Effects of beta-glucan on protection of young and aged rats from renal ischemia and reperfusion injury.

BACKGROUND: Ischemia-reperfusion injury is one of the leading causes of acute renal failure which is a common clinical event leading to development of chronic kidney disease and a high mortality; especially in elderly people. ß-glucans are glucose polymer groups with free-radical scavenger, macrophage activator, and immune defense inducer functions. We designed this study to determine the possible protective effects of ß-glucan against renal ischemia-reperfusion injury comparatively in young and aged rats. METHODS: Rats were assigned to the following groups: Young and aged sham, young and aged ischemia-reperfusion, young and aged ß-glucan, young and aged ischemia-reperfusion+ß-glucan. At the end of the experiment, following collection of blood samples, rats were sacrificed and kidneys were removed for histopathological and biochemical examination. RESULTS: Mean tissue histopathological damage scores of young ß-glucan group was lower than that of young ischemia-reperfusion group, and of aged ß-glucan group was lower than that of aged ischemia-reperfusion group. Urea and creatinine levels of young and aged of sham group and ß-glucan administered groups were all lower than those of ischemia-reperfusion and ß-glucan+ischemia-reperfusion groups. Oxidative stress indexes of ischemia-reperfusion groups were increased however ; oxidative stress indexes of ß-glucan administered to young and aged rats were lower than those of ischemia-reperfusion groups. CONCLUSIONS: We conclude that ß-glucan is effective to protect kidneys from ischemia-reperfusion-induced oxidative damage, especially in young rats (Fig. 6, Ref. 45).

Effect of melatonin and n-acetylcysteine on hepatic injury in rat induced by methanol intoxication: a comparative study.

BACKGROUND: Methanol intoxication leads liver injury; in contrast melatonin and n-acetyl cysteine (NAC) are known to have protective effects on liver. AIM: We aimed to investigate the ultrastructural effects of melatonin and NAC on livers of methanol intoxicated rats and compare potential protective effects of melatonin and NAC on their liver ultrastructure. MATERIALS AND METHODS: Fifty-six adult male Wistar rats were carried out and were randomized to eight groups that have seven rats each: Control groups (C 6h, C 24h), treated with intragastric (i.g.) 1.0 ml saline; Methanol groups (M 6h, M 24h), treated with a dose of 3 g/kg i.g. methanol; Melatonin plus methanol groups (MEL+M 6h, MEL+M 24h), treated with dose of 10 mg/kg i.p melatonin immediately, following with a dose of 3 g/kg i.g. methanol; NAC plus methanol groups (NAC+M 6h, NAC+M 24h), treated with dose of 150 mg/kg, following with a dose of 3 g/kg i.g. methanol. 24 h group rats were given the same dose of melatonin and NAC 12 h after intoxication. Electron microscopy was used to evaluate histological changes in liver tissue at both 6th and 24th hour. RESULTS: Histopathological damage was found to be higher in methanol-induced intoxicated rats compared with the controls. Extensive tubules of smooth endoplasmic reticulum, increased mitochondria, increased primary lysosomes and some marked openings of bile canaliculus were distinguished. Melatonin administration prevents liver injury especially in early hours and although not as effective as melatonin, NAC also prevents liver injury. CONCLUSIONS: Melatonin is much more efficient than NAC, as well as significantly greater hepatoprotective effect against the liver injury secondary to the methanol intoxication.

The effect of resveratrol on the prevention of cisplatin ototoxicity.

One of the most important adverse effects of cisplatin, a chemotherapeutic agent which is widely used in the treatment of cancer patients, is hearing loss. This has primarily been associated with the loss of inner ear hairy and spiral ganglion cells due to oxidative stress. Resveratrol is known to be an antioxidant agent, which has the theoretical potential of preventing cisplatin-related ototoxicity. This experimental study was approved by Animal Ethics Committee of Inonu University (2008-20) and supported by Inonu University Scientific Research Projects Support Fund (2009-17). Thirty-four 3-month-old Wistar albino female rats weighing 210-270 g were used in the study. The animals were allocated into four groups: in cisplatin group (Group A), a single dose of 12 mg/kg cisplatin was administered intraperitoneally to 10 rats; in cisplatin + resveratrol group (Group B), a single dose of 12 mg/kg cisplatin and 10 mg/kg resveratrol were administered intraperitoneally for 5 days to 10 rats; in resveratrol group (Group C), 10 mg/kg resveratrol was administered intraperitoneally for 5 days to seven rats and in control group (Group D), resveratrol solvent (5% alcohol-95% physiological saline) was administered intraperitoneally for 5 days to seven rats. Resveratrol administration has begun 1 day before cisplatin administration in the group treated with cisplatin and resveratrol combination. Distortion product otoacoustic emission (DPOAE) (Grason Stadler, Madison, USA) measurements were performed in the same ear of all rats (right ear) under general anesthesia at baseline, 1st and 5th days after drug administration. Statistically significant distortion product amplitude reductions were found in the cisplatin group at 1,418, 2,003, 3,363, 5,660, 8,003 and 9,515 Hz frequencies. Whereas in the cisplatin + resveratrol group, statistically significant difference was found between 1st and 5th day measurements only at 3,996 Hz frequency. No significant differences were noted between the measurements either in the resveratrol or in the control groups. According to these results, cisplatin-related ototoxicity has been greatly prevented by resveratrol use.

