone (p less than 0.05), although metabolizable energy intakes were similar across groups. Corn oil fed animals demonstrated higher carcass energy gains as fat compared with laboratory diet fed or menhaden oil fed groups. This was reflected in an increased fractional deposition of metabolizable energy intake in the group fed corn oil diet compared with the latter two groups. Fecal energy losses were lower in the group fed corn oil diet, and higher in the group fed laboratory diet alone, compared with other groups. Oxygen consumption did not differ between groups. These findings indicate that feeding dietary fish oil, compared with corn oil, favours energy substrate oxidation reducing the fraction of metabolizable energy partitioned for storage.     

Malondialdehyde production and erythrocyte membrane resistance to free radicals, in function of adequate or inadequate protein intake, associated with different oils (sunflower, soybean, coconut, salmon)]

Requirements in polyunsaturated fatty acids (PUFA) of series n-3 and n-6 may be amplified and their metabolism, transport, and utilization may be impaired in the long term, by protein depletion. The aim of this study was to evaluate, in young rats, malondialdehyde (MDA) production and erythrocyte membrane antioxidative defense, when they were fed balanced (20% casein) or depleted (2% casein) protein diet associated with various oils (sunflower, soybean, coconut or salmon). Over a short period (28 days), eight groups of 10 male Wistar rats were fed eight different diets: TOC (20% casein + 5% sunflower oil), TOd (2% casein + 5% soybean oil), SOC (20% casein + 5% soybean oil), SOd (2% casein + 5% soybean oil), COC (20% casein + 5% coconut oil), COd (2% casein + 5% coconut oil), SAC (20% casein + 5% salmon oil), SAd (2% casein + 5% salmon oil). Blood was removed, MDA was assessed in plasma (reaction with thiobarbituric acid). Washed erythrocytes were subjected to organic free radical generator (Kit KGRL 400 Spiral R.D., Couternon, 21560 France). The haemoglobin released was analysed by spectrophotometry. The total anti-radical defense status was expressed as the length of time to reach 50% hemolysis (T 50% in min). Plasma of deficient groups (2% casein) exhibited low concentrations of protein, particularly with coconut and salmon oils; phospholipid and total cholesterol, excepted with diet containing coconut oil; triacylglycerol; and VLDL. Malondialdehyde. In groups fed balanced protein diets, the lowest values were obtained with salmon and coconut oils. MDA contents of groups TOd, COd and SAd were higher than those of their respective control groups, but significantly only in group COd. Antiradical defense status. Total anti-radical defence status in erythrocytes was not modified in the short term by balanced or depleted protein diets which ever oil was used, despite deep changes in fatty acid composition of membrane phospholipids. In particular, phospholipid contents in eicosapentaenoic, docosahexaenoic acids were greatly enhanced by the consumption of salmon oil compared to the values obtained with coconut oil.     

Effects of chronic modification of dietary fat and carbohydrate on the insulin, corticosterone and metabolic responses of rats fed acutely with glucose, fructose or ethanol

1. Male rats were fed for 14 days on powdered diets containing (by weight) 53% of starch, or on diets in which 20g of starch per 100g of diet was replaced by lard or corn oil. They were then fed acutely by stomach tube with a single dose of glucose, fructose or ethanol of equivalent energy contents, or with 0.15m-NaCl. The serum concentrations of corticosterone, insulin, glucose, glycerol, triacylglycerol and cholesterol were measured up to 6h after this treatment. 2. Feeding saline (0.9% NaCl) acutely to the rats maintained on the three powdered diets produced a small transient increase in circulating corticosterone that was similar to that in rats maintained on the normal 41B pelleted diet. 3. Feeding glucose acutely to the rats on the powdered diets produced peak concentrations of corticosterone that were 2–3-fold higher than those seen in rats maintained on the 41B diet. The duration of this response increased in the order starch diet<lard diet<corn-oil diet. This abnormal corticosterone response to glucose feeding appeared to be responsible for an increased activity in phosphatidate phosphohydrolase in the livers of rats fed the starch and lard diets of 2.9- and 4.9-fold respectively. The latter increase was similar to that produced by ethanol, whereas glucose did not increase the phosphohydrolase activity in the liver of rats maintained on the 41B diet. 4. Feeding fructose acutely produced even more marked increases than glucose in the concentrations of circulating corticosterone in rats given the powdered diets, but unlike glucose did not increase circulating insulin. The duration of the corticosterone response again increased in the order starch diet<lard diet<corn-oil diet. The concentrations of circulating glucose were increased by fructose feeding in rats maintained on these diets, but they were not altered in the rats maintained on the 41B pellets. A prolonged increase in serum corticosterone concentrations was also observed when fructose was fed to rats maintained on pelleted diets enriched with corn oil or beef tallow rather than with starch or sucrose. However, these effects were less marked than those seen with rats fed on the powdered diets. 5. These results are discussed in relation to the mechanism whereby high dietary fat exaggerates the effects of ethanol, fructose and sorbitol in stimulating triacylglycerol synthesis in the liver.     

Fish oil enhancement of 131I-conjugated anti-human milk fat globule monoclonal antibody experimental radioimmunotherapy of breast cancer

BALB/c nude mice (nu/nu) carrying established human transplantable breast tumors (MX-1) and fed fat from either fish oil (MaxEPA), corn oil, or lard, were treated with either an unconjugated mixture or an 131I-labeled cocktail of Mc1, Mc3, Mc5 and Mc8 four anti-human milk fat globule monoclonal antibodies (MoAbs). MaxEPA diet by itself reduced mean volume of tumor MX-1 to 36% below that of both the corn oil and lard diets. Injection of unconjugated MoAbs reduced tumor volumes only in corn oil fed nude mice when each group was compared to their respective controls. Treatment with 131I-MoAbs produced large tumor volume reductions in all groups with the three different diets. The greatest reduction was obtained with the synergistic effect of MaxEPA and 131I-labeled MoAbs.     

Dietary manipulations of body fat-reducing potential of conjugated linoleic acid in rats.

To study whether the body fat-reducing potential of conjugated linoleic acid (CLA) could be increased through dietary manipulations, the effects of the combination of CLA with different proteins, fats, and sesamin were examined in rats. Male rats were fed diets containing 1% CLA or linoleic acid (LA) in combination with different proteins (20% of casein or soybean protein), fats (7% perilla oil or soybean oil) and 0.2% sesamin (SES) for 3 or 4 weeks. When the dietary fat source was soybean oil, CLA, as compared with LA, significantly reduced weights of epididymal and perirenal adipose tissues, irrespective of the dietary protein sources. However, the highest reducing effect was shown when soybean protein was given as a protein source. SES stimulated the reduction of epididymal and perirenal adipose tissue weights in both protein diets. In contrast, CLA increased the weight of brown adipose tissue, and SES further increased it in combination with soybean oil but not with perilla oil. No effect of dietary manipulation was observed on serum leptin and TNF-alpha levels. Thus, the body fat-reducing potential of CLA can be increased by an appropriate combination with food factors that may stimulate fatty acid beta-oxidation.