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PubMed1978

Inhibition of ultraviolet and phototoxic dermatitis in the mouse.

The effect of inhibitors on the inflammatory oedema elicited by medium-wave ultraviolet radiation (UVB) and long-wave ultraviolet radiation (UVA) in combination with chlorpromazine has been studied in the mouse, by means of a quantitative technique. Inhibition of the UVB reaction was observed with indomethacin, acetylsalicylic acid and betamethasone valerate, whereas the latter compound only was effective in the phototoxic state. No inhibition was obtained with hydrocortisone, phenylbutazone, epsilon-aminocaproic acid, polyphloretin phosphate, clemastin, alpha-tocopherol or ascorbic acid. With indomethacin and betamethasone valerate there was no inhibition at high doses when the compound was administered before UVB irradiation. These results are in accordance with a proposed central role for the prostaglandins in UVB inflammation. It is suggested that the phototoxic reaction to chlorpromazine may not be due to mediator action but rather to the effect of toxic photoproducts.

Animals↗

PubMed2002

Interaction of carboxylic acids with chitosan: effect of pK and hydrocarbon chain length.

Sorption of acetic, propionic, butyric, valeric, and isovaleric acid on chitosan and cross-linked chitosan was studied in aqueous solutions and water/ethanol mixtures. Langmuir, Freundlich, and Redlich-Peterson equations were used to fit experimental isotherms of sorption. Correlation between maximum sorption and the pK value of every carboxylic acid was found for sorption on chitosan in aqueous solutions, while sorption in water/ethanol mixtures was mainly determined by structure and the hydrocarbon chain length of the carboxylic acid. Slight molecular-sieves effect was found for carboxylic acids sorption on cross-linked chitosan.

Journal Article↗

PubMed1992

[Effect of monensin (USA, Czechoslovakia, Bulgaria) on fermentation of animal feed in an artificial rumen (Rusitec)].

An experiment was made with the Rumen Simulation Technique (Rusitec) in which the fermentation of a mixed ration of hay (12.8 g/d) and bruised barley (3.2 g/d) was compared with the fermentation of the same diet in the presence of 5 mg monensin/d from the USA, CSFR and Bulgaria. The fermentation of the mixed ration was significantly affected by all three kinds of monensin. The digestibility of dry matter (DM) in the rations declined in the presence of monensin from 48% to 40% (tab. I). The digestibility of detergent fibre, cellulose and hemicellulose also declined in the presence of monensin (tab. I). The production of methane decreased (-70%) and CO2 production dropped too, but this decrease could be accounted for by the changes in the production of volatile fatty acids and redistribution of metabolic hydrogen (tab. I). Monensin decreased the production of total volatile fatty acids (-21%), the production of acetic (-35%), n-butyric, n-valeric and isovaleric acids (tab. II) and increased the production of propionic acid (+60%). The production, utilization and recovery of metabolic hydrogen were significantly increased in the presence of all three kinds of monensin (tab. IV). The end products of fermentation were affected by an addition of monensin to the mixed ration. All three kinds of monensin increased energic efficiency of volatile fatty acids, decreased adenosinetriphosphate (ATP) production, the amounts of fermented hexose, organic matter fermented and utilization of glucose (tab. III).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

PubMed1999

Short-chain fatty acids and thyroid hormone interact in regulating enterocyte gene transcription.

