Sibel Konyalioglu

Essential oil composition and antioxidant activity of endemic Ziziphora taurica subsp. cleonioides

The essential oil of Turkish endemic Ziziphora taurica subsp. cleonioides aerial parts was found to contain (+)-pulegone (81.86%), limonene (4.48%) and piperitenone (2.30%) activity. The essential oil showed relevant antioxidant activity.

The effect of hyperbaric oxygen on neuroregeneration following acute thoracic spinal cord injury

AIMS Although hyperbaric oxygen (HBO) treatment following spinal cord injury (SCI) have been studied in terms of neurological function and tissue histology, there is a limited number studies on spinal cord tissue enzyme levels. MAIN METHODS The effect of HBO treatment in SCI was investigated by measuring superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), nitric oxide synthase (NOS) and nitric oxide (NO) activity in the injured tissue. SCI was induced by applying an aneurysm clip extradurally at the level of T9-T11 vertebrae. Preoperative HBO (preopHBO) treatment was applied for 5days and postoperative HBO (postopHBO) for 7days. KEY FINDINGS In the preopHBO group, a significant decrease was observed in NOS and NO compared to the SCI group. There was a decrease in SOD, NOS and NO in the postopHBO group when compared to the SCI group. In the pre-postHBO group SOD, GPx, NOS and NO decreased significantly. There was a decrease in SOD in postopHBO compared to preopHBO. In the prepostopHBO, SOD decreased significantly compared to that in the preopHBO group. The prepostopHBO presented a significant decrease in GPx compared to postopHBO (p<0.05 for all parameters). No significant difference was observed for catalase for all groups. Significant improvement was found in BBB scores for both postopHBO and prepostHBO groups when compared to the SCI group (p<0.05). SIGNIFICANCE HBO treatment was found to be beneficial following SCI in terms of biochemical parameters and functional recovery in the postoperative period.

The in vitro effects of Hypericum species on human leukocyte myeloperoxidase activity

Myeloperoxidase (MPO) is a major component of the antimicrobial system of polymorphonuclear neutrophils. The heme enzyme MPO catalyzes the conversion of hydrogen peroxide and chloride to hypochlorous acid. Hypochlorous acid is the major strong oxidant produced by neutrophils and may contribute to inflammatory tissue damage. It was reported that certain antiinflammatory drugs are capable of inhibiting MPO activity and this inhibition may account for their antiinflammatory effect. Hypericum L. is a genus of about 400 species, widespread throughout the world. Some species of genus exhibit a significant antiinflammatory activity beside their several pharmacological properties such as antidepressant, diuretic, antihelmintic, and antibacterial. In this study, we investigated the in vitro effects of three Hypericum species, which exhibit antiinflammatory activity, on human polymorphonuclear leukocyte MPO activity. We found that each extract of Hypericum species reduced the peroxidative and chlorinating activity of human leukocyte MPO in concentration-dependent manner. The antiinflammatory activity of these species may be related with inhibition of MPO activity.

Effects of resveratrol on hydrogen peroxide-induced oxidative stress in embryonic neural stem cells

Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.

Potential neuroprotective effect of γ-glutamylcysteine ethyl ester on rat brain against kainic acid-induced excitotoxicity

Abstract The aim of this study was to investigate the effect of γ-Glutamylcysteine Ethyl Ester (GCEE) on the levels of GSH, caspase-3 activity, DNA damage and the expressions of Bcl-2, Bax and p53 mRNAs in rat hippocampus after status epilepticus (SE) induced by systemic kainic acid (KA). The male rats were divided into four groups as controls, KA (10 mg/kg), GCEE (10 mg/kg) and KA+GCEE. Glutathione (GSH) levels and caspase-3 activity were determined spectrophotometrically and colourimetrically, respectively. DNA damage and Bcl-2, Bax and p53 mRNA expressions were quantified by comet assay and reverse transcription followed by RT-PCR, respectively. KA treatment significantly depleted GSH levels, induced DNA damage, caspase-3 activity and the expressions of p53 and Bax mRNA. GCEE treatment protected GSH levels, decreased DNA damage and the levels of p53 and Bax/Bcl-2 mRNA against KA injection. These results indicate that GCEE treatment at the dose of 10 mg/kg is capable to protect the depleted levels of GSH and shows an anti-apoptotic activity due to the decreased levels of apoptotic biomarkers in the rat hippocampus after SE induced by KA.

