Seckin Ozkanlar

Therapeutic Effects of Melatonin on Alveolar Bone Resorption After Experimental Periodontitis in Rats: A Biochemical and Immunohistochemical Study

BACKGROUND The present study aims to investigate the effects of systemic melatonin administration on alveolar bone resorption in experimental periodontitis in rats. METHODS Twenty-four male Sprague-Dawley rats were divided into three groups (control, experimental periodontitis [Ped], and experimental periodontitis treated with melatonin [Mel-Ped]). For periodontitis induction, first molars were ligatured submarginally for 4 weeks. After ligature removal, rats in the Mel-Ped group were treated with a daily single dose of 10 mg/kg body weight melatonin for 15 consecutive days. At the end of the study, intracardiac blood samples and mandible tissues were obtained for histologic, biochemical, and radiographic analysis. Serum markers related to bone turnover, calcium, phosphorus, bone alkaline phosphatase (b-ALP), and terminal C telopeptide of collagen Type I (CTX) were analyzed. Myeloperoxidase levels were determined in gingival tissue homogenates, and receptor activator of nuclear factor-kappa B ligand (RANKL) activation was analyzed in the mandible samples stereologically. Alveolar bone loss was also evaluated radiographically in the mandible samples of each group. RESULTS Melatonin treatment decreased serum CTX levels and increased b-ALP levels. Serum calcium and phosphorus levels were not statistically different among groups (P >0.05). Alveolar bone resorption and myeloperoxidase activity were statistically higher in the Ped group compared to the Mel-Ped group (P <0.05). Immunohistochemical staining of RANKL and osteoclast activity were significantly lower in the Mel-Ped group compared to the Ped group (P <0.05). CONCLUSION This study reveals that melatonin treatment significantly inhibits regional alveolar bone resorption and contributes to periodontal healing in an experimental periodontitis rat model.

Effects of Melatonin on Oxidative Stress Index and Alveolar Bone Loss in Diabetic Rats With Periodontitis

BACKGROUND The aim of this study is to evaluate the effects of systemic melatonin treatment on serum oxidative stress index (OSI) and alveolar bone loss (ABL) in rats with diabetes mellitus (DM) and periodontitis. METHODS Seventy Sprague Dawley rats were divided into control, experimentally induced periodontitis (EP), DM, EP-DM, EP and melatonin treatment (EP-MEL), DM and melatonin treatment (DMMEL), and EP-DM-MEL groups. DM was induced by alloxan, after which periodontitis was induced by ligature for 4 weeks. After removal of the ligature, the rats in the melatonin groups (EP-MEL, DM-MEL, and EP-DM-MEL) were treated with a single dose of melatonin (10 mg/body weight) every day for 14 consecutive days. At the end of the study, all of the rats were euthanized, and intracardiac blood samples and mandible tissues were obtained for biochemical and histologic analyses. Serum levels of total oxidant status/total antioxidant status and OSI were measured. In addition, neutrophil and osteoclast densities and myeloperoxidase activities were determined in gingival tissue homogenates, and ABL was evaluated with histometric measurements. RESULTS Melatonin treatment significantly reduced fasting plasma glucose levels in the rats with DM. In addition, reduced OSI and ABL levels were detected in the EP-MEL and DM-MEL groups; the reductions in the EP-DM-MEL group were found to be more prominent. Melatonin also significantly decreased the increased myeloperoxidase activities and osteoclast and neutrophil densities in the EP, DM, and EP-DM groups. CONCLUSION It is revealed in this experimental study that melatonin significantly inhibited hyperglycemia-induced oxidative stress and ABL through antiDM and antioxidant effects in rats with DM and periodontitis.

Effects of ramipril and darbepoetin on electromechanical activity of the heart in doxorubicin-induced cardiotoxicity

in doxorubicin-induced cardiotoxicity Yunusemre Ozkanlar ⁎, Mustafa Sinan Aktas , Mehmet Turkeli , Nergis Erturk , Ertan Oruc , Seckin Ozkanlar , Akin Kirbas , Burak Erdemci , Enbiya Aksakal f a Department of Internal Medicine, Faculty of Veterinary Medicine, Ataturk University, Erzurum, Turkey b Department of Medical Oncology, Faculty of Medicine, Ataturk University, Erzurum, Turkey c Department of Pathology, Faculty of Veterinary Medicine, Ataturk University, Erzurum, Turkey d Department of Biochemistry, Faculty of Veterinary Medicine, Ataturk University, Erzurum, Turkey e Department of Radiation Oncology, Faculty of Medicine, Ataturk University, Erzurum, Turkey f Department of Cardiology, Faculty of Medicine, Ataturk University, Erzurum, Turkey

