Selim Demirtas

The protective effect of quercetin on IMA levels and apoptosis in experimental ovarian ischemia-reperfusion injury.

OBJECTIVE To investigate the protective effect of quercetin (QE), an anti-inflammatory and anti-oxidant agent, on torsion-detorsion induced histopathological changes and blood IMA levels in experimental ovarian ischemia-reperfusion (IR) injury. STUDY DESIGN Twenty-four female Wistar rats were randomly divided into four groups in this study (n=6). Group I, (sham operation); Group II, torsion-detorsion plus saline (IR); Group III, torsion-detorsion plus solvent (dimethylsulfoxide: DMSO, IR+DMSO); Group IV, torsion-detorsion plus 15 mg/kg/bw quercetin (IR+QE) injected intraperitoneally 30 min prior to detorsion. After 3h of reperfusion, the right ovaries were removed surgically. The ovary tissue samples were fixed in 10% formalin solution for histopathological and immunohistochemical examination. Blood samples were obtained at the end of the procedures for each group of animals. RESULTS Ovarian sections in Groups II and III showed higher follicular cell degeneration, hemorrhage, vascular congestion and edema when compared with Group I. Administration of quercetin in rats significantly prevented degenerative changes in the ovary. Significantly less histopathological changes were found in Group IV compared with Groups II and III. Caspase-3 and TUNEL positive cells were detected in the ovarian surface, follicle epithelium, and stromal cells in all experimental groups, and there was a significant increase in Groups II and III compared with Group I (P<0.05). Treatment with quercetin decreased the number of caspase-3 and TUNEL positive cells. IR increased the ischemia modified albumin (IMA) levels in comparison to the sham group (1.06 ± 0.10 ABSU and 0.92 ± 0.08 ABSU, P<0.05). Quercetin administration before IR reduced the levels of IMA (0.93 ± 0.08 ABSU, P<0.05). CONCLUSION Administration of quercetin is effective in preventing tissue damage induced by IR injury in ovaries.

Effect of Topically Applied Azithromycin on Corneal Epithelial and Endothelial Apoptosis in a Rat Model of Corneal Alkali Burn.

Purpose: To investigate the antiapoptotic effect of topically administered azithromycin (AZM) on corneal epithelial and endothelial cells in a rat model of corneal alkali burn. Methods: Twenty-four Wistar albino rats were divided into 4 equal groups as pseudovehicle (group 1), control (group 2), alkali burned (group 3), and treatment (group 4) groups. Alkali injury was induced only in the right corneas of rats belonging to groups 3 and 4 using 1N NaOH. The rats in group 3 and the rats in group 4 were respectively treated either with an artificial tear gel or with 1.5% AZM eye drops for 5 days. At the fifth day of the experiment, the apoptosis in the corneal epithelium and endothelium of all rats was assessed using a terminal dUTP nick-end labeling (TUNEL) assay. In addition, tumor necrosis factor-alpha (TNF-&agr;) density in the corneal epithelium was measured in all rats. Results: The mean numbers of TUNEL+ cells in the corneal epithelium and endothelium of rats in group 3 were 117.1 ± 23.8 and 34.6.± 11.3, respectively, whereas in group 4, they were 75.8 ± 15.7 and 14.7 ± 3.5, respectively. Also the mean TNF-&agr; densities in the corneal epithelium in group 3 and group 4 were 2.65 ± 1.3 and 1.65 ± 1.1, respectively. There was a significant decrease in the mean number of TUNEL+ cells in the corneal epithelium and endothelium and in the mean TNF-&agr; density in the corneal epithelium of rats in group 4, when compared with group 3. Conclusions: Topically applied AZM can decrease TNF-&agr;–induced apoptosis in corneal alkali burn.

The Syk Inhibitor Fostamatinib Decreases the Severity of Colonic Mucosal Damage in a Rodent Model of Colitis

BACKGROUND AND AIMS Inflammatory bowel disease is a chronic inflammatory disease of the gastrointestinal system. In some cases, current medications used for inflammatory bowel disease may not be enough for remission, creating a need for more potent and reliable medications. There is no study showing the efficacy of fostamatinib, with proven effects on some inflammatory diseases, on ulcerative colitis. In our study we planned to research the efficacy of fostamatinib, a spleen tyrosine kinase inhibitor, on acetic acid-induced colitis. METHODS The study included 28 male Sprague-Dawley rats, randomly divided into control group, fostamatinib group, colitis group and fostamatinib + colitis group, each containing seven rats. Colitis induction was performed with 4% acetic acid. Colonic inflammation was assessed with disease activity index, macroscopic and histological damage scores, colonic myeloperoxidase, malondialdehyde and superoxide dismutase activity, and tumour necrosis factor alpha [TNFα], CD3, Syk, and phospho-Syk expression. RESULTS There was a significant difference between the colitis and control groups in terms of all parameters. The disease activity index, macroscopic and microscopic damage scores, immunohistochemical TNFα, CD3, Syk, and phospho-Syk expression, and tissue myeloperoxidase activity were found to be significantly lower in the colitis + fostamatinib group compared with the colitis group. There was no significant difference between the two groups in terms of myeloperoxidase and malondialdehyde activity. CONCLUSIONS Fostamatinib reduced the inflammatory damage in the experimental colitis. This effect may be due to suppression of TNFα, T-lymphocytes, and neutrophils in colonic mucosa via suppression of Syk. Fostamatinib may be an appropriate treatment alternative for ulcerative colitis. Further clinical studies are required to support this.