BACKGROUND: Enterocyte differentiation is known to be regulated by a variety of extracellular compounds, among which are triiodothyronine (T3) and the short-chain fatty acids (SCFAs). Because several SCFAs are known to induce histone hyperacetylation, and T3 action has been recently linked to chromatin structure, we sought to investigate the interplay between SCFAs and T3 in regard to the enterocyte differentiation marker, intestinal alkaline phosphatase (IAP). METHODS: Caco-2 cells were transiently transfected with a reporter construct containing 2.4 kb of the human IAP gene 5' flanking region (IAP2.4CAT). Cotransfections were carried out with and without thyroid hormone receptor-1 (TR beta-1) or histone deacetylase-1 (HDAC-1) expression plasmids. Cells were treated with 5 mmol/L SCFAs (propionic, butyric, valeric, or caproic acids as propionate, butyrate, valerate, or caproate, respectively), with and without 10 nmol/L T3. Reporter gene activity was measured and the level of histone acetylation assessed by means of acid-urea-triton (AUT) gel assays. RESULTS: TR beta-1 cotransfection caused a marked decrease in IAP reporter gene activity, which is consistent with the well-known phenomenon of ligand independent repression (LIR), whereas T3 treatment reversed the LIR and caused further reporter gene activation. Treatment with SCFAs similarly resulted in a complete blockage of LIR, and, in fact, turned the TR beta-1 into a transcriptional activator, even in the absence of T3. Concomitant treatment with T3 and butyric acid produced an additive effect on IAP transactivation. In contrast, cotransfection with HDAC-1 attenuated the effects of SCFAs on IAP gene activation. AUT gel studies demonstrated histone hyperacetylation in response to SCFA treatment. CONCLUSION: One or more DNA cis-elements in the human IAP gene mediate ligand independent repression by the TR beta-1, an effect that can be entirely reversed by those SCFAs that induce histone hyperacetylation. In addition T3 and SCFAs can act in concert to induce IAP gene transcription, demonstrating an important link between triiodothyronine and histone hyperacetylation in regard to enterocyte-specific gene expression.

Alkaline Phosphatase↗

PubMed2002

Therapeutic effect of topical application of linoleic acid and lincomycin in combination with betamethasone valerate in melasma patients.

Melasma is an acquired symmetric hypermelanosis characterized by irregular light-to gray-brown macules and patches on sun-exposed areas. Many therapeutic agents are available but are unsatisfactory. Recently, it has been demonstrated that lincomycin (LM) and linoleic acid (LA) can inhibit melanogenesis in vitro. Our purpose was to investigate the clinical efficacy of topical application of LM and LA in combination with betamethasone valerate (BV) in melasma patients. Forty-seven Korean female adults with clinically diagnosed melasma were enrolled in a 6-week, double-blind, randomized clinical trial. Patients were treated with one application of the vehicle (group A), 2% LM mixed with 0.05% BV (group B), or 2% LM mixed with 0.05% BV and 2% LA (group C) on the face every night. Determination of efficacy was based on the Melasma Area and Severity Index (MASI) score and objective assessment (no effect, mild, moderate, or excellent) at intervals of 2 weeks until the end of the study at 6 weeks. After 6 weeks, in comparison with the pre-treatment MASI score, the average MASI score of group C decreased to 68.9%, compared with 98% in group A (p<0.05) and 85.4% in group B. There was no statistically significant difference between group A and group B. Seven patients (43.7%) in group C revealed more than moderate improvement in objective assessment, compared with none in group A and two patients (12.5%) in group B. There were no significant side effects. Topical application of linoleic acid is considered to be effective in the treatment of melasma patients.

Administration, Topical↗

PubMed1996

Effect of deaerated water on serum biochemical values and on the cecum concentration of short-chain fatty acids in the rat.

The effects of drinking deaerated water on serum biochemical values, and on the concentrations of short-chain fatty acids (SCFAs) derived from bacterial fermentation in the colon were examined in rats. Drinking deaerated water decreased the levels of serum alkaline phosphatase (SAP) and serum urea nitrogen (SUN), and increased the serum potassium (SK) and serum phosphorus (SP) levels. Although the concentration of propionic acid in the cecum was decreased by drinking deaerated water, the concentrations of isobutyric, valeric, and isovaleric acid in the cecum were increased.

Alkaline Phosphatase↗

PubMed2001

Application of zirconium-modified silica gel as a stationary phase in the ion-exclusion chromatography of carboxylic acids. II. Separation of aliphatic carboxylic acids with pyromellitic acid as eluent and with suppressed conductimetric detection.

