Gaber E. El-Desoky

Modification of Hibiscus cannabinus fiber by graft copolymerization: application for dye removal

AbstractHibiscus cannabinus fiber was modified by graft copolymerization with vinyl monomer acrylic acid (AAc) and binary mixture of AAc and acrylamide (AAm). The different reaction parameters were optimized to get maximum grafting yield. The optimized percent grafting for AAc and binary mixture (AAc + AAm) was found to be 93.6 and 74.6%, respectively, at the molar concentration of 0.35 M for AAc and 0.4 M for AAm. The raw AAc grafted H. cannabinus fiber (Hcf-g-polyAAc) and AAc + AAm grafted H. cannabinus fiber (Hcf-g-polyAAc + AAm) were characterized by FTIR and scanning electron microscopy. The modified H. cannabinus fibers were used as potential candidate for the removal of dye from aqueous system.

Improvement of mercuric chloride-induced testis injuries and sperm quality deteriorations by Spirulina platensis in rats.

The present study was undertaken to investigate the protective effect of the filamentous cyanobacterium Spirulina platensis (S. platensis) on mercury (II) chloride (HgCl2)-induced oxidative damages and histopathological alterations in the testis of Wistar albino rats. The animals were divided into four equal groups, i ) control, ii ) HgCl2, iii ) S. platensis and iv ) combination of HgCl2+S. platensis. Oxidative stress, induced by a single dose of HgCl2 (5 mg/kg, bw; subcutaneously, s.c.), substantially decreased (P<0.01) the activity level of testicular key enzymatic antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT and glutathione peroxidase, GPx), oxidative stress makers (blood hydroperoxide; testicular reduced glutathione, GSH and malondialdehyde, MDA), and testicular mercury levels. Moreover, HgCl2 administration resulted in a significant (P<0.01) increase in the number of sperms with abnormal morphology and decrease in epididymal sperm count, motility, plasma testosterone level and testicular cholesterol. Furthermore, HgCl2 exposure induced histopathological changes to the testis including morphological alterations of the seminiferous tubules, and degeneration and dissociation of spermatogenic cells. Notably, oral pretreatment of animals with Spirulina (300 mg/kg, bw) lowered the extent of the observed HgCl2-mediated toxicity, whereby significantly reducing the resulting lipid peroxidation products, mercury accumulation in the testis, histopathological changes of the testes and spermatozoal abnormalities. In parallel, the pretreatment with Spirulina also completely reverted the observed Hg-Cl2-induced inhibition in enzymatic activities of antioxidant biomarkers (SOD, CAT and GPx) back to control levels. The pretreatment of rats with S. platensis significantly recovered the observed HgCl2-mediated decrease in the weight of accessory sex organs. Taken together, our findings clearly highlight the role of S. platensis as a protective modulator of HgCl2-induced testicular injuries and suggest some therapeutic potential in mammals. Further investigation of therapeutic strategies employing Spirulina against heavy metals toxicity in humans is therefore warranted.

Preparation of a novel chitosan-g-poly(acrylamide)/Zn nanocomposite hydrogel and its applications for controlled drug delivery of ofloxacin.

Chitosan-g-poly(acrylamide)/Zn (CPA-Zn) nanocomposite was synthesized using simple method in the presence of microwave radiations. CPA-Zn nanocomposite was characterized by various analytical techniques. CPA-Zn nanocomposite was used for controlled drug delivery of ofloxacin. The maximum drug release was 75% which was observed in acidic medium. The cumulative drug release and drug released kinetics of CPA-Zn was investigated. It was noticed that the drug release behavior depended upon the pH of medium as well as on the the nature of matrix. CPA-Zn nanocomposites were also studied for their antibacterial activity against E. coli bacteria.

Protection of α-tocopherol and selenium against acute effects of malathion on liver and kidney of rats

Protection from effects of the organophosphate insecticide, malathion on the liver and kidney of male Wistar albino rats by α-tocopherol and selenium was investigated. Significantly greater (P<0.01 ) mean concentrations of malondialdehyde (MDA) and lesser concentrations (P<0.01) of reduced glutathione (GSH) and tissues total proteins were observed in liver and kidney of rats exposed to malathion. Activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were less in livers and kidneys of rats exposed to malathion. These effects caused by exposure to malathion were reversed when rats were subsequently treated orally with 100 mg/kg b.w. tocopherol and/or 0.1 mg selenium/kg b.w. Both tocopherol and selenium (Se) reduced the concentration of MDA, and increased concentration of total proteins and reduced glutathione and mean activities of SOD, CAT and GPx, to levels that were not significantly different from unexposed, control rats, previous to exposure to malathion. Selenium was significantly ( P<0.05) more effective at recovering activities of SOD and GPx in liver and kidney of malathion treated rats than was αtocopherol, whereas, α-tocopherol was significantly ( P<0.05) more effective at recovering activities of CAT in liver and kidney than was Se. Both α-tocopherol and Se were effective in alleviating oxidative damage in liver and kidney of rats caused by malathion.

