Inhibition of uric acid excretion in rabbits given probenecid or salicylic acid.
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A fast and sensitive method of high-performance liquid chromatography (HPLC) for determination of acetylsalicylic acid (ASA) and products of salicylic acid (SA) hydrolysis in tablets has been elaborated. Extraction was done with the mixture of methanol: formic acid (98:2 v/v) and separation of the components was achieved by using the colon of Ultropac Lichrosorb RP-18, 10 um, 4 cm x 250 mm and diode array detector. The mobile phase of methanol:water: :mol/1 H3PO4 (60:35:5) v/v, pP = 2.6 and safe flow of 1 ml/min were used. Follow up of chromatographic separation of ASA, SA and internal standard beta-naphtole (ITS) was performed at the wave length of 290 microns. The threshold of ASA was 0.5 mg/ml and of SA 0.0025 mg/ml.
Topical corticosteroids and keratolytics are both used widely in the management of patients with psoriasis. A combination of the two types of agents may provide enhanced relief. The purpose of this study was to compare the efficacy and safety of the combination ointment mometasone furoate 0.1% plus salicylic acid 5% with that of mometasone furoate 0.1% ointment in the treatment of moderate-to-severe psoriasis vulgaris. A total of 408 patients were enrolled in this controlled, randomized, double-masked, parallel-group, multicenter comparison. Patients applied either mometasone furoate-salicylic acid ointment or mometasone furoate ointment alone to target lesions twice daily for 21 days. Severity of erythema, induration, and scaling were scored at baseline and at days 4, 8, 15, and 22. An evaluation of overall change in disease status of all treated lesions was performed at each follow-up visit. Adverse events were also monitored and scored, including signs of skin atrophy. Beginning on day 8, the combination of mometasone furoate-salicylic acid was significantly more effective than mometasone furoate alone, as indicated by the mean percentage of improvement in total disease scores, mean total disease sign scores, and the individual score for scaling. Similarly, the combination was more effective beginning on day 15, as indicated by the global evaluation of overall clinical response and individual scores for erythema and induration. Both treatments were well tolerated. Mometasone furoate-salicylic acid ointment provides more effective treatment of moderate-to-severe psoriasis than does mometasone furoate ointment alone and is safe and well tolerated.
The combination of 0.02% flumetasone pivalate and 1% salicylic acid in a water-alcohol solution (Locasalen) is a novel therapeutic for topical treatment of the hairy scalp and also for the cosmetically acceptable treatment of other skin areas, that is, exposed skin. An investigation was carried out in 6 patients with psoriasis capitis and 6 control subjects in order to determine whether the use of Locasalen Tincture on the hairy scalp leads to percutaneous absorption of the corticosteroid and the salicylic acid. In the patients with psoriasis a few slight transient changes in biochemical-endocrinological parameters were observed, but not in the control subjects. However, these changes remained within the normal, non-pathological range so that they are of no clinical consequence. Percutaneous absorption of salicylic acid was not observed in either patient group.
LCOs (lipochitin oligosaccharides, Nod factors) produced by the rhizobial symbiote of Vicia sativa subsp. nigra (vetch, an indeterminate-type nodulating plant) are mitogenic when carrying an 18:4 acyl chain but not when carrying an 18:1 acyl chain. This suggests that the 18:4 acyl chain specifically contributes to signaling in indeterminate-type nodulation. In a working hypothesis, we speculated that the 18:4 acyl chain is involved in oxylipin signaling comparable to, for example, signaling by derivatives of the 18:3 fatty acid linolenic acid (the octadecanoid pathway). Because salicylic acid (SA) is known to interfere with oxylipin signaling, we tested whether nodulation of vetch could be affected by addition of 10(-4) M SA. This concentration completely blocked nodulation of vetch by Rhizobium leguminosarum bv. viciae and inhibited the mitogenic effect of 18:4 LCOs but did not affect LCO-induced root-hair deformation. SA did not act systemically, and only biologically active SA derivatives were capable of inhibiting nodule formation. SA also inhibited R. leguminosarum bv. viciae association with vetch roots. In contrast, addition of SA to Lotus japonicus (a determinate-type nodulating plant responding to 18:1 LCOs) did not inhibit nodulation by Mesorhizobium loti. Other indeterminate-type nodulating plants showed the same inhibiting response toward SA, whereas SA did not inhibit the nodulation of other determinate-type nodulating plants. SA may be a useful tool for studying fundamental differences between signal transduction pathways of indeterminate- and determinate-type nodulating plants.
