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PubMed2001

The effect of temperature on the fatty acids and isozymes of a psychrotrophic and two mesophilic species of Xenorhabdus, a bacterial symbiont of entomopathogenic nematodes.

In the first part of this study, generation times relative to temperature, together with cardinal and conceptual temperatures, were determined for four strains of Xenorhabdus bacteria that represented three geographically distinct species. The data showed that the NF strain of Xenorhabdus bovienii, like the Umeå strain of the same species, is psychrotrophic, while Xenorhabdus sp. TX strain resembles Xenorhabdus nematophila All strain in being mesophilic. In the second part, the capacity of these bacteria to adapt to changes in temperature, shown by changes in fatty acid composition, was investigated. As temperature declined, the proportions of the two major unsaturated fatty acids, palmitoleic (16:1omega7) acid and oleic (18:1omega9) acid, increased significantly in all of the strains. The proportion of the prevalent saturated fatty acid, which was palmitic acid (16:0), decreased. In the All, NF, and Umeå strains, myristic acid (14:0), margaric acid (17:0), cyclopropane (17:0c), and arachidic acid (20:0) decreased with decreasing temperature. In the third part of the study, the synthesis of isozymes in response to changing temperature was investigated. For the seven enzymes studied, the numbers for which isozyme synthesis was temperature related were as follows: five for Umeå, four for All, three for NF, and two for TX. Where the study dealt with fatty acid composition and isozyme synthesis, the results show a broad capacity for physiological temperature adaptation among strains of different climatic origin.

Animals↗
PubMed2002

Drug-induced and postnatal hypothyroidism impairs the accumulation of diacylglycerol in liver and liver cell plasma membranes.

BACKGROUND: Thyroid hormones are well known modulators of signal transduction. The effect of hyper- and hypo-thyroidism on diacylglycerol/protein kinase C (DAG/PKC) signaling in cardiomiocytes has been determined. Triiodothyronine (T3) has been shown to prevent the alpha1-adrenoreceptor-mediated activation of PKC but does not alter the stimulation of enzyme and hepatic metabolism by phorbol ethers. It has been suggested that the elevation of endogenous DAG in senescent or hypothyroid cells changes the PKC-dependent response of cells to phorbol esters and hormones. In the present study, was examined the formation of DAG and activation of PKC in liver cells from rats of different thyroid status. RESULTS: The results obtained provide the first demonstration of DAG accumulation in liver and cell plasma membranes at age- and drug-dependent thyroid gland malfunction. The experiments were performed in either the [14C]CH3COOH-labeled rat liver, liver slices or hepatocytes labeled by [14C] oleic acid and [3H]arachidonic acid or [14C]palmitic acid as well as in the isolated liver cell plasma membranes of 90- and 720-day-old rats of different thyroid status. The decrease of T4 and T3 levels in blood serum of 720-day-old rats and mercazolil-treated animals was associated with increases of both the DAG mass in liver and liver cell plasma membranes and newly synthesized [14C]DAG level in liver and isolated hepatocytes. Hypothyroidism decreased PKC activity in both membrane and cytosol as well as phospholipid and triacylglycerol synthesis in liver. These hypothyroidism effects were restored in liver by injection of T4. T4 administration to the intact animals of different ages decreased the DAG level in liver and isolated plasma membranes and the content of newly synthesized DAG in liver. The reduction of DAG level in liver was not associated with increasing free fatty acid level. DAG labeling ratio 14C/3H in liver slices of rats of different thyroid state sharply differed from PL. DAG was relatively enriched in [14C]oleic acid whereas PL were enriched in [3H]arachidonic acid. CONCLUSIONS: The above data have indicated that thyroid hormones are important physiological modulators of DAG level in rat liver and cell plasma membranes. Age- and drug-induced malfunction of thyroid gland resulted in a prominent decrease of glycerolipid synthesis which may promote DAG accumulation in liver.

Aging↗
PubMed2002

Oxidative stability of polyunsaturated fatty acid in phosphatidylcholine liposomes.

