Antioxidant and photoprotective properties of an extract from buckwheat herb (Fagopyrum esculentum MOENCH).

In recent years, the incidence of skin cancer has risen remarkably. Sun light, especially the included ultraviolet (UV)-radiation, is seen as important trigger for the development of skin cancer. Thus, there is an increasing interest in the development of UV-protective substances to use them as sun care products. One approach is the topical application of herbal antioxidants. Plant-derived antioxidants are often extracts and therefore contain a complex mixture of constituents, like flavonoids and polyphenols, which contribute to the overall activity of the extract. In the present study an extract from buckwheat herb was compared to rutin, which is the main constituent of the extract, regarding their antioxidant and radical scavenging activity. Additionally, the photoprotective properties of the extract were compared to those of a commercial UV absorber. The antioxidant activity was quantified regarding the reactivity versus the 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH). The photoprotective properties of the extract were examined by the inhibition of the photosensitized lipid peroxidation of linolic acid. In the DPPH assay, the extract had significantly better antioxidant activity than pure rutin. The extract prevented more effectively the UV-induced peroxidation of linolic acid than rutin itself or the commercial UV absorber. The use of the extract from buckwheat herb seems to be more beneficial than the use of pure rutin. This can be referred to the presence of minor phenolic compounds in the extract. The results indicate that it is advisable to use antioxidants rather than only UV absorber to obtain a maximum of photo protection.

A trial of dipyridamole and aspirin in the prevention of smoking-induced changes in platelets and endothelium in men with coronary artery disease.

A random-order, double-blind crossover study compared the effects of placebo, dipyridamole and dipyridamole plus aspirin on smoking-induced changes in endothelium and platelets. Each of 12 male habitual smokers with coronary artery disease was given dipyridamole (75 mg) and aspirin (324 mg), dipyridamole (75 mg) and placebo for aspirin, or a placebo for each drug 3 times daily for 1 week before each of three 20-minute periods (separated by 2 weeks) of smoking 2 cigarettes after a 12-hour period of abstinence. During each period of smoking there were increases in the mean values of the plasma concentrations of beta-thromboglobulin, platelet factor 4 and nicotine, the endothelial cell count and the blood level of carboxyhemoglobin. In addition, the mean platelet aggregate ratio decreased during each period. After administration of placebos for both dipyridamole and aspirin, the respective mean values +/- standard deviations before and after smoking were 28 +/- 8 and 30 +/- 7 ng/ml (beta-thromboglobulin), 7.4 +/- 1.0 and 8.2 +/- 1.4 ng/ml (platelet factor 4), 3.7 +/- 0.6 and 15.7 +/- 3.5 ng/ml (nicotine), 4.2 +/- 1.4 and 5.4 +/- 1.7/counting chamber (endothelial cell count), 5.0 +/- 2.2 and 6.6 +/- 2.2% (carboxyhemoglobin) and 0.80 +/- 0.07 and 0.68 +/- 0.10 (platelet aggregate ratio). Each of the differences between the means before and after smoking was statistically significant (p less than or equal to 0.02). Neither dipyridamole alone nor in combination with aspiring significantly affected the mean smoking-induced change in any of these variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrathecal versus systemic corticosteroids in the treatment of multiple sclerosis: results of a pilot study.

Fifty patients with multiple sclerosis were treated either by corticosteroids given systemically or by intrathecal injection of a steroid crystal suspension. Before and 3 weeks after the beginning of the treatment we examined the patients according to the Expanded Disability Status Scale (EDSS). Four patients had to be excluded from evaluation. In 23 patients the examination revealed at least a small improvement in their disability status. There were 7 intrathecally and 5 systemically treated patients whose disability was significantly reduced. One patient under intrathecal treatment showed a minor deterioration in disability. There was no clear difference in the frequency of improved symptoms or in EDSS scores between the two therapies.

UV-induces formation of hydrogen peroxide based on the photochemistry of ketoprofen.

