Effects of Thymus kotschyanus var. glabrescens Boiss. extract on mitomycin-C induced chromosomal aberrations and sister chromatid exchanges in human lymphocytes

In this investigation, clastogenic effects of Thymus kotschyanus var. glabrescens Boiss. extract (TE) and anticlastogenic effects of this extract against Mitomycin C (MMC) induced chromosome damage have been evaluated in human peripheral blood lymphocytes in vitro. Two series of experiments were conducted. In the first, only 10⁻⁵, 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations of TE were used for 48 h to detect potential clastogenicity. In the second, MMC (0.38 μg ml⁻¹) plus 10⁻⁵, 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations of TE were used for 48 h to determine anticlastogenic effects. TE did not increase sister chromatid exchanges (SCEs) (except 10⁻² μl ml concentration) and chromosome aberrations (CAs) significantly compared with negative and solvent controls. However, it decreased the frequency of MMC induced chromosome aberrations. Decreasing was significant at 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations. On the other hand, TE significantly increased MMC-induced SCEs for all treatment groups compared with positive control.     

Antiviral and antimicrobial assessment of some selected flavonoids

In the current study, the results of antibacterial, antifungal, and antiviral activity tests of four flavonoid derivatives, scandenone (1), tiliroside (2), quercetin-3,7-O-alpha-L-dirhamnoside (3), and kaempferol-3,7-O-alpha-L-dirhamnoside (4), are presented. Antibacterial and antifungal activities of these compounds were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by a micro-dilution method. On the other hand, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza-3 (PI-3) were employed for antiviral assessment of the compounds using Madin-Darby bovine kidney and Vero cell lines. According to our data, all of the compounds tested were found to be quite active against S. aureus and E. faecalis with MIC values of 0.5 microg/ml, followed by E. coli (2 microg/ml), K. pneumoniae (4 microg/ml), A. baumannii (8 micro/g/ml), and B. subtilis (8 microg/ml), while they inhibited C. albicans at 1 microg/ml as potent as ketoconazole. However, only compound 3 displayed an antiviral effect towards PI-3 in the range of 8-32 microg/ml of inhibitory concentration for cytopathogenic effect (CPE).     

Purification and characterization of glucose 6-phosphate dehydrogenase from Lake Van fish (Chalcalburnus tarichii pallas, 1811) liver

Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate: NADP+ oxidoreductase, EC 1.1.1.49; G6PD) was purified from Lake Van fish (Chalcalburnus tarichii pallas, 1811) liver, using a simple and rapid method, and some characteristics of the enzyme were investigated. The purification procedure was composed of two steps: homogenate preparation and 2', 5'-ADP Sepharose 4B affinity gel chromatography, which took 7-8 hours. Thanks to the two consecutive procedures, the enzyme, having specific activity of 38 EU/mg protein, was purified with a yield of 44.39% and 1310 fold. In order to control the enzyme purification SDS polyacrylamide gel electrophoresis (SDS-PAGE) was done. SDS polyacrylamide gel electrophoresis showed a single band for enzyme. Optimal pH, stable pH, optimal temperature, Km and, Vmax values for NADP+ and glucose 6-phosphate (G6P) were also determined for the enzyme. In addition, molecular weight and subunit molecular weights were found by sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography respectively.     

Plasma levels of nitrites, PGF1α and nitrotyrosine in LPS-treated rats: functional and histochemical implications in aorta

We investigated the effects of lipopolysaccharide (LPS) administration on plasma nitrite, nitrotyrosine and 6-keto prostaglandin F1alpha, (PGF1alpha) levels and the related resultant changes in function and histochemistry of aorta in rats. Plasma nitrite and PGF1alpha nitrotyrosine levels were analysed after 5 mg/kg intravenous LPS was administered to rats compared with those in non-treated rats. The distribution of nitrotyrosine in the aorta was studied immunohistochemically. The contractile responses of aortic rings to phenylephrine (PE) from both the LPS-treated and control rats were studied in the organ baths. There were increases in plasma nitrite, PGF1alpha, and nitrotyrosine concentrations of LPS-treated rats compared to non-treated rats. Immunoreactivity of nitrotyrosine residues were detected in the endothelial and smooth muscle cells in LPS-treated but not in control rat aorta. The contractile responses to PE of the LPS-treated rat aortic rings were significantly reduced as compared with those of control rat's. Incubation of the aortic rings from LPS-treated rats with cyclooxygenase inhibitor indomethacine or with a combination of indomethacine and nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) increased the contractile responses to the levels observed in control rats suggesting that both prostanoids and particularly nitric oxide (NO) are involved in the reduced contractile responses in LPS-treated rats. These results supported the view that LPS might cause an increment in both NO and PGI2 levels. This increase in the NO and PGI2 levels may be responsible from the reduction in responses of aorta to contractile agents in LPS-treated rats. Increased peroxynitrite formation in LPS-treated rats may lead to nitration of the tyrosil residues of the proteins in the aorta.     