Protective effects of chronic melatonin treatment against renal ischemia/reperfusion injury in streptozotocin-induced diabetic rats.

AIMS: The purpose of this study was to investigate the effects of chronic administration of melatonin on renal ischemia/reperfusion (IR) injury in streptozotocin (STZ)-induced diabetic rats. METHODOLOGY: Male Sprague-Dawley rats were divided into six groups: control (C), diabetes mellitus (DM), control+IR (C+IR), DM+IR, Melatonin+IR (Mel+IR), DM+Mel+IR. Diabetic and non-diabetic rats were given melatonin 4 mg/kg/day, i.p., for 15 days. The left renal artery and vein of rats were occluded for 30 min at the 18th day, followed by 24 h of reperfusion. RESULTS: In comparison with control group, the levels of malondialdehyde (MDA), protein carbonyl (PC) and and nitric oxide (NO) were determined to be higher in the renal homogenates of DM, DM+IR and C+IR groups. MDA and NO levels were found to be similar in the DM+melatonin+IR and control groups. The most significant histological damage was found in the DM+IR group and this damage was significantly reduced by melatonin. CONCLUSION: Chronic melatonin treatment reduces renal injury by reducing lipid oxidation and NO production in STZ-induced diabetic rats exposed to IR.

Preventive and early therapeutic effects of ß-glucan on the bleomycin-induced lung fibrosis in rats.

OBJECTIVE: The ß-glucans are long-chain polymers of glucose, which comprise the fungal cell wall, stimulate cells of the innate immune system, enhance disturbed epithelization, and have antioxidant effects. Oxidative stress has been implicated in the pathogenesis of bleomycin-induced lung fibrosis and various antioxidant agents have been studied for prevention and treatment of the disease. In this experimental animal study, we assessed effects of ß-glucan, extracted from barley, on the bleomycin-induced lung fibrosis, and evaluated differences of starting before and after bleomycin instillation. MATERIALS AND METHODS: Male Spraque-Dawley rats were given a single dose of bleomycin in pulmonary fibrosis groups. First dose of ß-glucan and NAC was given three days before the bleomycin injection, and at one of the other group ß-glucan was started 12 hours after bleomycin and continued until 14th day. Fibrotic changes in lung were estimated by using Aschoft's criteria and measuring lung hydroxyproline content. RESULTS: Bleomycin induced severe pulmonary fibrosis with marked increase in hydroxyproline content of lung tissue and typical lung fibrosis, which was prevented by ß-glucan. Hydroxyproline level was significantly higher in bleomycin treated rats than the other groups, and its level was decreased in the therapeutic groups, especially in the ß-glucan post-bleomycin group fibrosis score, hydroxyproline and MDA levels returned to the control levels. On the other hand, reduced glutathione level elevated in the same group. CONCLUSIONS: The data suggest that ß-glucans have protective and early therapeutic effects against bleomycin-induced lung fibrosis in rats.

Caffeic acid phenethyl ester ameliorated ototoxicity induced by cisplatin in rats.