Synthesized PCs containing docosahexaenoic acid (DHA), arachidonic acid (AA), linoleic acid (LA), and palmitic acid (PA) at known positions in the glycerol moiety were oxidized in liposomes, bulk, and organic solvent. In bulk and organic solvent, the oxidative stability of PC decreased with increasing degrees of unsaturation. However, the degree of unsaturation had little effect on the stability of PC in liposomes. The oxidative stability of PC in liposomes would be affected by the chemical reactivity based on the degree of unsaturation and by the conformation of fatty acyl component in PC bilayers. When the oxidative stability of 1-PA-2-LA-PC or 1-PA-2-AA-PC was compared with that of a 1:1 (mol ratio) mixture of 1,2-diPA-PC + 1,2-diLA-PC, or 1,2-diPA-PC + 1,2-diAA-PC, respectively, the former PC was more oxidatively stable than that of the latter PC mixture in all oxidation systems, although the degree of unsaturation of 1-PA-2-PUFA-PC was the same as that of the corresponding mixture of diPA-PC + diPUFA-PC. The higher oxidative stability of 1-PA-2-PUFA-PC than that of a corresponding mixture of diPA-PC + diPUFA-PC in liposomes was suggested to be due to the different conformation of PC bilayers and the different rate of hydrogen abstraction by free radicals from intermolecular and intramolecular acyl groups.

Arachidonic Acid↗
PubMed2005

Detection and determination of chemical groups in an extract of Allophylus cominia (L.).

The preliminary chemical characterization of the aqueous extract of Allophylus cominia (L.) Sw leaves was carried out by a phytochemical screening, the determination of the protein concentration by Lowry's method, as well as the composition of fatty acids and carbohydrates by gaseous chromatography (GC). The presence of the free amine groups, free phenolics, tannins, leucoantocianidines, saponines, triterpens, and steroids was detected. The concentration of proteins were 6.22 mg/mL. The composition of fatty acids (%) were: lauric acid (C12): 1.87; miristic acid (C14): 9.13; palmitic acid (C16): 19.87; stearic acid (C18): 8.35; and araquidic acid (C20): 7.83. The identified carbohydrates (mg/mg totals) were: arabinose: 0.06; xilose: 0.025; galactose: 0.241; and glucose: 1.2. Some members of these analyzed groups are reported in literature as potent hypoglycemic agents. For this reason, the presence of these substances in the analyzed extract may be one of the factors that contribute to the pharmacological effect of their administration in experimental diabetic models.

Humans↗
PubMed2006

Production of biodiesel by immobilized Candida sp. lipase at high water content.

A new process for enzymatic synthesis of biodiesel at high water content (10-20%) with 96% conversion by lipase from Candida sp. 99-125 was studied. The lipase, a no-position-specific lipase, was immobilized by a cheap cotton membrane and the membrane-immobilized lipase could be used at least six times with high conversion. The immobilized lipase could be used for different oil conversion and preferred unsaturated fatty acids such as oleic acid to saturated fatty acids such as palmitic acid. The changes in concentration of fatty acids, diglycerides, and methyl esters in the reaction were studied and a mechanism of synthesis of biodiesel was suggested: the triglycerides are first enzymatically hydrolyzed into fatty acids, and then these fatty acids are further converted into methyl esters.

Alkanes↗
PubMed1988

Inhibitory effect of fatty acids on the binding of androgen receptor and R1881.

Unsaturated long chain fatty acids are known to inhibit the binding between estrogen and estrogen receptor, or progesterone and progesterone receptor in rat uterus. The effects of long chain fatty acids on the binding between androgen receptor of castrated rat prostate and 3H-R1881 were studied. The binding was not affected by saturated fatty acids such as palmitic acid (16:0) or stearic acid (18:0). But unsaturated fatty acids such as oleic acid (18:1), arachidonic acid (20:4) and docosahexaenoic acid (22:6) inhibited the binding between androgen receptor and 3H-R1881. The inhibitory effect of arachidonic acid was dose dependent. Scatchard analysis showed that the addition of arachidonic acid markedly decrease the number of binding sites of androgen receptor. But the dissociation constant was not affected. The inhibitory effect of arachidonic was not a competitive one.

