Evaluation of In Vitro Cytotoxic, Genotoxic, Apoptotic, and Cell Cycle Arrest Potential of Iron-Nickel Alloy Nanoparticles.

The use of iron-nickel alloy nanoparticles (Fe-Ni ANPs) is increasing daily in various fields. People are increasingly exposed to these nanoparticles for occupational and environmental reasons. Our study determined some of the effects of Fe-Ni ANP exposure and impacts on human health at the cellular level. The cytotoxic and genotoxic potentials of Fe-Ni ANPs were investigated by XTT, clonogenic, comet, and GammaH2AX analyses using Beas-2B cells. Annexin V, multicaspase, and cell cycle arrest methods were used to understand the apoptotic mechanism of action. The intracellular ROS method was used to determine the primary mechanism that leads to cytotoxic and genotoxic activity. The Fe-Ni ANPs showed cytotoxic activity with the XTT and clonogenic methods: they had genotoxic potential, as demonstrated via genotoxicity methods. It was determined that the cytotoxic effect was realized by the caspase-dependent apoptotic pathway, and the cells were stopped at the G0/G1 stage by Fe-Ni ANPs. Increased intracellular ROS due to Fe-Ni ANPs led to cytotoxic, genotoxic, and apoptotic activity. Potential risks to human health due to Fe-Ni ANPs were then demonstrated at the cellular level.

A potent drug candidature of Cu(II) pyrazino[2,3-f][1,10]phenanthroline complexes with bioactive ligands: synthesis, crystal structures, biomolecular interactions, radical scavenging and cytotoxicities.

A novel ternary copper(II) complexes, - [Cu(py-phen)(asn)(NO3)(H2O)] (1) and [Cu(py-phen)(trp)(H2O)]NO3 (2)- (py-phen: pyrazino[2,3-f][1,10]phenanthroline, asn: asparagine, trp: tryptophan), have been synthesized and characterized by CHN analysis, ESI-MS, FTIR and single-crystal X-ray diffraction techniques. Interaction of the complexes 1 and 2 with CT-DNA has been investigated by absorption spectral titration, EB and Hoechst 33258 displacement assay. The interaction between the complexes 1 and 2 and BSA was investigated by electronic absorption and fluorescence spectroscopy methods. The experimental outcomes indicate that the fluorescence quenching mechanism between the complexes 1 and 2 and BSA is a static quenching process. The Stern-Volmer constants, binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, ΔS) of BSA + complex systems were determined at different temperatures. The binding distance between the complexes 1 and 2 and BSA was calculated according to FRET. The effect of the complexes 1 and 2 on the conformation of BSA was also examined using synchronous, two dimensional (2D) and three dimensional (3D) fluorescence spectroscopy. Radical scavenging activity of the complex was determined in terms of EC50, using the DPPH and H2O2 method. The anticancer activities of the complexes 1 and 2 were investigated using an XTT assay against three cancer cell lines (MCF-7, Caco-2 and A549) and non-tumor cell line (BEAS-2B). Communicated by Ramaswamy H. Sarma.

New binary copper(II) complexes containing intercalating ligands: DNA interactions, an unusual static quenching mechanism of BSA and cytotoxic activities.