Caffeic acid phenethyl ester (CAPE), an active component of propolis, exhibits antioxidant properties. This experimental study was designed to determine the effect of CAPE on ototoxicity induced with cisplatin. Twenty-four adult Wistar albino rats were divided into four groups: cisplatin (n=6), saline (n=6), CAPE (n=6), and cisplatin plus CAPE (n=6). Rats were tested before and 5 days after cisplatin treatment with or without chemo protection. The Distortion Product Otoacoustic Emissions (DPOAEs) were elicited from the control and experimental animals utilizing the standard commercial Otoacoustic Emission (OAEs) apparatus. The animals in all groups were sacrificed under general anesthesia on the fifth day following last OAE measurements. For biochemical investigations, the blood samples were drawn from inferior vena cava. On day 0, the initial baseline DPOAEs measurement results presented similar values while comparing the groups in drug free phase (p>0.05). On day 5, intrasubject measurement parameters of DPgrams and I/O functions of cisplatin group were significantly deteriorated (p<0.05). The second measurements of the other groups revealed no significant differences between their DPgrams and I/O functions in all frequencies (p>0.05). Among the biochemical parameters, plasma xanthine oxidase (XO) activity was found to be more elevated in the cisplatin group than the saline group (p<0.05). CAPE led to more decreased XO activity than cisplatin (p<0.05). The results of this study show that prophylactic administration of CAPE for cisplatin ototoxicity ameliorated hearing deterioration in rats.

OXA- and GES-type ß-lactamases predominate in extensively drug-resistant Acinetobacter baumannii isolates from a Turkish University Hospital.

We determined the antibiotic susceptibility and genetic mechanisms of resistance in clinical strains of Acinetobacter baumannii from Istanbul, Turkey. A total of 101 clinical strains were collected between November 2011 and July 2012. Antimicrobial susceptibility was performed using the Vitek 2 Compact system and E-test. Multiplex PCR was used for detecting bla(OXA -51-like), bla(OXA -23-like), bla(OXA -40-like) and bla(OXA -58-like) genes. ISAba1, bla(IMP -like), bla(VIM -like), bla(GES), bla(VEB), bla(PER -2), aac-3-Ia and aac-6'-Ib and NDM-1 genes were detected by PCR and sequencing. By multiplex PCR, all strains were positive for bla(OXA -51), 79 strains carried bla(OXA -23) and one strain carried bla(OXA -40). bla(OXA -51) and bla(OXA -23) were found together in 79 strains. ISAba1 element was detected in 81 strains, and in all cases it was found upstream of blaOXA -51 . GES-type carbapenemases were found in 24 strains (GES-11 in 16 strains and GES-22 in 8 strains) while bla(PER -2), bla(VEB -1), bla(NDM -1), blaIMP - and blaVIM -type carbapenemases were not observed. Aminoglycoside modifying enzyme (aac-3-Ia and aac-6'Ib) genes were detected in 13 and 15 strains, respectively. Ninety-seven (96%) A. baumannii strains were defined as MDR and of these, 98% were extensively drug resistant (sensitive only to colistin). Colistin remains the only active compound against all clinical strains. As seen in other regions, OXA-type carbapenemases, with or without an upstream ISAba1, predominate but GES-type carbapenemases also appear to have a significant presence. REP-PCR analysis was performed for molecular typing and all strains were collected into 12 different groups. To our knowledge, this is the first report of GES-11 and OXA-40 in A. baumannii from Turkey.

Effects of iloprost on bleomycin-induced pulmonary fibrosis in rats compared with methyl-prednisolone.

OBJECTIVE: Prostacyclin (PGI2) has been shown to inhibit the expression of pro-inflammatory and pro-fibrotic mediators in pulmonary fibrosis. In this study, we aimed to test the preventive effects of intraperitoneally administered iloprost, a stable PGI2 analog, on bleomycin-induced pulmonary fibrosis in rats and to compare the effects of iloprost with the effects of methyl-prednisolone, a traditional therapy. METHODS: Rats were randomly allocated into four groups: 1. Saline alone (n=6); 2. Bleomycin+placebo (n=7); 3. Bleomycin+methyl-prednisolone (n=7); 4. Bleomycin+iloprost (n=7). Fibrotic changes in the lungs were demonstrated by analyzing the cellular composition of bronchoalveolar lavage fluid, histological evaluation and lung hydroxyproline content. RESULTS: Fibrosis was made in the lungs of rats by bleomycin experimentally. Fibrosis scores in the methyl-prednisolone and the iloprost groups were significantly lower than in the placebo group (p<0.05). Furthermore, the score of the iloprost group was significantly lower than the score of the methyl-prednisolone group. The hydroxyproline content was significantly less in the methyl-prednisolone and the iloprost groups (p<0.05). In the placebo group, the neutrophil percentage in bronchoalveolar lavage was significantly higher than in the other groups, whereas the macrophage percentage in placebo group was significantly lower (p<0.05). CONCLUSION: Iloprost has protective effect on the pulmonary fibrosis induced by bleomycin and it may be more effective in decreasing fibrotic changes than methyl-prednisolone.