Selim Demir

The effect of prenatal exposure to 900-MHz electromagnetic field on the 21-old-day rat testicle

The aim of this study was to investigate the effect of exposure to a 900-MHz electromagnetic field (EMF) in the prenatal term on the 21-old-day rat testicle. Pregnant rats were divided into control (CG) and EMF (EMFG) groups. EMFG was exposed to 900-MHz EMF during days 13-21 of pregnancy. Newborn CG rats were obtained from the CG and newborn EMFG (NEMFG) rats from the EMFG. Testicles were extracted at postnatal day 21. Lipid peroxidation and DNA oxidation levels, apoptotic index and histopathological damage scores were compared. NEMFG rats exhibited irregularities in seminiferous tubule basal membrane and epithelium, immature germ cells in the lumen, and a decreased diameter in seminiferous tubules and thickness of epithelium. Apoptotic index, lipid peroxidation and DNA oxidation were higher in NEMFG rats than in NCG. 21-day-old rat testicles exposed to 900-MHz EMF in the prenatal term may be adversely affected, and this effect persists after birth.

Antiproliferative and proapoptotic activity of Turkish propolis on human lung cancer cell line

abstract Cancer is a heterogeneous disease, two of whose characteristic features are uncontrollable cell proliferation and insufficient apoptosis. Various studies have investigated the antiproliferative effects of propolis, a natural bee product, from different countries, and its cytotoxic effects have been attributed to its polyphenol contents. The purpose of this study was to show the cytotoxic effects, and possible mechanisms involved, of ethanolic extract of Turkish propolis (EEP) on the human lung cancer (A549) cell line. Cytotoxic activity of EEP on A549 cells was revealed using the MTT assay. Mechanisms involved in the cytotoxic action of EEP on A549 cells were then investigated in terms of apoptosis, mitochondrial membrane potential and cell cycle using flow cytometry, endoplasmic reticulum stress using RT-PCR, and caspase activity using luminometric analysis. EEP exhibited selective toxicity against A549 cells compared to normal fibroblast cells. We determined that EEP arrested the cell cycle of A549 cells at the G1 phase, induced endoplasmic reticulum stress, caspase activity, and apoptosis and reduced mitochondrial membrane potential. These results indicate that Turkish propolis is capable of reducing cancer cell proliferation and may have a promising role to play in the development of new anticancer drugs in the future.

Preventive and protective effects of turkish propolis on H2O2-induced DNA damage in foreskin fibroblast cell lines

The aim of the present study was to evaluate the potential of Turkish propolis extracts if they prevent or protect foreskin fibroblast cells against hydrogen peroxide (H₂O₂)-induced oxidative DNA damage. Hydrogen peroxide (40 μM) was used as an inducer of oxidative DNA damage. The damage of DNA was evaluated by using the alkaline single cell gel electrophoresis (comet) assay. Turkish propolis extracts at concentrations of 25, 50, 75 and 100 μg/ml were prepared by ethanol. Anti-genotoxicity was assessed before, simultaneously, and after treatment of propolis extract (50 μg/ml) with H₂O₂. The results showed a significant decrease in H₂O₂-induced DNA damage in cultures treated with propolis extract. The antioxidant activity of phenolic components found in propolis may contribute to reduce the DNA damage induced by H₂O₂. Our findings confirmed the chemopreventive activity of propolis and showed that this effect may occur under different mechanisms.

Oxidant-Antioxidant Balance during On-Pump Coronary Artery Bypass Grafting

Backround. The aim of this study was to evaluate the changes in perioperative oxidant-antioxidant balance in ONCABG. Methods. Twenty-three patients were included in this study. Serum total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) values were assessed preoperatively, at 20 minutes after aortic clamping and at 30 minutes, 6 hours, and 48 hours after declamping (reperfusion). The patients were divided into 2 groups according to the median aortic cross clamping (XC) time: group 1 (XC time < 42 minutes) and group 2 (XC time ≥ 42 minutes). Results. TOS and OSI values of whole patients at 30 minutes after reperfusion were higher than preoperative values (P = 0.045, P = 0.015), while perioperative TAS levels of the patients were similar to the preoperative levels (P = 0.173). XC time was correlated with TOS levels at 30 minutes after reperfusion (r = 0.43, P = 0.041). In group 2, TOS and OSI values at 30 minutes after reperfusion were higher than preoperative values (P = 0.023, P = 0.048), whereas a significant difference was not found in group 1 (P = 0.601, P = 0.327). Conclusions. Oxidative imbalance and increase in TOS at reperfusion in ONCABG may be associated with XC time.

