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PubMed1991

Production of the polyunsaturated fatty acids arachidonic acid and eicosapentaenoic acid by the fungus Pythium ultimum.

Several strains of species of the fungal genus Pythium, and of Phytophthora cinnamomi, were screened for content of the polyunsaturated fatty acids (PUFAs) arachidonic acid (AA) and eicosapentaenoic acid (EPA). The aim of the investigation was to establish alternative sources of these PUFAs, which are of importance in human nutrition. As a relatively prolific producer of EPA and AA, P. ultimum strain #144 was selected for a study of conditions that enhance their production over baseline levels that are present in the fungus when cultured for 6 d at 25 degrees C with rotary shaking (120 r.p.m.) in Vogel's medium containing sucrose as the carbon substrate. The levels of AA and EPA under these conditions were 133 +/- 27 and 138 +/- 25 mg l-1 (n = 5), respectively. Maximal production of these fatty acids was accomplished by the following sequence of steps. (1) Incubate the cultures for 6 d after inoculation under the conditions described above. Then (2) add glucose to the cultures (2%, w/v, final concentration) and incubate for a further 6 d at 13 degrees C. Under these conditions, the AA content of the mycelium was 205% higher than baseline levels and the EPA content was 198% higher. (3) Allow the cultures to remain stationary for 10 d which increases the AA content to 253% above baseline levels and the EPA content by 236%. Using such a procedure, 322 mg AA l-1 and 383 mg EPA 1-1 were produced.

Arachidonic Acid↗
PubMedDate not supplied

Pharmacokinetics and pharmacodynamics of valproate analogues in rats. IV. Anticonvulsant action and neurotoxicity of octanoic acid, cyclohexanecarboxylic acid, and 1-methyl-1-cyclohexanecarboxylic acid.

We examined the pharmacodynamics of valproate (VPA) and three structural analogues, octanoic acid (OA), cyclohexanecarboxylic acid (CCA), and 1-methyl-1-cyclohexanecarboxylic acid (MCCA) in rats. A pentylenetetrazol (PTZ) infusion seizure model was used to determine threshold convulsive doses of PTZ; the increase in PTZ threshold dose after administration of test compound was taken as an index of anticonvulsant activity. Each of the compounds investigated antagonized PTZ-induced seizures, with MCCA evidencing the highest potency. Both CCA and MCCA appeared to have an approximate twofold advantage relative to VPA in protective index (i.e., the ratio of concentrations that produce toxicity to concentrations that produce anticonvulsant effect), based on a rotorod assay of neurotoxicity. Examination of the time course of PTZ antagonism indicated that there was significant dissociation between pharmacokinetics and pharmacodynamics of VPA, with a marked delay in production of maximal anticonvulsant activity. In contrast, only a slight delay in production of maximal protection against PTZ-induced seizures was observed for MCCA, and no delay was evident for CCA. The data indicate that the dynamics of anticonvulsant action differ between these low-molecular-weight carboxylic acids despite their similar chemical structures.

Animals↗
PubMed2002

Glucuronidation of the dietary fatty acids, phytanic acid and docosahexaenoic acid, by human UDP-glucuronosyltransferases.

Linoleic acid has recently been shown to be glucuronidated in vitro by human liver and intestinal microsomes and recombinant UGT2B7. In the present study, the dietary fatty acids (FA), phytanic acid (PA), and docosahexaenoic acid (DHA) have been used as substrates for human UDP-glucuronosyltransferases (UGTs). Both compounds were effectively glucuronidated by human liver microsomes (HLM; 1.25 +/- 0.36 and 1.12 +/- 0.32 nmol/mg x min for PA and DHA, respectively) and UGT2B7 (0.71 and 0.53 nmol/mg x min). Kinetic analysis produced relatively low K(m) values for PA with both HLM and UGT2B7 (149 and 108 microM, respectively). The K(m) for DHA glucuronidation by HLM (460 microM) was considerably higher than that for UGT2B7 (168 microM), suggesting the involvement in microsomes of other UGT isoforms in addition to UGT2B7. Glucuronidation of PA and DHA by gastrointestinal microsomes from 16 human subjects was determined. In general, both PA and DHA were glucuronidated by gastric and intestinal microsomes, and activity toward both substrates was lowest in the stomach, increased in the small intestine, and lower in the colon. However, there were large interindividual variations in UGT activity toward both substrates in all segments of the intestine, as has been seen with other substrates. Thus, PA and DHA are effective in vitro substrates for human liver, gastric and intestinal microsomes, and glucuronidation may play a role in modulating the availability of these FA as ligands for nuclear receptors.

