Ayla Çelik

Cytogenetic effects of lambda-cyhalothrin on Wistar rat bone marrow.

In this study, the genotoxic and cytotoxic potential of lambda-cyhalothrin (LCT), a synthetic pyrethroid insecticide, was investigated in Wistar rat bone-marrow cells, using the structural chromosomal aberration (SCA) and micronucleus (MN) test systems. LCT was administrated to adult female albino rats as repeated i.p. doses of 6.12, 3.06, 0.8 mg/kg BW for 13 days at 48 h intervals. Mitomycin C (MMC) was used as a positive control (2 mg/kg BW). All the doses of LCT increased the number of structural chromosomal aberrations and the frequency of micronucleated erythrocytes, compared with the control group. It was also observed that LCT caused a significant decrease in the number of polychromatic erythrocytes. Our results demonstrate that LCT has a clastogenic/genotoxic potential as measured by the bone marrow SCA and MN tests in Wistar rats.

A study on the investigation of cadmium chloride genotoxicity in rat bone marrow using micronucleus test and chromosome aberration analysis

In this study, we investigated the genotoxic and cytotoxic potential of cadmium chloride (CdCl2)in Wistar rat tibia bone marrow cells, using the structural chromosomal aberration (SCA) and micronucleus (MN) test systems. CdCl2 was administered to adult female rats as repeated i.p. doses of 0.5 mg/kg b.w. for 18 week (four months) at 48 h intervals. Mitomycin C (MMC) was used as a positive control (2 mg/kg b.w.). This study shows that cadmium chloride treatment significantly induced the frequency of micronucleus in polychromatic erythrocytes in tibia bone marrow. This increase in micronucleus frequency shows that cadmium has a genotoxic effect on bone marrow at this level. Also, in order to determine cytotoxicity in bone marrow, the ratio of polychromatic erythrocytes to normochromatic erythrocytes was calculated in bone marrow. The results of this study indicate that CdCl2 decreased this ratio. The decrease of this ratio in bone marrow shows CdCl2 may lead to cytotoxicity. We have reported that 0.5 mg/kg-level chronic exposure to cadmium (Cd) has an injurious effect on bone marrow. Our findings indicate that CdCl2 has a cytotoxic and genotoxic effect on rat bone marrow at chronic exposure.

The frequency of sister chromatid exchanges in cultured human peripheral blood lymphocyte treated with metronidazole in vitro.

5-Nitroimidazoles are a group of antiprotozoal and antibacterial agents. Thanks to their antimicrobial activity, these chemotherapeutic agents inhibit the growth of both anaerobic bacteria and certain anaerobic protozoa. One of the useful drugs used in the treatment of infections caused by Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia is metronidazole (MTZ). The mutagenicity of metronidazole [1-(hydroxyethyl)-2-methyl-5-nitroimidazole] has been previously shown in different prokaryotic systems but not in eukaryotic systems. The objective of this study is to determine the mutagenic and cytotoxic effects of MTZ at plasma concentration and higher in vitro. In this study, we evaluated the mutagenicity and cytotoxicity of MTZ in cultured human peripheral blood lymphocytes. Doses were selected according to plasma concentration of drug. End points analyzed included mitotic index (MI), replication index (RI), and sister chromatid exchange (SCE). An analysis of variance test (ANOVA) was performed to evaluate the results. A significant decrease (p < 0.001) in MI and RI as well as an increase in SCE frequency (p < 0.001) was observed compared with control cultures. Our results indicate the genotoxic and cytotoxic effect of MTZ in cultured human peripheral blood lymphocytes at plasma concentrations slightly higher than encountered therapeutically

The protective role of curcumin on perfluorooctane sulfonate-induced genotoxicity: Single cell gel electrophoresis and micronucleus test

Perfluorooctane sulfonate (PFOS) is a man-made fluorosurfactant and global pollutant. PFOS a persistent and bioaccumulative compound, is widely distributed in humans and wildlife. Therefore, it was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in May 2009. Curcumin is a natural polyphenolic compound abundant in the rhizome of the perennial herb turmeric. It is commonly used as a dietary spice and coloring agent in cooking and anecdotally as an herb in traditional Asian medicine. In this study, male rats were treated with three different PFOS doses (0.6, 1.25 and 2.5 mg/kg) and one dose of curcumin, from Curcuma longa (80 mg/kg) and combined three doses of PFOS with 80 mg/kg dose of curcumin by gavage for 30 days at 48 h intervals. Here, we evaluated the DNA damage via single cell gel electrophoresis or comet assay and micronucleus test in bone marrow in vivo. PFOS induced micronucleus frequency and decreased the ratio of polychromatic erythrocyte to normochromatic erythrocyte in bone marrow. Using the alkaline comet assay, we showed that all doses of the PFOS strongly induced DNA damage in rat bone marrow and curcumin prevented the formation of DNA damage induced by PFOS.