The protective effect of resveratrol against dentin bonding agents-induced cytotoxicity

This study was designed to evaluate the cytotoxicity of four dentin bonding agents and the effects of an antioxidant addition. Group A: G-aenial Bond, Group B: Optibond All in One, Group C: Gluma Self Etch and Group D: Clearfil S(3) Bond were added to the medium using extract method. The cells were cultured with or without resveratrol (RES) addition. MTT, reactive oxygen species (ROS), DCF, Comet and 8-OHdG measurements were performed. The agents had a dose-dependent (1:1>1:10>1:20) cytotoxic effect. Considering 1:10 concentration; Group D at 1 h (p<0.01) and Group B and D at 24 h had the weakest cytotoxic effect (p<0.05). After RES addition, the highest cell viability was determined in Groups B+RES and D+RES at 1 h and in Groups A+RES and B+RES at 24 h (p<0.01). The dentin bonding agents induced ROS production and DNA damage regarding to their composition. However, RES addition decreased the indicated parameters.

SERUM BIOCHEMISTRY OF FARMED BLUEFIN (Thunnus thynnus L.) IN THE AEGEAN SEA

Values of blood biochemistry are important for all animals in terms of health and welfare, providing knowledge of evidence in diseases. One of the most economically important fish species bluefin tuna-BFT ( Thunnus thynnus L.) in aquaculture considering high prices in the related business. Accordingly, farmers care about fattening fishes and some analyses provide significant knowledge, especially blood analyses for them. In the study, blood samples were recovered from fishes (10 male and 12 female) in fattening farms at Ildir, Cesme, Izmir province, East of Aegean Sea. Fork length and weight values were 140–180cm, and 40–80kg, respectively. Water quality parameters such as temperature, salinity, dissolved oxygen, pH and turbidity were indicated as 16–20 o C, ‰ 35.7–38.2g L -1 , % 6.9-7.8mgL -1 , 36.8–38.2m. The research measured uric acid 4.32mg/100mL -1 , creatinine 1.12mg/100mL -1 , serum urea concentration 15.04mg/100mL -1 ), albumin 2.30g/100mL -1 , globulin 2.56g/100mL -1 , total protein 6.15g/100mL -1 , serum glutamic oxaloacetic transaminase 178.24UL -1 , serum glutamate pyruvate transaminase 141.52UL -1 , alkaline phosphatase 54.26UL -1 , g-glutamyl transferase 220.14UL -1 , total cholesterol 272.04mg/100mL -1 , triglycerides 320.75mg/100mL -1 , high-density lipoprotein 88.68mg/100mL -1 and low-density lipoprotein 180.18mg/100mL -1 . Results during the fattened period in growing cages indicates that BFTs were under pressure and stress attacks because of unnatural habitats such as feeding, narrow area etc. in farm area. Also, males were more sensitive and undergo more stress than females.

Effects of Embryonic Neural Stem Cell Transplantation on DNA Damage in the Brain and Spinal Cord Following Spinal Cord Injury

Embryonic neural stem cell (ENSC) transplantation is used experimentally for the improvement of spinal cord repair following spinal cord injury (SCI). However, the effects of such intervention on oxidative stress and cell death remain unknown. We used in vivo Comet assay in the acute and chronic SCI groups compared with the SCI+ENSC transplantation groups of experimental rats in order to evaluate DNA damage in the spinal cord. Chronic SCI resulted in the generation of oxidative DNA damage in the spinal cord brain and kidneys, as indicated by high Comet assay parameters, including the percentage of DNA in the tail (T%, or TD), tail moment (TM), and tail length (TL). The DNA damage levels significantly decreased after ENSC transplantation in the spinal cords of acute and chronic SCI groups within the lesion site and rostrally and caudally to the injury, and in the brains and kidneys of the chronic SCI group. Thus, ENSC transplantation is found to be an effective tool for limitation of DNA damage following spinal cord injury.