Dietary flavonoids with a catechol structure increase alpha-tocopherol in rats and protect the vitamin from oxidation in vitro

To identify dietary phenolic compounds capable of improving vitamin E status, male Sprague-Dawley rats were fed for 4 weeks either a basal diet (control) with 2 g/kg cholesterol and an adequate content of vitamin E or the basal diet fortified with quercetin (Q), (-)-epicatechin (EC), or (+)-catechin (C) at concentrations of 2 g/kg. All three catechol derivatives substantially increased concentrations of alpha-tocopherol (alpha-T) in blood plasma and liver. To study potential mechanisms underlying the observed increase of alpha-T, the capacities of the flavonoids to i) protect alpha-T from oxidation in LDL exposed to peroxyl radicals, ii) reduce alpha-tocopheroxyl radicals (alpha-T (.) ) in SDS micelles, and iii) inhibit the metabolism of tocopherols in HepG2 cells were determined. All flavonoids protected alpha-T from oxidation in human LDL ex vivo and dose-dependently reduced the concentrations of alpha-T (.) . None of the test compounds affected vitamin E metabolism in the hepatocyte cultures. In conclusion, fortification of the diet of Sprague-Dawley rats with Q, EC, or C considerably improved their vitamin E status. The underlying mechanism does not appear to involve vitamin E metabolism but may involve direct quenching of free radicals or reduction of the alpha-T (.) by the flavonoids.     

Characterization of esterases from Cucurbita pepo cv. "Eskandrani"

Two of the six esterases identified in Cucurbita pepo cv. "Eskandrani" were purified to homogeneity using two chromatography steps: anion exchange and gel filtration. The molecular weights of C. pepo esterases EIc and EII were 50,000 +/- 1500 and 68,000 +/- 1900 Da from gel filtration and 47,000 and 66,000 Da from SDS/PAGE, respectively, suggesting a monomeric structure for both enzymes. Esterases EIc and EII had K(m) values of 1.22 and 1.56 mM and pH optima at 9.0 and 8.0, respectively. The substrate specificity of C. pepo esterases EIc and EII were determined for a number of p-nitrophenyl esters, where their affinity toward these substrates were decreased as carbon atom number increased. Esterases EIc and EII had the same temperature optima, 40 degrees C. Thermal stability studies of esterases EIc and EII indicated that half maximal activities of EIc and EII esterases were reached at 55 degrees C and 50 degrees C, while they lost 45%, 51% and 70%, 77% of their activities after 30 and 90 min of incubation at 40 degrees C, respectively. The effect of different metal cations and inhibitors were examined. The inhibition studies revealed that the active sites of the two esterases contain serine and cysteine residues. The characteristics of C. pepo esterases are closely similar to those of microbial esterases used in food processing and food industry.     

Neuropeptides of the vasoactive intestinal peptide/helodermin/pituitary adenylate cyclase activating peptide family elevate plasma cAMP in mice: comparison with a range of other regulatory peptides

A number of regulatory peptides were investigated for their ability to elevate plasma cAMP. Pituitary adenylate cyclase activating peptide (PACAP)-27, PACAP-38, helodermin, helospectin I and II, vasoactive intestinal peptide (VIP), glucagon, parathyroid hormone (PTH), calcitonin and calcitonin gene-related peptide were among the peptides that were highly effective in raising plasma cAMP when given intravenously in equimolar doses to conscious mice. PACAP-27 and -38 were more effective than any of the other peptides. PACAP 16–38, secretin, gastrin-17, galanin, somatostatin, cholecystokinin-8s, pancreatic polypeptide, substance P, peptide YY and neuropeptide Y were inactive and also did not interfere with the PACAP-27-evoked rise in plasma cAMP levels. Repeated injections of PACAP-27 every 30 min caused a progressive reduction in the plasma cAMP response (measured 5 min after each injection). Forskolin, an activator of adenylate cyclase, dose-dependently raised the plasma concentration of cAMP and displayed a synergistic effect when given in a low dose concurrently with PTH or PACAP-38. The phosphodiesterase inhibitor rolipram dose-dependently raised the plasma concentration of cAMP. Combined treatment with PACAP-27 and a threshold dose of rolipram resulted in an exaggerated plasma cAMP response. Kidney hilus ligation suppressed the responses to PACAP-38, PTH, helodermin, helospectin, VIP, glucagon and calcitonin. Hepatectomy suppressed the response to glucagon but was without effect on the response to the other peptides. Pancreatectomy and spleenectomy reduced the response to VIP, but was without effect on the response to the other peptides. PACAP-27 stimulated cAMP efflux from the isolated rat tail vein. Hence, it cannot be excluded that blood vessels contribute to the peptide evoked plasma cAMP response in vivo.     

