Oil In Rats Research Articles

Protective role of Peanut oil in rats exposed to two different doses of gamma radiation that produced oxidative stress and bone injury

Introduction: Exposure to ionizing radiation represents a genuine, increasing threat to mankind and our environment. The steadily increasing applications of radiation in clinical practice, industrial and agricultural activities, on top of residual radioactivity resulting from nuclear test explosions, have a measurable impact contributing to possible radiation hazards in humans. Control of radiation hazards is considered as one of the most important challenges in order to protect our lives from radiation damages. The trans-3,4,5-trihydroxystibeneis a phyto-chemical present in peanuts and grapes with beneficial effects such as protection against cardiovascular disease and cancer prevention. Purpose: The present study aims to clarify the role of peanut oil as a radioprotector in male albino rats against oxidative stress and bone injury induced by two different doses of gamma irradiation. Material and Methods: Rats were subjected to a dose of 5 Gy (group 3) or 10 Gy ( group 4 ) ( single dose/ whole body ) in comparison with control group ( group 1 ). Prior to the two doses of gamma radiation, rats received peanut oil subcutaneously, ( 0.75 ml/kg ) over one month period, on three days/week ( group 5 and 6 ). Group 2, rats received peanut oil subcutaneously, ( 0.75 ml/kg ) as group 5, but without exposure to radiation. Results: The results showed that whole body gamma irradiation revealed significant acceleration in the level of lipid peroxide (MDA), with significant depletion in glutathione content (GSH), superoxide dismutase (SOD) and catalase (CAT) activities. Meanwhile. Also, the study showed significant increase in serum calcium with concomitant decrease in the bone calcium and significant increase in serum inorganic phosphorous concomitant with a decrease in bone phosphorous after radiation exposure. Administration of peanut oil pre-irradiation has significantly ameliorated the radiation induced disturbance in all the investigated parameters. Conclusion: Metabolism can be controlled to some extent by peanut oil administrated prior to irradiation.

Protective role of Peanut oil in rats exposed to two different doses of gamma radiation that produced oxidative stress and bone injury

Introduction: Exposure to ionizing radiation represents a genuine, increasing threat to mankind and our environment. The steadily increasing applications of radiation in clinical practice, industrial and agricultural activities, on top of residual radioactivity resulting from nuclear test explosions, have a measurable impact contributing to possible radiation hazards in humans. Control of radiation hazards is considered as one of the most important challenges in order to protect our lives from radiation damages. The trans-3,4,5-trihydroxystibeneis a phyto-chemical present in peanuts and grapes with beneficial effects such as protection against cardiovascular disease and cancer prevention. Purpose: The present study aims to clarify the role of peanut oil as a radioprotector in male albino rats against oxidative stress and bone injury induced by two different doses of gamma irradiation. Material and Methods: Rats were subjected to a dose of 5 Gy (group 3) or 10 Gy ( group 4 ) ( single dose/ whole body ) in comparison with control group ( group 1 ). Prior to the two doses of gamma radiation, rats received peanut oil subcutaneously, ( 0.75 ml/kg ) over one month period, on three days/week ( group 5 and 6 ). Group 2, rats received peanut oil subcutaneously, ( 0.75 ml/kg ) as group 5, but without exposure to radiation. Results: The results showed that whole body gamma irradiation revealed significant acceleration in the level of lipid peroxide (MDA), with significant depletion in glutathione content (GSH), superoxide dismutase (SOD) and catalase (CAT) activities. Meanwhile. Also, the study showed significant increase in serum calcium with concomitant decrease in the bone calcium and significant increase in serum inorganic phosphorous concomitant with a decrease in bone phosphorous after radiation exposure. Administration of peanut oil pre-irradiation has significantly ameliorated the radiation induced disturbance in all the investigated parameters. Conclusion: Metabolism can be controlled to some extent by peanut oil administrated prior to irradiation.