The aim of this work was to describe a fully automated system for the in vitro release testing of semisolid dosage forms based on SIA technique. The system was tested for monitoring release profiles of different ointments containing 3% of salicylic acid (Belosalic, Diprosalic, Triamcinolone S). The native fluorescence of salicylic acid was used for fluorimetric detection. Phosphate buffer pH 7.4 was the receptor medium; samples were taken at 10 min intervals during 6 h of the release test; and each test was followed by calibration with five standard solutions. The linear calibration range was 0.05-10 microg ml(-1) (r = 0.9996, six standards); the maximal SIA sample throughput for this system was 120 h(-1), sample volume being 50 microl and flow rate 50 microl s(-1). The detection limit for salicylic acid was 0.01 microg ml(-1).
The distribution of salicylic acid between the intracellular and extracellular phases has been used to estimate the intracellular pH in the Ehrlich cell and Escherichia coli. The validity of the method was established by: (i) comparison of the results obtained with salicylic acid with those obtained with 5,5-dimethyloxazolidine-2,4-dione; (ii) by following changes of the apparent intracellular pH under circumstances in which such changes are predictable, e.g., the addition of weak acids or proton conductors to the incubation medium during incubation at acidic pH; (iii) by comparison of the apparent intracellular pH changes with the uptake of H+ by the cells estimated from the changes of the medium pH. Optimal results are obtained with this indicator when the extracellular pH is below 5.5, because in this case the indicator is to a sufficient extent in its penetrating form, so that its movement can reflect intracellular pH changes occurring in less than 30 s. When the intracellular pH falls below 5.2 measurable binding of salicylic acid to the intracellular material of the Ehrlich cell takes place, but above this pH no binding has been found. The Ehrlich cell and cells of Escherichia coli behaved similarly under various experimental circumstances tested, but striking difference were found in the inherent permeability of the membrane to H+ and in the changes in this parameter by lowering the temperature to 2 degrees C.
The simultaneous determination of salicylic acid in binary and/or ternary mixtures and its two main urinary metabolites is proposed. Mixtures of salicylic, salicyluric and gentisic acids are resolved by synchronous spectrofluorimetry, in combination with first-derivative measurements. The urine is extracted with diethyl ether in acid medium. Salicylic and salicyluric acids are re-extracted into glycine-sodium hydroxide buffer solution of pH 11.6 and determined at that pH, and salicylic and gentisic acids are re-extracted into boric acid-sodium hydroxide buffer solution of pH 8.5 and determined at pH 6.
The change in fluorescence of human serum albumin (HSA) and salicylic acid due to their interaction has been studied in 0.05 mol/L, pH 9.50 borate buffer (contains 0.01 mol/L KCl). The dissociation constant of salicylic acid from HSA was obtained by using two different methods.