The application of zirconium-modified silica gels (Zr-Silica) as stationary phases for ion-exclusion chromatography with conductimetric detection (IEC-CD) for C1-C8 aliphatic carboxylic acids (formic, acetic, propionic, butyric, valeric, caproic, heptanoic and caprylic acids) was carried out using pyromellitic acid as the eluent. Zr-Silicas were prepared by the reaction of the silanol group on the surface of silica gel with zirconium tetrabutoxide [Zr(OCH2CH2CH2CH3)4] in ethanol solution. An ASRS-Ultra anion self-regenerating suppressor in the K+ form was used for the enhancement of conductimetric detector response of these aliphatic carboxylic acids. A Zr-Silica adsorbed on 10 mg zirconium g(-1) silica gel was the most suitable stationary phase in IEC-CD for the separation of these aliphatic carboxylic acids. Excellent simultaneous separation and highly sensitive detection for these aliphatic carboxylic acids were achieved in 25 min by IEC-CD with the Zr-Silica column (250x4.6 mm I.D.) and a 0.2 mM pyromellitic acid containing 0.15% heptanol as the eluent.

Benzoates↗

PubMed1996

Use of a semi-continuous culture system (RUSITEC) to study the effect of pH on microbial metabolism of thiamin (Vitamin B1).

Polioencephalomalacia (P.E.M.) in ruminants is often associated with high concentrate diets and rumen acidosis; this syndrome is classically related to a disturbance of the rumen metabolism of thiamin. An in vitro model using a semicontinuous system (RUSITEC) was used to investigate the effect of pH on microbial metabolism and on production of thiamin in the rumen. These effects were tested using either a natural diet (hay/wheat) or a semi-synthetic one. Lowering the pH decreased total volatile fatty acids, methane and microbial nitrogen production. Molar proportions of VFA were modified by an increase in butyric, valeric and caproic acids. Microbial production of thiamin was comparable to in vivo synthesis but decreased when the diet was enriched with thiamin. The diet of the donors of inoculum had no effect on this metabolism. For all diets, lowering of pH did not reduce microbial production of thiamin. Thiaminase activity in the liquid phase of fermentors was very low and was not modified by pH. Thus lowering of pH in vitro, had no deleterious effect on microbial production of thiamin. Therefore, lowering of the rumen pH in acidotic conditions may not be a factor which promotes P.E.M.

Animals↗

PubMed1997

The crystal structure of plant acetohydroxy acid isomeroreductase complexed with NADPH, two magnesium ions and a herbicidal transition state analog determined at 1.65 A resolution.

Acetohydroxy acid isomeroreductase catalyzes the conversion of acetohydroxy acids into dihydroxy valerates. This reaction is the second in the synthetic pathway of the essential branched side chain amino acids valine and isoleucine. Because this pathway is absent from animals, the enzymes involved in it are good targets for a systematic search for herbicides. The crystal structure of acetohydroxy acid isomeroreductase complexed with cofactor NADPH, Mg2+ ions and a competitive inhibitor with herbicidal activity, N-hydroxy-N-isopropyloxamate, was solved to 1.65 A resolution and refined to an R factor of 18.7% and an R free of 22.9%. The asymmetric unit shows two functional dimers related by non-crystallographic symmetry. The active site, nested at the interface between the NADPH-binding domain and the all-helical C-terminus domain, shows a situation analogous to the transition state. It contains two Mg2+ ions interacting with the inhibitor molecule and bridged by the carboxylate moiety of an aspartate residue. The inhibitor-binding site is well adjusted to it, with a hydrophobic pocket and a polar region. Only 24 amino acids are conserved among known acetohydroxy acid isomeroreductase sequences and all of these are located around the active site. Finally, a 140 amino acid region, present in plants but absent from other species, was found to make up most of the dimerization domain.