Evaluation of cytotoxic and mutagenic effects of Coriolus versicolor and Funalia trogii extracts on mammalian cells.

This study examined the in vitro cytotoxic activities of standardized aqueous bioactive extracts prepared from Coriolus versicolor and Funalia trogiiATCC 200800 on HeLa and fibroblast cell lines using a MTT (3-[4,5-dimetiltiazol-2-]-2–5-difeniltetrazolium bromide) cytotoxicity assay. F. trogii and C. versicolor extracts were cytotoxic to both cell lines. At 10 μL treatment level, F. trogii and C. versicolor extracts inhibited proliferation of HeLa cancer cells by 71.5% and 45%, respectively, compared with controls. Toxicity was lower toward normal fibroblasts. In the latter case, treatment at 10 μL level with F. trogii and C. versicolor extracts reduced cell proliferation by 51.3% and 38.7%, respectively. In separate experiments, the mitotic index (MI) obtained with 3 μL treatment level of unheated extracts of the two fungi was comparable to the MI value obtained by treatment with 4 μg/mL MMC (anticancer agent mitomycin-C). A significant induction of sister chromatid exchange (SCE) was observed in normal cultured lymphocytes treated with MMC (4 μg/mL). MMC treatment reduced replication index compared with treatment with unheated F. trogii extract and negative controls (p < 0.001). In contrast to MMC, F. trogii extracts did not affect the proliferation of human lymphocytes compared with controls (p > 0.05). Laccase and peroxidase enzyme activities in F. trogii extract were implicated in their inhibitory effect on cancer cells. F. trogii extract was concluded to have antitumor activity.

Assessment of Cadmium Genotoxicity in Peripheral Blood and Bone Marrow Tissues of Male Wistar Rats

In this study, Cadmium (Cd) genotoxicity was investigated in both bone marrow and peripheral blood treatment using rat micronucleus technique as genotoxicity test at acute and chronic treatment in the same animals. This study evaluated the frequency of micronuclei in the peripheral blood and bone marrow of male rats treated with unique cadmium dose (15 mg/kg. body w/day) by gavage for 60 days and acute treatment for 24 h, respectively. Mitomycin C (MMC) 2 mg/kg body wt was used as a positive control. This study shows that cadmium chloride treatment significantly induced the frequency of micronucleus in polychromatic erythrocytes in both tibia bone marrow and peripheral blood (p < 0.001, p < 0.01, respectively). This increase in micronucleus frequency shows that cadmium has a genotoxic effect on bone marrow and peripheral blood at this level. Also, in order to determine cytotoxicity in bone marrow and peripheral blood, the ratio of polychromatic erythrocytes to normochromatic erythrocytes was calculated in bone marrow and peripheral blood. Cd treatment decreased this ratio in only bone marrow. The results of this study demonstrate that Cd has both toxic and genotoxic potential in bone marrow and only genotoxic potential in peripheral blood. There is a significant difference between the control group and exposed group, including acute and chronic treatment for blood Cd level (p < 0.001). No significant difference was found between acute and chronic exposure group (p > 0.05).

SiO2 Nanoparticule-induced size-dependent genotoxicity – an in vitro study using sister chromatid exchange, micronucleus and comet assay

Abstract Fine particles with a characteristic size smaller than 100 nm (i.e. nanoparticlesspread out in nowadays life. Silicon or Si, is one of the most abundant chemical elements found on the Earth. Its oxide forms, such as silicate (SiO4) and silicon dioxide, also known as silica (SiO2), are the main constituents of sand and quartz contributing to 90% of the Earths crust. In this work, three genotoxicity systems “sister chromatid exchange, cytokinesis block micronucleus test and single cell gel electrophoresis (comet) assay” were employed to provide further insight into the cytotoxic and mutagenic/genotoxic potential of SiO2 nanoparticules (particle size 6 nm, 20 nm, 50 nm) in cultured peripheral blood lymphocytes as in vitro. It was observed that there is a significant decrease in Mitotic index (MI), Cytokinesis block proliferation index (CBPI), proliferation index (PRI) values expressed as Cell Kinetic parameters compared with negative control (p < 0.05). There is a statistically significant difference between negative control culture and culture exposed to SiO2 (6 nm, 20 nm, 50 nm) (p < 0.01, p < 0.01, p < 0.05, respectively). It is found that SiO2 nanoparticles at different size (6, 20, 50 nm) progressively increased the SCE frequency and DNA damage on the basis the AU values compared with negative control (p < 0.05). Results showed that the genotoxic/mutagenic and cytotoxic effects of SiO2 nanoparticules is dependent to particule size.