Effects of nutrition on zinc, folic acid, and vitamin B12 levels during pregnancy

In this article, we report the results of a case control study carried out on 290 Turkish pregnant women at 5–24 wk of gestation to determine their zinc, folic acid, and vitamin B₁₂ levels in relation to their nutritional and socioconomic status. The women were divided into two groups (n=145 each), depending on the stage of gestation. Group I consisted of women in the first trimester of gestation; those in the second trimester were allocated into group II. Twenty-five age-matched, healthy nonpregnant women were selected as controls. The nutritional status of the subjects was determined by means of a survey. Based on this, the women were subdivided into three subgroups: malnourished (PN), moderately nourished (MN), and well nourished (WN). Also from the survey, the socioeconomic status was classified as good (G) or bad (B). A statistically significant decrease on zinc and folic acid was observed in group I women, as their socioeconomic status worsened. In group II, zinc decreased only in the PN and MN subgroups, p<0.001. The folic acid and vitamin B₁₂ levels did not change significantly during the second trimester of gestation in all subgroups. Regarding zinc, nutrition, or dietary habits are more relevant than socioeconomic status, but poor nutrition affects folic acid levels only during the first trimester of gestation.     

Anti-mitotic and anti-genotoxic effects of Plantago lanceolata aqueous extract on Allium cepa root tip meristem cells

Plantago is the most important genus of Plantaginaceae family and is used in traditional medicine around the world for different purposes. Plantago coronopus L., Plantago major L., Plantago media L. and Plantago lanceolata L. are most commonly used species of Plantago in traditional medicine in Turkey. The main goal of this study was to investigate the eventual anti-mitotic and anti-genotoxic effects of P. lanceolata L. leaf aqueous extracts (15 g/L and 30 g/L) on Allium cepa L. root tip meristem cells which were treated with 0.7% hydrogen peroxide. For this purpose, two different experiments were performed under the same conditions. In the first experiment, Allium cepa onion bulbs were treated with 0.7% H₂O₂ for 1 h. After the H₂O₂ treatment, the onion bulbs were treated with two different concentrations (15 g/L and 30 g/L) of P. lanceolata extracts for 24 h. In the second experiment, A. cepa onion bulbs were treated with two different extract concentrations (15 g/L and 30 g/L) for 24 h and then with 0.7% H₂O₂ for 1 h. The test concentrations were determined according to doses which are recommended in alternative medicinal usage by people. As positive and negative control 0.7% H₂O₂ and tap water was used, respectively. As a result, it was determined that aqueous extracts reduced mitotic index and chromosome aberrations in treatment groups in comparison with controls. These results showed that P. lanceolata aqueous extracts have anti-mitotic and anti-genotoxic effects.     

TGF-β1 signaling plays a dominant role in the crosstalk between TGF-β1 and the aryl hydrocarbon receptor ligand in prostate epithelial cells

Crosstalk between the aryl hydrocarbon receptor (AhR) and transforming growth factor-β1 (TGF-β1) signaling has been observed in various experimental models. However, both molecular mechanism underlying this crosstalk and tissue-specific context of this interaction are still only partially understood. In a model of human non-tumorigenic prostate epithelial cells BPH-1, derived from the benign prostatic hyperplasia, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) persistently activates the AhR signaling pathway and induces expression of xenobiotic metabolizing enzymes, such as CYP1A1 or CYP1B1. Here we demonstrate that TGF-β1 suppresses the AhR-mediated gene expression through multiple mechanisms, involving inhibition of AhR expression and down-regulation of nuclear AhR, via a SMAD4-dependent pathway. In contrast, TCDD-induced AhR signaling does not affect either TGF-β1-regulated gene expression or epithelial-to-mesenchymal transition. These observations suggest that, in the context of prostate epithelium, TGF-β1 signaling plays a dominant role in the crosstalk with AhR signaling pathway. Given the importance of TGF-β1 signaling in regulation of prostate epithelial tissue homeostasis, as well as the recently revealed role of AhR in prostate development and tumorigenesis, the above findings contribute to our understanding of the mechanisms underlying the crosstalk between the two signaling pathways in the prostate-specific context.     

Celecoxib reduces fluidity and decreases metastatic potential of colon cancer cell lines irrespective of COX-2 expression

CLX (celecoxib), a selective COX-2 (cyclo-oxygenase-2) inhibitor, has numerous pleiotropic effects on the body that may be independent of its COX-2 inhibitory activity. The cancer chemopreventive ability of CLX, particularly in CRC (colorectal cancer), has been shown in epidemiological studies. Here we have, for the first time, examined the biophysical effects of CLX on the cellular membranes of COX-2 expressing (HT29) and COX-2 non-expressing (SW620) cell lines using ATR-FTIR (attenuated total reflectance-Fourier transform IR) spectroscopy and SL-ESR (spin label-ESR) spectroscopy. Our results show that CLX treatment decreased lipid fluidity in the cancer cell lines irrespective of COX-2 expression status. As metastatic cells have higher membrane fluidity, we examined the effect of CLX on the metastatic potential of these cells. The CLX treatment efficiently decreased the proliferation, anchorage-independent growth, ability to close a scratch wound and migration and invasion of the CRC cell lines through Matrigel. We propose that one of the ways by which CLX exerts its anti-tumorigenic effects is via alterations in cellular membrane fluidity which has a notable impact on the cells' metastatic potential.