Chemopreventive Effects of Dietary Canola Oil on Colon Cancer Development

Fatty acid composition of dietary fat plays a vital role in colon tumor development in animal models. Fats containing ω-6 fatty acids (e.g., corn oil) enhanced and ω-3 fatty acids (e.g., flaxseed oil) reduced chemically induced colon tumor development in rats. The objective of the present investigation was to study the effects of dietary canola oil, a source of ω-3 fatty acid on azoxymethane-induced colon cancer development in Fischer rats and compare with dietary corn oil. Dietary canola oil significantly (P < 0.05) decreased colonic tumor incidence and tumor multiplicity as compared to dietary corn oil in rats. Fatty acid analysis showed that corn oil group had higher levels of ω-6 fatty acid levels, whereas the canola oil groups exhibited higher levels of ω-3 fatty acids from the colon and serum samples of rats. For the mechanistic study, COX-2 expression in the colon samples from the canola oil group was significantly lower (P < 0.05) as compared to the corn oil group. Taken together, dietary canola oil may be chemopreventive for colon tumor development in Fischer rats as compared to possibly by increasing ω-3 fatty acid levels and decreasing COX-2 levels.

Intestinal passage of microencapsulated fish oil in rats following oral administration

Fish oil labelled with [(14)C-linolenin] tracer was orally administered by gavage as an oil-water mixture (free oil) or as an oil-in-water emulsion formulation (microencapsulated oil) to fasted rats. Groups of rats were then given food after gavage or alternatively not fed to examine the effect of food on intestinal passage. Feeding after gavage drives lumenal free oil faster through the gastrointestinal (GI) tract. Microencapsulation slows down the lumenal progression in the GI tract with feeding. Non-feeding also slows down the lumenal progress of free oil in the GI tract but this is not influenced by microencapsulation. Analysis of the relative distribution of the label along the GI tract tissue wall showed that the upper small intestine was the main site of label accumulation in the GI tract. Of the oil that remained in the lumen, there was slight protection against early uptake and metabolism in the stomach and upper GI tract in rats that were either fed or not fed after dosing when microencapsulated oil was administered. Microencapsulation increased the levels of radiolabel in the liver and blood. The primary organ for accumulation of radiolabel for both free and microencapsulated oils in rats that were fed or fasted after dosing was the liver.

Effect of red yeast rice on toxicity of oxidized cholesterol and oxidized fish oil in rats

Summary Background & aims A study was undertaken to investigate the effect of red yeast rice on oxidized cholesterol and oxidized fish oil-induced toxicity in male Wistar rats. Methods The rats were divided into five groups, 30 male Wistar rats were fed with diets supplemented with 1% red yeast rice, 2% oxidized cholesterol or 3% oxidized fish oil for 6 weeks. Results Red yeast rice increase the levels of high-density lipoprotein cholesterol (HDL-C) in plasma, and glutathione (GSH) level in plasma, and decrease the activities of alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) in plasma, and the levels of low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), triacylglycerols and total cholesterol in plasma, and relative ratios of liver weight to body weight and thiobarbituric acid-reactive substances (TBARS) level in the liver of rats caused by oxidized cholesterol and oxidized fish oil. That red yeast rice might reduce the biochemical parameters characteristic in the plasma and liver of rats caused by oxidized cholesterol and oxidized fish oil. Conclusions It was also found that red yeast rice may play an important role in suppressing and a good recovering on short-term preventing effect from the toxicity of oxidized cholesterol and oxidized fish oil-induced toxicity in rats.