Comparison of the potential of Ficus sycomorus latex and horseradish peroxidases in the decolorization of synthetic and natural dyes

The aim of this study was to compare the potential of Ficus sycomorus latex peroxidase (POL) and horseradish peroxidase (HRP) in the decolorization of a wide spectrum of eight synthetic dyes and two natural dyes, hibiscus flower color and pomegranate juice. We study for the first time the decolorization of natural dyes enzymatically. The highest decolorization percent was reported at 20 mg/l for all dyes treated with POL and HRP. Both the enzymes had lower decolorization % for azo-carmin (30–33%). During decolorization treatment, both natural dyes and titan yellow formed precipitates which settled down and were removed by centrifugation. The enhancement of the decolorization % of the most tested dyes by treatment with POL and HRP was reported in the presence of some redox mediators. The rate of decolorization was enhanced by increasing the time and the most significant changes were observed during the first 6 h of incubation. One hundred percent enhancement in decolorization was reported for azo-carmine in the presence of histidine and α-naphthol as redox mediators. A few of redox mediators caused no significant effect or decreases the decolorization % for a little number of tested dyes. The decolorization of dyes by POL and HRP in the presence of redox mediators appeared without the formation of precipitate. A similar decolorization % for all the tested dyes by POL and HRP was detected. The data suggested that the peroxidase/mediator system was an effective biocatalyst for the decolorization of synthetic and natural dyes, and POL could be used as a potential option for the application of dye decolorization.     

Pharmaceutical and Pharmacokinetic Evaluation of a Novel Fast Dissolving Film Formulation of Flupentixol Dihydrochloride

The objective of the present study was to develop fast dissolving oral film of the antipsychotic drug, flupentixol dihydrochloride, to enhance its bioavailability, optimize its therapeutic effect when used to treat depression with anxiety, and increase the convenience and compliance by the mentally ill, developmentally disable, elderly, and pediatric patients. Six formulae were prepared with different concentrations of water-soluble polymers vis. hydroxypropyl methylcellulose (HPMC E5) and carboxymethyl cellulose (CMC) by solvent casting technique. The prepared films were subjected to characterization for folding endurance, weight variations, thickness, disintegration time, drug release pattern, and drug content. Physical compatibility between the drug and excipients was guaranteed in the selected formulation (2% HPMC) by means of differential scanning calorimetry analysis and Fourier-transform infrared spectroscopy. This formulation revealed high stability after testing according to the International Conference on Harmonisation guidelines. In vivo studies based on single phase parallel design were carried out for the optimized formulation in healthy human volunteers. The concentration of flupentixol dihydrochloride in plasma samples was analyzed by a developed validated LC-MS/MS assay method and the pharmacokinetic parameters of the established formulation were compared with the commercially available oral tablets. Faster rate of absorption of flupentixol could be obtained from the oral film formulation and the relative bioavailability was found to be 151.06% compared to the marketed product.KEY WORDS: fast dissolving, flupentixol dihydrochloride, LC-MS/MS analysis, oral film, pharmacokinetics     

Solitary fibrous tumor of the kidney: a case report and review of the literature

A solitary fibrous tumor (SFT) is an unusual spindle cell neoplasm that usually occurs in the pleura but has recently been described in diverse extrapleural sites. Urogenital localization is rare, and only 19 cases of SFT of the kidney have been described. We report a case of a large SFT clinically thought to be renal cell carcinoma arising in the kidney of a 70-year-old man. The tumor was well circumscribed and composed of a mixture of spindle cells and dense collagenous bands, with areas of necrosis or cystic changes noted macroscopically and microscopically. Immunohistochemical studies revealed reactivity for CD34, CD99, and Bcl-2 protein, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of SFT. This tumor is benign in up to 90% of cases. The immunohistochemical study is the key to diagnosis.     

The Effects of Exendin-4 Treatment on Graft Failure: An Animal Study Using a Novel Re-Vascularized Minimal Human Islet Transplant Model