Docosahexaenoic Acids↗
PubMed2006

Antitumor activity of the retinoid-related molecules (E)-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid (ST1926) and 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) in F9 teratocarcinoma: Role of retinoic acid receptor gamma and retinoid-independent pathways.

The retinoid-related molecules (RRMs) ST1926 [(E)-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid] and CD437 (6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid) are promising anticancer agents. We compared the retinoic acid receptor (RAR) trans-activating properties of the two RRMs and all-trans-retinoic acid (ATRA). ST1926 and CD437 are better RARgamma agonists than ATRA. We used three teratocarcinoma cell lines to evaluate the significance of RARgamma in the activity of RRMs: F9-wild type (WT); F9gamma-/-, lacking the RARgamma gene; F9gamma51, aF9gamma-/-derivative, complemented for the RARgamma deficit. Similar to ATRA, ST1926 and CD437 activate cytodifferentiation only in F9-WT cells. Unlike ATRA, ST1926 and CD437 arrest cells in the G2/M phase of the cell cycle and induce apoptosis in all F9 cell lines. Our data indicate that RARgamma and the classic retinoid pathway are not relevant for the antiproliferative and apoptotic activities of RRMs in vitro. Increases in cytosolic calcium are fundamental for apoptosis, in that intracellular calcium chelators abrogate the process. Comparison of the gene expression profiles associated with ST1926 and ATRA in F9-WT and F9gamma-/-indicates that the RRM activates a conspicuous nonretinoid response in addition to the classic and RAR-dependent pathway. The pattern of genes regulated by ST1926 selectively, in a RARgamma-independent manner, provides novel insights into the possible molecular determinants underlying the activity of RRMs in vitro. Furthermore, it suggests that RARgamma-dependent responses are relevant to the activity of RRMs in vivo. Indeed, the receptor hinders the antitumor activity in vivo, in that both syngeneic and immunosuppressed SCID mice bearing F9gamma-/- tumors have increased life spans after treatment with ST1926 and CD437 relative to their F9-WT counterparts.

Adamantane↗
PubMed1977

Pulmonary fatty acid synthesis. II. Amino acids as fatty acid precursors in rat lung.

The incorporation of various 14C-labeled amino acids into CO2 and lipids by rat lung slices was examined. Alanine, valine, leucine, isoleucine, aspartate, and glutamate were oxidized by lung tissue, whereas glycine and phenylalanine were not oxidized. Carbon originating from alanine, leucine, and glutamate was incorporated into pulmonary fatty acids by a mechanism indicative of de novo synthesis. Experiments with specifically labeled [14C]aspartate and [14C]glutamate revealed that the complete citrate-malate cycle described by Patel et al. (25) is of minor importance in pulmonary lipogenesis due to the extremely low activity of NADP-malate dehydrogenase. Glucose and pyruvate were also actively incorporated into fatty acids, and it is suggested that citrate in pulmonary tissue, as in other tissues, plays an important role in the transport of acetyl units from the mitochondria to the cell cytosol during lipogenesis from various carbohydrate and amino acid substrates.

