Ahmet Özer Şehirli

Marmara University, İstanbul, Istanbul, Turkey

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Publications (7)13.85 Total impact


  • No preview · Conference Paper · Sep 2012

  • No preview · Conference Paper · Jun 2012

  • No preview · Conference Paper · May 2012
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    ABSTRACT: Acrylamide (AA), used in many fields, from industrial manufacturing to laboratory work, is also formed during the heating process through the interactions of amino acids. Therefore, AA poses a significant risk for both human and animal health. This study aimed to elucidate whether N-acetyl-L-cysteine (NAC) treatment could modulate AA-induced oxidative changes in the brain, lung, liver, kidney, and testes tissues of the rat. Rats were divided into 4 groups, as the control (C), NAC [150 mg/kg intraperitoneally (i.p.)], AA (40 mg/kg i.p.), and NAC + AA groups. After 10 days, the rats were decapitated and the tissues were excised.alondialdehyde (MDA) and glutathione (GSH)levels, and myeloperoxidase activity (MPO) were determined in the tissues, while oxidant-induced tissue fibrosis was determined using the collagen contents. Serum enzyme activities, cytokine levels, and leukocyte apoptosis were assayed in the plasma. In the AA group, GSH levels decreased significantly, while the MDA levels, MPO activity, and collagen content increased in the tissues suggesting oxidative organ damage. In the NAC + AA group, oxidant responses reversed significantly. Serum enzyme activities, cytokine levels, and leukocyte apoptosis, which increased following AA administration, decreased with NAC treatment. Therefore, supplementing with NAC can be useful when there is a risk of AA toxicity, as NAC inhibits neutrophil infiltration, balances the oxidant-antioxidant status, and regulates the generation of inflammatory mediators to protect tissues.
    No preview · Article · Jan 2012 · Turkish Journal of Veterinary and Animal Sciences
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    ABSTRACT: The present study aimed to determine the effects of alpha lipoic acid (ALA) on blood and tissue biochemical parameters, as well as tissue histopathology, in an experimental rat model of cerulein-induced acute pancreatitis (AP). Three groups consisting of eight rats each were used, as follows: Group 1, controls; Group 2, cerulein-induced pancreatitis group treated with saline; and Group 3, cerulein-induced pancreatitis group treated with ALA. AP was induced by intraperitoneal administration of cerulein (20 µg/kg) 4 times at 1-hour intervals. The animals were decapitated 12 hours after the last dose of cerulein. Blood amylase, lipase, interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α levels, pancreas tissue glutathione (GSH) and malondialdehyde (MDA) levels, as well as myeloperoxidase (MPO) and Na+-K+-ATPase activity were measured. Pancreatic tissue samples were also evaluated histopathologically under a light microscope. While plasma amylase, lipase, IL-1ß, and TNF-α levels, and tissue MDA and MPO levels significantly increased in rats with cerulean-induced AP, tissue GSH and Na+-K+-ATPase activity significantly reduced. These changes were reversed and improved with ALA treatment. Our findings suggest that ALA may significantly reduce morbidity and mortality by preventing organ dysfunction induced by free radicals in the pancreas.
    Full-text · Article · Sep 2011 · Ulusal travma ve acil cerrahi dergisi = Turkish journal of trauma & emergency surgery: TJTES
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    ABSTRACT: Purpose: Alpha-Lipoic acid (ALA), which has been intensely investigated as a therapeutic agent for several diseases, is elucidated for its possible protective effect as a potent antioxidant on colonic inflammation.Material and Methods: Following intracolonic administration of trinitrobenzene sulphonic acid, Sprague-Dawley rats were treated orally either with saline or ALA (100 mg/kg/day), for three days. On the 4th day, rats were decapitated and distal colon was removed for the macroscopic and microscopic damage scoring, for the measurement of malondialdehyde (MDA), glutathione (GSH) and collagen levels, myeloperoxidase (MPO) and Na+- K+-ATPase activity, luminol and lucigenin chemiluminescences (CL) and oxidant-induced DNA fragmentation. Lactate deydrogenase (LDH) activity, TNF- α, IL-1β, IL-6 and antioxidant capacity (AOC) were assayed in blood samples.Results: Colitis caused significant increases in the colonic macroscopic and microscopic damage scores, MDA, and collagen levels, MPO activity and CL values, along with a significant decrease in tissue GSH level and Na+- K+-ATP ase activity. Similarly, serum cytokines as well as LDH were elevated in the vehicle-treated colitis group as compared to control group. On the other hand, ALA treatment reversed all these biochemical indices, as well as histopathological alterations induced by TNBS.Conclusion: ALA protects the colonic tissue via its antioxidant and membrane stabilizing properties.
    No preview · Article · Jan 2009 · Erciyes Tip Dergisi
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    ABSTRACT: : Regarding the mechanisms of methotrexate (MTX) hepatotoxicity and nephrotoxicity, several hypotheses have been put forward, among which oxidative stress (including depletion of glutathione) is likely. This investigation elucidates the role of free radicals in MTX-induced toxicity and the protection by melatonin. Wistar albino rats were injected with MTX intraperitoneally. Following a single dose of MTX (20 mg/kg), either saline (MTX group) or melatonin (10 mg/kg, MTX + Mel group) was administered for 5 days. In other rats, physiologic saline (control group) or melatonin (10 mg/kg, Mel group) was injected for 5 days, following a single injection of saline. On the sixth day, rats were killed to obtain blood, liver, and kidney tissue samples. Malondialdehyde (MDA), an end product of lipid peroxidation, and glutathione (GSH), a key antioxidant, levels were evaluated in blood and tissue homogenates. Reactive oxygen metabolite-induced inflammatory changes in kidney and liver tissues were evaluated by measuring myeloperoxidase (MPO) activity, an index of neutrophil infiltration. MTX administration resulted in increased MDA levels and MPO activity and decreased GSH levels in the blood, liver, and kidney whereas melatonin reversed these effects. When melatonin was administered alone, no significant changes in biochemical parameters were noted. In conclusion, the present study suggests that melatonin may be of therapeutic benefit when used with MTX.
    Full-text · Article · May 2003 · Journal of Pineal Research