Effects of sphingosylphosphorylcholine against oxidative stress and acute lung ınjury ınduced by pulmonary contusion in rats

BACKGROUND/PURPOSE The goal of this study was to evaluate effects of exogenous sphingosylphosphorylcholine (SPC) administration on acute lung injury induced by pulmonary contusion in rats. METHODS Eight animals were included in each of the following five groups: control, contusion, contusion phosphate-buffered solution (PBS), contusion SPC 2, contusion SPC 10. SPC was administered 3 days at a daily two different doses of 2 μm/ml and 10 μm/ml intraperitoneally. The severity of lung injury was determined by the neutrophil activation and histological and immunohistochemical changes in the lung. Malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH) were determined to evaluate the oxidative status in the lung tissue. RESULTS Treatment with 2 μM SPC inhibited the increase in lung MDA and NO levels significantly and also attenuated the depletion of SOD, GPx, and GSH in the lung injury induced by pulmonary contusion. These data were supported by histopathological findings. The inducible nitric oxide synthase (iNOS) positive cells and apoptotic cells in the lung tissue were observed to be reduced with the 2 μM SPC treatment. But, the 10 μM SPC treatment did not provide similar effects. CONCLUSIONS In conclusion, these findings suggested that 2 μM SPC can attenuate lung damage in pulmonary contusion by prevention of oxidative stress, inflammatory process and apoptosis. All these findings suggest that low dose SPC may be a promising new therapeutic agent for acute lung injury.

Antioxidant and antiapoptotic effects of erdosteine in a rat model of ovarian ischemia-reperfusion injury

Objective(s): To evaluate the protective effect of erdosteine, an antiapoptotic and antioxidant agent, on torsion–detorsion evoked histopathological changes in experimental ovarian ischemia-reperfusion (IR) injury. Materials and Methods: Eighteen female Wistar albino rats were used in control, IR, and IR+Edosteine (IR-E) groups, (n=6 in each). The IR-E group received the erdosteine for seven days before the induction of torsion/retorsion, (10 mg/kg/days). The IR and IR-E groups were exposed to right unilateral adnexal torsion for 3 hr. Three hours later, re-laparotomy was performed, and the right ovaries were surgically excised. Oxidant and antioxidants levels were determined in serum. The ovarian tissue samples were received and fixed with 10% neutral buffered formalin. The sections were stained with H&E, anti-PCNA, and TUNEL. Results: The IR group were showed severe acute inflammation, polynuclear leukocytes and macrophages, stromal oedema and haemorrhage. Treatment with erdosteine in rats significantly retained degenerative changes in the ovary PCNA (+) cell numbers were significantly decreased in the IR and IR-E groups unlike the control group. However, its numbers were significantly increased in the IR-E group unlike the IR group. TUNEL (+) cell numbers were significantly increased in the IR group unlike the control and the IR-E groups. In erdosteine treated group, TUNEL (+) cells were detected significantly less than the IR group (P<0.05). Conclusion: In conclusion, erdosteine maybe a protective agent for ovarian damage and decreasing lipid peroxidation products and leukocytes aggregation after adnexal torsion in animals.

Evaluation of the protective effects of hesperetin against cisplatin-induced ototoxicity in a rat animal model.

OBJECTIVES We aimed to investigate the effects of hesperetin as a flavanon both histopathologically and immunohistochemically on cochlear apoptosis in a rat model of cisplatin-induced ototoxicity (CIO). The evaluation of the effects of hesperetin on cisplatin-induced hearing loss was performed using distortion product otoacoustic emission (DPOAE). METHODS Twenty-eight wistar albino rats were used in the current study. The rats were randomly divided into four groups with seven rats in each group. Group C was exposed to a single dose of cisplatin (12mg/kg) by intraperitoneal injection. Group CH received intraperitoneally cisplatin (12mg/kg) and hesperetin (20mg/kg). Group H was exposed to hesperetin (20mg/kg) intraperitoneally. The sham group (group S) received normal saline (6cc) intraperitoneally. The measurements of DPOAE and signal-noise ratios (SNR) were performed before the treatment and again on the first and 6 days after administration of the drugs. Rats were sacrificed and cochleae were dissected 10 days after drug administration. The cochlear tissue was assessed in all groups by histopathologic, immunohistochemical and TUNEL assay. In addition, serum oxidative stress markers and antioxidant parameters were analyzed. RESULTS There was a significant difference between the basal value and the sixth day at frequencies 8.4, 9.6 and 9.96 for group C. We also found a significant difference between the first and sixth day at frequencies 7.2, 8.4, 9.6 and 9.96. On the 6th day, there were significant differences between C and S groups at all frequencies except 2.4. We showed a significant difference between C and H groups at frequencies 4.8, 6.0, 8.4, 9.6 and 9.96. There was also a significant difference between C and CH groups at frequencies 2.4, and 3.6. We found lower levels of oxidants and higher levels of antioxidants in CH group as compared to C group. C group had a significantly greater number of TUNEL-positive cells than did S, H and CH groups. The number of TUNEL-positive cells in CH group was higher than in S and H groups. There was a significant difference between the positive PCNA cells of CH group compared to S and H groups in spiral ganglion and stria vascularis. In addition, there were no positive PCNA cells in C group. CONCLUSIONS Hesperetin may prevent ototoxicity by increased antioxidant enzymes and reduced oxidant parameters and protected against apoptosis resulting from a proliferation of cochlear cells in CIO.