Anti-hyperlipidemic and Cardioprotective Effects of Ocimum sanctum L. Fixed Oil in Rats Fed a High Fat Diet

Ocimum sanctum (OS) has a lipid-lowering action in both normal and diabetic animals. Because OS leaves are rich in oil, the present study was conducted to explain the anti-hyperlipidemic and organ-protective effect of OS fixed oil in rats fed with a high fat (HF) diet. OS fixed oil was extracted by hexane and the fatty acids composition identified by GC-MS. Four groups of male Wistar rats included a normal control group, a high fat fed-diet (HF) group, a HF group treated with OS fixed oil, and a HF group treated with a reference drug simvastatin. The results show that OS fixed oil contains five kinds of fatty acids, of which alpha-linolenic acid was the major fatty acid. OS fixed oil depressed high serum levels of total cholesterol, triglyceride, LDL-C, and AI, whereas no significant effect on HDL-C was observed. OS fixed oil also suppressed high levels of liver cholesterol and triglyceride with no significant effect on both lipids in feces. In addition, OS fixed oil normalized the high serum levels of LDH and CK-MB but no significant effect on high serum levels of ALT, AST, and ALP was obtained. We conclude that treatment with OS fixed oil during the last three weeks of HF diet feeding decreased the high serum lipid profile and expressed antiartherogenic and cardioprotective actions against hyperlipidemia. The anti-hyperlipidemic action of OS fixed oil was mainly resulted from the suppression of liver lipid synthesis. Linolenic acid and linoleic acid contained in OS fixed oil were possibly responsible for both lipid-lowering and cardiac protective action against hyperlipidemia.

Cardiovascular effects induced by Cymbopogon winterianus essential oil in rats: involvement of calcium channels and vagal pathway

This study has investigated the cardiovascular effects of the Cymbopogon winterianus essential oil (EOCW) in rats. C. winterianus is a plant used in folk medicine for the treatment of hypertension. For the measurement of haemodynamic and ECG parameters, male Wistar rats under anaesthesia were cannulated in the abdominal aorta and lower vena cava and electrodes were subcutaneously implanted in their paws. For an in-vitro approach, the rats were killed and the superior mesenteric artery was removed and cut into rings (1-2 mm). These rings were then mounted in organ baths containing Tyrode's solution at 37 degrees C and gassed with carbogen. In rats, EOCW (1-20 mg/kg, i.v.) induced dose-dependent hypotension and tachycardia. These effects were not affected by L-NAME or indometacin, but were partially reduced after atropine administration. EOCW (20 mg/kg only) also induced bradycardia-associated sinoatrial blockade, junctional rhythm, and first-degree atrioventricular block, which was abolished after atropine administration or vagotomy. In arterial rings, EOCW (0.1-3000 microg/ml) induced relaxation of phenylephrine tonus that was not affected by removal of the endothelium. These relaxations were similar to those observed in rings without endothelium precontracted with KCl 80 mm. EOCW was able to antagonize the CaCl(2) (30-300 mum) induced contractions in depolarizing solution (KCl 60 mm). These results demonstrated that EOCW induced hypotension and vasorelaxation. These effects appeared to be mainly mediated by Ca(+2)-channel blocking. Furthermore, the higher dose of EOCW induced transient bradycardia and arrhythmias due to a cardiac muscarinic activation secondary to a vagal discharge.

Effect of oxyethylene moiety in polyoxyethylene sorbitan esters on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with polyoxyethylene sorbitan esters and soybean oil in rats.

Oil-in-water (O/W) lipid emulsions are suitable drug carriers for lipophilic drugs; however, the effects of numbers or chains of oxyethylene units within a surfactant molecule such as polyoxyethylene sorbitan esters (PSs) on the biological fate of these lipid emulsions have not yet been clarified. In this study, a series of PSs and soybean oil (SO) were utilized to prepare menatetrenone-incorporated lipid emulsions (SO/PSs), and the biological fate of menatetrenone administered as SO/PSs was studied at a clinical injection volume (0.1 mL kg(-1)) in rats. The plasma concentration and organ uptake of menatetrenone administered as SO/20OE-PSs (PSs with 20 oxyethylene units) was similar to that of SO/egg-yolk phosphatides (SO/EYP). The plasma concentration of menatetrenone was extensively lower for SO/6OE-PSs (PSs with 6 oxyethylene units) and SO/20OE-3FA-PSs (PSs with 20 oxyethylene units and 3 fatty acid chains) than that for SO/EYP, and menatetrenone uptake by the liver and spleen was higher for SO/6OE-PSs and SO/20OE-3FA-PSs, respectively, than those for SO/EYP. Furthermore, menatetrenone uptake by the lungs was also increased for SO/6OE-PS and SO/20OE-3FA-PS with double bonds in the fatty acid moieties of the PSs. These findings suggested that shortening the oxyethylene units or decreasing the oxyethylene chain numbers of emulsifiers resulted in a rapid clearance of the lipid emulsions from the circulation by extensive uptake via the liver, spleen or lungs.