Alcohol Oxidoreductases↗

PubMed2000

Net portal appearance of volatile fatty acids in sheep intraruminally infused with mixtures of acetate, propionate, isobutyrate, butyrate, and valerate.

The net portal appearance of volatile fatty acids (VFA) was investigated in four ruminally fistulated and multicatheterized sheep. During the experiments, the sheep were fed once every hour for 14 h and intraruminally infused with mixtures of VFA for the 12 h commencing 2 h after the initiation of the hourly feeding protocol. Paired arterial and portal blood samples were obtained hourly during the last 6 h of the experiments. In the control treatment (1), only water was infused intraruminally. In Treatments 2 through 4, the intraruminal infusion rates of propionate (40 mmol/h), isobutyrate (5 mmol/h), and valerate (5 mmol/h) were unchanged. In Treatments 2, 3, and 4, the acetate infusion rate was 100, 60, and 20 mmol/h, respectively, and the butyrate infusion rate was 10, 30, and 50 mmol/h, respectively. Thus, the infusion rate of VFA carbon was constant across Treatments 2 through 4. Portal recovery estimated from the increased net portal appearance in Treatments 2 through 4 compared to the control treatment was 85% for propionate and 60% for isobutyrate, and these recoveries were unaffected by treatment. The portal recovery of butyrate increased (from 21 to 32%) with increasing infusion rate of butyrate and decreasing infusion rate of acetate, as did the portal recovery of valerate (from 14 to 31%). The portal recovery of acetate was 55%, when measured as net portal appearance. Thus, it seems that the capacity for beta-oxidation in ruminal epithelium is limited, which would explain the increasing portal recovery of butyrate and valerate with increasing infusion rate of butyrate, when infusion rate of VFA carbon is unchanged.

Acetates↗

PubMed1983

In vitro and in vivo effects on brain GABA metabolism of (S)-4-amino-5-fluoropentanoic acid, a mechanism-based inactivator of gamma-aminobutyric acid transaminase.

The effects of intraperitoneal administration of (S)-4-amino-5-fluoropentanoic acid, a mechanism-based covalent inactivator of gamma-aminobutyric acid transaminase (GABA-T), on whole brain GABA metabolism in mice were investigated. A dose-dependent and time-dependent irreversible inactivation of GABA-T was observed with a concomitant increase in whole brain GABA levels. The compound exhibited no in vitro nor in vivo time-dependent inhibition of glutamate decarboxylase (GAD), alanine transaminase, or aspartate transaminase (Asp-T). It was, however, a potent competitive reversible inhibitor of GAD and a weak competitive inhibitor of Asp-T. The chloro analogue, (S)-4-amino-5-chloropentanoic acid, was ineffective.

4-Aminobutyrate Transaminase↗

PubMed1992

Simple and rapid method for determination of short-chain fatty acids in biological materials by high-performance liquid chromatography with ultraviolet detection.

A new and versatile method for the identification and quantification of short-chain fatty acids, such as formic, acetic, propionic, butyric, isobutyric, valeric, isovaleric and mercaptoacetic acids, in biological specimens by high-performance liquid chromatography is described. After sample purification by vacuum transfer and concentration by alkaline freeze-drying, the acids were measured without any further preparative step, using a sulphonated polystyrene-divinylbenzene column as stationary phase. Ultraviolet detection of the native acids was done at 214 nm. Peak resolution and reproducibility were as good as with gas chromatography. Many examples of the application of this method to a variety of biological specimens and fluids both from the rats and humans are described.

Animals↗

PubMed1983

Treatment of epileptic patients with valproic acid does not modify plasma and urine short-chain-fatty acids.

