Protective effects of a PPARgamma agonist pioglitazone on anti-oxidative system in testis of diabetic rabbits.

In the present study, modulation of oxidative stress by pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, was examined in testis of alloxan-induced diabetic rabbits. In diabetic animals, an increase in the activity of anti-oxidative enzymes: superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R), and in the level of glutathione (GSH) but a decrease in the level of ascorbic acid (AA) were observed. These effects were accompanied by a significant increase in testicular lipid and protein oxidation. Pioglitazone affected the activity of Cu,Zn-SOD, normalized the activity of CAT, the level of AA as well as the levels of LPO and PCG without having any significant effect on blood glucose level.

Interleukin-6 and oxidative stress in plasma of alloxan-induced diabetic rabbits after pioglitazone treatment.

There is evidence that oxidative stress might be implicated in promoting a state of systemic inflammation in diabetic patients. Understanding the role of reactive oxygen species in the inflammatory response in diabetes becomes essential in finding preventive treatments. Pioglitazone is a new oral antidiabetic agent with potent antioxidant and anti-inflammatory properties. The drug is a high affinity ligand of peroxisome proliferator-activated receptor gamma. This receptor seems to be involved in the control of inflammation by modulating the production of inflammatory mediators. In the present study, the changes in some markers of enhanced oxidative stress and in the level of pro-inflammatory interleukin-6 (IL-6) were examined in plasma of diabetic rabbits after 4 and 8 weeks of pioglitazone treatment. Ascorbic acid (AA) concentration and total antioxidant status (TAS) in plasma of diabetic animals were diminished and significantly elevated after pioglitazone treatment (p < 0.05). Protein carbonyl groups (PCG) content and IL-6 concentration were elevated in plasma of diabetic animals and significantly diminished after pioglitazone treatment. The results obtained in the present study confirm the relations of cytokine systems with oxidative stress in plasma of diabetic subjects. They also suggest the antioxidative and antinflammatory properties of pioglitazone.

Development and validation of a HPLC method for the determination of cetirizine in pharmaceutical dosage forms.

A rapid, simple and accurate HPLC method is described for the assay of cetirizine in commercial dosage forms. Methanol was found to be a suitable extraction solvent for tablets and for preparing solutions from drops and oral liquids. The samples were chromatographed on a Nova-Pak C18 column and UV detected at 227 nm. The elution was achieved isocratically with a mobile phase of 0.067 M phosphate buffer pH 3.40/acetonitrile (1:1, v/v). Ketotifen was applied as an internal standard. The method was validated for linearity, precision, accuracy and limit of detection. The recovery (mean +/- SD) for tablets was 100.88% +/- 0.8967, for drops 100.35% +/- 0.4062 and for solutions 101.20% +/- 1.1698.

Differences in antioxidant status in skeletal muscle tissue in experimental diabetes.

BACKGROUND: It has been suggested that oxidative stress may play an important role in pathogenesis of diabetic complications. The present study was designed to evaluate the oxidative stress-related parameters in alloxan (A)-induced long-term diabetes in rabbits. METHODS: After 3, 6 and 12 weeks of diabetes, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R) and concentrations of ascorbic acid (AA) and free sulfhydryl compounds (SH) were measured in skeletal muscle of diabetic rabbits and the normal control subjects. The products of lipid peroxidation (MDA) were also estimated. RESULTS: In our tests, the muscle SOD activity, SH and AA concentrations were significantly reduced. CAT activity increased significantly at all time intervals. GSH-Px activity decreased after 3 weeks and then remained at the control level. GSSG-R activity decreased progressively at 3rd and 6th week and then significantly increased. MDA level increased initially, dropped below baseline after 6 weeks and then remained at the level of the control group. CONCLUSIONS: The changes observed in the present experiment suggest a significant imbalance in antioxidative system in the skeletal muscle of rabbits with alloxan-induced diabetes. Such study may lead to therapeutic approaches for limiting the damage from oxidation reactions and preventing the diabetic complications.

High-performance liquid chromatographic assay of trandolapril in capsules.