Effect of acyl chains of phosphatidylcholines on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with phosphatidylcholines and soybean oil in rats.

Oil-in-water (O/W) lipid emulsions were prepared with phosphatidylcholines (PCs) of various acyl chains and soybean oil (SO) using a microfluidizer system, and the pharmacokinetics of menatetrenone incorporated in these oil particles were examined at the clinical injection volume (0.1 mL kg(-1)) in rats. The plasma half-life of menatetrenone incorporated in the oil particles prepared with SO and dipalmitoylphosphatidylcholine (DPPC) (SO/DPPC) was longer than that prepared with SO and eggyolk phosphatides (EYP) (SO/EYP) by 3 fold, while those of menatetrenone as oil particles prepared with SO and either dilauroyl phosphatidylcholine (DLPC), dimyristoyl phosphatidylcholine (DMPC), distearoyl phosphatidylcholine (DSPC), dioleoyl phosphatidylcholine (DOPC) or dilinoleoyl phosphatidylcholine (DLoPC) (SO/DLPC, SO/DMPC, SO/DSPC, SO/DOPC and SO/DLoPC, respectively) were similar to that of menatetrenone as SO/EYP. The menatetrenone uptake by the liver was not significantly different from that as SO/EYP in all SO/PCs examined, but the menatetrenone uptake by the spleen as SO/DPPC and SO/DSPC was higher than that as SO/EYP. The menatetrenone uptake by the lungs as SO/DPPC was also higher than that as SO/EYP. These findings suggest that SO/DPPC is a good candidate drug carrier for the prolonged plasma circulation of lipophilic drugs.

Acute effect of Copaifera reticulata Ducke copaiba oil in rats tested in the elevated plus-maze: an ethological analysis

Abstract Objectives Copaiba oil oleoresin exuded from Copaifera reticulata Ducke (CRD) is commonly used in anti-inflammatory, healing and anti-tumoral folk medicines. The purpose of this study was to investigate the putative anxiolytic effect of acute administration of CRD. Methods CRD was administered (100, 400 and 800 mg/kg, p.o.) to male Wistar rats submitted to the elevated plus-maze model of anxiety using an ethopharmacological analysis. Key findings In comparison with control rats, CRD increased the percentage of entries in the open arms over the entire dose range tested (vehicle, 33.6 ± 4.5; CRD 100 mg/kg, 44.67 ± 3.68; CRD 400 mg/kg, 47.2 ± 2.3; CRD 800 mg/kg, 50.7 ± 2.2) and the percentage of time spent in the open arms of the elevated plus-maze at the highest dose (800 mg/kg) (vehicle, 26.4 ± 5.7; CRD 800 mg/kg, 52.0 ± 2.7). A standard anxiolytic, diazepam (3 mg/kg, p.o.), was used as a positive control. In a similar way, diazepam increased the percentage of entries and time spent in the open arms when compared with vehicle (% open entries: vehicle, 45.4 ± 1.3; diazepam, 50.7 ± 1.9; % time spent in open arms: vehicle, 28.2 ± 0.9; diazepam, 38.9 ± 1.2). Regarding ethological measures, CRD at the highest dose (800 mg/kg) reduced peeping out (anxiety-related behaviour) (vehicle, 3.1 ± 0.6; CRD, 0.9 ± 0.2) and increased end-arm activity (vehicle, 0.2 ± 0.2; CRD, 2.0 ± 0.4), indicating an enhanced tendency of the rats to explore actively the potentially dangerous areas of the maze. Diazepam decreased peeping out (vehicle, 3.3 ± 0.3; diazepam, 1.0 ± 0.2) and flat-back approach (vehicle, 0.8 ± 0.2; diazepam, 0.2 ± 0.1) and increased end-arm activity (vehicle, 0.3 ± 0.1; diazepam, 2.5 ± 0.3) and head-dipping (vehicle, 8.2 ± 0.4; diazepam, 12.0 ± 0.5). Conclusions These data showed, for the first time, that acute treatment with CRD copaiba oil produced a dose-dependent anxiolytic-like effect over the dose range tested, on conventional and ethological parameters, without adversely affecting general activity levels.