Chemiluminescence determination of folic acid by a flow injection analysis assembly

A flow injection (FI) method is reported for the determination of folic acid by chemiluminescence method. This method is based on the reaction of folic acid with Ru(bipy)(3)(2+) and Ce(IV) to produce chemiluminescence. The calibration curve was linear over the range of 2.5×10(-5)-3.1×10(-7) mol/L with a detection limit of 2.3×10(-8) mol/L (S/N=3). The relative standard deviation of 1.0×10(-6) mol/L folic acid was found 3.5% (n=11). The influences of potential interfering substances were studied. The recovery was higher than 95.3%. The method was accurate, sensitive, and effective for assay of folic acid. This CL method was successfully applied to the determination of folic acid in pharmaceutical preparations. The mechanism of CL reaction was also studied.

Amino acid and vitamin determinations by TLC/HPTLC: review of the current state

AbstractSeveral methods to determine amino acids and vitamins in biological and pharmaceutical samples have been reported. Thin layer chromatography (TLC) finds its place when the relatively costly equipment required by other methods is unavailable. This review covers the 1991–2010 literature on TLC/HPTLC (high performance thin layer chromatography) amino acid and vitamin determinations. It gives an overview of the special features as well as the problems in TLC/HPTLC determinations of amino acids and vitamins. Various chromatographic systems useful in amino acid and vitamin identification, separation and quantitation of are presented in tabular form. Future prospects of TLC/HPTLC for amino acid and vitamin determinations are also discussed.

Nicotinic acid adsorption thermodynamics study on carboxymethyl cellulose Ce(IV) molybdophosphate composite cation-exchanger

The thermodynamics of nicotinic acid adsorption from aqueous solution on carboxymethyl cellulose Ce(IV) molybdophosphate composite cation exchanger were studied. The composite cation exchanger was synthesized by sol–gel method and thereby characterized using scanning electron microscopy, thermogravimetric analysis, X-ray powder diffraction and fourier transform infra red spectroscopy. The analytical applicability and thermodynamic parameters, such as Freundlich constant, thermodynamic equilibrium constant (Kο), standard free energy changes (ΔG°), standard enthalpy changes (ΔH°) and standard entropy changes (ΔS°) of this composite cation exchanger have been evaluated. The thermodynamic parameters showed that the adsorption of nicotinic acid onto composite cation exchanger is feasible, spontaneous and exothermic, suggesting their suitability for the potential application of nicotinic acid removal from waste water.

Antidiabetic and hypolipidemic effects of Ceylon cinnamon (Cinnamomum verum) in alloxan-diabetic rats

The objective of this study was to examine the effects of increasing doses of Ceylon cinnamon’s aqueous extract on fasting plasma glycemic and lipidemic profiles, as well as body weight gain, food intake and food efficiency ratio (FER) in alloxan-diabetic rats. Cinnamon extract was administered to rats at different dosages (200, 400, 600 and 1200 mg/kg bw) for thirty days followed by a fifteen day wash out period. After thirty days, the administration of diabetic rats with the lowest dose (200 mg/kg bw) of cinnamon extracts was the most efficient in affecting significant (P < 0.05) reduction in the levels of fasting blood glucose (FBG), but no hypoglycaemic activity was observed in the untreated diabetic control rats. Moreover, cinnamon treatment significantly (P < 0.05) lowered the serum levels of total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides (TG), compared with the diabetic positive control (PC) rats. The observed hypoglycemic and hypolipidemic effects of cinnamon extracts in diabetic rats were associated with significant improvements in body weight gain, FI and FER. While, after the 15-day wash-out period, the level of FBG, TC, LDL and TG gradually increased, they were still lower than that in the diabetic PC group of rats. It can be concluded that cinnamon extract exhibits a modulatory role of glycemic and lipidimic profiles in diabetic rats.

Synergistic Effect of Polyaniline Modified Silica Gel for Highly Efficient Separation of Non Resolvable Amino Acids

Herein, we present a comparative study for the analysis of amino acids on silica gel (SIG) and polyaniline (Pani) modified SIG as stationary phases using 1% ethanolic solution of boric acid as mobile phase. The separation studies revealed that in the case of modified SIG, improved separations of two component mixtures of amino acids were achieved. Some new combinations of binary separations were achieved on Pani modified SIG layer, which were not efficiently separated in the case of pure SIG. Thus, by the modification of SIG surface with Pani, sorbent with enhanced chromatographic performance can be achieved.

Aqueous Urea Solution Promoted Resolution of Five-Component Mixture of Amino Acids on Silica TLC Plates

A thin-layer chromatographic system comprising of silica gel as stationary phase and 1.0% aqueous urea solution as mobile phase (pH 7.44) has been developed for the mutual separation of five-component mixture of amino acids [lysine (RF = 0.38), histidine (RF = 0.59), leucine (RF = 0.78), alanine (RF = 0.87), and glutamic acid (0.98)]. The presence of foreign substances such as metal cations, anions, and vitamins as impurities in the sample on the separation was also examined. Thin-layer chromatographic parameters such as standard deviation (SD), ΔRF, separation factor (α), and resolution (RS) values of separated components of the mixture of these five amino acids were calculated. The limits of detection for lysine, leucine, and alanine were found to be 1.5 µg spot−1, whereas for histidine and glutamic acid, these were 1.2 µg and 3.0 µg spot−1, respectively. The proposed TLC system is applicable for the identification and separation of amino acids in pharmaceutical formulations.