The purpose of this study was to evaluate the possible modifications of the plasma and urine short-chain-fatty acid (SCFA) patterns indiced by treatment with valproic acid (VPA). Increased amounts of SCFAs in patients under VPA treatment may explain the presence of VPA-induced hyperammonemia, toxic encephalopathies and rarer Rey-like syndromes recently observed. For this reason we assayed SCFA levels in the plasma and looked for propionic acid in the urine of 10 epileptic patients to whom it was decided to add VPA to their previously unsatisfactory anti-epileptic treatment. This was carried out prior to and during therapy with VPA. 5 of these patients developed toxic encephalopathy with hyperammonemia induced by VPA. Our data show that plasma and urine SCFAs are not modified by VPA treatment. This is so even in patients who have toxic encephalopathy with hyperammonemia indiced by this drug.

Adolescent↗

PubMedDate not supplied

[The possibility of using the data on the content of volatile fatty acids for the indirect demonstration of the causative agents of suppurative-inflammatory diseases in the pathological material].

The use of the quantitative content of volatile fatty acids as marker for the indication of the causative agents of pyo-inflammatory diseases in material taken from wounds is proposed. Thus, in 71% of cases the detection of acetic acid in a purulent wound coincided with the bacteriological isolation of monocultures, as well as associations, of facultative anaerobic bacteria. The analysis of isobutyric, butyric, isovaleric, valeric and acetic acids permitted the rapid detection of associations of obligate and facultative anaerobic bacteria in an individual patient. Changes in the quantitative content of volatile fatty acids in pathological material integrally reflected the dynamics of the causative agents of purulent infections and the effectiveness of the prescribed therapy.

Acute Disease↗

PubMed1997

Low molecular weight hydrophilic chemicals that attract Echinostoma trivolvis and E. caproni cercariae.

A Petri dish bioassay was used to study chemoattraction of the cercariae of Echinostoma trivolvis and E. caproni in the presence of various bench chemicals prepared as 5 mM solutions in agar. The design compared the attraction of cercariae migrating toward the plugs impregnated with chemicals compared to unimpregnated plugs (controls). Cercariae of both species were significantly attracted to an array of amino acids and to some carbohydrates. Cercariae of E. trivolvis but not E. caproni were attracted to the peptide glutathione. Cercariae of E. trivolvis and E. caproni were repelled from valeric and butyric acids, respectively. Cercariae of E. caproni but not E. trivolvis were repelled from dextrose. Although broad specificity exists for echinostome cercarial penetration in snail intermediate hosts, results of these studies suggest that there are specific differences in cercarial chemoattractants between E. trivolvis and E. caproni.

Amino Acids↗

PubMed1977

Induction of human choriogonadotropin in heLa-cell cultures by aliphatic monocarboxylates and inhibitors of deoxyribonucleic acid synthesis.

The ectopic production of the glycopeptide hormone human placental choriogonadotropin by HeLa(65) cells was measured by radioimmunoassay with antiserum against the beta-subunit of choriogonadotropin and with the (125)I-labelled beta-subunit as a tracer antigen. Choriogonadotropin synthesis was markedly (500-fold) stimulated by sodium butyrate. Kinetic studies and the use of an inhibitor of protein synthesis, cycloheximide, indicated that protein synthesis was required for this induction. Investigation of the efficiency of 22 aliphatic short-chain fatty acids and derivatives in causing increased choriogonadotropin synthesis by HeLa cells showed stringent structural requirements. Induction of choriogonadotropin synthesis in HeLa cells was not restricted to butyrate. Other aliphatic acids (propionate, isobutyrate, valerate and hexanoate) were also capable of inducing choriogonadotropin synthesis at 10-50% of the efficiency of butyrate. Hydroxy derivatives of monocarboxylate inducers, related mono- and di-carboxylic acids, alcohols, amines, ketones, esters and sulphoxide were ineffective in increasing choriogonadotropin production by HeLa cells. A saturated C(4) straight-chain acid without substituent hydroxyl groups but with a methyl group at one end and a carboxyl moiety at the other appeared to be most efficient in activating choriogonadotropin production. A second clonal line of HeLa cells, HeLa(71), showed a higher constitutive synthesis of choriogonadotropin than HeLa(65) cells, which was also markedly increased by butyrate. Butyrate and other aliphatic monocarboxylate inducers of choriogonadotropin synthesis inhibited HeLa-cell growth and DNA synthesis. This inhibition of DNA replication may be related to the mechanism of choriogonadotropin synthesis, since two well-characterized anti-neoplastic inhibitors of DNA synthesis, hydroxyurea and 1-beta-d-arabinofuranosylcytosine, also stimulated a 300-fold increase in choriogonadotropin synthesis in HeLa cells and were synergistic with butyrate in promoting choriogonadotropin synthesis. Thus activation in tumour cells of genes normally expressed by foetal tissue and the consequent ectopic synthesis of polypeptide hormones may require neither cell division nor DNA synthesis.