The role of carnitine on ovariectomy and inflammation-induced osteoporosis in rats

This study was carried out to assess the protective bone-sparing effect of carnitine with anti-inflammatory properties on chronic inflammation-induced bone loss in ovariectomised (OVX) rats. A total of 64 rats were divided into eight groups. Sixteen rats were sham-operated (SH) while the others were ovariectomised (OVX). (1) SH, (2) sham + inflammation (SHinf), (3) OVX, (4) ovariectomy + inflammation (OVXinf), (5) OVX + CAR1, (6) OVX + CAR2, (7) OVXinf + CAR1, (8) OVXinf + CAR2. After the ovariectomy surgery, all the groups (3, 4, 5, 6, 7, and 8) were allowed to recover for two months. Sixty days after the OVX, inflammation was induced by subcutaneous injections of talc in groups 2, 4, 7, and 8. Group 5 and 7 were given 50 mg/kg CAR; Group 6 and 8 were given 100 mg/kg CAR from the 60th to the 80th day. Serum levels of TNF-α, IL-1, IL-6, OP, and OC were assessed to determine inflammation and to evaluate osteoblastic activity. Bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry in femur bones of rats. Carnitine administration was able to restore BMD up to values measured in both the OVX and the SH animals. The serum levels of TNF-α, IL-1β, and IL-6 were increased significantly in the OVXinf rats compared with the SH group. In OVX rats, inflammation which is evaluated by serum cytokine levels exacerbated this bone loss, as supported by values of BMD of the total femur. The two different doses of carnitine reduced bone loss and improved inflammatory biomarkers.

Effect of agomelatine on adult hippocampus apoptosis and neurogenesis using the stress model of rats.

Agomelatine (AG) is an agonist of melatonin receptors and an antagonist of the 5-HT2C-receptor subtype. The chronobiotic properties of AG are of significant interest due to the disorganization of internal rhythms, which might play a role in the pathophysiology of depression. The present study was designed to assess the effects of the antidepressant-like activity of AG, a new antidepressant drug, on adult neurogenesis and apoptosis using stress-exposed rat brains. Over the period of 1 week, the rats were exposed to light stress twice a day for 1h. After a period of 1 week, the rats were given AG treatment at a dose of either 10mg/kg or 40mg/kg for 15 days. The animals were then scarified, and the obtained tissue sections were stained with immuno-histochemical anti-BrdU, Caspase-3, and Bcl-2 antibodies. Serum brain-derived neurotrophic factor (BDNF) concentrations were measured biochemically using a BDNF Elisa kit. Biochemical BDNF analysis revealed a high concentration of BDNF in the serum of the stress-exposed group, but the concentrations of BDNF were much lower those of the AG-treated groups. Immuno-histochemical analysis revealed that AG treatment decreased the BrdU-positive and Bcl-2-positive cell densities and increased the Caspase-3-positive cell density in the hippocampus of stress-induced rats as compared to those of the stress group. The results of the study demonstrated that AG treatment ameliorated the hippocampal apoptotic cells and increased hippocampal neurogenesis. These results also strengthen the possible relationship between depression and adult neurogenesis, which must be studied further.

Influences of Fucoxanthin on Alveolar Bone Resorption in Induced Periodontitis in Rat Molars

The aim of this study was to evaluate the effects of systemic fucoxanthin treatment on alveolar bone resorption in rats with periodontitis. Thirty rats were divided into control, experimental periodontitis (EP), and experimental periodontitis-fucoxanthin (EP-FUCO) groups. Periodontitis was induced by ligature for four weeks. After removal of the ligature, the rats in the EP-FUCO group were treated with a single dose of fucoxanthin (200 mg/kg bw) per day for 28 consecutive days. At the end of the study, all of the rats were euthanized and intracardiac blood and mandible tissue samples were obtained for biochemical, immunohistochemical, and histometric analyses. Fucoxanthin treatment resulted in a slight decrease in tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels and a significant decrease in oxidative stress index. It was observed that fucoxanthin caused a significant reduction in receptor activator of nuclear factor kappa-β ligand (RANKL) levels and a statistically non-significant elevation in osteoprotegerin and bone-alkaline phosphatase levels. There were no significant differences in alveolar bone loss levels between the EP and EP-FUCO groups. This experimental study revealed that fucoxanthin provides a limited reduction in alveolar bone resorption in rats with periodontitis. One of the mechanisms underlying the mentioned limited effect might be related to the ability of fucoxanthin to inhibit oxidative stress-related RANKL-mediated osteoclastogenesis.