Genotoxicity of thimerosal in cultured human lymphocytes with and without metabolic activation sister chromatid exchange analysis proliferation index and mitotic index.

Thimerosal is an antiseptic containing 49.5% of ethyl mercury that has been used for years as a preservative in many infant vaccines and in flu vaccines. Thimerosal is an organic mercurial compound used as a preservative in biomedical preparations. In this study, we evaluated the genotoxic effect of thimerosal in cultured human peripheral blood lymphocytes using sister chromatid exchange analysis in culture conditions with and without S9 metabolic activation. This study is the first report investigating the genotoxic effects of thimerosal in cultured human peripheral blood lymphocyte cells using sister chromatid exchange analysis. An analysis of variance test (ANOVA) was performed to evaluate the results. Significant induction of sister chromatid exchanges was seen at concentrations between 0.2 and 0.6 microg/ml of thimerosal compared with negative control. A significant decrease (p<0.001) in mitotic index (MI) and proliferation index (PRI) as well as an increase in SCE frequency (p<0.001) was observed compared with control cultures. Our results indicate the genotoxic and cytotoxic effect of TH in cultured human peripheral blood lymphocytes at tested doses in cultures with/without S9 fraction.

Bio-monitoring for the genotoxic assessment in road construction workers as determined by the buccal micronucleus cytome assay

Buccal micronucleus cytome (BMCyt) assay monitors genetic damage, cell proliferation and cell death in humans exposed to occupational and environmental agents. BMCyt is used as an indicator of genotoxic exposure, since it is associated with chromosomal instability. There is little research on the occupational exposure among road construction workers for genotoxicity testing. In the present study, we evaluated MN frequencies and other nuclear changes, karyorrhexis (KR), karyolysis (KL), broken egg (BE), binucleate (BN), condensed chromatin cell (CCC), and picnotic cell (PC) in buccal mucosa cells of 40 road construction workers (twenty smokers and twenty non-smokers) and 40 control groups consisting of healthy persons (twenty smokers and twenty non-smokers). Microscopic observation was performed of 2000 cells per individual in both road construction workers and control group. In control and worker groups, for each person repair index (RI) was calculated via formula KR+L/BE+MN. The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group (p<0.001). There is no significant difference between smokers and non-smokers for incidence of MN or nuclear changes and value of RI in exposed group. In road construction workers, RI is lower than the control group. There is a significant difference between workers and control group (p<0.001) for RI. Our data reveal that asphalt fumes during road paving operations are absorbed by workers and that asphalt fume exposure is able to significantly induce cytogenetic damage in buccal mucosa cells of workers after controlling some possible confounding factors, such as age, sex and smoking habits. In addition to determination of nuclear changes and the micronucleus, the determination of RI value presents a new approach to genotoxic bio-monitoring assessment studies of occupationally exposed population.

Cytogenetic Biomonitoring of Carpet Fabric Workers Using Micronucleus Frequency, Nuclear Changes, and the Calculation of Risk Assessment by Repair Index in Exfoliated Mucosa Cells

The micronucleus (MN) assay in exfoliated buccal cells is a minimally invasive method for monitoring genetic damage in human populations and is used as an indicator of genotoxic exposition, as it is associated with chromosome aberrations. In this study, we evaluated MN frequencies and other nuclear changes (NCs), such as karyorrhexis (KR), karyolysis (KL), broken egg (BE), and binucleus in buccal mucosa cells of 50 carpet fabric workers (25 smokers and 25 nonsmokers) and 50 healthy control subjects (25 smokers and 25 nonsmokers). Microscopic observation of 2000 cells per individual was performed in both workers and control subjects. In both the control group and the exposed group, for each person a repair index (RI) was calculated via the following formula: (KR+KL)/(BE+MN). The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group. There is a significant difference between worker and control groups (p<0.001) for RI. We believe that the calculation of RI values, in addition to nuclear changes, presents a new approach in risk assessment in relation to occupational exposure.