Animals↗
PubMedDate not supplied

Chemical composition of the fixed and volatile oils of Nigella sativa L. from Iran.

The chemical composition of the extracted fixed oil (total fatty acid composition) and volatile oil of Nigella sativa L. seeds grown in Iran were determined by GC and GC/MS. Eight fatty acids (99.5%) and thirty-two compounds (86.7%) have been identified in the fixed and volatile oils, respectively. The main fatty acids of the fixed oil were linoleic acid (55.6%), oleic acid (23.4%), and palmitic acid (12.5%). The major compounds of the volatile oil were trans-anethole (38.3%), p-cymene (14.8%), limonene (4.3%), and carvone (4.0%).

Cyclohexane Monoterpenes↗
PubMed1997

Thiazolidinediones downregulate stearoyl-CoA desaturase 1 gene expression in 3T3-L1 adipocytes.

Thiazolidinediones (TZDs) are known to have potent increases of insulin sensitivity. Because peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a receptor for TZDs, is mainly expressed in adipocytes, we tried to search the TZD-targeted genes in mouse 3T3-L1 adipocytes. By the mRNA differential display method, one band repressed by troglitazone was obtained, which corresponded to the partial sequences of the stearoyl-CoA desaturase 1 (SCD1) gene. Troglitazone dramatically decreased SCD1 mRNA levels in 3T3-L1 adipocytes in a dose-dependent manner. Pioglitazone also repressed the SCD1 mRNA expression, whereas WY-14,643 had no apparent effect. Both troglitazone and pioglitazone raised the composition (weight percentage) of myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), but lowered the composition of the delta9-cis desaturated fatty acids such as myristoleic acid (C14:1, delta9), palmitoleic acid (C16:1, delta9), oleic acid (C18:1, delta9), and linoleic acid (C18:2, delta9,12). These results indicate that TZDs repress SCD1 activity in 3T3-L1 adipocytes via downregulating SCD1 enzyme gene expression.

3T3 Cells↗
PubMed1982

Lamellar bodies isolated from adult human lung tissue.

Lamellar bodies, the intracellular storage form of pulmonary surfactant, were isolated from adult human lung tissue. As shown by electron microscopy, the isolated human lamellar bodies resembled the lamellar bodies isolated from experimental animals. Chemical analysis revealed that the lamellar bodies consisted largely of lipids, particularly phospholipids (85%). The major phospholipid was phosphatidylcholine, which accounted for 71% of the total phospholipids. Phosphatidylglycerol and phosphatidylethanolamine were 10 and 8%, respectively, of the lamellar body phospholipid. Phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, and sphingomyelin were minor components. Cholesterol was found to represent 60% of the neutral lipids or 9% of the total lipids. Phosphatidylcholine contained largely saturated fatty acids, of which palmitic acid was the most abundant. Disaturated phosphatidylcholines comprised 67% of the total phosphatidylcholines. Phosphatidylglycerol and phosphatidylethanolamine contained considerably less saturated fatty acids. Only 24% of phosphatidylglycerol was disaturated. The chemical composition of adult human lamellar bodies was very similar to that of lamellar bodies derived from experimental animals. The similarities in morphology and chemical composition of lamellar bodies suggest that surfactant metabolism in human lung may be similar to that of other mammals.

Aged↗
PubMed2005

Dietary conjugated linoleic acid reduces lipid peroxidation by increasing oxidative stability in rats.