ATP Citrate (pro-S)-Lyase↗
PubMed1980

Concomitant increases in serum growth hormone and hypothalamic somatostatin in rats after injection of gamma-aminobutyric acid, aminooxyacetic acid, or gamma-hydroxybutyric acid.

gamma-Aminobutyric acid (GABA; 50 or 500 microgram/10 microliter) was injected into the right lateral ventricle of urethane- or pentobarbital-anesthetized male rats. The animals were decapitated 15 min after injection. Serum GH and hypothalamic somatostatin (SRIF) concentration were measured by specific RIAs. Intraventricular GABA caused a dose-related increase in GH and SRIF. In another study, aminooxyacetic acid (5 or 20 mg) was injected ip into urethane-anesthetized rats. Aminooxyacetic acid at 20 mg produced a significant increase in both serum GH and hypothalamic SRIF. Furthermore, 12.5 mg gamma-hydroxybutyric acid (GHB) injected ip into urethane- or pentobarbital-anesthetized rats elicited a significant increase in both serum GH and hypothalamic SRIF. Pretreatment with 20 mg L-dopa produced decreases in the GHB-induced serum GH increase and in hypothalamic SRIF in pentobarbital-anesthetized rats. These results show that GABA and GHB stimulated GH secretion, which was accompanied by increased hypothalamic SRIF. Thus, the GH release induced by GABA or GHB may be partly involved in inhibiting the release of hypothalamic SRIF. As the GHB-induced GH release was inhibited by L-dopa, the stimulatory effect of GHB on GH secretion might be mediated by inhibition of the dopaminergic mechanism.

Acetates↗
PubMed2006

Simultaneous determination of protocatechuic acid, syringin, chlorogenic acid, caffeic acid, liriodendrin and isofraxidin in Acanthopanax senticosus Harms by HPLC-DAD.

A high performance liquid chromatography (HPLC) method was developed for the first time to quantify simultaneously the six major active ingredients in Acanthopanax senticosus (Rupr. et Maxim.) Harms, namely protocatechuic acid, syringin, chlorogenic acid, caffeic acid, liriodendrin and isofraxidin. The analysis was performed by a reverse phase gradient elution with an aqueous mobile phase (containing 0.05% phosphoric acid) modified by acetonitrile and diode-array multiple-wavelength UV detector (DAD). Six regression equations showed good linear relationships between the peak area of each marker and concentration. The recoveries of the markers listed above were 92.3%, 93.9%, 90.3%, 93.1%, 94.3% and 90.7%, respectively. The relative standard deviation of intra-day and inter-day were less than 2.7% and 3.1%, respectively. This method was validated for specificity, accuracy, precision and limits of quantification. Medicinal materials of ten commercial brands were analyzed and found to contain different amounts of the six bioactive markers. The method developed can be used for the quality control of Acanthopanax senticosus (Rupr. et Maxim.) Harms.

Caffeic Acids↗
PubMed2002

Bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids, as an ascorbic acid supplement in rats and guinea pigs.

The bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G), as an ascorbic acid (AA) supplement was investigated in rats and guinea pigs. Oral administration of 6-Acyl-AA-2G to rats resulted in an increase in the plasma AA level. However, the intact form was not detectable in the plasma by high-performance liquid chromatography, indicating its hydrolysis through the process of absorption. After an intravenous injection to rats of 6-Octa-AA-2G as a representative derivative, the intact form rapidly disappeared from the plasma, being followed by a prolonged and marked elevation of the plasma AA level. Various tissue homogenates from guinea pigs were examined for their releasing activity of AA, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and 6-O-acyl-AA from 6-Acyl-AA-2G. High activity was observed in the small intestine. These hydrolytic activities to AA and 6-O-acyl-AA were completely inhibited by castanospermine, an alpha-glucosidase inhibitor, and AA-2G was observed as the only resulting hydrolysate, suggesting the participation of alpha-glucosidase and esterase in the in vivo hydrolysis of 6-Acyl-AA-2G. 6-Octa-AA-2G was found to exhibit an obvious therapeutic effect in scorbutic guinea pigs from its repeated oral administration. These results indicate that 6-Acyl-AA-2G is a readily available source of AA activity in vivo, and may be useful as an effective pharmacological agent and as a promising food additive.

