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PubMed1978

Enhancement of bioavailability of a hydrophobic amine antimalarial by formulation with oleic acid in a soft gelatin capsule.

The relative availability of the orally administered hydrophobic antimalarial alpha-(dibutylaminomethyl)-6,8-dichloro-2-(3',4'-dichlorophenyl)-4-quinolinemethanol (I) from two dosage forms was determined in beagle dogs. Compound I was soluble in oleic acid to the extent of 23.5% (w/w), and oleic acid was suitable for encapsulation in soft gelatin capsules. The availability of I formulated as its hydrochloride salt in a standard hard gelatin capsule formulation was significantly lower than that of I formulated in a soft gelatin capsule with oleic acid as the solvent. A 20% solution of I in oleic acid (soft gelatin capsules) maintained at 23 degrees provided 4% of the oleic acid ester of I iwithin 1 month. Further reaction, however, was not seen over 2 years.

Animals↗
PubMed1982

Responses of serum and lung angiotensin-converting enzyme activities in the early phase of pulmonary damage induced by oleic acid in dogs.

Changes in angiotensin-converting enzyme (ACE) activity in the lung tissue, edema fluid, and bloodstream were studied during induction of lung edema by oleic acid. Left lungs of 25 mongrel dogs were unilaterally treated with oleic acid (0.1 ml/kg) injected into the right atrium during right pulmonary artery occlusion for 2.5 min. Lung tissue and serum ACE activities and physiologic parameters were followed for as long as 180 min. Serum ACE activity increased to 106% at 2.5 min (p less than 0.025) and to 128% at 180 min. The ACE activity of treated lung tissue decreased compared with the zero time control in terms of tissue DNA content (at 180 min, p less than 0.05). Furthermore, the left to right activity ratio of the precipitate fraction decreased to 0.59 as early as 5 min after oleic acid injection (p less than 0.01). Changes in these ACE activities preceded those of arterial oxygen tension and base transthoracic electrical impedance. Edema fluid at 45 min had a specific activity that was 1.62 times greater than that in serum. These data indicated that the change in ACE activity reflected the impairment of pulmonary vascular endothelial cells and that the oleic acid injured endothelial cells of the pulmonary capillaries as early as 2.5 min after administration.

Animals↗
PubMed1993

[Plasma cholecystokinin levels in rats with pancreatic insufficiency induced by intra ductal injection of oleic acid].

Plasma cholecystokinin (CCK) levels in rats with pancreatic insufficiency induced by a single injection of 50 microliters oleic acid into the pancreatic duct were determined by a sensitive and specific bioassay using the isolated rat pancreatic acini. Treatment with oleic acid significantly decreased pancreatic wet weight within 7 days, which lasted until the end of observation (56 days). Histologic examination revealed the destruction of acinar cells and the epithelium of intra- and interlobular ducts. Plasma CCK bioactivity was significantly increased from the pre-treatment values of 0.8 +/- 0.1pM to 5.1 +/- 1.4pM at 24h after oleic acid treatment. After this peak, plasma CCK levels gradually decreased. Even after 56 days, however, plasma CCK levels in oleic acid-treated rats were significantly high compared with those in control rats. In the present study, plasma CCK levels in rats with chronic pancreatitis did not correlate with the progress of pancreatic insufficiency.

Animals↗
PubMed1995

Stability studies and effect of the initial oleic acid concentration on lipase production by Candida rugosa.

The production of lipase by Candida rugosa in batch cultures was studied. The initial concentration of the carbon source employed, oleic acid, had an important effect on the final lipolytic activity levels. The maximum lipase/substrate yield and specific productivity obtained correspond to an initial oleic acid concentration of 2 g/l. At higher concentrations, up to 8 g/l oleic acid, specific productivity decreased. Lipase production was not observed below 1 g/l oleic acid. Lipase inactivation in culture broth due to surface forces and shear stress at the gas/liquid interface was not observed. There was no shear stress denaturation at stirring rates of 250, 500 and 750 rpm. No temperature inactivation was detected up to 50 degrees C. Two different lipases with a similar molecular weight of 60 kDa were purified from culture broth.

Candida↗
PubMed2005

Products and mechanisms of the reaction of oleic acid with ozone and nitrate radical.