The antioxidative effect of conjugated linoleic acid (CLA) was examined by determining lipid peroxidation and antioxidative enzyme activities. Male Sprague-Dawley rats were fed one of the experimental diets-normal diet, vitamin E-deficient control diet, 0.5% CLA vitamin E-deficient diet, or 1.5% CLA vitamin E-deficient diet for 5 wk. Hepatic thiobarbituric acid reactive substances (TBARS) were increased in the vitamin E-deficient control group, but they were was significantly lowered in the CLA groups. Similarly, hepatic glutathione peroxidase activity was increased in the vitamin E-deficient diet and reduced by CLA supplementation. In addition, CLA caused a significant decrease in superoxide dismutase activity while having no effect on catalase activity. Analyses of the fatty acid composition revealed that dietary CLA was incorporated into hepatic microsomal membrane dose-dependently. Compared to the vitamin E-deficient control, CLA resulted in significantly higher saturated and monounsaturated fatty acids (palmitic and oleic acids) while lowering levels of oxidation-susceptible polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acids) in both plasma and hepatic membrane. The concentrations of plasma cholesterol and triacylglycerol (TG) were lower in the 1.5% CLA group than in other groups. These results suggest that dietary CLA has antiatherosclerotic and antioxidant activity by increasing oxidative stability in plasma and hepatic membrane in the vitamin E-deficient rats.

Alanine Transaminase↗
PubMed1982

The effects of endogenous energy, type of diet, and addition of bile salts on true metabolizable energy values in young chicks.

A trial was carried out using 3-week-old chickens of a commercial breed to study the effects of either a fat-free diet or a diet containing 150 g/kg of animal fat on the endogenous energy losses measured with starved birds. The effects of the addition of different levels of bile salts to such diets and the accuracy of true metabolizable energy (TME) with respect to the other modes of expression of metabolizable energy were also examined. The excreted endogenous energy values were shown to vary not only according to the type of diet (P less than .01) but also in relation to the dietary intake level (P less than .01). Because it is directly related to endogenous energy, TME proved to be an inaccurate parameter in young chicks unless values were corrected for N-balance. If the values of both apparent metabolizable energy (AME) and TME are corrected for N-balance, they are normally comparable and independent of the dietary intake level if the diet contains virtually no added fat. These findings indicate that most of the endogenous excreta are composed of nitrogenous metabolites. However, neither AME nor TME values of fat-rich diets are independent of dietary intake. The addition of bile salts had no effect on the metabolizable energy values of the fat-free diet. However, in the case of the diet rich in saturated fats, they compensated either for insufficient bile secretion or for endogenous bile salts degraded by the intestinal microflora. Thus, the digestive utilization of dietary fat, especially that of the saturated fatty acids, palmitic and stearic acids, was increased. In addition, metabolizable energy was significantly improved (P less than .01) by the addition of bile salts when the dietary intake level increased to the ad libitum level.

Animals↗
PubMed2000

Long-chain fatty acid-induced changes in gene expression in neonatal cardiac myocytes.

Long-chain fatty acids are the most important substrates for the heart. In addition, they have been shown to affect signalling pathways and gene expression. To explore the effects of long-chain fatty acids on cardiac gene expression, neonatal rat ventricular myocytes were cultured for 48 h with either glucose (10 mm), fatty acids (palmitic and oleic acid, 0.25 mm each), or a combination of both as exogenous substrates. Exposure to fatty acids (both in the absence or presence of glucose) neither affected cellular morphology and protein content nor induced alterations in the expression of phenotypic marker genes like atrial natriuretic factor and the Ca-ATPase SERCA2. However, incubation with fatty acids (with or without glucose) resulted in up to 4-fold increases of the mRNA levels of fatty acid translocase (FAT/CD36), heart-type fatty acid-binding protein, acyl-CoA synthetase, and long-chain acyl-CoA dehydrogenase. In contrast, the expression of genes coding for proteins involved in glucose uptake and metabolism, i.e., glucose transporter GLUT4, hexokinase II, and glyceraldehyde 3-phosphate dehydrogenase, remained constant or even declined under these conditions. These changes corresponded with a 60% increase in cardiomyocyte fatty acid oxidation capacity. Interestingly, the peroxisome proliferator-activated receptor-alpha (PPARalpha)-ligand Wy 14,643, but not the PPARgamma-ligand ciglitazone, also resulted in increased mRNA levels of genes involved in fatty acid metabolism. In conclusion, fatty acids specifically and co-ordinately up-regulate transcription of genes coding for proteins involved in cardiac fatty acid transport and metabolism, most likely through activation of PPARalpha.