New binary copper(II) complexes - [Cu(4-mphen)2(NO3)]NO3·H2O (1), [Cu(5-mphen)2 (NO3)]NO3·H2O (2), the known complex [Cu(dmphen)2(NO3)]NO3 (3) and [Cu(tmphen)2 (NO3)]NO3·H2O (4) - (4-mphen: 4-methyl-1,10-phenanthroline, 5-mphen: 5-methyl-1,10-phenanthroline, dmphen: 4,7-dimethyl-1,10-phenanthroline, tmphen: 3,4,7,8-tetramethyl-1,10-phenanthroline), have been synthesized and characterized by CHN analysis, ESI-MS, FTIR and single-crystal X-ray diffraction techniques. Interaction of these complexes with calf thymus DNA (CT-DNA) has been investigated by absorption spectral titration, ethidium bromide (EB) and Hoechst 33,258 displacement assay and thermal denaturation measurement. These complexes cleaved pUC19 plasmid DNA in the absence and presence of an external agent. Notably, in the presence of H2O2 as an activator, the cleavage abilities of these complexes are obviously enhanced at low concentration. Addition of hydroxyl radical scavengers like DMSO shows significant inhibition of the DNA cleavage activity of these complexes. BSA quenching mechanism was investigated with regard to the type of quenching, binding constant, number of binding locations and the thermodynamic parameters. The experimental results suggested that the probable quenching mechanism was an unusual static process and hydrophobic forces play a dominant role. The CT-DNA and BSA binding efficiencies of these complexes follow the order: 4 > 3 > 1 > 2. Furthermore, in vitro cytotoxicities of these complexes on tumor cells lines (Caco-2, MCF-7 and A549) and healthy cell line (BEAS-2B) showed that these complexes exhibited anticancer activity with low IC50 values. The effect of hydrophobicity of the methyl-substituted phenanthrolines on DNA and protein binding activities of these complexes is discussed.

Olea europaea Leaf Extract Improves the Efficacy of Temozolomide Therapy by Inducing MGMT Methylation and Reducing P53 Expression in Glioblastoma.

Unmethylated O6-methylguanine-DNA-methyltransferase (MGMT) promoter leads to Temozolomide (TMZ) resistance in most of the glioblastoma multiforme (GBM) patients. We previously investigated the synergistic effect of Olea europaea leaf extract (OLE) on TMZ cytotoxicity through modulating microRNA expression. To date, knowledge about the effect of OLE on MGMT methylation is insufficient. The aim of the current study was to evaluate the potential modulating effect of OLE on the TMZ response of GBM tumors through MGMT methylation. Exposure to 1 mg/mL OLE caused a significant induction of CpG island methylation in the MGMT gene using Methyl quantitative PCR assay (P < 0.001). In WST-1 analysis, the use of 350 µM TMZ plus 1 mg/mL OLE significantly increased the TMZ response of MGMT unmethylated cells (P = 0.003). Using the comet assay, the impact of 1 mg/mL OLE plus 350 µM TMZ on the formation of DNA strand breaks was significantly higher than that of 450 µM TMZ alone (P < 0.001) and Western blot analysis revealed that, when cells are treated with 1-mg/mL OLE, the total p53 protein levels tended to decrease. The results presented in this study uniquely demonstrated that OLE synergistically increased the TMZ response of GBM tumors by regulating MGMT gene methylation and p53 expression. However, further studies to validate our findings are required.

Synthesis and crystal structures of novel copper(II) complexes with glycine and substituted phenanthrolines: reactivity towards DNA/BSA and in vitro cytotoxic and antimicrobial evaluation.

New copper(II) complexes-dimeric-[Cu(nphen)(gly)(H2O)]+ (1) and [Cu(dmphen)(gly)(NO3)(H2O)] (2) (nphen = 5-nitro-1,10-phenanthroline, dmphen = 4,7-dimethyl-1,10-phenanthroline, and gly = glycine)-have been synthesized and characterized by CHN analysis, single-crystal X-ray diffraction techniques, FTIR, EPR spectroscopy, and cyclic voltammetry. The CT-DNA-binding properties of these complexes have been investigated by thermal denaturation measurements and both absorption and emission spectroscopy. The DNA cleavage activity of these complexes has been studied on supercoiled pUC19 plasmid DNA by gel electrophoresis experiments in the absence and presence of H2O2. Furthermore, the interaction of these complexes with bovine serum albumin (BSA) has been investigated using absorption and emission spectroscopy. The thermodynamic parameters, free-energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS) for BSA + complexes 1 and 2 systems have been calculated by the van't Hoff equation at three different temperatures (293.2, 303.2, and 310.2 K). The distance between the BSA and these complexes has been determined using fluorescence resonance energy transfer (FRET). Conformational changes of BSA have been observed using the synchronous fluorescence technique. In addition, in vitro cytotoxicities of these complexes on tumor cell lines (Caco-2, A549, and MCF-7) and healthy cells (BEAS-2B) have been examined. The antimicrobial activity of the complexes has also been tested on certain bacteria cells. The effect of mono and dimeric in the above complexes is presented and discussed. New copper(II) complexes-dimeric-[Cu(nphen)(gly)(H2O)]+ (1) and [Cu(dmphen)(gly) (NO3)(H2O)] (2) (nphen = 5-nitro-1,10-phenanthroline, dmphen = 4,7-dimethyl-1,10-phenanthroline and gly = glycine)-have been synthesized and characterized by CHN analysis, single-crystal X-ray diffraction techniques, FTIR and EPR spectroscopy. They have been tested for their in vitro DNA/BSA interactions by the spectroscopic methods. These complexes exhibited higher cytotoxic and antimicrobial activities. Complex 1 shows better DNA / BSA interactions in comparison to complex 2.