The heterogeneous reactions of deposited, millimeter-sized oleic acid droplets with ozone and nitrate radicals are studied. Attenuated total reflectance infrared spectroscopy (ATR-IR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS) are used for product identification and quantification. The condensed-phase products of the ozonolysis of oleic acid droplets are 1-nonanal (30 +/- 3% carbon yield), 9-oxononanoic acid (14 +/- 2%), nonanoic acid (7 +/- 1%), octanoic acid (1 +/- 0.2%), azelaic acid (6 +/- 3%), and unidentified products. The infrared spectra show that a major fraction of the unidentified products contain an ester group. Additionally, the mass spectra show that at least some of the unidentified products have molecular weights greater than 1000 amu, which implicates a polymerization reaction. The observed steps of 172 amu (9-oxononanoic acid) and 188 amu (azelaic acid Criegee intermediate) in the mass spectra suggest that these species are the monomers in the condensed-phase polymerization reactions. 9-Oxononanoic acid is proposed to lengthen the molecular chain via secondary ozonide formation; the azelaic acid Criegee intermediate links molecules units via ester formation (specifically, alpha-acyloxyalkyl hydroperoxides). For the reaction of oleic acid with nitrate radicals, functional groups including -ONO(2), -O(2)NO(2), and -NO(2) are observed in the infrared spectra, and high molecular weight molecules are formed. Environmental scanning electron microscopy (ESEM) is employed to examine the hygroscopic properties of the oleic acid droplets before and after exposure to ozone or nitrate radical. After reaction, the droplets take up water at lower relative humidities compared to the unreacted droplets. The increased hygroscopic response may indicate that the oxidative aging of atmospheric organic aerosol particles has significant impact on radiative forcing.

Journal Article↗
PubMed1989

Effect of oleic acid on diffusion of drugs through hairless mouse skin.

The effect of oleic acid in propylene glycol or 2-ethyl-1,3-hexanediol vehicle systems on the skin permeability of 17 beta-estradiol, triamcinolone acetonide and trifluorothymidine was studied in vitro. The largest enhancement was obtained from a vehicle containing oleic acid in propylene glycol and the enhancement increased with increasing aqueous solubility of the drug. Oleic acid gave far less enhancement when propylene glycol was replaced by 2-ethyl-1,3-hexanediol.

Animals↗
PubMed2003

Effects of rosiglitazone and oleic acid on UCP-3 expression in L6 myotubes.

AIMS: The regulation of uncoupling protein-3 (UCP-3) expression in muscle remains unclear, specifically in relation to dietary and drug treatments. The present study evaluated the effects of oleic acid and rosiglitazone on UCP-3 mRNA expression in differentiated L6 myotubes. METHODS: L6 myocytes were cultured and differentiated prior to exposure to rosiglitazone 10 micro mol/l, oleic acid 100 micro mol/l, or the combination, for 24 h, prior to semiquantitative evaluation of UCP-3 mRNA relative to GAPDH mRNA by RT-PCR. RESULTS: Exposure to oleic acid produced a significant increase in UCP-3 mRNA (0.012 +/- 0.007 vs. 0.0011 +/- 0.0006 for untreated cells, relative to GAPDH mRNA, p < 0.001). Rosiglitazone alone had no effect on UCP-3 expression and nor did the glitazone affect oleic-acid-induced upregulation of UCP-3. CONCLUSIONS: In L6 myotubes, 24-h exposure to oleic acid produced a 10-fold increase in UCP-3 mRNA expression, but rosiglitazone had no effect. Oleic-acid-induced upregulation of UCP-3 was not affected (positively or negatively) by glitazone exposure.

Animals↗
PubMed1982

The effect of intraduodenal installation of oleic acid on plasma neurotensin-like immunoreactivity and on gastric acid secretion stimulated by betazole and sham feeding in man.

Intraduodenal administration of oleic acid has previously been shown to inhibit gastric acid secretion induced by pentagastrin in man. This inhibition was dose-dependent and significantly correlated to a rise in plasma concentration of neurotensin-like immunoractivity (NTLI). Maximal inhibition occurred with a volume of oleic acid of 20 ml. In the present study intraduodenal instillation of 20 ml. of oleic acid inhibited acid secretion evoked by sham feeding in healthy subjects but did not significantly inhibit the near-maximal acid secretion stimulated by the histamine analogue betazole. The inhibition of acid secretion induced by sham feeding was the same (about 45%) as the inhibition of pentagastrin-stimulated secretion. Plasma NTLI rose significantly in both the sham feeding and betazole experiments and peaked at about 145 pM. The results are in agreement with the inhibitory characteristics of neurotensin and support the hypothesis that the inhibition of gastric acid secretion by small amounts of intestinal fat is at least partly mediated by neurotensin.

