Genotoxicity evaluation of polluted ground water in human peripheral blood lymphocytes using the comet assay

Abstract The aim of this study was to evaluate the genetic damage in human peripheral blood lymphocytes following 24 and 48- hour exposure to a commercial diazinon formulation Basudin 60EM® at concentrations between 0.01 and 40 μg mL-1. For this purpose we used the micronucleus (MN), fluorescence in situ hybridization (FISH), and alkaline single cell gel electrophoresis (comet) assay. Diazinon significantly increased the frequency of micronucleated cells compared to control. Forty-eight-hour exposure increased this frequency even at lower concentrations (0.01-10 μg mL-1). The FISH results revealed aneugenic effects at 10 μg mL-1. The comet assay also confirmed DNA damage at concentrations between 10 and 40 μg mL-1. Our findings have confirmed the genotoxic potential of diazinon and its cytotoxic effect on human lymphocytes. The increased DNA damage in our study raises concern about the current assessment of the health risk posed by this pesticide and calls for a high level of caution in agricultural and household use.

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In vitro assessment of the cytotoxic, DNA damaging, and cytogenetic effects of hydroquinone in human peripheral blood lymphocytes

Archives of Industrial Hygiene and Toxicology ◽

10.1515/aiht-2017-68-3060 ◽

2017 ◽

Vol 68 (4) ◽

pp. 322-335 ◽

Cited By ~ 7

Author(s):

Karlo Jurica ◽

Irena Brčić Karačonji ◽

Vesna Benković ◽

Nevenka Kopjar

Keyword(s):

Comet Assay ◽

Peripheral Blood ◽

Human Peripheral Blood ◽

Metabolic Activation ◽

Peripheral Blood Lymphocytes ◽

Alkaline Comet Assay ◽

Blood Lymphocytes ◽

Human Peripheral Blood Lymphocytes ◽

Cytogenetic Effects

Abstract This study investigated the mechanisms of hydroquinone toxicity and assessed the relationships between its cytotoxic, genotoxic, and cytogenetic effects tested at 8, 140, and 280 μg mL-1 in human peripheral blood lymphocytes exposed for 24 h. The outcomes of the treatments were evaluated using the apoptosis/necrosis assay, the alkaline comet assay, and the cytokinesis-block micronucleus (CBMN) cytome assay. The tested hydroquinone concentrations produced relatively weak cytotoxicity in resting lymphocytes, which mostly died via apoptosis. Hydroquinone’s marked genotoxic effects were detected using the alkaline comet assay. Significantly decreased values of all comet parameters compared to controls indicated specific mechanisms of hydroquinone-DNA interactions. Our results suggest that the two higher hydroquinone concentrations possibly led to cross-linking and adduct formation. Increased levels of DNA breakage measured following exposure to the lowest concentration suggested mechanisms related to oxidative stress and inhibition of topoisomerase II. At 8 μg mL-1, hydroquinone did not significantly affect MN formation. At 140 and 280 μg mL-1, it completely blocked lymphocyte division. The two latter concentrations also led to erythrocyte stabilization and prevented their lysis. At least two facts contribute to this study’s relevance: (I) this is the first study that quantifies the degree of reduction in total comet area measured in lymphocyte DNA after hydroquinone treatment, (II) it is also the first one on a lymphocyte model that adopted the “cytome” protocol in an MN assay and found that lymphocytes exposure even to low hydroquinone concentration resulted in a significant increase of nuclear bud frequency. Considering the limitations of the lymphocyte model, which does not possess intrinsic metabolic activation, in order to unequivocally prove the obtained results further studies using other appropriate cell lines are advised.

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Cytotoxic, clastogenic and genotoxic effects of cis-tetraammine(oxalato)ruthenium(III) dithionate on human peripheral blood lymphocytes

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v42i1.50517 ◽

2020 ◽

Vol 42 ◽

pp. e50517

Author(s):

Manuela da Rocha Matos Rezende ◽

Vivianne de Souza Velozo-Sá ◽

Cesar Augusto Sam Tiago Vilanova-Costa ◽

Elisangela Silveira-Lacerda

Keyword(s):

Comet Assay ◽

Peripheral Blood ◽

Human Peripheral Blood ◽

Human Lymphocytes ◽

Low Frequency ◽

Peripheral Blood Lymphocytes ◽

Negative Control ◽

Blood Lymphocytes ◽

Human Peripheral Blood Lymphocytes

There is a concern about stablishing the clinical risk of drugs used for cancer treatment. In this study, the cytotoxic, clastogenic and genotoxic properties of cis-tetraammine(oxalato)ruthenium(III) dithionite - cis-[Ru(C2O4)(NH3)4]2(S2O6), were evaluated in vitro in human lymphocytes. The mitotic index (MI), chromosomal aberrations (CA) and DNA damage by comet assay were also analyzed. The MTT test revealed that the ruthenium compound showed a slight cytotoxic effect at the highest concentration tested. The IC50 value for the compound after 24 hours of exposure was 185.4 µM. The MI values of human peripheral blood lymphocytes treated with 0.015, 0.15, 1.5 and 150 µM of cis-[Ru(C2O4)(NH3)4]2(S2O6) were 6.1, 3.9, 3.2 and 0.2%, respectively. The lowest concentration, 0.015 µM, did not show any cytotoxic activity. The CA values for the 0.015, 0.15 and 1.5 µM concentrations presented low frequency (1.5, 1.6 and 2.3%, respectively), and did not express clastogenic activity when compared to the negative control, although it was observed clastogenic activity in the highest concentration tested (150 µM). The results obtained by the comet assay suggest that this compound does not present genotoxic activity at lower concentrations. The results show that cis-[Ru(C2O4)(NH3)4]2(S2O6) has no cytotoxic, clastogenic or genotoxic in vitro effects at concentrations less than or equal to 0.015 µM. This information proves as promising in the treatment of cancer and is crucial for future trials.

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