Ketoprofen (KP) is a potent nonsteroidal anti-inflammatory drug. However, application to the skin is problematic because the photosensitizing properties of the benzophenone moiety may cause phototoxic effects when the treated skin region is exposed to UVA light. Using capillary electrophoresis with electrochemical detection we are able to differentiate the peroxides formed during illumination of KP-containing solutions of linoleic acid. Contrary to other profens a high amount of hydrogen peroxide was found among the reaction products. For investigation of the skin damaging effect human keratinocytes were used as models. Cell viability, DNA synthesis efficiency and intracellular concentration of peroxides were determined. Viability and proliferation behavior was not altered under the influence of KP. While lower concentrations of KP (10-100 nM) led to a protection against the UVA-induced (8 J/cm2) cell proliferation damage, higher concentrations (10-100 microM) led to an amplification of the proliferation decrease. With UVB irradiation at relevant doses the effects were lower than using UVA. Furthermore, intracellular peroxide content was increased after UV irradiation and KP addition. In conclusion some efforts have to be done to avoid these side effects in the use of KP for topical or transdermal application.

Determination of peroxides by capillary zone electrophoresis with amperometric detection.

The combination of cathodic amperometric detection with capillary zone electrophoresis is demonstrated to be a versatile method for the quantification of organic and inorganic peroxides. A gold microelectrode, polarized at -600 mV against an Ag/AgCl reference electrode, is placed at the end of the capillary. Since the electroosmotic flow purges the detector electrode from oxygen, no degassing of the detector cell or the sample is necessary. With an injection volume of ca. 1 nl, hydrogen peroxide, peroxosulfate, peroxy alkanoic acids and the hydroperoxides of linoleic acid can be detected down to 10 micromol/l. Separation of the isomeric hydroperoxides of the unsaturated fatty acids is achieved by addition of beta-cyclodextrin to the electrolyte.

Pulsed amperometric detection of calystegines separated by capillary electrophoresis.

Calystegines are polyhydroxyalkaloids with a nortropane skeleton. They are oxidized by pulsed amperometry at a gold electrode due to their vicinal hydroxyl groups similar to monosaccharides, but at a slightly higher potential. Compared to carbohydrates, calystegines exhibit lower acidity, thus the effective electrophoretic mobility as anions in 0.1 M NaOH is lower, independent of their molecular mass. The acidity and mobility of calystegines increase with the number of hydroxyl groups. The influence of temperature and power dissipation in the capillary and changes of the inner surface on the migration times was eliminated by cooling and subtraction of the electroosmotic flow velocity. The high resolving power of capillary zone electrophoresis allows the separation of calystegines with the same number of hydroxyl groups. Detection is linear from 2 to 200 mg L(-1) with a 1 nL injection volume. Calystegines were determined in crude plant sap after filtration without further sample purification.

Characterization of interaction between cephalosporins and charged surfactants using capillary zone electrophoresis.

Capillary electrophoresis offers a new way of characterizing the interaction between surfactants and drugs. This interaction was studied using capillary zone electrophoresis (CZE). It was observed that addition of tetraalkylammonium bromide to the electrolyte buffer at different concentrations of dodecyl trimethylammonium bromide (DTAB) led to a change of the migration time (tm) and of the ionic mobility (mu) of cephalosporins. For quantitative evaluation, a physicochemical model was developed to calculate the aggregation constants (k) and the stoichiometric coefficients (m) between DTAB and cephalosporins. The relative standard deviation of the effective mobilities and of the EOF were estimated.

Capillary zone electrophoresis with electrochemical detection--a simple and effective method to analyze oxygen-consuming and peroxide-forming processes.

Numerous biological, chemical and photochemical processes consume molecular oxygen, thereby forming peroxides, hydroperoxides and even hydrogen peroxide. This paper describes a new system for monitoring quasi simultaneously oxygen uptake and peroxide formation. For this purpose capillary electrophoresis with electrochemical detection was connected to a new automated injector that periodically injects a sample of the reaction mixture into the capillary electrophoresis system without any contact with the atmosphere. The device was tested with some pharmacologically relevant reactions such as enzymatic oxidation of glucose catalyzed by glucose oxidase, enzymatic lipid oxidation by lipoxygenase and the photodynamic reaction of the anti-inflammatory drug ketoprofen.

Application of capillary electrophoresis of characterizing interactions between drugs and bile salts. Part I.