Adult↗
PubMed1997

Synergistic inhibition of calcification of porcine aortic root with preincubation in FeCl3 and alpha-amino oleic acid in a rat subdermal model.

Postimplant calcific degeneration is a frequent cause of clinical failure of glutaraldehyde crosslinked porcine aortic valve bioprostheses. We demonstrated previously in rat subdermal and circulatory implants that alpha-amino oleic acid used as a bioprosthesis pretreatment was highly effective in mitigating aortic valve cusp but not aortic wall calcification. In this study we investigated the feasibility of synergistically applying two proven anticalcification agents (alpha-amino oleic acid and FeCl3) as pretreatments for mitigating both bioprosthetic cusp and aortic wall calcification. alpha-Amino oleic acid is hypothesized to prevent calcification by disrupting calcium phosphate formation kinetics, whereas suppression of alkaline phosphatase activity and ferric-phosphate complexation at a cellular membrane initiation sites may be important factors in ferric ion's inhibition of calcification. In vivo implant studies (21-day rat subdermal model) indicated that individually FeCl3 (0.01 or 0.1 M for 24 h) or alpha-amino oleic acid (saturated solution) treatments were equally effective in mitigating cuspal calcification (tissue calcium levels: 30.2 +/- 10.2, 29.8 +/- 2.7, and 31.6 +/- 7.8 micrograms/mg tissue, respectively). However, sequential application of first alpha-amino oleic acid and then FeCl3 synergistically reduced aortic wall calcification more effectively than either of the agents alone. The benefit of a synergistic application of two anticalcification treatments, alpha-amino oleic acid and FeCl3, was demonstrated. However, the synergistic effect was observed on aortic wall only at a higher FeCl3 concentration. (i.e., 0.1 M).

Animals↗
PubMed1989

Oleic acid reduces pulmonary microvascular sieving capacity in sheep.

Changes in pulmonary microvascular permeability in sheep, after oleic acid injection, were studied using estimations of the osmotic reflection coefficient (sigma d) for total protein, albumin, immunoglobulins (Ig) G and M and calculation of the equivalent small and large pores of the microvessels. A chronic lung fistula was prepared in eight sheep. After a base-line period, left atrial pressure (Pla) was increased. Oleic acid (0.05 mg/kg body wt) was injected after a filtration-independent state had been obtained, and the spontaneously ventilating animals were then followed for 2 h. The sigma d for the normal lung was 0.65 +/- 0.03, 0.59 +/- 0.02, 0.72 +/- 0.04, and 0.84 +/- 0.02 for total protein, albumin, IgG, and IgM, respectively. The equivalent pore radii were 54 and 225 A. After oleic acid infusion, arterial pressure and arterial O2 tension decreased and leukocytes and platelets were consumed. At the end of the experiment, sigma d's were 0.27 +/- 0.04, 0.24 +/- 0.07, 0.33 +/- 0.06, and 0.55 +/- 0.04 for total protein, albumin, IgG, and IgM, respectively. The equivalent pore radii were 54 and 275 A, and the number of large pores was increased by 195%. The results indicate that oleic acid produces an increased vascular permeability by increasing the size and the numbers of large pores of the pulmonary microvascular walls.

Animals↗
PubMed1992

Effects of oleic acid and endogenous bile on duodenal secretion of somatostatin in man.

We studied the effects of intraduodenal oleic acid on the release of somatostatin to plasma and the correlation between endogenous bile output and plasma somatostatin. In five normal persons infusion of 0, 5, 10, 20, and 40 mM oleic acid dose-dependently increased the levels of somatostatin during as well as after gallbladder emptying. The difference between somatostatin concentration during and after gallbladder emptying was not significant. The amylase secretion also was significantly correlated to the dose of fat, whereas the output of bile salts was the same for all fat doses used. Our observations indicate that intraduodenal oleic acid--and not bile salts--releases somatostatin from the gut.

Adult↗
PubMed1989

Syncytia formation in HIV-1 infected cells is associated with an increase in cellular oleic acid.