Acute and Repeated Dose (28 Days) Oral Safety Studies of an Alkoxyglycerol Extract from Shark Liver Oil in Rats

Shark liver oil has been used for over 50 years as both a therapeutic and preventive agent. The active ingredients in shark liver oil have been found to be a group of ether-linked glycerols known as alkoxyglycerols. Despite its popularity, there is little published toxicology data on alkoxyglycerols. The toxicity of a supercritical fluid extract of shark liver oil (AKG-1 extract) has been evaluated in acute and repeated dose (28 days) oral toxicity studies in rats at doses of 200 and 100 times the maximum recommended dose by supplement manufacturers in humans, respectively. The AKG-1 extract administered in a single oral gavage dose of 2000 mg kg(-1) of body weight resulted in no adverse events or mortality. The AKG-1 extract administered as a daily dose of 1000 mg kg(-1) of body weight for 28 days by gavage resulted in no adverse effects or mortality. For both studies, no abnormal clinical signs, behavioral changes, body weight changes, or change in food and water consumption occurred. There were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. It is concluded that the AKG-1 extract is well tolerated in rats at an acute dose of 2000 mg kg(-1) and at a subchronic (28 days) dose of 1000 mg kg(-1).

Acute effect of &lt;I&gt;Copaifera reticulata&lt;/I&gt; Ducke copaiba oil in rats tested in the elevated plus-maze: an ethological analysis

Copaiba oil oleoresin exuded from Copaifera reticulata Ducke (CRD) is commonly used in anti-inflammatory, healing and anti-tumoral folk medicines. The purpose of this study was to investigate the putative anxiolytic effect of acute administration of CRD. CRD was administered (100, 400 and 800 mg/kg, p.o.) to male Wistar rats submitted to the elevated plus-maze model of anxiety using an ethopharmacological analysis. In comparison with control rats, CRD increased the percentage of entries in the open arms over the entire dose range tested (vehicle, 33.6 +/- 4.5; CRD 100 mg/kg, 44.67 +/- 3.68; CRD 400 mg/kg, 47.2 +/- 2.3; CRD 800 mg/kg, 50.7 +/- 2.2) and the percentage of time spent in the open arms of the elevated plus-maze at the highest dose (800 mg/kg) (vehicle, 26.4 +/- 5.7; CRD 800 mg/kg, 52.0 +/- 2.7). A standard anxiolytic, diazepam (3 mg/kg, p.o.), was used as a positive control. In a similar way, diazepam increased the percentage of entries and time spent in the open arms when compared with vehicle (% open entries: vehicle, 45.4 +/- 1.3; diazepam, 50.7 +/- 1.9; % time spent in open arms: vehicle, 28.2 +/- 0.9; diazepam, 38.9 +/- 1.2). Regarding ethological measures, CRD at the highest dose (800 mg/kg) reduced peeping out (anxiety-related behaviour) (vehicle, 3.1 +/- 0.6; CRD, 0.9 +/- 0.2) and increased end-arm activity (vehicle, 0.2 +/- 0.2; CRD, 2.0 +/- 0.4), indicating an enhanced tendency of the rats to explore actively the potentially dangerous areas of the maze. Diazepam decreased peeping out (vehicle, 3.3 +/- 0.3; diazepam, 1.0 +/- 0.2) and flat-back approach (vehicle, 0.8 +/- 0.2; diazepam, 0.2 +/- 0.1) and increased end-arm activity (vehicle, 0.3 +/- 0.1; diazepam, 2.5 +/- 0.3) and head-dipping (vehicle, 8.2 +/- 0.4; diazepam, 12.0 +/- 0.5). These data showed, for the first time, that acute treatment with CRD copaiba oil produced a dose-dependent anxiolytic-like effect over the dose range tested, on conventional and ethological parameters, without adversely affecting general activity levels.