Binary and ternary new water soluble copper(II) complexes of l-tyrosine and substituted 1,10-phenanthrolines: effect of substitution on DNA interactions and cytotoxicities.

Binary and ternary water soluble copper(II) complexes - [Cu(nphen)2(H2O)](NO3)2·H2O (1), [Cu(phen)2(H2O)](NO3)2 (2), [Cu(nphen)(l-tyr)(H2O)]NO3·2H2O (3), [Cu(phen)(tyr)(H2O)] NO3·2H2O (4) - and diquarternary salts of nphen and phen (nphen=5-nitro-1,10-phenanthroline, phen=1,10-phenanthroline and tyr=l-tyrosine) have been synthesized and characterized by CHN analysis, (1)H NMR, (13)C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by thermal denaturation measurements, absorption and emission spectroscopy. The supercoiled pUC19 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by using XTT method. The complexes 1-4 exhibit significant high cytotoxicity with low IC50 values in compared with cisplatin. The effect of the substituents of phen and coordinated amino acid in the above complexes are presented and discussed.

New water-soluble copper (II) complexes including 4,7-dimethyl-1,10-phenanthroline and L-tyrosine: synthesis, characterization, DNA interactions and cytotoxicities.

Two new water-soluble copper(II) complexes, [Cu(dmphen)2(NO3)]NO3 (1), [Cu(dmphen)(tyr)(H2O)]NO3·H2O (2) and the diquarternary salt of dmphen (dmphen = 4,7-dimethyl-1,10-phenanthroline and tyr = L-tyrosine), have been synthesized and characterized by elemental analysis, (1)H NMR, (13)C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by absorption, emission spectroscopy and thermal denaturation measurements. The supercoiled pBR322 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by the XTT method. Complexes 1 and 2 exhibit significant cytotoxicity, with lower IC50 values than those of cisplatin.

Radio-protective effect of cinnamic acid, a phenolic phytochemical, on genomic instability induced by X-rays in human blood lymphocytes in vitro.

The present study was designed to determine the protective activity of cinnamic acid against induction by X-rays of genomic instability in normal human blood lymphocytes. This radio-protective activity was assessed by use of the cytokinesis-block micronucleus test and the alkaline comet assay, with human blood lymphocytes isolated from two healthy donors. A Siemens Mevatron MD2 (Siemens AG, USA, 1994) linear accelerator was used for the irradiation with 1 or 2 Gy. Treatment of the lymphocytes with cinnamic acid prior to irradiation reduced the number of micronuclei when compared with that in control samples. Treatment with cinnamic acid without irradiation did not increase the number of micronuclei and did not show a cytostatic effect in the lymphocytes. The results of the alkaline comet assay revealed that cinnamic acid reduces the DNA damage induced by X-rays, showing a significant radio-protective effect. Cinnamic acid decreased the frequency of irradiation-induced micronuclei by 16-55% and reduced DNA breakage by 17-50%, as determined by the alkaline comet assay. Cinnamic acid may thus act as a radio-protective compound, and future studies may focus on elucidating the mechanism by which cinnamic acid offers radioprotection.

Effects of fullerenol nanoparticles on acetamiprid induced cytoxicity and genotoxicity in cultured human lung fibroblasts.

