Red Propolis and Its Dyslipidemic Regulator Formononetin: Evaluation of Antioxidant Activity and Gastroprotective Effects in Rat Model of Gastric Ulcer.

Propolis has various pharmacological properties of clinical interest, and is also considered a functional food. In particular, hydroalcoholic extracts of red propolis (HERP), together with its isoflavonoid formononetin, have recognized antioxidant and anti-inflammatory properties, with known added value against dyslipidemia. In this study, we report the gastroprotective effects of HERP (50-500 mg/kg, p.o.) and formononetin (10 mg/kg, p.o.) in ethanol and non-steroidal anti-inflammatory drug-induced models of rat ulcer. The volume, pH, and total acidity were the evaluated gastric secretion parameters using the pylorus ligature model, together with the assessment of gastric mucus contents. The anti-Helicobacter pylori activities of HERP were evaluated using the agar-well diffusion method. In our experiments, HERP (250 and 500 mg/kg) and formononetin (10 mg/kg) reduced (p < 0.001) total lesion areas in the ethanol-induced rat ulcer model, and reduced (p < 0.05) ulcer indices in the indomethacin-induced rat ulcer model. Administration of HERP and formononetin to pylorus ligature models significantly decreased (p < 0.01) gastric secretion volumes and increased (p < 0.05) mucus production. We have also shown the antioxidant and anti-Helicobacter pylori activities of HERP. The obtained results indicate that HERP and formononetin are gastroprotective in acute ulcer models, suggesting a prominent role of formononetin in the effects of HERP.

Development of Chitosan/Silver Sulfadiazine/Zeolite Composite Films for Wound Dressing.

Biopolymeric films with silver sulfadiazine (AgSD) are proposed as an alternative to the occlusive AgSD-containing creams and gauzes, which are commonly used in the treatment of conventional burns. While the recognized cytotoxicity of AgSD has been reported to compromise its use as an antimicrobial drug in pharmaceuticals, this limitation can be overcome by developing sustained-release formulations. Microporous materials as zeolites can be used as drug delivery systems for sustained release of AgSD. The purpose of this work was the development and characterization of chitosan/zeolite composite films to be used as wound dressings. Zeolite was impregnated with AgSD before the production of the composite films. The physicochemical properties of zeolites and the films were evaluated, as well as the antimicrobial activity of the polymeric films and the cytotoxicity of the films in fibroblasts Balb 3T3/c. Impregnated zeolite exhibited changes in FTIR spectra and XRD diffraction patterns, in comparison to non-impregnated composites, which corroborate the results obtained with EDX-SEM. The pure chitosan film was compact and without noticeable defects and macropores, while the film with zeolite was opaquer, more rigid, and efficient against Candida albicans and some gram-negative bacteria. The safety evaluation showed that although the AgSD films present cytotoxicity, they could be used in a concentration-dependent fashion.

Analysis of in vivo absorption of didanosine tablets in male adult dogs by HPLC / 药物分析学报

Didanosine is an effective antiviral drug in untreated and antiretroviral therapy-experienced patients with Human Immunodeficiency Virus (HIV).An automated system using on-line solid extraction and High performance Liquid Chromatography (HPLC) with ultraviolet (UV) detection was developed and validated for pharmacokinetic analysis of didanosiae in dog plasma.Modifications were introduced on a previous methodology for simultaneous analysis of antiretroviral drugs in human plasma.Extraction was carried out on C18 cartridges,with high extraction yield as stationary phase,whereas mobile phase consisted of a mixture of 0.02 M potassium phosphate buffer,acetonitrile (KH2PO4:acetonitrile:96∶4,v/v) and 0.5％ (w/v) of heptane sulphonic acid.The pH was adjusted to 6.5 with triethylamine.All samples and standard solutions were chromatographed at 28℃.For an isocratic run,the flux was 1.0 mL/min,detection was at 250nm and injected volume was 20μL.The method was selective and linear for concentrations between 50 and 5000 ng/mL.Drug stability data ranged from 96％ to 98％,and limit of quantification was 25 ng/mL.Extraction yield was up to 95％.Drug stability in dog plasma was kept frozen at -20℃ for one month after thee freeze-thaw cycles,and for 24 h after processing in the auto sampler.Assay was successfully applied to measure didanosine concentrations in plasma dogs.