Anti-lipase and lipolytic activities of ursolic acid isolated from the roots of Actinidia arguta

The aim of this study was to investigate the anti-obestic effects of ursolic acid isolated from the roots of Actinidia arguta, as well as the mechanism of action of this compound. This was conducted by testing whether ursolic acid inhibited the elevation of the rat plasma triacylglycerol levels after oral administration of a lipid emulsion containing corn oil in rats. Ursolic acid prevented the elevation of plasma triacylglycerol levels 2 h after oral administration of the lipid emulsion at a dose of 100 mg/kg. Furthermore, ursolic acid inhibited phosphodiesterase activity in vitro with an IC(50) of 51.21 muM and enhanced lipolysis in rat fat cells. We suggest that the inhibitory effects of ursolic acid, isolated from the roots of A. arguta, on obesity, might be attributable to the inhibition of lipid absorption through the inhibition of pancreatic lipase and by enhancing lipolysis in fat cells.

Safety assessment of heated diacylglycerol oil: Subchronic toxicity study in rats

Diacylglycerol oil is an edible oil with similar taste and usability characteristics as conventional edible oil rich in triacylglycerol oil. The objective of the present study was to evaluate potential adverse effects of heated diacylglycerol and triacylglycerol oil in rats following subchronic administration. The heated diacylglycerol and triacylglycerol oils were prepared separately following deep frying potato slices at 180 °C for 8 h per day for three days. Sprague Dawley rats were fed diets containing different ratios (concentrations) of heated to unheated diacylglycerol oil. The ratio of heated to unheated diacylglycerol was as follows: 0%/5.5% (control-1; Group 1), 1.0%/4.5% (Group 2), 2.75%/2.75% (Group 3), and 5.5%/0% (Group 4). Two additional groups received the feed containing 5.5% of unheated or 5.5% of heated triacylglycerol oil. Compared to the unheated oils, feeding of heated diacylglycerol or triacylglycerol oil did not reveal any toxicologically significant changes in clinical observation, body weights, body weight gains, feed consumption, ophthalmic examinations, functional observational battery and motor activity, clinical pathology evaluations and organ weights. Similarly, terminal necropsy did not reveal treatment-related gross or histopathology findings. Based on the results of this subchronic study, the no-observed-effect levels (NOELs) of heated diacylglycerol or triacylglycerol oil were 5.5%, the highest levels tested. The mean dietary exposure levels at the highest dose for the heated diacylglycerol and triacylglycerol oil for male and female rats ranged from 3178 to 4120 mg/kg/day.