Animals↗
PubMed1996

[Interrelationship of reflux bile acid concentration and the gastric mucosal change with reference to the pathophysiologic significance of taurine conjugated deoxycholic acid and chenodeoxycholic acid].

Since chronic gastritis is adversely affected by reflux bile acids, we are interested in which of these bile acids cause the most damage to the gastric mucosa as ulcerogenic factors in the stomach. We examined 34 patients suffering from the peptic ulcers, and have assumed that taurine conjugated deoxycholic acid (TDC) and chenodeoxycholic acid (TCDC) may act as the mst ulcerogenic factors. Moreover TCDC was suggested to be associated with the cystic dilatation of the gastric gland. It was also suggested that TDC is involved in the increased frequency of intestinal metaplasia as a factor backgrounding cancer.

Adult↗
PubMedDate not supplied

Induction of hydroxycinnamic acid amides and tryptophan by jasmonic acid, abscisic acid and osmotic stress in barley leaves.

The effects of jasmonic acid (JA) and abscisic aid (ABA) on secondary metabolism in barley (Hordeum vulgare L.) were investigated. Treatment with JA at 100 microM for 48 h induced accumulation of four compounds in barley primary leaves. The accumulation of these compounds was also observed after treatment with ABA at 100 microM. The induced compounds were identified as p-coumaroylputrescine, p-coumaroylagmatine, p-coumaroyl-3-hydroxyagmatine and tryptophan by spectroscopic methods. The profiles of compounds induced by application of JA and ABA were different. JA exhibited stronger inducing activity for hydroxycinnamic acid amides than ABA, while ABA was more active in tryptophan accumulation. The major hydroxycinnamic acid amides in JA- and ABA-treated leaves were p-coumaroylagmatine and p-coumaroyl-3-hydroxyagmatine, respectively. These differences suggested that JA and ABA act in distinct modes. The induction of these compounds was also observed in leaf segments treated with 1 M sorbitol and glucose. These findings suggested that JA and ABA are involved in accumulation of hydroxycinnamic acid amides and tryptophan in response to osmotic stress in barley.

Abscisic Acid↗
PubMed1986

Effects of cholic acid, 7 beta-hydroxy- and 12 beta-hydroxy-isocholic acid on bile flow, lipid secretion and bile acid synthesis in the rat.

The effects of three epimeric trihydroxy-cholanoic acids, cholic acid (C), 7 beta-hydroxy-(7 beta) and 12 beta-hydroxy-(12 beta) isocholic acids on bile flow, lipid secretion, bile synthesis and bile micellar properties were studied in the rat with a bile fistula. The bile salts were infused intraduodenally starting 72 hours after cannulation when endogeneous bile salt synthesis had plateaued after the bile salt pool was drained. The bile salts were infused at two levels approximately 2 and 4 mumol min-1 kg-1. All three bile salts were absorbed and secreted almost quantitatively into the bile. Cholic acid was secreted in the conjugated form, 7 beta conjugated to approximately 60% and 12 beta completely in the unconjugated form. The bile salts did not undergo any significant biotransformations during the one passage from the intestine through the liver. Bile flow increased from the preinfusion level for all three bile salts infused in the order 7 beta greater than 12 beta greater than C. The bile flow increased linearly with bile salt secretion more for 7 beta than for C and 12 beta. Infusion of C increased the secretion into bile of phospholipid (PL) and cholesterol (CH) over the preinfusion values. Infusion of 7 beta as well as 12 beta resulted in a parallel decrease in the secretion of PL as well as CH compared to the preinfusion values. The infusion of C and 7 beta at the two levels used decreased the secretion of newly synthesized bile salt below the control level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2001

Caffeic acid, chlorogenic acid, and dihydrocaffeic acid metabolism: glutathione conjugate formation.

