Prolonged use of antibiotics can cause toxicity in human and animal cells and lead to the development of antibiotic resistance. The development of drug delivery systems for enhanced antibacterial properties of antibiotics could reduce toxic effects and minimize the development of resistance. The aim of this study was to evaluate the effectiveness of oxytetracycline in complexes with new polyphosphate ester-type transporters and to investigate the antimicrobial effect of these complexes on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus growth in vitro. Two polyphosphate ester-type transporters with different molecular weights were synthesized, and oxytetracycline was attached through the phosphorus groups. To determine the sensitivities of microorganisms, oxytetracycline hydrochloride and oxytetracycline complexes with polyphosphate ester-type transporters (P4 and P6) were added to liquid and solid media with E. coli, P. aeruginosa, and S. aureus in different doses. Oxytetracycline in complex with polyphosphate ester-type transporters at low doses (2.3 to 3.8 μg/disk or μg/mL) in both solid and liquid media inhibits the growth of S. aureus more effectively than oxytetracycline alone. The maximum influence on E. coli growth on solid media is observed at a dose of 8 μg/disk of oxytetracycline in combination with both P4 and P6 polyphosphate ester-type transporters. P. aeruginosa growth under the influence of oxytetracycline in combination with polyphosphate-ester type transporters in a liquid medium depends on the dose of antibiotic and the day of cultivation.

Determination of Benzalkonium Chloride in a Disinfectant by UV Spectrophotometry and Gas and High-Performance Liquid Chromatography: Validation, Comparison of Characteristics, and Economic Feasibility: Simple, fast, and validated UV-spectrophotometric, HPLC, and GC methods for the analysis of benzalkonium chloride in a disinfectant were developed. UV-spectrophotometric determination was based on measuring the amount of light absorption of aqueous solutions of benzalkonium chloride at 268nm. HPLC determination was achieved with a 150mm×4.6mm, 5.0μm C18 column. The mobile phase consisted of a 0.01 water solution of triethylamine (with pH 2.5) and acetonitrile in the ratio of 40:60v/v. The column temperature was kept at 30°C, and the injection volume was 10μL. The flow rate was 1.0mL/min, and the diode array detector was set at 215nm. GC determination was performed using a flame ionization detector on a glass capillary column ZB-WAX plus 30m×0.25mm with an inner coating thickness of 0.25μm. It creates a gradient increase in the temperature of the furnace to the maximum of 200°C. The temperature of the injector was 250°C, 1μl was injected, and the separation of the sample was 1:100. Helium was used as a carrier gas, and the gas flow rate was constant, equaling 1.6ml/min. The temperature of the detector was 250°C, and a mixture of hydrogen, helium, and air in a ratio of 30:8.5:350 was used in the split of the detector. All proposed methods were validated according to ICH guidelines with respect to the accuracy, precision (interday, intraday, and reproducibility), linearity, the limit of detection, the limit of quantitation, and robustness. All three methods were linear (R²=0.9970.999) over a concentration range of 400600μg/ml for UV and 80120μg/ml for HPLC and GC, accurate (recovery was 98.4101.7 for all methods), precise (RSD <2), and robust. The cost of the analysis of one sample of the disinfectant for the content of benzalkonium chloride by three methods was calculated. The comparison of the obtained results facilitates a more efficient allocation of laboratory resources, depending on the goal.

The effect of long-term oral taurine administration to rats on activity of lactate dehydrogenase (LDH), its isozyme content and activity in the whole blood, liver, thigh muscle, brain and testes tissues were studied in the present work. For this purpose male Wistar rats with body weight 190-220 g were randomly divided into three groups, they were orally administered drinking water (control group) or taurine solution 40 and 100 mg per kg of body weight ( groups I and II, respectively). The total lactate dehydrogenase activity was measured spectrophotometrically, the percentage content of isozymes was determined by electrophoresis in 7.5% poliacrylamide gel withfurther staining according to J. Garbus. It was found that the total lactate dehydrogenase activity increased in all studied tissues. In testes of animals of both groups and in brain of group I animals, the total percentage contents of isozymes that are responsible for lactate production (LDH4+LDH5) increased. In liver of animals of both groups and in whole blood of group II animals, the total percentage content of isozymes that produce pyruvate (LDH1+LDH2) increased. In thigh muscle of both groups and in brain of group II animals the balance between LDH1+LDH2 and LDH4+LDH5 content did not differ from control values, though total lactate dehydrogenase activity was significantly higher, than that in the control group. Thus, the increase in the lactate dehydrogenase activity under long-term oral taurine administration in different rat tissues was found to be tissue- and dose-dependent and was caused by the increase in the content of different isozymes. Such increase in group I animals might be explained by adaptive mechanisms to hypoxia caused by high doses of taurine. For group II animals high doses of taurine were toxic and directly affected metabolic processes in the animal bodies.

Biol. Stud. 2015: 9(2); 59–70 • DOI: https://doi.org/10.30970/sbi.0902.432 ANTIOXIDANT DEFENSE OF RAT ORGANISM AT LONG-TERM PER ORAL INJECTIO OF TAURINE

Досліджено вплив тривалого перорального введення таурину на фізіолого-біохімічні показники крові щурів як маркери функціонального стану організму тварин. Дослідження проведені на самцях щурів лінії Wistar (n=16) віком 4 місяці та масою 140–160 г. Тварин розділяли на чотири групи (по n=4) – контрольну, щурам якої протягом 28 діб щоденно вводили у стравохід питну воду (контроль), і три дослідні, яким вводили 5 (І дослідна група), 10 (ІІ дослідна група) та 20 (ІІІ дослідна група) мг таурину/кг маси тіла. Встановлено, що у тварин ІІ дослідної групи зростає вміст гемоглобіну як у цільній крові, так і в одному еритроциті. У щурів ІІ та ІІІ дослідних груп швидкість оксигенації гемоглобіну зростає щодо контролю у 1,5 та 2,5 разу відповідно, а концентрація глюкози у плазмі крові знижується на 36,7 та 18,4 %. Вміст холестерину у плазмі крові щурів усіх дослідних груп залишається на рівні контролю, а активність лактатдегідрогенази у цільній крові зростає. У плазмі крові тварин ІІІ дослідної групи знижується активність лужної фосфатази й аланінамінотрансферази. Активність аспартатамінотрансферази у плазмі крові тварин усіх дослідних груп не відрізняється від значень контролю. За таких умов коефіцієнт де Рітіса зростає у щурів І та ІІІ дослідних груп. Обговорюється роль таурину як активатора метаболізму.