Endothelin Receptor Inhibition with Bosentan Delays Onset of Liver Injury in Streptozotocin-Induced Diabetic Condition

BACKGROUND This study was designed to investigate the protective effects of bosentan an orally active non-peptide mixed ETA/ETB receptor antagonist, on liver injury in streptozotocin-induced diabetic rats. METHODS 24 Albino-Wistar rats were randomly divided into 4 groups: healthy (Group 1), diabetic (Group 2) (60 mg/kg of streptozotocin i.p.), diabetic treated with bosentan 50 mg/kg (Group 3) and diabetic treated with bosentan 100 mg/kg (Group 4). The treatment of bosentan was initiated after streptozocin injection and continued for 60 days. RESULTS Liver from diabetic rats showed significant increase in malondialdehyde (MDA) level and significant decrease in glutathione (GSH), and superoxide dismutase (SOD) activity. Endothelin (ET-1), tumor necrosis factor (TNF-α) and transforming growth factor beta (TGF-β) gene expression significantly increased in the diabetic groups in the rat liver tissue. Bosentan treatment showed a significant up-regulatory effect on ET-1, TNF-α and TGF-β mRNA expression. Results from histopathological evaluation of the liver were in accordance with our biochemical and molecular results. CONCLUSIONS These data provide clear evidence that bosentan treatment is associated with promising hepatoprotective effect against diabetes-induced liver damage via reduction of cell inflammation and oxidative damage. These data suggest that ET receptors may be an important actor in diabetes-related liver damage, and blockage of these receptors may become a target for preventing diabetic complications in the future.

Biochemical and histopathologic analysis of the effects of periodontitis on left ventricular heart tissues of rats

BACKGROUND AND OBJECTIVE Current epidemiological works have suggested that chronic infections, such as periodontitis, are associated with an increased risk of cardiovascular diseases, including hypertrophy and heart failure. However, mechanisms behind the association are not known. The aim of this study was to evaluate the effects of periodontitis on the serum lipid levels, inflammatory marker levels and left ventricular heart muscle tissues of rats. MATERIAL AND METHODS Eighteen male Sprague-Dawley rats were randomly divided into two groups: control (without ligature) and experimental periodontitis (EP; ligatured). Periodontitis was induced by placing ligatures (3.0 silk) at a submarginal position of the lower first molar teeth for 5 wk. Serum samples were collected for biochemical studies (C-reactive protein, interleukin-1β, tumor necrosis factor-α and serum lipids), after which the rats were killed and heart tissue samples were obtained for histopathological and immunological studies (nuclear factor kappa B and β-myosin heavy chain). RESULTS Significant increases in C-reactive protein and interleukin-1β levels and no statistically significant increase in tumor necrosis factor-α level were observed in the EP group compared to the control group. In addition, total cholesterol, low-density lipoprotein cholesterol and triglyceride levels were significantly higher in the EP group. Stereological and immunological findings showed that the number of nuclear factor kappa B-p65- and β-myosin heavy chain-positive cardiomyocytes increased significantly in the left ventricular tissue samples of the rats with periodontitis. CONCLUSION Early chronic phase effects of periodontitis on heart tissue are in the form of degenerative and hypotrophic changes. Prolonging the exposure to systemic inflammatory stress may increase the risk of occurrence of hypertrophic changes.

Therapeutic Effects of Melatonin On Liver And Kidney Damages In Intensive Exercise Model of Rats

Extensive exercise induces inflammatory reactions together with high production of free radicals and subsequent liver and kidney tissues damage. This study was designed to investigate for effects of melatonin on liver and kidney tissues in the extensive exercise exposed rats and non-exercised rats. In this research, 24-male Sprague-Dawley rats were divided into four groups. For exercise rat model, the rats were exposed to slow pace running with the velocity of 10 m/min for 5 minutes for five days just before the study. And for last ten days after adaptation period, the exercise was improved as 15 min with the speed of 20 m/min and intra-peritoneal melatonin injection has been performed to the melatonin treated groups with the dose of 10 mg/kg. Biochemical results revealed a decrease in the parameters of kidney and liver enzymes in exercise-group and an increase in the parameters of serum, liver and kidney enzymes in the group that melatonin-exercise-group. As for histological analysis, while it is observed that there are cellular degenerations in the liver and kidney tissues with exercise application, a decrease has been observed in these degenerations in the group that melatonin was applied. At the end of the research, it has been determined that exercise application causes some damages on liver and kidney, and these damages were ameliorated with melatonin treatment.

Preventive effects of quercetin on liver damages in high-fat diet-induced obesity

Abstract Background: Obesity is a worldwide health problem and causes many important illnesses. The current study aimed to investigate the influence of quercetin over apoptosis by inflammatory activity on high-fat