Utility of gold nanoparticles in luminescence determination of trovafloxacin: comparison of chemiluminescence and fluorescence detection

Two novel sensitive sequential injection chemiluminescence analysis and fluorescence methods for trovafloxacin mesylate detection have been developed. The methods were based on the enhancement effect of gold nanoparticles on luminol–ferricyanide–trovafloxacin and europium(III)–trovafloxacin complex systems. The optimum conditions for both detection methods were investigated. The chemiluminescence signal was emitted due to the enhanced effect of gold nanoparticles on the reaction of luminol–ferricyanide–trovafloxacin in an alkaline medium. The response was linear over a concentration range of 1.0 × 10^–9 to 1.0 × 10^–2 mol/L (%RSD = 1.3), (n = 9, r = 0.9991) with a detection limit of 1.7 × 10^–10 mol/L (S/N = 3). The weak fluorescence intensity signal of the oxidation complex of europium(III)–trovafloxacin was strongly enhanced by gold nanoparticles and detected at λ_ex = 330 and λ_em = 540 nm. Fluorescence detection enabled the determination of trovafloxacin mesylate over a linear range of 1.0 × 10^–8 to 1.0 × 10^–3 mol/L (%RSD = 1.2), (n = 6, r = 0.9993) with a detection limit of 3.3 × 10^–9 mol/L. The proposed methods were successfully applied to the determination of the studied drug in its bulk form and in pharmaceutical preparations. The results were treated statistically and compared with those obtained from other reported methods. Copyright © 2015 John Wiley & Sons, Ltd.     

Assessment of anti-mutagenic,anti-histopathologic and antioxidant capacities of Egyptian bee pollen and propolis extracts

Bee pollen and propolis are popular, traditional health foods. The objective of the current study was to investigate the anti-mutagenic, anti-histopathologic and antioxidant effects among water extracts of Egyptian bee pollen (WEBP) and brown powder of water-soluble derivative propolis (WSDP) on cisplatin (CDDP) induced hepatic, renal, testicular and genotoxicity in male albino mice (Mus muscullus), in addition to their effects on the oxidant/antioxidant status in the tested organs. Hepatic, renal and testicular dysfunctions were evaluated histologically; while genotoxicity and cytotoxicity were evaluated by the bone marrow chromosomal aberration assay and mitotic index, respectively. Moreover, oxidative stress was explored via determination of lipid peroxidation, catalase activity and the concentration of the reduced form of glutathione. The treatment of mice with WEBP and WSDP at doses 140 and 8.4 mg/kg b. wt./day, respectively for 14 days simultaneously with CDDP (2.8 mg/kg b. wt.) resulted in significant protection. The positive control animals taken CDDP alone showed toxic histological and genetical manifestations (at P < 0.05) accompanied with an elevated content of peroxidized lipid and lowered catalase activity and glutathione concentration in the homogenate of liver, kidney and testis tissues (at P < 0.001). These toxic side effects in all tested organs were greatly ablated with a significant reduction in lipid peroxidation level and elevation in catalase activity and glutathione concentration (P < 0.001) when using both WEBP and WSDP. On the basis of the present assays, Bee pollen appears more potent in exerting an ameliorative effect and this effect was more pronounced in testis.     

Application of silver nanoparticles to the chemiluminescence determination of cefditoren pivoxil using the luminol–ferricyanide system

A new simple, accurate and sensitive sequential injection analysis chemiluminescence (CL) detection method for the determination of cefditoren pivoxil (CTP) has been developed. The developed method was based on the enhancement effect of silver nanoparticles on the CL signal arising from a luminol–potassium ferricyanide reaction in the presence of CTP. The optimum conditions relevant to the effect of luminol, potassium ferricyanide and silver nanoparticle concentrations were investigated. The proposed method showed linear relationships between relative CL intensity and the investigated drug concentration at the range 0.001–5000 ng/mL, (r = 0.9998, n = 12) with a detection limit of 0.5 pg/mL and quantification limit of 0.001 ng/mL. The relative standard deviation was 1.6%. The proposed method was employed for the determination of CTP in bulk drug, in its pharmaceutical dosage forms and biological fluids such as human serum and urine. The interference of some common additive compounds such as glucose, lactose, starch, talc and magnesium stearate was investigated. In addition, the interference of some related cephalosporins was tested. No interference was recorded. The obtained sequential injection analysis‐CL results were statistically compared with those from a reported method and did not show any significant differences. Copyright © 2014 John Wiley & Sons, Ltd.     

Determination of the anti‐viral drug Ribavirin in dosage forms via micelle‐enhanced spectrofluorimetric method

A simple and sensitive spectrofluorimetric method was developed for the determination of Ribavirin in pharmaceutical formulations. The proposed method was based on the fluorescence spectral behaviour of Ribavirin in a sodium dodecyl sulfate (SDS) micellar system. In an aqueous acetate buffer solution of pH 4.0, the fluorescence intensity of Ribavirin was significantly enhanced by about 217% in the presence of SDS. Fluorescence intensity was measured at 396 nm after excitation at 270 nm for Ribavirin. The fluorescence‐concentration plot was rectilinear over the range of 0.01‐3.0 µg/mL for Ribavirin with a lower detection limit of 5.02 x 10^‐3 µg/mL. The method was successfully applied to the analysis of the drug in its commercial capsules. Results were in good agreement with those obtained with the official method. The application of the proposed method was extended to stability studies of Ribavirin after exposure to different forced degradation conditions such as acidic, alkaline, photo and oxidative conditions according to ICH guidelines. Copyright © 2012 John Wiley & Sons, Ltd.     