The aim of this study was to investigate the effects of water soluble fullerene (fullerenol) nanoparticles on the in vitro genotoxicity induced by the insecticide acetamiprid. Healthy human lung cells (IMR-90) were treated with fullerenol C60(OH)n (n: 18-22) alone and in combination with acetamiprid for 24h. The micronucleus test, comet assay and γ-H2AX foci formation assays were used as genotoxicity endpoints. Cytotoxicity was evaluated using the clonogenic assay. The maximum tested concentration of fullerenol (1.600 µg/ml) induced 77% survival where as the lowest concentration (25 µg/ml) was not cytotoxic where as acetamiprid was cytotoxic. Fullerenol did not induce genotoxicity at tested concentrations (50-1600 µg/L). On the other hand, acetamiprid (>50 µM) significantly induced formation of micronuclei, and double and single stranded DNA breaks in IMR-90 cells. For simultaneous exposure studies, two non-cytotoxic concentrations (50 and 200 µg/ml) of fullerenol and three cytotoxic concentrations of acetamiprid (100, 200 and 400 µM) were selected. As a result, we observed that co-exposure with fullerenol significantly reduced the cytotoxicity and genotoxicity of acetamiprid in IMR-90 cells. Our results indicated the protective effect of water soluble fullerene particles on herbicide induced genotoxicity.

Evaluation of in vitro cytotoxicity and genotoxicity of copper-zinc alloy nanoparticles in human lung epithelial cells.

In the present study, in vitro cytotoxic and genotoxic effect of copper-zinc alloy nanoparticles (Cu-Zn ANPs) on human lung epithelial cells (BEAS-2B) were investigated. XTT test and clonogenic assay were used to determine cytotoxic effects. Cell death mode and intracellular reactive oxygen species formations were analyzed using M30, M65 and ROS Elisa assays. Genotoxic effects were evaluated using micronucleus, comet and γ-H2AX foci assays. Cu-Zn ANPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential measurements. Characterization of Cu-Zn ANPs showed an average size of 200nm and zeta potential of -22mV. TEM analyses further revealed the intracellular localization of Cu-Zn ANPs in cytoplasm within 24h. Analysis of micronucleus, comet and γ-H2AX foci counts showed that exposure to Cu-Zn ANPs significantly induced chromosomal damage as well as single and double stranded DNA damage in BEAS-2B cells. Our results further indicated that exposure to Cu-Zn ANPs significantly induced intracellular ROS formation. Evaluation of M30:M65 ratios suggested that cell death was predominantly due to necrosis.

Investigation of genotoxicity in acromegaly from peripheral blood lymphocyte cultures using a micronucleus assay.

CONTEXT: Although patients with acromegaly may have an increased risk of developing several types of cancers, the degree of risk for malignancy in these patients is unresolved. OBJECTIVE: The present study aimed to investigate the potential genotoxic effects of acromegaly on the cell cycle in peripheral blood lymphocyte cultures. DESIGN: This was a single center, crossover, case-control study conducted on the acromegalic patients in Turkey. SETTING: The study was conducted in the outpatient clinic of a university hospital. PATIENTS: Seventy-one consecutively screened acromegalic patients and 56 controls participated in the study. INTERVENTION: Patients were included, regardless of the disease activity status and their treatment duration before the study. MAIN OUTCOME MEASURES: The primary end point was the frequency of micronucleus (MN) in the peripheral blood lymphocyte cultures, and the secondary end point was its clinical correlations. RESULTS: The MN level was 3.82 ± 1.49 in the control group and 18.00 ± 6.13 in the acromegalic group (P < .01), whereas the nuclear division index (NDI) was 1.79 ± 0.12 in the control group and 1.68 ± 0.07 in the acromegalic group (P < .01). Neither MN nor NDI was correlated with age, GH, IGF-I, initial GH, initial IGF-I, duration of the remission period, and initial tumor size. Only the MN level was positively correlated with the duration of disease (r = 0.323, P = .014). CONCLUSION: Our results indicated that acromegalic patients had genotoxic damage at a substantial level, and there was a positive correlation between the duration of disease and genotoxicity level.