The antioxidant properties of the dietary dihydroxycinnamic acids [caffeic (CA), dihydrocaffeic (DHCA), and chlorogenic (CGA) acids] have been well studied but little is known about their metabolism. In this article, evidence is presented showing that CA, DHCA, and CGA form quinoids and hydroxylated products when oxidized by peroxidase/H(2)O(2) or tyrosinase/O(2). Mass spectrometry analyses of the metabolites formed with peroxidase/H(2)O(2)/glutathione (GSH) revealed that mono- and bi-glutathione conjugates were formed for all three compounds except CGA, which formed a bi-glutathione conjugate only when GSH was present. In contrast, the metabolism of the dihydroxycinnamic acids by tyrosinase/O(2)/GSH resulted in the formation of only mono-glutathione conjugates. In the absence of GSH, hydroxylated products and p-quinones of CA or CGA were formed by peroxidase/H(2)O(2). DHCA formed a hydroxylated adduct (even though GSH was present), as well as the corresponding p-quinone and dihydroesculetin, an intramolecular cyclization product. NADPH also supported rat liver microsomal-catalyzed CA-, CGA-, and DHCA-glutathione conjugate formation, which was prevented by benzylimidazole, a cytochrome P450 inhibitor. Furthermore, the cytotoxicity of CA, CGA, and DHCA toward isolated rat hepatocytes was markedly enhanced by hydrogen peroxide or cumene hydroperoxide-supported cytochrome P450 and was prevented by benzylimidazole. Cytotoxicity was also markedly enhanced by dicumarol, an NADPH/oxidoreductase inhibitor. These results suggest that dihydroxycinnamic acids were metabolically activated by P450 peroxidase activity to form cytotoxic quinoid metabolites.

Animals↗
PubMed1976

Bile acids. XLIX. Allocholic acid, the major bile acid of Uromastix hardwickii.

Tauroallocholate is the major bile salt of the lizard, Uromastix hardwickii. Alkaline hydrolysis of bile from 25 gallbladders provided 1.21 g of acidic material, about 90% of which was allocholic acid. Analyses by gas-liquid chromatography, and mass spectrometry verified the presence of almost 10% of deoxycholic acid and smaller amounts of other 5alpha and 5beta-bile acids.

Animals↗
PubMed2003

Physiologic melatonin concentration, omega-3 fatty acids, and conjugated linoleic acid inhibit fatty acid transport in rodent hind limb skeletal muscle in vivo.

Melatonin (MLT), the circadian neurohormone secreted by the pineal gland in mammals during darkness, eicosapentanoic acid (EPA), and conjugated linoleic acid (CLA) have established regulatory roles in cancer growth. Investigations in our laboratory have indicated that these agents inhibit fatty acid (FA) transport by tumors and several sub-types of white adipose tissue via inhibitory G protein-coupled receptor mechanisms. Skeletal muscle constitutes over 45% of human body mass and plays an important role in cancer cachexia and obesity-related diseases. Since fatty acid oxidation is a major source of energy for this tissue, we tested the hypothesis that physiologic MLT levels, EPA, or CLA injected intravenously, inhibit FA uptake in rat skeletal muscle in vivo. We used a surgical technique for catheterizing the femoral vein in rats that allows rapid blood collection from the entire hind limb, while ensuring continuous blood flow to the tissue. Blood acid/gas tensions and hematocrit were monitored and remained constant during the course of each experiment. The MLT, EPA, and CLA inhibited FA uptake by the tissue and lowered cAMP values. Glucose uptake and glycerol production in the hind limb were not affected. These investigations suggest a novel role for MLT, omega-3 FAs, and CLA in the regulation of FA transport and fat metabolism in skeletal muscle.

Animals↗
PubMed1989

[Nature, origin and role of fatty acids of the nervous system: an essential fatty acid, an alpha-linolenic acid, changing the structure and the cerebral function].

