The protective effects of vitamin C on the DNA damage, antioxidant defenses and aorta histopathology in chronic hyperhomocysteinemia induced rats.

The aim of this study was to investigate the protective effect of vitamin C towards hyperhomocysteinemia (hHcy) induced oxidative DNA damage using the comet assay. The increase in plasma homocysteine levels is an important risk factor for vascular and cardiovascular diseases through free radical production. This study was also conducted to investigate the histopathological changes in the thoracic aorta and the oxidant/antioxidant status in heart, liver and kidney tissues. Twenty-four adult male Wistar rats were divided as control, hHcy and hHcy+vitamin C group. Chronic hHcy was induced by oral administration of l-methionine (1g/kg/day) for 28 days. Vitamin C was given 150mg/kg/day within the specified days. DNA damage was measured by use of the comet assay in lymphocytes. Levels of malondialdehyde (MDA) and glutathione (GSH) as well as catalase (CAT) and superoxide dismutase (SOD) activities were determined in heart, liver and renal tissues. Results show that l-methionine administration significantly increased % Tail DNA and Mean Tail Moment in hHcy group as compared with other groups. Vitamin C treatment significantly decreased the high MDA levels and increased activity of antioxidant enzymes in tissues. Aortic diameter and thickness of aortic elastic laminae were significantly lower in hHcy+vitamin C group. Comet assay can be used for the assessment of primary DNA damage caused by hHcy. Histopathological findings showed that vitamin C may have a preventive effect in alleviating the negative effects of hHcy. Vitamin C might be useful in the prevention of endothelial dysfunction caused by hHcy.

Comparison of in vitro antimicrobial susceptibility in Flavobacterium psychrophilum isolated from rainbow trout fry.

The aim of this study was to demonstrate the presence of Flavobacterium psychrophilum in the west Aegean region of Turkey and to evaluate the in vitro susceptibility of F. psychrophilum (isolated from the fry of rainbow trout Oncorhynchus mykiss) to seven antimicrobial agents, as determined by the disk diffusion and agar dilution methods. A total of 250 rainbow trout fry (weight = 2-5 g; total length = 3-6 cm) were examined, and 20 bacterial isolates were phenotypically identified. Antimicrobial agents included in this investigation were amoxicillin-clavulanic acid (AMC), erythromycin (E), enrofloxacin (ENR), florfenicol (FFC), gentamicin (CN), oxytetracycline (OT), and sulfamethoxazole-trimethoprim (SXT). Disk diffusion and agar dilution methods were performed according to published standards. Minimum inhibitory concentration (MIC) ranges were determined using the agar dilution method for F. psychrophilum isolates. Resistance of F. psychrophilum to CN (disk diffusion method: 70%; agar dilution method: 95%), E (65%; 100%), and SXT (75%; 100%) was high using both methods. Resistance to ENR (10%; 15%) and FFC (25%; 25%) was low with both methods; MIC90 (minimum concentration required to inhibit bacterial growth by 90%) was 4 microg/mL for ENR and 16 microg/mL for FFC. Ninety percent of the F. psychrophilum isolates were resistant to AMC based on the disk diffusion method, while only 15% of isolates showed resistance based on the agar dilution method. For OT, 20% of isolates were resistant based on disk diffusion, while 75% exhibited resistance based on agar dilution. The importance of susceptibility testing when facing an outbreak of F. psychrophilum at a fish farm is obvious; however, the discrepancies between testing methods for AMC and OT require further studies.

The effect of diet type on the plasma disposition of triclabendazole in goats.

The effect of two different diet types (concentrate feed+hay and grazing) on the pharmacokinetic profiles of triclabendazole following oral administration in goats was investigated. A total of 12 goats were randomly allocated into two groups which were either indoor and fed concentrate + hay ration (housed group) or were grazing on pasture (grazing group). Triclabendazole was administered orally to animals in two groups at 10 mg/kg bodyweight. Blood samples were collected from 1 h to 192 h post-treatment and analyzed by high performance liquid chromatography (HPLC). Feeding with different diets significantly effected the plasma disposition of triclabendazole sulphoxide. Maximum plasma concentration (C(max): 13.22+/-2.81 microg/ml), time to reach maximum plasma concentration (t(max): 18.4+/-2.19 h), area under the curve (AUC: 613+/-137 microg h/ml), half-life (t(1/2): 24.77+/-1.94 h) and mean resident time (MRT: 40.22+/-4.36 h) of triclabendazole sulphoxide in housed group were significantly different from those of grazing group (C(max): 10.17+/-1.51 microg/ml, t(max): 14.0+/-2.19 h, AUC: 406+/-98 microg h/ml), t(1/2): 16.16+/-1.17 h and MRT: 34.48+/-4.40 h). It is concluded that anthelmintically more active sulphoxide metabolite has higher plasma concentration when triclabendazole is administered to goats fed with concentrate feed + hay compared to grazing goats.