Plasma Endocan Levels in Patients With Isolated Coronary Artery Ectasia

Endocan is a soluble proteoglycan, secreted by human vascular endothelial cells. Endocan is a marker for vascular pathologies and an important mediator of angiogenesis, strongly associated with inflammation, vascular endothelial dysfunction, and atherosclerosis. The relationship between coronary artery ectasia (CAE) and endocan has not been evaluated. We aimed to investigate this association. Fifty-four patients with isolated CAE without coronary stenosis and 30 controls with normal coronary angiogram were included in this study. Endocan plasma concentrations were measured using an enzyme-linked immunosorbent assay. Patients with isolated CAE had significantly higher levels of endocan compared to the controls (18.9 ± 7.3 vs 15.6 ± 3.6 ng/mL; P = .007). There was a significant correlation between endocan levels and severity of isolated CAE according to the Markis classification (r = −.593, P < .001). Plasma endocan levels may reflect the presence and severity of isolated CAE, suggesting that endocan may be involved in pathogenesis of isolated CAE.

Morus Rubra Extract Induces Cell Cycle Arrest and Apoptosis in Human Colon Cancer Cells Through Endoplasmic Reticulum Stress and Telomerase.

ABSTRACT Many studies have reported cytotoxic effects of different Morus species, but there have been only limited studies on the cytotoxic effect of Morus rubra. The aims of this study were to evaluate the cytotoxic effect of dimethyl sulfoxide extract of M. rubra and to investigate, for the first time, its probable cytotoxic activity in human colon cancer (WiDr) cells, together with the mechanism involved. The cytotoxic activity of extract was determined using MTT assay. The mechanism involved in the cytotoxic effect of extract was then evaluated in terms of apoptosis, and the cell cycle using flow cytometry, mitochondrial membrane potential (MMP) was investigated using the fluorometric method, and expression levels of telomerase and C/EBP homologous protein (CHOP) were investigated using reverse-transcription PCR (RT-PCR). M. rubra extract exhibited moderate selective cytotoxicity on colon cancer cells compared with fibroblast cells. Extract induced cell cycle arrest at the G1 phase and apoptosis via reduced MMP in WiDr cells. Additionally, M. rubra extract significantly repressed telomerase and induced CHOP expressions in WiDr cells. Our results demonstrate that targeting telomerase and endoplasmic reticulum stress represents a promising strategy in colon cancer therapy, and M. rubra may have considerable potential for development as a novel natural product-based anticancer agent.

Antiproliferative and apoptotic effect of Morus nigra extract on human prostate cancer cells

Background: Morus nigra L. belongs to the family Moraceae and is frequently used in traditional medicine. Numerous studies have investigated the antiproliferative effects of various extracts of different Morus species, but studies involving the in vitro cytotoxic effect of M. nigra extract are very limited. The purpose of this study was to evaluate the phenolic composition and antioxidant activity of dimethyl sulfoxide extract of M. nigra (DEM) and to investigate, for the first time, the probable cytotoxic effect in human prostate adenocarcinoma (PC-3) cells together with the mechanism involved. Methods: Total polyphenolic contents (TPC), ferric reducing antioxidant power (FRAP) and phenolic compounds of DEM were evaluated using spectrophotometric procedures and HPLC. The cytotoxic effect of DEM on PC-3 cells was revealed using the MTT assay. Mechanisms involved in the cytotoxic effect of DEM on PC-3 cells were then investigated in terms of apoptosis, mitochondrial membrane potential and cell cycle using flow cytometry, while caspase activity was investigated using luminometric analysis. Results: TPC and FRAP values were 20.7 ± 0.3 mg gallic acid equivalents and 48.8 ± 1.6 mg trolox equivalents per g sample, respectively. Ascorbic acid and chlorogenic acid were the major phenolic compounds detected at HPLC analysis. DEM arrested the cell cycle of PC-3 cells at the G1 phase, induced apoptosis via increased caspase activity and reduced mitochondrial membrane potential. Conclusions: Our results indicate that M. nigra may be a novel candidate for the development of new natural product based therapeutic agents against prostate cancer.