Islet transplantation has become a viable clinical treatment, but is still compromised by long-term graft failure. Exendin-4, a glucagon-like peptide 1 receptor agonist, has in clinical studies been shown to improve insulin secretion in islet transplanted patients. However, little is known about the effect of exendin-4 on other metabolic parameters. We therefore aimed to determine what influence exendin-4 would have on revascularized minimal human islet grafts in a state of graft failure in terms of glucose metabolism, body weight, lipid levels and graft survival. Introducing the bilateral, subcapsular islet transplantation model, we first transplanted diabetic mice with a murine graft under the left kidney capsule sufficient to restore normoglycemia. After a convalescent period, we performed a second transplantation under the right kidney capsule with a minimal human islet graft and allowed for a second recovery. We then performed a left-sided nephrectomy, and immediately started treatment with exendin-4 with a low (20μg/kg/day) or high (200μg/kg/day) dose, or saline subcutaneously twice daily for 15 days. Blood was sampled, blood glucose and body weight monitored. The transplanted human islet grafts were collected at study end point and analyzed. We found that exendin-4 exerts its effect on failing human islet grafts in a bell-shaped dose-response curve. Both doses of exendin-4 equally and significantly reduced blood glucose. Glucagon-like peptide 1 (GLP-1), C-peptide and pro-insulin were conversely increased. In the course of the treatment, body weight and cholesterol levels were not affected. However, immunohistochemistry revealed an increase in beta cell nuclei count and reduced TUNEL staining only in the group treated with a low dose of exendin-4 compared to the high dose and control. Collectively, these results suggest that exendin-4 has a potential rescue effect on failing, revascularized human islets in terms of lowering blood glucose, maintaining beta cell numbers, and improving metabolic parameters during hyperglycemic stress.     

Characterization of photophysical and base-mimicking properties of a novel fluorescent adenine analogue in DNA

To increase the diversity of fluorescent base analogues with improved properties, we here present the straightforward click-chemistry-based synthesis of a novel fluorescent adenine-analogue triazole adenine (A(T)) and its photophysical characterization inside DNA. A(T) shows promising properties compared to the widely used adenine analogue 2-aminopurine. Quantum yields reach >20% and >5% in single- and double-stranded DNA, respectively, and show dependence on neighbouring bases. Moreover, A(T) shows only a minor destabilization of DNA duplexes, comparable to 2-aminopurine, and circular dichroism investigations suggest that A(T) only causes minimal structural perturbations to normal B-DNA. Furthermore, we find that A(T) shows favourable base-pairing properties with thymine and more surprisingly also with normal adenine. In conclusion, A(T) shows strong potential as a new fluorescent adenine analogue for monitoring changes within its microenvironment in DNA.     

Development of novel flexible sugar ester vesicles as carrier systems for the antioxidant enzyme catalase for wound healing applications

The antioxidant enzyme catalase (CAT) was encapsulated in biocompatible flexible non-ionic sugar esters (SEs) nano-vesicles for potential topical administration. The effects of the SE hydrophilic lipophilic balance (HLB) value and the carbon chain length of the fatty acid ester of different SEs on the encapsulation efficiency (EE) were studied. Morphology of the vesicles was not altered upon CAT encapsulation using freeze fracture electron microscopy. The extrusion measurements indicated that there was an increase in the vesicle's flexibility index upon the inclusion of phospholipids. The mean diameter of the CAT-EV (ester vesicle; HSC and HSC–PL) was 222–275 nm using laser diffraction measurements. The catalytic efficiency (V_max/K_m) of CAT was improved after encapsulation by a factor of 1.7. Both free CAT and CAT-EV showed maximum catalytic activity at pH 7.0, and CAT-EV was more stable than free CAT at acidic pH, which is advantageous for successful topical delivery. Encapsulation of CAT in SE vesicles protected it against trypsin treatment. Encapsulated CAT retained more than 60% residual activity after 12 successive decomposition cycles of H₂O₂. CAT-EV activity was significantly preserved compared to that of free CAT at 4 °C for 180 days. The in vivo study showed a significant effect of the prepared CAT nano-vesicles on wound healing.     

Molecular detection of the <Emphasis Type="Italic">Aeromonas</Emphasis> virulence aerolysin gene in retail meats from different animal sources in Egypt

Meat commonly contain the same Aeromonas spp. which occur in human diarrhoeal and non-diarrhoeal faecal samples. Motile Aeromonas were isolated from 5.6% of total 302 samples. The distribution of the isolates were 5.9 and 5.2% in fresh and frozen samples, respectively. Of the 302 samples taken of the four animal meat species investigated, the genus Aeromonas were isolated in 12.3% of the fresh samples collected from buffalo meat, in 6.5% of the samples collected from sheep meat and 14.0% from the samples collected from the cattle frozen meat samples. The camel meat did not reveal any Aeromonas isolates. Aeromonas hydrophila was isolated as the most prevalent species with 6.8%, followed by Aeromonas caviae with 2.7% and Aeromonas sobria with 2.1% from the total meat samples. Aerolysin toxin gene (aerA) was detected in 3/17 isolates of A. hydrophila isolated from contaminated meat. Infection due to bacterial pathogen with such virulent factor through contact with contaminated meat while handling them, poses health hazards to humans.