In vivo exposure to microcystins induces DNA damage in the haemocytes of the zebra mussel,Dreissena polymorpha, as measured with the comet assay

A novel galacto-oligosaccharide (GOS) manufactured by a two-step enzyme reaction of lactose was examined in a comet assay for its potential to induce DNA damage in vivo by estimating the DNA fragmentation level in the cellular nuclei of the glandular stomach, colon, and peripheral blood. GOS was orally administered at doses of 0 (vehicle alone), 500, 1000, and 2000 mg/kg/day to five male Crl: CD(Sprague Dawley) rats per group three times (48, 24, and 3 h before the animals were terminated). The specimens were prepared in accordance with the standard protocol (version 14.2) of the “International Validation of the In Vivo Rodent Alkaline Comet Assay for the Detection of Genotoxic Carcinogens” organized by the Japanese Center for the Validation of Alternative Methods. No significant differences in the percentage of DNA in the tail were observed between the GOS-treated groups and vehicle controls in any of the organs evaluated. Additionally, no GOS-related clinical signs or effects on body weight were seen. Based on these results, the comet assay of GOS in the glandular stomach, colon, and peripheral blood using rats was judged negative. Therefore, it is concluded that GOS did not induce DNA damage in vivo under the conditions employed in this study.

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Effects of photopolymerisation on genotoxicity of composite adhesives in the comet assay

Genetika ◽

10.2298/gensr1602617d ◽

2016 ◽

Vol 48 (2) ◽

pp. 617-627

Author(s):

Stefan Dacic ◽

Ninoslav Djelic ◽

Milena Radakovic ◽

Nada Lakic ◽

Aleksandar Veselinovic ◽

...

Keyword(s):

Dna Damage ◽

Comet Assay ◽

Human Lymphocytes ◽

Negative Control ◽

In Vivo Studies ◽

Halogen Lamp ◽

Genotoxic Effects ◽

Significant Difference ◽

Isolated Human Lymphocytes

Certain in vivo studies have shown that the application of adhesives directly onto the open pulp or on a thin layer of dentin causes inflammation and pulpal abscesses. This reaction is related to toxic effects of monomers from adhesives. It has been confirmed that after proper illumination the adhesives become less toxic. The aim of the study was to examine genotoxicity of non-polymerised, partly polymerised and polymerised adhesives on isolated human lymphocytes using the alkaline Comet assay. Adper Single bond2 and Adper Easy One/3M ESPE adhesive photopolymerisation was performed by Elipar Highlight 3M ESPE halogen lamp for 0, 10 and 40 sec, at final concentrations of 100, 200, 500 and 1000 ?g/mL. With both adhesives, photopolymerisation at 0 and 10 seconds showed statistically significant increase in DNA damage in comparision to the negative control (solvent). On the other hand, after 40 seconds of photopolymerisation of both adhesives in all tested concentrations, the degree of DNA damage in Comet assay had no significant difference (P>0.05, ?2 test) compared to the negative control. Therefore, only the 40 seconds of photopolymerisation prevented genotoxic effects of both adhesives in the Comet assay.

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DNA Damaging Effects, Oxidative Stress Responses and Cholinesterase Activity in Blood and Brain of Wistar Rats Exposed to Δ9-Tetrahydrocannabinol

Molecules ◽

10.3390/molecules24081560 ◽

2019 ◽

Vol 24 (8) ◽

pp. 1560 ◽

Cited By ~ 3

Author(s):

Nevenka Kopjar ◽

Nino Fuchs ◽

Suzana Žunec ◽

Anja Mikolić ◽

Vedran Micek ◽

...

Keyword(s):

Oxidative Stress ◽

Dna Damage ◽

Comet Assay ◽

Stress Responses ◽

Blood Cells ◽

Genome Stability ◽

White Blood Cells ◽

Brain Cells ◽

Alkaline Comet Assay

Currently we are faced with an ever-growing use of Δ9-tetrahydrocannabinol (THC) preparations, often used as supportive therapies for various malignancies and neurological disorders. As some of illegally distributed forms of such preparations, like cannabis oils and butane hash oil, might contain over 80% of THC, their consumers can become intoxicated or experience various detrimental effects. This fact motivated us for the assessments of THC toxicity in vivo on a Wistar rat model, at a daily oral dose of 7 mg/kg which is comparable to those found in illicit preparations. The main objective of the present study was to establish the magnitude and dynamics of DNA breakage associated with THC exposure in white blood and brain cells of treated rats using the alkaline comet assay. The extent of oxidative stress after acute 24 h exposure to THC was also determined as well as changes in activities of plasma and brain cholinesterases (ChE) in THC-treated and control rats. The DNA of brain cells was more prone to breakage after THC treatment compared to DNA in white blood cells. Even though DNA damage quantified by the alkaline comet assay is subject to repair, its elevated level detected in the brain cells of THC-treated rats was reason for concern. Since neurons do not proliferate, increased levels of DNA damage present threats to these cells in terms of both viability and genome stability, while inefficient DNA repair might lead to their progressive loss. The present study contributes to existing knowledge with evidence that acute exposure to a high THC dose led to low-level DNA damage in white blood cells and brain cells of rats and induced oxidative stress in brain, but did not disturb ChE activities.

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