Antineoplastic Agents↗

PubMed1985

The 65-kDa phorbol-diester hydrolase in mouse plasma is esterase 1 and is immunologically distinct from the 56-kDa phorbol-diester hydrolase in mouse liver.

Esterase 1, a well-characterized mouse plasma protein of unknown function, has activity against a wide range of ester substrates including beta-alanine nitrophenyl esters and 17 beta-esters of estradiol. In this article, we report that esterase 1 is also responsible for a majority of the phorbol-12-ester hydrolase activity in mouse plasma. Incubation of homogeneous esterase 1 with 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA) at either 4 or 37 degrees C for up to 18 h yielded phorbol 13 alpha-acetate as the only hydrolysis product. Specific polyclonal antibodies to esterase 1 inhibited 95% of PMA hydrolysis by a purified esterase 1 preparation and 65% of PMA hydrolysis by mouse plasma. Perfused mouse liver homogenates contain two distinct phorbol diester hydrolases with apparent molecular masses of 65 kDa and 56 kDa, respectively. The 65-kDa protein appears to be immunologically identical to the plasma enzyme, while the 56-kDa protein, found in liver but not in plasma, is immunologically distinct. Phorbol 12-myristate, phorbol 12,13-dibutyrate, and PMA were found to be competitive inhibitors of the beta-alanine-nitrophenyl esterase activity of esterase 1 with Ki values of approximately 7 microM. Phorbol 13-acetate and phorbol itself were less effective with Ki values of 37 and 140 microM, respectively. Sodium salts of valeric and myristic acids did not inhibit at 10 microM. The above results indicate that efficient substrate binding requires a phorbol 12-ester. Similar results were obtained with estradiol 17 beta-valerate which is a better substrate for esterase 1 than is PMA. Our results strongly suggest that esterase 1 and a recently described phorbol ester hydrolase isolated from mouse serum (Saito, M., and Egawa, K. (1984) J. Biol. Chem. 259, 5821-5826) are the same and are immunologically and kinetically distinct from the 56-kDa phorbol 12-ester hydrolase in mouse liver.

Animals↗

PubMed1976

Effect of short-chain Fatty acids extracted from beef cattle manure on germination and seedling development.

Composted and fresh beef cattle manure samples were extracted with distilled water, acetone, methanol, 2 N sodium hydroxide, 2 N hydrochloric acid, and ether. Bioassay techniques, using the extracts, showed that composted manure extracts had limited effect on seed germination and seeding development of wheat and sorghum. All the extracts of fresh manure, other than distilled water, retarded germination. Acetic, butyric, propionic, valeric, and isovaleric acids were found in ether extracts of fresh manure at average concentrations of 348, 876, 578, 34, and 19 mug/g, respectively, on a dry-weight basis. However, only trace amounts of these acids were present in composted manure. Propionic acid up to the 200-mug/ml level stimulated seedling growth. Acetic and butyric below the 200-mug/ml level had no detrimental or beneficial effects on seedling development. When acetic, butyric, and propionic acids were mixed in equal parts, germination and seedling growth were reduced at all levels (50 to 500 mug/ml).

Journal Article↗