Rapid, simple and accurate chromatographic (HPLC) method for the determination of trandolapril was elaborated. Samples were chromatographed on a LiChrosorb RP-18 column and the mobile phase was acetonitrile -0.067 M phosphate buffer pH 2.7 (7:3, v/v). The UV detection at 220 nm and benazepril as an internal standard were used. The method was tested for linearity (over the range 4-20 micrograms.ml-1), precision and accuracy and was successfully applied for the quantitative determination of trandolapril in capsules.

Application of derivative UV spectrophotometry for the determination of enoxacin and nalidixic acid in tablets.

First-, second-, third- and forth-order derivative spectrophotometric methods, using "peak-zero" (P-O) and "peak-peak" (P-P) techniques of measurement have been developed for the determination of enoxacin and nalidixic acid in tablets. The calibration curves were linear in the concentration range of 2.0-12.0 micrograms ml-1 for the analysed quinolones. The procedure was simple, rapid and the results were reliable.

Application of derivative UV spectrophotometry for the determination of ciprofloxacin, norfloxacin and ofloxacin in tablets.

The first-, second-, third- and fourth-order derivative spectrophotometric methods, by using the "peak-zero" (P-0) and "peak-peak" (P-P) techniques of measurement have been developed for the determination of ciprofloxacin hydrochloride, norfloxacin and ofloxacin in tablets. The calibration curves are linear within the concentration range of 2.0-12.0 micrograms ml-1 for ciprofloxacin hydrochloride, 1.0-10.0 micrograms ml-1 for norfloxacin and 2.5-15.0 micrograms ml-1 for ofloxacin. The procedure is simple, rapid and the results are reliable.

Determination of fluoxetine in human plasma using reserved phase HPLC.

A rapid, simple, accurate method for the determination of fluoxetine in human plasma is presented. Liquid-liquid extraction of fluoxetine was carried out using diethyl ether. Chlorprothixene was applied as an internal standard. The samples were chromatographed on a LiChrosorb RP-18 (10 microns) column and the mobile phase was acetonitrile/phosphate buffer pH 2.70 (9:1). The detection was carried at 254 nm. A linear quantitative response curve was generated over a concentration range of 100-600 ng/ml. Overall extraction efficiency of the extraction procedure was found to be 86 to 91% with a correlation coefficient of 0.992.

Chromatographic analysis (TLC) of fluoxetine, doxepine, imipramine and opipramol in human plasma.

Fluoxetine, imipramine, doxepine and opipramol after liquid-liquid extraction were separated by TLC on silica gel 60 GF254 by ascending and horizontal technique using suitable mobile phases. The substances were identified by UV irradiation at 254 nm and by spraying of Amelinka's reagnet (up to the amount 0.25 microgram fluoxetine and 0.05 microgram imipramine, doxepine and opipramol).

[Extraction of glutethimide and methyprylon from blood using thin layer chromatography]. / Wykrywanie glutetimidu i metyprylonu we krwi metoda chromatografii cienkowarstwowej.

Glutethimide and methyprylone were extracted from blood and plasma at pH ca. 4 (acetate buffer) thrice with chloroform, using 2.5 solvent volume ratio to that of aqueous phase. Phenobarbital was used as an internal standard in thin-layer chromatography experiments on silica gel--to obtain of comparable ratios of Rf values of glutethimide and/or methyprylone to that of phenobarbital. Suitable conditions of the separation of three substances were established using one of following mobile phases: benzene-dioxane-aq.ammonia (15:4:1), chloroform-acetone-aq.ammonia (25:25:1), chloroform-acetone-diaethylamine (5:4:1) and chloroform-diethyl ether-acetone (5:3:2); on 7.5 x 2.5 cm plates; development time (at 5 cm distance) was up to 10 minutes. The concentrations as small as 0.1 microg of examined substances in 1 cm3 of plasma may be identified on chromatograms using 20% Na2CO3 solution.

Determination of drugs containing fluorine with ion-selective electrode. Part 1: Synthetic glucocorticosteroids.

Synthethic glucocorticosteroids (fludrocortisone acetate, fluocinolone acetate, flumethasone pivalate, triamcinolone acetonide and dexamethasone acetate) were determined on the basis of their fluoride content, when deflagrated after Schöniger, in three ways: by potentiometric titration or by direct potential measurement of ion-selective fluoride electrode or by spectrophotometry with lanthanum alizarin complexan.