Comparative genotoxic and cytotoxic effects of the oral antidiabetic drugs sitagliptin, rosiglitazone, and pioglitazone in patients with type-2 diabetes: a cross-sectional, observational pilot study.

This cross-sectional, observational pilot study was designed to investigate the frequency of different endpoints of genotoxicity (sister-chromatid exchange, total chromosome aberrations, and micronucleus formation) and cytotoxicity (mitotic index, replication index, and nuclear division index) in the peripheral lymphocytes of patients with type-2 diabetes treated with different oral anti-diabetic agents for 6 months. A total of 104 patients who met the American Diabetes Association criteria for type-2 diabetes were enrolled in the study. Of the 104 patients, 33 were being treated with sitagliptin (100mg/day), 25 with pioglitazone (30mg/day), 22 with rosiglitazone (4mg/day), and 24 with medical nutrition therapy (control group). The results for all the genotoxicity endpoints were significantly different across the four study groups. Post hoc analysis revealed that the genotoxicity observed in the sitagliptin group was significantly higher than that observed in the medical nutrition therapy group, but lower than that occurring in subjects who received thiazolidinediones. All of the three cytotoxicity endpoints were significantly lower in patients treated by oral anti-diabetic agents compared with those who received medical nutrition therapy. However, the three indexes did not differ significantly in the sitagliptin, rosiglitazone, and pioglitazone groups. Taken together, these pilot data indicate that sitagliptin and thiazolidinediones may exert genotoxic and cytotoxic effects in patients with type-2 diabetes. Further investigations are necessary to clarify the possible long-term differences between oral anti-diabetic drugs in terms of genotoxicity and cytotoxicity, and how these can modulate the risk of developing diabetic complications in general and cancer in particular.

Radioprotection by two phenolic compounds: chlorogenic and quinic acid, on X-ray induced DNA damage in human blood lymphocytes in vitro.

The present study was designed to determine the radioprotective effect of two phytochemicals, namely, quinic acid and chlorogenic acid, against X-ray irradiation-induced genomic instability in non-tumorigenic human blood lymphocytes. The protective ability of two phenolic acids against radiation-induced DNA damage was assessed using the alkaline comet assay in human blood lymphocytes isolated from two healthy human donors. A Siemens Mevatron MD2 (Siemens AG, USA, 1994) linear accelerator was used for irradiation. The results of the alkaline comet assay revealed that quinic acid and chlorogenic acid decreased the DNA damage induced by X-ray irradiation and provided a significant radioprotective effect. Quinic acid decreased the presence of irradiation-induced DNA damage by 5.99-53.57% and chlorogenic acid by 4.49-48.15%, as determined by the alkaline comet assay. The results show that quinic acid and chlorogenic acid may act as radioprotective compounds. Future studies should focus on determining the mechanism by which these phenolic acids provide radioprotection.

Sublethal toxicity of esbiothrin relationship with total antioxidant status and in vivo genotoxicity assessment in fish (Cyprinus carpio L., 1758) using the micronucleus test and comet assay.

Esbiothrin, synthetic pyrethroid with quick activity against insects, is widely used against household pests and in public health. Despite widespread use, data on ecotoxicity and genotoxic effects are extremely scarce. The aim of the present study is to evaluate the genotoxic potential of esbiothrin on a model fish species Cyprinus carpio L., 1758 (Pisces: Cyprinidae, koi) using the micronucleus test and comet assay in peripheral blood erythrocytes. Effects of two sublethal exposure concentrations on plasma total antioxidant status (TAS mmol/L), and Hct values were examined. On the basis of the 96 h LC50 data from U.S. EPA ecotox database (32 µg/L) two sublethal exposure concentrations (5 and 10 µg/L) were used together with ethyl methanesulfonate (EMS) (5 mg/L) as positive control. Five fish were used for each dose/duration group (24, 48, and 72 h) under controlled laboratory conditions. The fish showed behavioral changes at the higher dose. Plasma TAS (mmol/L) levels decreased in 24 h; an increase was observed slightly for 48 and obviously for 72 h in both exposure doses. Similarly, hematocrit (Hct) values differed between exposure duration but no significant differences in mean values were found between groups of the same exposure time. The general trend was a rise after 48 h, which decreased afterwards. Our results revealed significant increases in the frequencies of micronuclei and levels of DNA strand breaks and thus demonstrated the genotoxic potential of this pesticide on fish, a nontarget organism of the aquatic ecosystem. To our knowledge this is the first study to report observable genotoxic effects of esbiothrin on fish.