Effects of xylene and formaldehyde inhalations on renal oxidative stress and some serum biochemical parameters in rats.

In this study, it was aimed to demonstrate the possible renal oxidative stress and some serum biochemical parameters and their alterations caused by the exposure to xylene and formaldehyde (HCHO) in rats. Weighing 150-200g, 12-week-old, 24 female Sprague-Dawley rats were used. The rats were randomly divided into four groups: Group 1 (control), Group 2 (300-ppm technical xylene), Group 3 (6-ppm HCHO) and Group 4 (150-ppm technical xylene + 3-ppm HCHO). The animals were exposed to gases eight hours per day for six weeks. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, glutathione (GSH) and malondialdehyde (MDA) levels were measured. In addition, serum total protein, albumin, urea and creatinine levels were evaluated. Compared with the control animals, urea levels increased significantly in all groups (P < 0.001). GSH activities and MDA levels increased in xylene and xylene + HCHO groups (P < 0.05). No statistically considerable differences were found in SOD, CAT and GSH-Px activities, total protein, albumin and creatinine levels among all groups (P > 0.05). The present study indicates but not statistically confirms the renal toxicity of the exposures to xylene, HCHO and a mixture of them.

Plasma disposition and faecal excretion of oxfendazole, fenbendazole and albendazole following oral administration to donkeys.

Fenbendazole (FBZ), oxfendazole (fenbendazole sulphoxide, FBZSO), and albendazole (ABZ) were administered orally to donkeys at 10mg/kg bodyweight. Blood and faecal samples were collected from 1 to 120 h post-treatment. The plasma and faecal samples were analysed by high performance liquid chromatography (HPLC). The parent molecule and its sulphoxide and sulphone (FBZSO(2)) metabolites did not reach detectable concentrations in any plasma samples following FBZ administration. ABZ was also not detected in any plasma samples, but its sulphoxide and sulphone metabolites were detected, demonstrating that ABZ was completely metabolised by first-pass mechanisms in donkeys. Maximum plasma concentrations (C(max)) of FBZSO (0.49microg/mL) and FBZSO(2) (0.60microg/mL) were detected at (t(max)) 5.67 and 8.00h, respectively, following administration of FBZSO. The area under the curve (AUC) of the sulphone metabolite (10.33microg h/mL) was significantly higher than that of the parent drug FBZSO (5.17microg h/mL). C(max) of albendazole sulphoxide (ABZSO) (0.08g/mL) and albendazole sulphone (ABZSO(2)) (0.04microg/mL) were obtained at 5.71 and 8.00h, respectively, following ABZ administration. The AUC of the sulphoxide metabolite (0.84microg h/mL) of ABZ was significantly higher than that of the sulphone metabolite (0.50microg h/mL). The highest dry-faecal concentrations of parent molecules were detected at 32, 34 and 30h for FBZSO, FBZ and ABZ, respectively. The sulphide metabolite was significantly higher than the parent molecule after FBZSO administration. The parent molecule was predominant in the faecal samples following FBZ administration. After ABZ administration, the parent molecule was significantly metabolised, probably by gastrointestinal microflora, to its sulphoxide metabolite (ABZSO) that showed a similar excretion profile to the parent molecule in the faecal samples. The AUC of the parent FBZ was significantly higher than that of FBZSO and ABZ in faeces. It is concluded that the plasma concentration of FBZSO was significantly higher than that of FBZ and ABZ. Although ABZ is not licensed for use in Equidae, its metabolites presented a greater plasma kinetic profile than FBZ which is licensed for use in horses. A higher metabolic capacity, first-pass effects and lower absorption of benzimidazoles in donkeys decrease bioavailability and efficacy compared to ruminants.