Imaging of bacterial infection with 99mTc-labeled HBD-1

The aim of this study was to evaluate 99mTc labeled human β-defensin-1 (HBD-1) for discrimination between bacterial infection and sterile inflammation. For this purpose, HBD-1 was radiolabeled with 99mTc and its in vivo distribution was evaluated in inflamed rats with Staphylococcus aureus (S. aureus) and sterile inflamed rats with turpentine oil. After injection into inflamed and sterile inflamed rats, 99mTc-HBD-1 was rapidly removed from the circulation via the kidneys. Binding of 99mTc-HBD-1 to inflamed muscle (T/NT = 20 at 120 min) was two times higher than binding to sterile inflamed muscle (T/NT = 10 at 120 min) of rats. It was demonstrated that 99mTc-HBD-1 can be used to detect S. aureus inflammation in rats. However, the radiolabeled antimicrobial peptide showed only poor uptake in sterile inflammation with turpentine oil in rats. As a result, 99mTc-HBD-1 can be useful for detection of bacterial inflammation.

Effect of Oxyethylene Numbers on the Pharmacokinetics of Menatetrenone Incorporated in Oil-in-Water Lipid Emulsions Prepared with Polyoxyethylene-Polyoxypropylene Block Copolymers and Soybean Oil in Rats

We have prepared lipid emulsions of approximately 200 nm in diameter with soybean oil (SO) and a series of Pluronics with various numbers of oxyethylene units and about 60 oxypropylene units (SO/Pluronics), and studied the pharmacokinetics of menatetrenone incorporated into SO/Pluronics in rats. Emulsions of approximately 200 nm in diameter were obtained when SO contents were 2.5% and 20% (w/w) for 2.4% (w/w) PL101 and Pluronics that more than 30% was made up by oxyethylene units, respectively. The half-life of menatetrenone in plasma when oxyethylene units made up less than 30% of the Pluronic (SO/PL101 and SO/PP103) was similar to that for SO/egg yolk phosphatides (SO/EYP), but longer than that when oxyethylene units composed more than 40% of the Pluronic (SO/PP104 and SO/PF108, by 3- and 10-fold, respectively). Pretreatment with dextran sulfate 500000, an inhibitor of emulsion uptake by the reticuloendothelial system (RES), resulted in a higher plasma concentration and a lower liver uptake of menatetrenone as SO/PL101 at 10 min and SO/PP103 at 60 min, indicating that both SO/PL101 and SO/PP103 were taken up by the RES, although SO/PP103 required some time to be recognized by the RES. These findings suggested that larger numbers of oxyethylene units of Pluronics with 60 oxypropylene units were required for the longer plasma circulation of SO/Pluronics due to evasion of the RES.

Antiulcer activity of cod liver oil in rats.

Objective:Cod liver oil is used widely as a dietary supplement. The present study was carried out to evaluate the effect of cod liver oil (0.5 g/kg, p.o. and 1 g/kg, p.o.) on gastric and duodenal ulcers.Materials and Methods:The study was carried out on different gastric ulcer models such as acetic acid induced chronic gastric ulcers, pylorus ligation, indomethacin induced ulcers, stress induced ulcers and ethanol induced ulcers. The duodenal ulcers were induced using cysteamine hydrochloride (HCl). Ranitidine (50 mg/kg p.o.) and misoprostol (100 µg/kg, p.o.) were used as standard drugs.Results:Both doses of cod liver oil showed gastric ulcer healing effect in acetic acid induced chronic gastric ulcers, produced gastric antisecretory effect in pylorus-ligated rats and also showed gastric cytoprotective effect in ethanol-induced and indomethacin-induced ulcer. Cod liver oil also produced a significant reduction in the development of stress induced gastric ulcers and cysteamine induced duodenal ulcer. The high dose of cod liver oil (1 g/kg, p.o.) was more effective compared to the low dose (0.5 g/kg, p.o.).Conclusion:Cod liver oil increases healing of gastric ulcers and prevents the development of experimentally induced gastric and duodenal ulcers in rats.