The efficacy of tyrosine kinase inhibitor dasatinib on colonic mucosal damage in murine model of colitis

BACKGROUND AND OBJECTIVE Ulcerative colitis is an inflammatory condition of the colon in the gastrointestinal system. Currently, the most potent medications used for ulcerative colitis produce no response in 20-30% of cases. There is a need for more efficient and reliable medications. Tyrosine kinase inhibitors have shown efficacy in some inflammatory diseases. Although dasatinib, a tyrosine kinase inhibitor, suppresses proinflammatory cytokines in colonic tissue, there are a few cases of hemorrhagic colitis with dasatinib. There is no study investigating the effect of dasatinib on experimental colitis. We aimed to investigate the effect of dasatinib in a colitis model induced with acetic acid in our study. METHODS In the study, 24 male Sprague-Dawley rats randomly distributed into 4 groups of 6 rats each as control, dasatinib, colitis and dasatinib+colitis groups. For colitis induction, 4% acetic acid was used. Sacrificing of the rats was performed on the seventh day. Disease activity, morphologic and histological injury, superoxide dismutase, myeloperoxidase and malondialdehyde activity, TNFα and CD3 expression were assessed in colonic tissue. RESULTS Apart from malondialdehyde, significant difference in all parameters between the control and colitis groups was determined. Difference between the colitis and colitis+dasatinib groups was not significant in only weight loss and biochemical parameters. Though dasatinib does not fully resolve the changes in colitis, there was significant regression. CONCLUSIONS Dasatinib decreased the inflammation in a rodent model of colitis. It may be provide this effect by the suppression of TNFα. Dasatinib may be one of the treatment options for ulcerative colitis.

Effects of hyperthyroidism on expression of vascular endothelial growth factor (VEGF) and apoptosis in fetal adrenal glands.

This study investigated the expression of vascular endothelial growth factor (VEGF), vascular density, and apoptosis in fetal rat adrenal glands with hyperthyroidism in late gestation. Twelve mature female Wistar albino rats with the same biological and physiological features were used for this study. Rats were divided into two groups: control and hyperthyroidism. Hyperthyroidism was induced by daily subcutaneous injections of L-thyroxine (250 µg/kg) before pregnancy for 21 days and during pregnancy. Rats in the control and hyperthyroidism groups were caged according to the number of male rats. Zero day of pregnancy (Day 0) was indicated when the animals were observed to have microscopic sperm in vaginal smears. Pregnant rats were sacrificed on the 20th day of pregnancy; blood from each animal was collected to determine the concentrations of maternal adrenocorticotropic hormone and thyroxine. Rat fetuses were then quickly removed from the uterus, and the adrenal glands of the fetuses were dissected. VEGF expression, vascular density, and apoptosis were analyzed in fetal rat adrenal glands. Maternal serum levels of the ACTH and free thyroxine were significantly higher in the hyperthyroidism group than in the control group. Immunohistochemistry revealed that the number of VEGF positive cells and vessel density significantly increased in the hyperthyroidism rat fetal adrenal group compared with the control group. Hyperthyroidism did not change the fetal and placental weights and the number of fetuses. This study demonstrates that hyperthyroidism may have an effect on the development of rat adrenal glands mediated by VEGF expression, angiogenesis, and apoptosis.

Streptozotocin-Induced Diabetic that Histochemical and Immunohistochemical Examination of Mast Cells Distribution in Ovary and Uterus During Different Stages of Estrous Cycle in Rats

METHODS: In the present study 64 adult female wistar albino rats were used. Subjects have been randomly separated into 8 different groups, four of which constituted the control group while the remaining four were the actual experimental group. Diabetes was induced by intraperitoneal injection of 60 mg/kg streptozotocin; the control group received physiological saline (5 mL kg–1). At the end of this period, both groups were processed for every cycle after detecting their menstrual cycles according to the vaginal smear findings.