In order to assess whether exogenous application of salicylic acid (SA) through the rooting medium could modulate the photosynthetic capacity of two wheat cultivars differing in salinity tolerance, a hydroponic experiment was conducted under greenhouse conditions. Seeds of a salt tolerant (S-24) and a moderately salt sensitive (MH-97) cultivar were germinated at 0 or 150 mM NaCl in Hoagland's nutrient solution containing different levels of salicylic acid (SA) (0, 0.25, 0.50, 0.75 and 1.00 mM) for 7d. Seven-day old wheat seedlings were transferred to hydroponics and grown at 0, or 150 mM NaCl for for further 30 d. Different levels of salicylic acid (SA) were also maintained in the solution culture. After 30 d, four plants out of six were harvested and the remaining plants were left for the estimation of yield attributes Salt stress reduced the growth and grain yield of both cultivars. However, cv. S-24 performed better than MH-97 under salt stress with respect to leaf area, and grain yield. Exogenous application of SA promoted growth and yield, and counteracted the salt stress-induced growth inhibition of salt tolerant S-24, whereas for MH-97 there was no improvement in growth or grain yield with SA application. Of the varying SA levels used, the most effective levels for promoting growth and grain yield were 0.75 and 0.25 mM under normal and saline conditions, respectively. The improvement in growth and grain yield of S-24 due to SA application was associated with improved photosynthetic capacity. Changes in photosynthetic rate due to SA application were not due to stomatal limitations, but were associated with metabolic factors, other than photosynthetic pigments and leaf carotenoids.
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The degree of migration of optically active, racemic and non-optically active acids and bases on cellulose, silica gel and alumina thin layers is examined in various pH buffer solutions using thin layer electrophoresis. The results indicate different mobilities of the acidic and basic compounds in the various pH buffers of the experiment.
Wheat ( Triticum aestivum L.) roots released proteins showing peroxidase activity in the apoplastic solution in response to wound stress. Preincubation of excised roots with 1 mM salicylic acid at pH 7.0 enhanced the guaiacol peroxidase activity of the extracellular solution (so-called extracellular peroxidase). The soluble enzymes were partially purified by precipitation with ammonium sulfate followed by size exclusion and ion exchange chromatography. Despite an increase in the total activity of secreted peroxidase induced by pretreatment of excised roots with salicylic acid, the specific activity of the partially purified protein was significantly lower compared to that of the control. Purification of the corresponding proteins by ion exchange chromatography indicates that several isoforms of peroxidase occurred in both control and salicylic acid-treated samples. The activities of the extracellular peroxidases secreted by the salicylic acid-treated roots responded differently to calcium and lectins compared with those from untreated roots. Taken together, our data suggest that salicylic acid changes the isoforms of peroxidase secreted by wounded wheat roots.
1. The growth of rats treated with 3,5-dimethyoxy salicylic acid was retarded in comparison to that of normal rats. 2. The free cholesterol level of plasma of rats treated with 3,5-dimethoxy salicylic acid diminished while the pyruvate level of erythrocyte under the same condition increased in comparison with their normal levels; but on administration of thiamine both the cholesterol and pyruvate levels became normal. 3. The growth of a thiamine dependent strain of S. aureus was retarded when the organism was incubated in the medium containing 3,5-dimethoxy salicylic acid and this growth can be restored with the supplementation of thiamine in the medium.
A column-switching liquid chromatographic method is described for the simultaneous determination of aspirin and salicylic acid in human plasma. Blood samples are taken into chilled tubes containing a fluoride anticoagulant, and the plasma is isolated by centrifugation. Following a simple acidification step, a 200 microL aliquot of the sample is injected directly onto the HPLC system. The C-18 extraction column is washed with acidified water for 2 min, after which time the compounds are removed by back-flushing directly onto the analytical column (C-8 Nucleosil, 5 microns, 250 mm x 4.6 mm). The flow rate through both columns is 1 mL/min, and the analytes are quantified by measurement of their UV absorbance at 225 nm. The mobile phase is a mixture of water-methanol-acetonitrile-orthophosphoric acid (650:200:150:1 v/v/v/v). The method is linear in the concentration ranges 0.10-5.00 micrograms/mL for aspirin and 0.25-15.00 micrograms/mL for salicylic acid. Both compounds have a limit of quantitation of 0.10 microgram/mL and a limit of detection of 0.04 microgram/mL. Extensive stability tests have been carried out, and validation studies reveal the method to be reproducible and repeatable. Excellent recoveries from plasma obviate the need for an internal standard. The procedure is easier to execute and requires less sample handling than methods currently described in the literature. It has been successfully applied to the investigation of the levels of aspirin and salicylic acid in a healthy, nonfasting volunteer following a 600 mg oral dose of aspirin.