Capillary electrophoresis offers a new way of characterizing interactions between different bile salts and drugs. The observed interactions were characterized with modified model functions known from affinity capillary electrophoresis (ACE) an micellar electrokinetic capillary electrophoresis (MECC). The methodical background of both methods is the change of the ionic mobility of the drug caused by partition between phases and aggregation with the bile salt molecules, respectively. This phenomenon is described by two different physicochemical models. A parameter estimation was carried out in order to obtain the partition coefficients KP as well as constants for the aggregate formation KA. Furthermore, an expression about the specific molar volume of the micelles and stoichiometric coefficients can be given.

Characterization of partition and thermodynamic properties of cephalosporins using micellar electrokinetic chromatography in glycodeoxycholic acid solution.

Micellar electrokinetic chromatography (MEKC) was introduced to evaluate the hydrophobicity of cephalosporins (cefpim, cefpirom, cefazolin, ceftazidim, cephradin, cefuroxim, cefotaxim, cephapirin and cephalothin). Partition coefficients of cephalosporins were calculated between a micelle and an aqueous phases from the measurement of the migration time, provided the critical micelle concentration and the phase ratio are known. Thermodynamic quantities such as enthalpy and entropy changes of micellar solubilization were calculated from the temperature dependence on the partition coefficients. Sodium glycodeoxycholate in low-salt aqueous solutions was employed to prepare a micellar solution. Substances for pharmaceutical purposes have to meet several requirements to be well-tolerated. Therefore, they are often derived from naturally occurring ones, e.g., from the bile salts in bile juice. The electrophoretic velocity of a micelle and the phase ratio between the micelle of the glycodeoxycholic acid and the aqueous phase were calculated. Partial specific volumes at different temperatures (from 20 to 45 degrees C) were measured using dynamic light scattering. The logarithm of the partition coefficients and the migration factor in the micellar system were correlated with the logarithm of the 1-octanol-water partition coefficients.

Treatment of multiple sclerosis with 15 +/- deoxyspergualin. Design of a controlled study with close MRI-monitoring.

The rationale and design of a prospective randomized double blind study of 15 +/- Deoxyspergualin in the treatment of Multiple Sclerosis are presented. The study was started in autumn 1992 and will include more than 200 patients who will be randomized either to DSG low dose or DSG high dose or placebo. Average number of contrast enhancing lesions in monthly cranial MRIs during the first six months of treatment and change in EDSS at the end of the two-year study period will be the main efficacy parameters.

Penetration profile of taurine in the human skin and its distribution in skin layers.

PURPOSE: To measure in vitro release of taurine from a semisolid standard formulation (amphiphilic cream, DAC) containing 1% taurine, a multi-layer membrane system was used. The content and distribution of taurine in different healthy skin layers (stratum corneum, epidermis and dermis) before (native taurine) and after application of the DAC cream were determined using capillary electrophoresis. METHODS: The release of taurine from the DAC cream was studied using a multilayer membrane system. Due to the high hydrophilic properties of taurine, the artificial model membranes consisted of collodion as matrix and glycerol as the acceptor phase. In order to determine whether taurine shows the potential for dermal penetration a Franz diffusion cell system was used. The distribution of taurine in the skin layers was determined before and after application of the DAC cream followed by the incubation in a Franz diffusion cell. The excised skin sample was cut in horizontal sections using a cryomicrotome. In order to detect taurine, fluorescamine was used as a derivatization agent. RESULTS: Experiments with a multilayer membrane system were performed to verify the release of taurine at different times (1, 2 and 5 h). Approximately 42.5% taurine was released from the semisolid standard formulation, accumulating in the first membrane (17.63%). The native taurine content was quantified in human isolated skin layer before and after the application of the semisolid standard formulation followed by incubation in a Franz-type diffusion cell for 1 and 5 h. No statistically significant difference (p < 0.05) of the taurine content in the skin layers existed between exposure times (1 and 5 h) studied. The highest taurine content was found in the epidermis both before (256.01 microg taurine/g skin layer) and after (555.5 microg taurine/g skin layer) the application of the DAC cream. CONCLUSIONS: The distribution profile of taurine in the skin layers was very similar for the times studied, which suggests that taurine is accumulated in specific cells of the skin. The study suggests that taurine is effectively released from the semisolid standard formulation and can be used for topical application in dermatopharmaceutics.

The touch corpuscles of the plantar surface of the big toe. Histological and histometrical investigations with respect to age.