Infection of cells with the human immunodeficiency virus type-1 (HIV-1) usually results in the formation of giant multinuclear cells (syncytia) [(1986) Nature 322, 470-474; (1986) Nature 322, 725-728; (1985) Hum. Pathol. 18, 760-765; (1987) Ann. Neurol. 21, 490-496]. The appearance of syncytia is associated with an increase in the monounsaturated oleic acid content. This report describes experiments which compare the activity of known antiviral agents with that of saturated fatty acid derivatives in inhibiting oleic acid and syncytia formation. A concept is introduced which proposes that infection of cells with the human immunodeficiency virus causes a rise in cellular oleic acid which leads to increased membrane fluidity.

Cell Line↗
PubMed1989

Hypoxic pulmonary vasoconstrictor response with asymmetric oleic acid injury in the dog.

The hypoxic pulmonary vasoconstrictive (HPV) response is characterized by two components: intrapulmonary blood flow redistribution and pulmonary artery pressure (PAP) augmentation. Whether both remain intact after oleic acid lung injury has not been assessed. In an asymmetric model of right lung oleic acid edema, we examined the relative magnitude of each component on the HPV response to right lung inspired hypoxia. Before oleic acid administration, right lung hypoxia decreased perfusion to the right lung from 1.41 +/- 0.12 to 1.16 +/- 0.15 L/min (p = .07), while PAP increased from 15.8 +/- 0.8 to 18.1 +/- 0.6 mm Hg (p less than .05). Regional hypoxia caused right lung pulmonary vascular resistance (PVR) to increase from 480 +/- 45 to 797 +/- 114 dyne.sec/cm5 (p less than .01). After right lung injury with oleic acid, regional hypoxia decreased perfusion to the right lung from 0.91 +/- 0.11 to 0.71 +/- 0.10 L/min (p less than .05), while PAP increased from 18.8 +/- 0.8 to 21.5 +/- 1.0 mm Hg (p less than .05). With hypoxia, right lung PVR increased from 1232 +/- 260 to 1933 +/- 336 dyne.sec/cm5 (p less than .01). We conclude that the pulmonary vasoconstrictive response to inspired hypoxia persists after oleic acid lung injury, causing significant increases in PVR. Consequently, both the blood flow redistribution and the PAP augmentation components of the HPV response to inspired hypoxia remain unchanged.

Animals↗
PubMed1995

Lipid levels of expeditioners in Antarctica: response to a reduced-fat, oleic acid and carbohydrate-enriched diet.

The study examined the effects of a reduced-fat, oleic acid and carbohydrate-enriched diet on serum lipid profiles and body weight in the setting of an isolated Australian Antarctic station. A 12-week dietary intervention period was provided for 30 healthy, free-living expeditioners against a background diet typical of the Australian population. The diet tested a "modified U.S. Dietary Goals" regimen which increased oleic acid preferentially (29% energy from fat and 46% from carbohydrate, polyunsaturated: monounsaturated: saturated fatty acid ratio [P:M:S] of 0.6:1.3:1.0, 30 g fibre/day, less than 300 mg cholesterol/day). During the intervention period, mean serum HDL-cholesterol (HDL-C) levels remained relatively stable while mean serum total cholesterol (TC) fell significantly (a fall of 0.95 mmol/l, p < 0.05). The mean serum triglyceride (TG) level rose initially (1.44 to 1.64 mmol/l, p < 0.05) but the level returned to baseline (1.41 mmol/l) by the end of the intervention period. The change in TG level was associated with increased dietary carbohydrate but not with changes in body weight, alcohol intake or season. The study demonstrates that a reduced-fat, oleic acid and carbohydrate-enriched diet can result in significant improvements in serum lipid profiles. The diet was acceptable to the subjects and was easily provided in Antarctica with unobtrusive changes to the typical Australian diet.

Adult↗
PubMed1998

Growth modulating effects of chlorinated oleic acid in cell cultures.

Chlorinated fatty acids represent a major fraction of extractable, organically bound chlorine in fish. After dietary intake such fatty acids may be transferred from the mother to the foetus through the placenta, and via breast milk to the child. In the present work we have studied the effect of chlorinated oleic acid on the growth of three widely differing types of cells in culture. Chlorinated oleic acid inhibited growth of Human Microvascular Endothelial Cells (HMVEC), Immortilized Human Kidney Epithelial (IHKE) cells, and human Hepatoma cells (HepG2). The order of potency was: HMVEC > IHKE > HepG2. Vitamin E counteracted the inhibitory effect of chlorinated oleic acid on HepG2 cells, but did not significantly affect the fatty acid effect on HMVEC or IHKE. Defatted serum albumin stimulated the growth of HMVEC and IHKE. With HMVEC there was no major interaction between the effect of albumin and chlorinated oleic acid on cell growth. In contrast, with IHKE albumin at low concentration abolished the growth inhibiting effect of chlorinated oleic acid and appreciably counteracted growth inhibition by the fatty acid of HepG2. We conclude that the growth modulation by chlorinated oleic acid and its interaction with vitamin E and albumin are cell specific.