Animals↗
PubMedDate not supplied

Permeation kinetics of ketotifen fumarate alone and in combination with hydrophobic permeation enhancers through human cadaver epidermis.

Permeation kinetics for ketotifen fumarate from transdermal system through hairless mice skin and hog skin have been reported. However, permeation of ketotifen fumarate through human skin is not available till date. In view of the above, permeation profile and related kinetic parameters of ketotifen fumarate alone and in presence of three compatible enhancers namely Myristic acid isopropyl ester, Palmitic acid propyl ester and Lauric acid propyl ester through normal and delipidized human cadaver have been reported in the present study. The observed permeability flux, permeation coefficient and epidermal partition coefficient through 50% dried human cadaver epidermis were found to increase in presence of the three enhancers, amongst which the effect was found to be maximum with Myristic acid isopropyl ester. The more pronounced enhancing effect of Myristic acid isopropyl ester regarding permeability flux, permeation coefficient, epidermal partition coefficient and diffusion coefficient was attributed with solubility parameter being nearer to the skin lipid solubility parameter and probably due to its passage across the skin barrier through the lipid pathway.

Administration, Topical↗
PubMed2001

A novel phospholipase D of Arabidopsis that is activated by oleic acid and associated with the plasma membrane.

Oleate-dependent phospholipase D (PLD; EC 3.1.4.4) has been reported in animal systems, but its molecular nature is unkown. Multiple PLDs have been characterized in plants, but none of the previously cloned PLDs exhibits the oleate-activated activity. Here, we describe the biochemical and molecular identification and characterization of an oleate-activated PLD in Arabidopsis. This PLD, designated PLDdelta, was associated tightly with the plasma membrane, and its level of expression was higher in old leaves, stems, flowers, and roots than in young leaves and siliques. A cDNA encoding the oleate-activated PLD was identified, and catalytically active PLDdelta was expressed from its cDNA in Escherichia coli. PLDdelta was activated by free oleic acid in a dose-dependent manner, with the optimal concentration being 0.5 mM. Other unsaturated fatty acids, linoleic and linolenic acids, were less effective than oleic acid, whereas the saturated fatty acids, stearic and palmitic acids, were totally ineffective. Phosphatidylinositol 4,5-bisphosphate stimulated PLDdelta to a lesser extent than oleate. Mutation at arginine (Arg)-611 led to a differential loss of the phosphatidylinositol 4,5-bisphosphate-stimulated activity of PLDdelta, indicating that separate sites mediate the oleate regulation of PLDdelta. Oleate stimulated PLDdelta's binding to phosphatidylcholine. Mutation at Arg-399 resulted in a decrease in oleate binding by PLDdelta and a loss of PLDdelta activity. However, this mutation bound similar levels of phosphatidylcholine as wild type, suggesting that Arg-399 is not required for PC binding. These results provide the molecular information on oleate-activated PLD and also suggest a mechanism for the oleate stimulation of this enzyme.

Amino Acid Sequence↗
PubMed2001

Glucose suppresses the enhancement by free fatty acids on thrombin- stimulated production of prostacyclin in cultured aortic endothelial cells.

BACKGROUND: Prostacyclin (PGI2) is a potent vasodilator and inhibitor of platelet aggregation. It may reduce in diabetic patients to contribute to the platelet hyperaggregability and acceleration of atherosclerosis. While the major clinical manifestation of diabetes mellitus is increased blood levels of glucose, elevation of free fatty acids (FFA) levels in the circulation has also been reported. METHODS: Cultured rat aortic endothelial cells were treated with media containing high concentration of FFA (oleic acid 0.5 mM, palmitic acid 0.25 mM, linoleic acid 0.25 mM, stearic acid 0.06 mM, arachidonic acid 0.04 mM, total 1.1 mM, and the molar ratio of FFA/albumin < 2), glucose (22 mM) or both. Then the PGI2 release was studied by measuring 6-keto-PGF1alpha in the media. RESULTS: We found that high concentration of FFA increased the PGI2 production at basal (1.227 +/- 0.031 vs 0.762 +/- 0.028 ng/mg protein, n = 6, p = 0.002) and when stimulated by 0.5 unit/ml of thrombin (2.708 +/- 0.115 vs 1.337 +/- 0.225 ng/mg protein, n = 6, p = 0.002). Two-day treatment with high-glucose did not affect PGI2 production. However, in the presence of high-glucose, the enhancement by high FFA of thrombin stimulated PGI2 production disappeared (high-glucose 1.461 +/- 0.312 ng/mg, normal-glucose 2.708 +/- 0.115 ng/mg, n = 6, p = 0.002). CONCLUSIONS: The interaction between glucose and FFA can reduce PGI2 production in thrombin-stimulated state. Our findings further support their role in the pathogenesis of platelet hyperaggregability and acceleration of atherosclerosis in diabetes.