Genotoxic and anti-genotoxic effects of vanillic acid against mitomycin C-induced genomic damage in human lymphocytes in vitro.

Vanillic acid, a vegetable phenolic compound, is a strong antioxidant. The aim of the present study was to determine its effects on mitomycin C-induced DNA damage in human blood lymphocyte cultures in vitro, both alone and in combination with mitomycin C (MMC). The cytokinesis block micronucleus test and alkaline comet assay were used to determine genotoxic damage and anti-genotoxic effects of vanillic acid at the DNA and chromosome levels. MMC induced genotoxicity at a dose of 0.25 µg/ml. Vanillic acid (1 µg/ml) significantly reduced both the rates of DNA damaged cells and the frequency of micronucleated cells. A high dose of vanillic acid (2 µg/ml) itself had genotoxic effects on DNA. In addition, both test systems showed similar results when tested with the negative control, consisting of dimethyl sulfoxide (DMSO) in combination with vanillic acid (1 µg/ml) +MMC. In conclusion, vanillic acid could prevent oxidative damage to DNA and chromosomes when used at an appropriately low dose.

Influence of naringin on cadmium-induced genomic damage in human lymphocytes in vitro.

Cadmium is an important toxic environmental heavy metal. Generally, occupational and environmental exposures to cadmium result from heavy metal mining, metallurgy and industrial use and the manufacturing of nickel-cadmium batteries, pigments and plastic stabilizers. Cadmium induces oxidative stress and alters the antioxidant system, resulting in oxidative DNA damage and lipid peroxidation. The effect of naringin, a grapefruit flavonone, on cadmium-induced genomic damage was studied by using an in vitro system to test for chromosomal aberrations and sister chromatid exchanges. Cadmium significantly increased the total chromosomal aberrations in human lymphocytes at concentrations of 20 and 40 µM, and although naringin alone did not induce any chromosomal aberrations, it decreased those induced by cadmium. The mitotic index was not affected by either cadmium or naringin. Cadmium also induced a significant number of sister chromatid exchanges, but naringin alone did not induce sister chromatid exchanges and was unable to decrease the frequency of sister chromatid exchanges induced by cadmium. Replicative index analysis revealed that naringin and cadmium did not significantly alter replicative index frequencies. In this study, we show that plant-based flavonoids, such as naringin, may reduce the genomic damage induced by cadmium and may protect the cellular environments from free radical damage by its possible antioxidative potential.

Evaluation of genotoxicity from Nilufer Stream (Bursa/Turkey) water using piscine micronucleus test.

In the present study, the in vivo micronucleus (MN) test in fish erythrocytes was used to evaluate the genotoxic potentials of water samples collected from four different sites along the Nilufer Stream which empties into the Marmara Sea on the north-west of Turkey. Nilufer Stream receives discharges of industrial and domestic wastes resulting from industrialization and urbanization activities in Bursa city. Nile tilapias (Oreochromis niloticus) were exposed to collected water samples under laboratory conditions for 3 and 6 days. Micronuclei analyses were carried out in peripheral blood erythrocytes. In addition to micronuclei, other nuclear abnormalities (NAs) such as bi-nucleated cells and binuclei with nucleoplasmic bridge and cells with blebbed, notched and lobbed nuclei, were assessed in the erythrocytes. Chemical analyses were also carried out in the water samples to assess the presence of major pollutants. MN and NA frequencies were significantly elevated in fishes exposed to water from polluted areas compared to those exposed to clean water sample. The results of this study indicate that Nilufer Stream is contaminated with potential genotoxic chemicals and the genotoxicity is possibly related with the industrial, agricultural and domestic activities.

