Search results for "Comet Assay"

Induction of heme oxygenase-1 and adaptive protection against the induction of DNA damage after hyperbaric oxygen treatment.

2000

Hyperbaric oxygen (HBO) treatment of human subjects (i.e. exposure to 100% oxygen at a pressure of 2.5 ATA for a total period of 3 x 20 min) caused clear and reproducible DNA damage in lymphocytes, as detected with the comet assay (single cell gel electrophoresis). Induction of DNA damage was found only after the first HBO exposure and not after further treatments of the same individuals. Furthermore, blood taken 24 h after HBO treatment was significantly protected against the induction of DNA damage by hydrogen peroxide (H(2)O(2)) in vitro, indicating that adaptation occurred due to induction of antioxidant defenses. The cells were not significantly protected against the genotoxic effects …

Assessment of the cytotoxic potential of an aqueous-ethanolic extract from Thalassia testudinum angiosperm marine grown in the Caribbean Sea

2018

Abstract Objectives Reported antioxidant, anti-inflammatory and neuroprotective properties for one aqueous-ethanolic extract from Thalassia testudinum which grows in the Caribbean Sea compelled us to explore about extract cytotoxic effects. Methods Cell viability was assayed on tumour (HepG2, PC12, Caco-2 and 4T1) and non-tumour (VERO, 3T3, CHO, MCDK and BHK2) cell lines. The extract effects upon primary cultures of rat and human hepatocytes and human lymphocytes were assayed. Key findings The extract exhibited cytotoxicity against cancer cells compared to normal cells, and the IC50 values were 102 μg/ml for HepG2, 135 μg/ml for PC12, 165 μg/ml for Caco-2 and 129 μg/ml for 4T1 cells after 4…

Blood levels of nitric oxide and DNA breaks assayed in whole blood and isolated peripheral blood mononucleated cells in patients with multiple sclero…

2019

Abstract Oxidative stress, especially overproduction of nitric oxide (NO), is considered to be one of the crucial factors in the pathogenesis of multifactorial multiple sclerosis (MS). DNA breaks could be one of the consequences of oxidative stress; however, data on DNA breakage in MS are very few and contradictory. There are no data on direct measurements of NO production in the blood of MS patients. The goal of this study was to determine the level of single-stranded DNA breaks in whole blood or isolated peripheral blood mononuclear cells (PBMNCs) by means of alkaline single cell gel electrophoresis (comet assay) and to evaluate production of NO in the human blood by applying electron par…

Evaluation of inflammatory reactions and genotoxic effects after exposure of nasal respiratory epithelia to benzene.

2003

<i>Background:</i> The aim of this study was to identify inflammatory changes as well as genotoxic effects in cultivated human respiratory epithelial cells after in vitro exposure to benzene. <i>Methods:</i> Primary cell cultures of nasal respiratory mucosa were exposed to synthetic air enriched with 5,000 µg/m<sup>3</sup> of benzene at an air/liquid interface over 8 h and then to synthetic air only over the following 24 h. Controls were continuously exposed to synthetic air over 32 h. To detect inflammatory reactions, release of prostaglandin E<sub>2</sub> was quantified using a competitive enzyme immunoassay. The Comet Assay was used to quan…

Chronic occupational noise exposure: Effects on DNA damage, blood pressure, and serum biochemistry

2019

Abstract Noise levels experienced by industrial workers may cause both auditory and non-auditory harmful effects. We have studied the effects of chronic industrial noise exposure on DNA damage, blood pressure, and serum biochemistry in factory workers. Male workers (109 individuals) in three parts of a food factory in Shahroud, Iran were enrolled as the exposed group and male office workers (123 individuals) were the unexposed control group. Noise exposure was measured (dosimetry) and the comet assay was used to evaluate DNA damage in peripheral blood mononuclear cells. Glutathione peroxidase (GPx) and ceruloplasmin (Cp) levels were measured in serum samples. GPx levels, systolic and diasto…

DNA damage in leukocytes and serum nitrite concentration are negatively associated in type 1 diabetes.

2020

Abstract Chronic hyperglycaemia leads to DNA damage in diabetes and might be associated with nitrosative stress. In this study, we aimed at assessing the level of DNA strand breaks in leukocytes, serum nitrite and nitrate in patients with type 1 diabetes and healthy controls and associations of these parameters with diabetes-related outcomes in a prospective study. The level of DNA damage was determined in 71 patients with type 1 diabetes and 57 healthy controls by comet assay and scored with arbitrary units (AU). The chemiluminescence method was used to measure nitrite and nitrate. Clinical information and data on consumption of alcohol, physical activity and smoking were collected. Progre…

Biological effects of inorganic arsenic on primary cultures of rat astrocytes

2010

It is well established that inorganic arsenic induces neurotoxic effects and neurological defects in humans and laboratory animals. The cellular and molecular mechanisms of its actions, however, remain elusive. Herein we report the effects of arsenite (NaAsO2) on primary cultures of rat astrocytes. Cells underwent induction of heat shock protein 70 only at the highest doses of inorganic arsenic (30 and 60 microM), suggesting a high threshold to respond to stress. We also investigated arsenic genotoxicity with the comet assay. Interestingly, although cells treated with 10 microM arsenite for 24 h maintained >70% viability, with respect to untreated cells, high DNA damage was already observed…

METODI FISICO E BIOLOGICO DI IDENTIFICAZIONE DI ALIMENTI IRRADIATI CONTENENTI CELLULOSA ATTRAVERSO L'USO DELLA DNA COMET ASSAY E DELLE SPETTROSCOPIA …

2013

Artesunate derived from traditional Chinese medicine induces DNA damage and repair.

2008

Abstract Artesunate is a semisynthetic derivative from artemisinin, a natural product from the Chinese herb Artemisia annua L. It exerts antimalarial activity, and, additionally, artemisinin and its derivatives are active against cancer cells. The active moiety is an endoperoxide bridge. Its cleavage leads to the formation of reactive oxygen species and carbon-centered radicals. These highly reactive molecules target several proteins in Plasmodia, which is thought to result in killing of the microorganism. DNA damage induced by artemisinins has not yet been described. Here, we show that artesunate induces apoptosis and necrosis. It also induces DNA breakage in a dose-dependent manner as sho…

Use of HepG2 cell line for direct or indirect mutagens screening: comparative investigation between comet and micronucleus assays.

2003

International audience; In the present study, DNA-damage and clastogenic or aneugenic effects of genotoxic compounds were examined in a metabolically competent human cell line (HepG2 cells) using the micronucleus and the comet assays. Compounds with various action mechanisms were tested: direct mutagens such as 4-nitroquinoline-N-oxide (4-NQO) and methyl methanesulfonate (MMS) and indirect mutagens requiring biotransformation to be active such as N-nitrosodimethylamine (NDMA), benzo[a]pyrene (B[a]P) and 2-acetylaminofluorene (2-AAF). The compounds were first tested for cytotoxicity by measuring their effects on RNA synthesis inhibition in HepG2 cells. 4-NQO, B[a]P and 2-AAF were the most po…