Saturated and monounsaturated fatty acids are synthetized in cytosol, endoplasmic reticulum and mitochondria. Their mechanisms of synthesis and fate are different according to the organelle. For some of them, a nutritional origin is not excluded. Minimum dietary linoleic and alpha-linolenic acid to ensure normal brain structure and function are respectively 2.4% and 0.4% of the calories. Alpha-linolenic acid deficiency alters membrane composition and fluidity, changes the fluidizing effect of ethanol, reduces some enzymatic activities (ATP ase, 5' nucleotidase), diminishes the efficiency of the blood-brain barrier, affects electroretinogram, reduces learning capacities and makes the animals more fragile in the presence of neurotoxins. Very long polyunsaturated chains, which could be the essential fatty acids for the brain, must be considered at the level of nutrition, pharmacology and toxicology (alteration of structures and peroxidations).

Animals↗
PubMedDate not supplied

The effect of amino acid derivative of clofibric acid (WKLB-5), and theophylline monoester of nicotinic acid (ME1) on the development of experimental atherosclerosis in rabbits.

In order to determine the efficacy of new compounds--an amino acid derivative of clofibric acid (WKLB-5), and a theophylline monoester of nicotinic acid (ME1)--a high fat diet (HFD) was applied to rabbits for 3 months, with or without the above mentioned compounds. The HFO included coconut oil, cholesterol and cholic acid. A substantial hypolipemic activity of those compounds was demonstrated; however, the studied lipid fractions did not undergo normalization, except FFA whose level after ME1 administration was distinctly lower than in control animals. Sudanophilic changes were found on 83% of surface of the interior membrane of aorta in rabbits kept on the HFD only, on 35% of surface--in rabbits treated with the HFD + WKLB-5, and on 75% of surface--in rabbits treated with the HFD + ME1. Thus in those animals no parallelism between the hypolipemic and antiatherosclerotic activities was observed.

Animals↗
PubMed1986

Sensitive determination of tyrosine metabolites, p-hydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenyl-acetic acid and 4-hydroxy-3-methoxymandelic acid, by gas chromatography-negative-ion chemical-ionization mass spectrometry. Application to a stable isotope-labelled tracer experiment to investigate their metabolism in man.

A method has been established for studying the dynamic metabolism of tyrosine to its metabolites in humans using a deuterium-labelled amino acid. Phenylalanine-d5 was administered orally to human subjects (5 mg/kg) and the levels of p-hydroxyphenylacetic acid-d4, 4-hydroxy-3-methoxyphenylacetic acid-d3, and 4-hydroxy-3-methoxymandelic acid-d3 excreted into urine every hour were determined by gas chromatography-negative-ion chemical-ionization mass spectrometry. This method was also applied to some patients with depression and it was possible to detect a slight alteration in the excretion of some compounds compared with the control.

Chromatography, High Pressure Liquid↗
PubMed1985

Response of the cockroach brain gamma-aminobutyric acid system to isonicotinic acid hydrazide and mercaptopropionic acid.

The presence of gamma-aminobutyric acid (GABA) as well as glutamic acid decarboxylase (GAD) and GABA-transaminase (GABA-T) enzymes was demonstrated in the cockroach (Periplaneta americana) brain. Isonicotinic acid hydrazide (INH) in vivo (2.19 mumol/g) inhibited brain GAD activity, the inhibition lasted for about 2 hours and the normal activity levels reappeared at 4 h after INH administration. Brain GABA levels increased initially but then declined and were restored to normal levels at 4 h after INH administration. GABA-T activity was strongly inhibited by INH and a total 100% inhibition was observed at 2-3 h following INH treatment. The GABA-T activity, however, began to recover after 3 h but only 37% of the total enzyme activity was released from inhibition. Mercaptopropionic acid (MPA) in vivo (32 micrograms/g) inhibited brain GAD activity and depleted GABA level also. Results indicate that INH response of the cockroach brain GABA system is similar to that reported for the chick brain but differs from that of the mammalian brain.

3-Mercaptopropionic Acid↗