Albumins↗
PubMed1981

Enhanced phagocytosis of group A streptococci M type 6 by oleic acid.

M protein, located on the surface fimbriae of group A streptococci, is antiphagocytic by unknown means. It is known that oleic acid kills group A streptococci and distorts the fimbriae. The effect of oleic acid on phagocytosis of group A streptococci was examined. Phagocytosis of a strain possessing M protein (M+) and its M- variant was assessed by uptake of radiolabeled bacteria and by chemiluminescence. The M- but not the M+ streptococci were well phagocytized and induced chemiluminescence. Oleic acid-killed and heat-killed streptococci (both M+ and M-) were readily phagocytized and induced sustained chemiluminescence. M+ streptococci killed by ultraviolet irradiation were inefficiently phagocytized and did not induce chemiluminescence. Oleic acid-killed M+ streptococci absorbed type-specific antibody. An extract of M protein reduced the bactericidal capacity of oleic acid. It is proposed that oleic acid may bind to and alter the M protein of group A streptococci and thereby enhance phagocytosis.

Absorption↗
PubMed1988

Pulmonary vascular pressure-flow plots in canine oleic acid pulmonary edema. Effects of prostaglandin E1 and nitroprusside.

We investigated the effects of prostaglandin E1 (PGE1) and of sodium nitroprusside (NP) on multipoint pulmonary arterial pressure (PAP)/cardiac index (Q) plots in 24 pentobarbital-anesthetized and ventilated dogs with pulmonary hypertension secondary to oleic acid lung injury. The PAP/Q plots were rectilinear in all experimental conditions. In control dogs (n = 8), PAP was increased over the entire range of Q studied, from 1 to 4 L/min.m2, 90 min after oleic acid 0.09 ml/kg, and remained so during 2 consecutive 5-point PAP/Q plots, each of them being constructed in about 30 min. Oleic acid increased the extrapolated pressure intercept (p less than 0.001) but not the slope of the PAP/Q plots. Infusion of PGE1 0.4 micrograms/kg.min intravenously (n = 8) reduced PAP at each level of Q, with a reduction of the extrapolated pressure intercept (p less than 0.01) and no change in slope of the PAP/Q plots. In contrast, NP 5 micrograms/kg.min intravenously (n = 8) slightly reduced PAP only at the highest Q studied, without any significant change in extrapolated pressure intercept or slope of PAP/Q plots. Systemic blood pressure was decreased by 21% after PGE1 and by 24% after NP. Neither drug affected Q nor blood gases after oleic acid. The results suggest that pulmonary hypertension secondary to oleic acid pulmonary edema may be due more to an increase in effective outflow pressure of the pulmonary circulation than to an increase in incremental vascular resistance, and that active vasoconstriction contributes to this type of pulmonary hypertension.

Alprostadil↗
PubMed1994

Comparative analysis of percutaneous absorption enhancement by d-limonene and oleic acid based on a skin diffusion model.

Percutaneous absorption-enhancing effects of d-limonene and oleic acid were investigated using three model drugs with different lipophilicities in in vitro diffusion experiments with guinea pig skin. Pretreatment of the skin with d-limonene resulted in a large penetration enhancement for the lipophilic butylparaben (BP) and amphiphilic 6-mercaptopurine (6-MP) but had little effect on the hydrophilic mannitol (MT). Oleic acid caused a large effect only on 6-MP penetration. The penetration profiles were analyzed with a two-layer skin diffusion model consisting of stratum corneum with polar and nonpolar routes and viable epidermis plus dermis. Through curve-fitting, six parameters corresponding to drug diffusivity and partitioning in these three regions of the skin were obtained, and the mechanisms of enhancers were assessed in comparison with those of 1-geranylazacycloheptan-2-one (GACH) reported previously. Increased penetration was caused mainly by modification of the barrier property of the nonpolar route in the stratum corneum in all cases. In the nonpolar route, d-limonene increased mainly drug diffusivity, while GACH enhanced predominantly drug partitioning. On the other hand, oleic acid moderately increased both parameters.

Animals↗