Meissner's corpuscles of the plantar surface of the big toe of 30 persons were investigated histologically and histometrically with respect to age. The number of corpuscles decreases exponentially with increasing age. During the first decades of life the corpuscles exhibit a steady lateral and longitudinal growth. At an advanced age an atrophy of Meissner's corpuscles occurs. In spite of considerable individual variations, a distinct dependency on age can be noticed. Certain diseases, particularly disorders resulting in polyneuropathies, may initiate changes in the numbers and the structure of the corpuscles. Possible interrelationships between morphological neurophysiological and clinical findings are discussed.

Characterization of partitioning behavior of cephalosporins using microemulsion and micellar electrokinetic chromatography.

Electrokinetic chromatography (EKC) was introduced to determine the partitioning behavior of various cephalosporins (cefpim, cefpirom, cefaloridin, cefaclor, cephalexin, cefuroxim, cefotaxim) in microemulsions (ME) and micellar (MC) systems. The partitioning behavior of cephalosporins in microemulsions was characterized calculating the capacity factor. The required parameters for the determination of the capacity factor (micro(aq) and micro-me are the electrophoretic mobilities of the solutes in the aqueous phase and the microemulsion phase, micro(eff) is the effective mobility in the microemulsion solution) were measured by EKC using cationic and anionic microemulsion systems consisting of the surfactants/n-heptane/1-butanol/10 mM phosphate buffer solution, pH 7.0. Electrokinetic chromatography was shown to be a useful method to quantify the partitioning behavior of drugs in oil/water microemulsion. The logarithm of the capacity factor was correlated with the logarithm of the 1-octanol/water partitioning coefficients.

Smoking-induced changes in endothelium and platelets are not affected by hydroxyethylrutosides.

A random-order, double-blind crossover study was carried out to compare the effects of placebo and hydroxyethylrutosides on the endothelial cell count, platelet aggregate ratio and plasma concentrations of beta-thromboglobulin and platelet factor 4 in venous blood before and after smoking. Each of 24 male habitual smokers and 22 male non-smokers smoked two cigarettes during each of two 20 min periods separated by 1 week. The subjects were asked to take 600 mg of o-(beta-hydroxyethyl)-rutosides (Venoruton) or a placebo four times before each experimental smoking period and to abstain from smoking for 12 h before each period. Blood was obtained just before and after experimental smoking. The mean endothelial cell count and beta-thromboglobulin concentration increased and platelet aggregate ratio decreased to a statistically significant extent after taking placebo or rutosides while the platelet factor 4 concentration did not change significantly on either occasion. Plasma nicotine concentrations were not significantly correlated with the other variables after smoking. Neither the mean presmoking values nor smoking-induced changes in any variable were significantly affected by rutosides. The data suggest that smoking caused acute endothelial cell desquamation and enhanced platelet function which were not prevented by rutosides.

Cigarette smoking--induced enhancement of platelet function: lack of prevention by aspirin in men with coronary artery disease.

Increased cardiovascular morbidity and mortality among cigarette smokers may be mediated in part by enhanced platelet function. Previous data showed that cigarette smoking--induced lowering of the platelet aggregate ratio of normal individuals was prevented by taking aspirin before smoking. Our study was undertaken to determine whether similar results would occur in men with coronary artery disease and whether platelet factor 4 would be released. A random-order, double-blind crossover study comparing the effects of placebo, 0.15 gm aspirin, and 0.30 gm aspirin was done in 30 male habitual smokers with coronary artery disease. Each man took a tablet containing placebo or aspirin and then abstained from smoking for 12 hours before each of three 20-minute periods of smoking two tobacco cigarettes. Immediately before and after smoking, the platelet aggregate ratio and the concentration of platelet factor 4 in platelet-poor plasma were determined from antecubital venous blood. Twelve hours after placebo, the geometric mean concentration of platelet factor 4 was 13.6 ng/ml before and 19.7 ng/ml after smoking (P = 0.0006). The mean platelet aggregate ratio was 0.77 and 0.72, respectively (P less than 0.00001). Neither dose of aspirin affected the presmoking value of or the smoking-induced change in either variable. The data indicate that smoking stimulated platelet aggregate formation and release of the contents of platelet alpha-granules, which were unaffected by preadministration of aspirin. This contrasts with the previous study of normal habitual smokers whose ingestion of 0.32 gm aspirin prevented a smoking-induced decrease in the platelet aggregate ratio.