Hepcidin levels in children with chronic liver disease

Background/Aim: We aimed to analyze serum hepcidin level in children with chronic liver disease (CLD) and its relationship with serum cytokines level, liver function tests, hepatic iron content, and liver fibrosis. Patients and Methods: The study included 34 children with CLD, and 15 age- and gender-matched healthy children. Serum hepcidin, ferritin, iron level, interleukin-6 (IL-6), transforming growth factor-β (TGF-β ), total oxidant status (TOS), and antioxidant status (TAS) were studied in all patients and in the control group. Liver iron content (LIC) was measured from the liver biopsy specimen. Results: Serum ferritin levels were higher in patients with CLD than control group (100.1 ± 98.2 ng/mL vs 50.5 ± 32.2 ng/mL, P = 0.016). No significant difference was found in hepcidin levels. Hepcidin levels in children with CLD was positively correlated with ferritin (r = 0.75, P = 0.001), pediatric end-stage liver disease (PELD) score (r = 0.56, P = 0.001), TAS (r = 0.42, P = 0.02), but negatively correlated with albumin level (r = −0.45, P = 0.008). Transferrin saturation and hepcidin:ferritin ratio were significantly low in patients with severe fibrosis compared with patients with mild/without fibrosis (15.5 ± 5.5 vs 34.3 ± 30.1, P = 0.017 and 1 ± 0.5 vs 1.9 ± 1.4, P = 0.04, respectively). Conclusion: Serum hepcidin levels in children with CLD reflect both liver functions and TAS, and severe fibrosis is associated with low hepcidin:ferritin ratio in children with CLD.

Detection of autoantibodies against carbonic anhydrase I and II in the plasma of patients with gastric cancer

Cancer is the second leading cause of death and gastric cancer is the fourth most common cancer type worldwide. Investigation of autoantibodies in cancer patients has been a popular research area in recent years. The aim of the current study was to investigate carbonic anhydrase I and II (CA I and II) autoantibodies in the plasma of subjects with gastric cancer based on the information and considerations of autoimmune relation of gastric cancer. Anti-CA I and II antibody levels were investigated by ELISA in plasma samples of fifty two patients with gastric cancer and thirty five healthy peers. Anti-CA I and II antibody titers of the gastric cancer group were significantly higher compared with the control group (p = 0.004, p = 0.0001, respectively). Plasma anti-CA I levels of the metastatic group were lower than the non-metastatic group and this difference was found statistically significant (p < 0.05), but there was no statistical difference between plasma anti-CA II levels of the groups. CA I and II autoantibody titers in patients with gastric cancer were found higher compared to healthy subjects and the results suggest that these autoantibodies may be involved in the pathogenesis of gastric cancer.

GENETIC ASSOCIATION BETWEEN ARTERIAL STIFFNESS-RELATED GENE POLYMORPHISMS IN BRVO AND CRVO PATIENTS IN A TURKISH POPULATION.

Purpose: To investigate possible associations between five different single-nucleotide polymorphisms, from genes associated with arterial stiffness and branch retinal vein occlusion (BRVO), or central retinal vein occlusion. Methods: A total of 187 patients with retinal vein occlusion (133 with BRVO and 54 with central retinal vein occlusion), and 167 controls, were enrolled in this study. All subjects were screened for hypertension, diabetes, smoking status, body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, total cholesterol, and very low-density lipoprotein. The genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, eNOS E298D, and p22phox −242 C/T polymorphisms was performed using real-time polymerase chain reaction. Results: The percentage of the adiponectin +275 T allele carriers was significantly higher in the BRVO patients (37%) than in the controls (23%, P < 0.001). Similarly, the percentage of AGTR1 1166 C allele carriers was significantly higher in the BRVO patients (38%) than in the controls (24%, P < 0.001). At the multiple logistic regression analysis, the adiponectin +275 T allele carrier and AGTR1 1166 C allele carrier status were found to be associated with an increased risk of BRVO (TT vs. GG and TG: odds ratio = 2.278, P = 0.002, 95% confidence interval: 1.370–3.789; CC vs. AA and AC: odds ratio = 1.804, P = 0.025, 95% confidence interval: 1.079–3.017). The genotype distributions or allelic frequencies of ACE I/D, eNOS E298D, and p22phox −242 C/T did not significantly differ between the patients with BRVO and the control subjects. There was no significant difference between the central retinal vein occlusion patients and controls for the genotype or the allele frequency distributions of all evaluated single-nucleotide polymorphisms. Conclusion: Adiponectin +276 G/T and AGTR1 A1166C single-nucleotide polymorphism are likely to be risk factors for BRVO.