Abstract

      Background and Objectives: Antibiotic resistance in bacteria has actuated researchers toward evaluating many new antibacterial compounds of which are the thiazoles. In this research the inhibitory effects of novel thiazole derivatives were unraveled on Staphylococcus aureus, Streptococcus agalactiae, Pseudomonas aeruginosa and Klebsiella pneumoniae and oxothiazole liver toxicity effects were assessed on mice.

       Methods: The antibacterial effect of thiazole derivatives was evaluated by measuring the halo zone with disk diffusion method and dilution procedure in microplate in order to discriminate the minimum inhibitory concentration (MIC) and the liver toxicity of oxothiazole, also, was discerned by injecting 160 mg/kg, 265 mg/ kg and 350 mg/kg doses to mice as well as scrutinizing the liver histopathology.

      Results: Derivatives utilized in experiment had no inhibitory effect on Pseudomonas aeruginosa and Klebsiella pneumoniae, though their inhibitory effect was observed on Staphylococcus aureus and Streptococcus agalactiae. For Staphylococcus aureus and Streptococcus agalactiae the diameters of growth inhibition zone were 8.9-22.3 mm and 16.1-25.6 mm, respectively and MIC of 50-200 and 25-100 µg/ml by order. Additionally, by increasing the injection dose of oxothiazole with 160 mg/ml, 265 mg/ml and 350 mg/ml doses, the hepatitis lesions and liver necrosis were observed in experimental mice.

       Discussion: The thiazole derivatives possessed more inhibitory trace on gram positive bacteria than gram negative ones. Furthermore, the likely presence of oxygen link to thiazole ring in tested compounds results in the enhancement of inhibitory potency of these substances. Besides, our results suggest that high doses of oxothiazole cause severe liver damage and rapid death less than 24 hours.

       Keywords: Thiazole derivatives, Antibacterial effects, Oxothiazole, Liver toxicity.

ABSTRACT

         Background and Objectives: Size of silver nanoparticles synthesized by ethanol and Bacillus lichenioformisis 20 nm and 15 nm, respectively. Nanoparticles can be used in treatment of several diseases. Chemical and biological methods have been used to synthesize silver nanoparticles. The aim of this study was to compare the size, shape and coating of silver nanoparticles synthesized by the chemical and biological methods.

        Methods: Ethanol was used in the chemical reduction method and B. licheniformis was used in the biological method. Physical evaluation (salt test), absorbance measurement at 450 nm and imaging by transmission electron microscopy were performed to compare nanoparticles in terms of size, shape and coating.

         Results: Observed maroon color, maximum absorption at 400-450 nm range and electron microscopy images confirmed the presence of nanoparticles. The shape of nanoparticles synthesized by the two methods was spherical. However, biosynthesized nanoparticles were smaller and had protein coating.

          Conclusion: Given the smaller size of biosynthesized nanoparticles and presence of coating confirmed by the electron microscopy images, biosynthesis is recommended because of enhanced nanoparticles properties and reduced toxicity.

            Keywords: Nanoparticles, Coating, Toxicity.

ABSTRACT

       Background and Objective: Raw fish is a highly perishable product that deteriorates due to chemical changes and microbial growth. Biogenic amines (BAs) are generated in course of bacterial spoilage in fish that may lead to BA toxicity, particularly in adverse storage conditions. The purpose of this study was to prevent the BAs toxicity caused by common carp (Cyprinus carpio).

       Methods: Live Common carps were purchased from a local market. The samples were first divided into control and lactic acid treatment groups, and then stored at 4 C. the  concentrations of three BAs were determined (histamine, putrescine and cadaverine) with high performance liquid chromatography equipped with UV detector.

        Results: Cadaverine and putrescine had the highest concentrations in control group (400.42 and 293.90 mg/kg, respectively). Histamine remained undetectable until the middle of storage period. Histamine and cadaverine concentrations in the lactic acid group were significantly lower compared to that of control group (p < 0.05).

         Conclusion: The formation of histamine and cadaverine is effectively controlled by lactic acid treatment, although such effect was not observed on putrescine in the entire storage period.

          Keywords: Biogenic Amines, Toxicity, Carps, Histamine.

ABSTRACT

       Background and Objective: Doxorubicin (DOX) is an effective anticancer drug. It has been shown that  a short-term exercise performed prior to DOX-treatment has no effect on cardiotoxicity in young rats. In the present study, old and young rats were evaluated to determine the protective effects of pre-treatment with short-term exercise on DOX-induced oxidative damage in cardiac tissue.

        Methods: Forty-eight male Wistar rats were randomly divided into two groups of young and old, and later divided into three sub-groups of young+DOX, young+training+DOX, young+training+salin, old+DOX, old+training+DOX and old+training+salin. The training protocol included treadmill running for 25-39 min/day at 15-17 m/min, 5 days/week for three weeks. All treatments were carried out 24h after the last exercise bout. The rats were sacrificed 48h

 after DOX administration.

        Results: Although DOX injection significantly affected the cardiac tissue of old rats compared to young rats, pretreatment with endurance training in DOX-treated rats caused an increase in Heat shock protein (3.02% vs. 23.36) and superoxide dismutase (30.12% vs. 31.12), and a decrease in malondialdehyde (10.92% vs. 19.60) in both old and young rats.

         Conclusion: Although DOX-induced production of free radicals and cardiotoxicity in aged rats is more than that in young rats,  the short-term aerobic exercise reduced the damaging effects of free radicals in the old rats more than in young ones. The concentration of antioxidant enzymes also increases with exercise in the old rats compared to young rats.

          Keywords: Cardiotoxicity, Doxorubicin, Oxidative Stress, Aerobic Exercise.