Evaluation of chromosome aberrations, sister chromatid exchange and micronuclei in patients with type-1 diabetes mellitus.

Oxidative stress-induced DNA damage seems to play a role in the pathogenesis of type-1 diabetes mellitus and its complications. Several in vitro assays have been used to measure the DNA damage produced by oxidative stress. In the present study, we aimed to investigate the frequency of sister chromatid exchange (SCE), chromosomal aberrations (CA) and micronuclei (MN) in type-1 diabetes mellitus patients compared with healthy controls. SCE, CA and MN tests were carried out with the blood-cell cultures from 35 type-1 diabetic patients and 15 healthy, age- and sex-matched control subjects. The mean age of the type-1 diabetic patients was 31.89 +/- 10.01 years, with a mean duration of the diabetes of 7.8 +/- 6.02 years. The mean level of HbA1c of the type-1 diabetic patients was 8.37+/-1.36%. Only three (8.5%) patients with type-1 diabetes mellitus had an HbA1c level below 7%. Patients with type-1 diabetes mellitus showed a higher frequency of SCE compared with controls (5.44 +/- 1.47 and 2.54 +/- 0.82, respectively, p < 0.001), but there was no significant correlation between the duration of diabetes, HbA1c and SCE. No significant difference was found in CA or MN frequency in type-1 diabetic patients compared with controls. In conclusion, these results suggest that type-1 diabetes mellitus is a condition with genomic instability characterized by an increased level of SCE. Hyperglycemia-induced oxidative stress may be the underlying factor of the increased SCE frequency.

Anti-hyperglycemic and antigenotoxic potential of Ulva rigida ethanolic extract in the experimental diabetes mellitus.

An increased reactive oxygen species (ROS) and insufficient antioxidant activity is known in diabetes mellitus (DM). Antioxidant compounds in the human foods or supplementary diets can be used to counteract several diseases. The analysis of micronuclei (MN) is a cytogenetic technique used to show chromosomal damage caused by clastogenic affects. The present study was designed to evaluate: (i) the effects of diabetes mellitus on bone marrow MN frequency, (ii) the effect of oral administration of Ulva rigida ethanolic extract (URE) on MN frequency produced by DM, and (iii) some hematological values in normal and streptozotocin-induced diabetic rats. Daily fluid and food consumptions, weekly body weights, blood glucose concentrations and serum insulin levels were also examined in the study groups during the two different administration periods. The blood glucose concentration and MN frequency have been significantly increased in diabetic rats compared with the normal rats (p<0.0001). Especially, URE-30d group treatment in diabetic rats was significantly decreased blood glucose concentrations and MN frequency. This is the first report on the anti-hyperglycemic, anti-oxidative and genotoxic/antigenotoxic capacity of U. rigida in vivo. Our results suggest that URE shows strong anti-hyperglycemic and antigenotoxic effect on the genotoxicity produced by DM in rats.

Investigation of MMAC/PTEN gene mutations and protein expression in low grade gliomas.

The MMAC/PTEN tumor suppressor gene has an essential biological role in the formation of glioblastomas. It is known that there are variations in genetic alterations in tumors that develop in patients with different ethnic backgrounds; thus, we aimed to evaluate the incidence of MMAC/PTEN mutations and protein expression among various low grade gliomas of Turkish patients. We investigated 28 low grade gliomas for mutations of the MMAC/PTEN gene using single strand conformational polymorphism method followed by DNA sequencing. Additionally, the level of MMAC/PTEN protein expression in the tissues of 26 tumors was assessed by immunohistochemistry. In our investigation, MMAC/PTEN mutations were detected in 2 of 28 tumors (7.14%). One novel sequence variant G --> A transition at codon 159 was identified. This missense variation was a result of an alteration from AGG (Arginine) to AAG (Lysine). Moreover, it was observed that MMAC/PTEN protein expression was reduced to 73.08% of tumors. In conclusion, reduced MMAC/PTEN expression by genetic and/or epigenetic mechanisms in low grade gliomas might be associated with glioma tumorigenesis.