Animals↗
PubMed2002

[The ratio of components of sphingomyelin cycle and lipid composition in patients with viral hepatitis].

The aim of the study is the investigation of the content of the lipids and the sphingomyelin cycle components in the liver of the patients suffered from viral hepatitis. The methods used were thin layer chromatography for the detection of the lipid pattern and gas liquid chromatography for evaluation of the sphingomyelin fatty acid's and spectrum and ceramides. In the patients suffered from viral hepatitis HCV with moderate activity of the process cholesterin and triglycerides level were less and lysophospholipids content was two-fold and sphingomyelin level was insignificantly higher comparingly than in patients with low activity of the process. In the group of patients suffered from mixt infection (HCV + HBV) there is decreased cholesterin and both phosphatidylcholin and the sphingomyelin content along with lysophospholipids level elevation. In the fatty acid spectrum the palmitate acid (16:0) and the long chain acids (C22-C24) content were higher comparingly with ceramides. Significant difference is observed in oleic acid (18:1) content being as small as 9.3-9.9% in the liver damaged by viral hepatitis.

Adult↗
PubMed2001

[Effect of various substrate nutrient on the spore germination and infective germ tube inducing of Pandora delphacis].

The influence of nutrients on spore germmination of P. delphacis was investigated using amino acids, fatty acids, carbohydrates, vitamins, minerals, and extracts of aphids or planthoppers. It was found that the formation of germ tubes from primary conidia was significantly stimulated by cysteine, asparagine, behenic acid (C22:0), trehalose, fructose, glycerol, maltose, ascorbic acid, thiamine(VB1), Folic acid, ZnSO4, FeSO4 and extracts of aphids and planthoppers. Of these many could suppress the formation of secondary conidia from primary conidia, e.g., cysteine, behenic acid (C22:0), myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), arachidic acid (C20:0), lignoceric acid (C24:0), ascorbic acid, thiamine (VB1), riboflavin (VB2), folic acid, nicotinic acid, ZnSO4, and FeSO4. However, the nutrients not conducive to the formation of germ tubes were stimulants to the formation of secondary conidia. These included tyrosine, alanine, glucose, galactose, sucrose, glycogen, inositol, pyridoxal (VB6), NaCl, and KCl. Moreover, nutrients including asparagine, trehalose, glycerol, maltose, fructose, thiamine (VB1), and folic acid stimulated the formation of both germ tubes and secondary conidia. The result above indicated that the substrate nutrients which can stimulate the formation of germ tubes were general in planthoppers and aphids, it means the formation of aggressive germ tubes was one of important factors of successful for infection to the hosts. Of which it confirmed that the host specificity for P. delphacis against N. lungus and M. persicae.

Amino Acids↗
PubMed1997

[Supercritical-CO2 fluid extraction of the fatty oil in Terminalia chebula and GC-MS analysis].

The fatty oils in Terminulia chebula were extracted by supercritical-CO2 fluid extraetion, and their fatty acids and its relative contents were determined by GC-MS. 12 fatty acids were identified. Palmitic acid, linoleic acid and oleic acid of them are main constituents. Compared with petroleum ether extraction method, the extraction rate from SFE-CO2 is higher and extraction time shorter.

Carbon Dioxide↗

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