Lucrative antioxidant effect of metformin against cyclophosphamide induced nephrotoxicity

Cyclophosphamide is anticancer drug with a well-Known nephrotoxicity. This work was applied to study the lucrative antioxidant influence of metformin as co-therapy on the nephrotoxicity induced by cyclophosphamide in the treatment of different cancer diseases. Four groups of male Sprague Dawley rats were used; Control group (C) received single I.P. injection of 0.2 ml saline, Metformin (MET) group received daily gavage of 200 mg/kg metformin for two weeks, Cyclophosphamide (CP) group received single I.P. injection of 200 mg/kg CP, Protector group (CP.MET) received daily gavage of 200 mg/kg metformin for two weeks and single I.P. injection of 200 mg/kg CP at day 7. By day 14 rats were euthanized. Samples were collected from kidney tissues and blood for kidney function evaluation, histopathological and assessment of oxidative stress markers. The results disclosed that CP yields many functional and structural damage to the kidney, worsened oxidative stress markers and kidney function indicators. The protector group displayed better kidney tissue morphology, acceptable kidney function indicators as well as satisfactory oxidative stress markers.In assumption, metformin could be combined with CP owing to its lucrative effect counter to CP persuaded nephrotoxicity.     

Common Antigen(s) in Cotton to Fusarium oxysporum f. sp. vasinfectum

Antigen-antibody reactions in agar gel, as demonstrated by the double diffusion technique, between cotton seed globulins and the antisera specific to each of the tested Fusarium oxysporum f. sp. vasinfectum isolates as well as the antiserum of F. moniliforme revealed that all the tested antisera of F. oxysporum f. sp. vasinfectum reacted with seed globulins except the Menoufi cultivar globulins. No precipitin lines were detected in the reaction between the antigenof the cotton cultivar Acala SJ2 versus the antiserum of P10 isolate. The 5 cultivars behaved differently with each fungal antiserum to the extent that they could be distinguished accordingly. When the seed globulins of the susceptible cultivars (Giza 74, and Bahtim 110) reacted with antiserum of the tested F. oxysporum f. sp. vasinfectum isolates, more precipitin lines were formed than the resistant cultivars. On the other hand, no obvious reaction was detected in case of F. moniliforme antiserum.     

Using HHsearch to tackle proteins of unknown function: A pilot study with PH domains

Advances in membrane cell biology are hampered by the relatively high proportion of proteins with no known function. Such proteins are largely or entirely devoid of structurally significant domain annotations. Structural bioinformaticians have developed profile‐profile tools such as HHsearch (online version called HHpred), which can detect remote homologies that are missed by tools used to annotate databases. Here we have applied HHsearch to study a single structural fold in a single model organism as proof of principle. In the entire clan of protein domains sharing the pleckstrin homology domain fold in yeast, systematic application of HHsearch accurately identified known PH‐like domains. It also predicted 16 new domains in 13 yeast proteins many of which are implicated in intracellular traffic. One of these was Vps13p, where we confirmed the functional importance of the predicted PH‐like domain. Even though such predictions require considerable work to be corroborated, they are useful first steps. HHsearch should be applied more widely, particularly across entire proteomes of model organisms, to significantly improve database annotations.      

Prospects for using a new sequential chemiluminescence strategy for monitoring the caffeine content in soft and energy drinks via the catalytic activities of different nano‐metal oxides

This article suggests a new sequential injection analysis chemiluminescence (SIA‐CL) strategy for monitoring the caffeine (CAF) content in soft and energy drinks using the catalytic activities of different nano‐metal oxides. The present study describes three different SIA‐CL systems (luminol–ferricyanide (III) coupled with Fe₂O₃ or ZnO nanoparticles (NPs), and luminol–H₂O₂ coupled with CuONPs. All experimental conditions were optimized and the linear concentration ranges of pure CAF were evaluated using the calibration graphs. The selectivity of the developed SIA‐CL systems was studied under the influence of various interfering species that may be present in soft or energy drinks such as sodium ions, sucrose, glucose, sodium benzoate, sodium citrate, riboflavin, niacin, citric, phosphoric and ascorbic acids. International Council for Harmonization (ICH) guidelines were obeyed for the validation of the suggested CL methods. The developed SIA‐CL systems displayed linear relationships over the concentration ranges 1.0–350, 5.0–400 and 10.0–400 μg ml^?1 with Fe₂O₃ NPs, ZnO NPs and CuO NPs, respectively. The recorded lower limits of detection and quantification were 0.7, 2.7 and 7.8 μg ml^?1, and 1.0, 5.0 and 10.0 μg ml^?1 for the previously mentioned SIA‐CL systems. The results revealed high selectivity for CAF determination and were in good agreement with those obtained by other reported methods.     

Nature-inspired male contraceptive and spermicidal products

Phytochemistry Reviews - The use of hazardous female contraceptives is still the first choice in family planning programs. Moreover, all the drugs examined to be used as infertility inducers in...