Size-Based Distributions of Postprandial Lipoproteins in Lymph and Serum after Oral Administration of Triacylglycerol and Diacylglycerol Oils in Rats

Several studies in humans and rodents suggest that postprandial serum triglyceride (TG) levels are decreased by a single oral administration of diacylglycerol (DAG) oil compared with administration of control triacylglycerol (TAG) oil. To gain further insight into the mechanisms underlying the metabolic properties of DAG in a postprandial state, we analyzed the size-based distributions of postprandial lipoproteins in the lymph and serum using gel filtration-based high-performance liquid chromatography. In thoracic duct lymph pooled for 3 h after oral administration of TAG or DAG, the size-based distributions of postprandial lymphatic lipoprotein-TG and -cholesterol levels did not differ significantly, suggesting that DAG did not affect the size of lipoprotein particles secreted from the small intestine. Serum lipoprotein-TG (60%) and -cholesterol levels (90%), however, were significantly different among fractions with a diameter of greater than 80 nm 1 to 2 h after the administration of DAG compared to TAG. In addition, there was a considerable, but nonsignificant, reduction in lipoprotein-TG levels (approximately 40%) in fractions with a diameter of 80 to 30 nm, suggesting that DAG-derived chylomicrons as well as DAG-derived chylomicron remnants were catabolized rapidly. In conclusion, dietary DAG reduced the amount of large-size lipoproteins in the serum, but did not affect the size distribution of lipoproteins produced in the small intestine. Thus, compared with TAG, dietary DAG may reduce the postprandial serum total TG levels.

One-generation reproductive toxicity study of DHA-rich oil in rats

Polyunsaturated fatty acids, including docosahexaenoic acid (DHA), are natural constituents of the human diet. DHA-algal oil is produced through the use of the marine protist, Ulkenia sp. The reproductive toxicity of DHA-algal oil was assessed in a one-generation study. Rats were provided diets containing DHA-algal oil at concentrations of 1.5, 3.0, or 7.5%, and the control group received a diet containing 7.5% corn oil. Males and females were treated for 10 weeks prior to mating and during mating. Females continued to receive test diets during gestation and lactation. In parental animals, clinical observations, mortality, fertility, and reproductive performance were unaffected by treatment. Differences in food consumption, body weight, and liver weight in the treated groups were not considered to be due to an adverse effect of DHA-algal oil. Spleen weight increases in treated animals were associated with extramedullary hematopoiesis. Yellow discoloration of abdominal adipose tissue was observed in rats from the high-dose group, and histological examination revealed steatitis in all treated parental groups. Exposure to DHA-algal oil did not influence the physical development of F 1 animals. These results demonstrate that DHA-algal oil at dietary concentrations of up to 7.5% in rats does not affect reproductive capacity or pup development.

Dietary fat content and flavor reinforcement by intragastric sucrose and corn oil in rats.

The influence of dietary fat level on the relative reinforcing potency of intragastric (IG) corn oil and sucrose was tested with flavor preference conditioning. Rats were given ad libitum access to a low-fat chow (LF; 12% fat kcal) or a high-fat chow (HF; 48% fat kcal) maintenance diet. They were given four 22-h/day one-bottle training sessions each with CS+F, CS+C, and CS− flavors paired with IG 7.1% oil emulsion, 16% sucrose solution and water, respectively. During training the LF and HF rats consumed equal amounts of CS+F and CS− and less of the CS+C. Overall, the training nutrient intakes of the LF group averaged 18% protein/55% carbohydrate/27% fat, whereas the HF group averaged 12/37/51%. In two-bottle choice tests the groups showed equally strong preference for the CS+F over the CS− (82–86%). They also preferred the CS+C over the CS−, but the LF rats had a stronger preference (93%) than did the HF rats (77%). The CS+C was preferred to the CS+F; the LF group's 72% preference did not differ significantly from HF group's 60% CS+C preference. The results extend prior work showing IG fat is less reinforcing than IG carbohydrate. Relative to the LF diet, the primary effect of HF diet was attenuation of carbohydrate-based flavor preference, perhaps due to greater satiation effects by carbohydrates when they comprise less of the overall diet. Supported by DK031135.