The use of comet assay in measuring DNA damage and repair efficiency in child, adult, and old age populations

Abstract

In the present study, we used the Comet assay to estimate basal DNA damage in three distinct populations aged 5-10, 40-50, and 60-70 years old. The DNA damage induced by hydrogen peroxide and gamma-irradiation in the lymphocytes of these populations, as well as their repair activity, was also studied. Finally, we measured apoptosis and necrosis after the effect of these agents. Our results indicate that the older population (60-70 years old) showed higher basal levels of DNA damage and was more sensitive to the effects of the DNA-damaging agents than the adult one (40-50 years old), who, in turn, was more sensitive than the younger population (5-10 years old). A decline of the repair efficiency with age to the DNA damage induced by the two agents was also observed. Apoptosis and necrosis were also affected by age.

DNA-damage response associated with occupational exposure, age and chronic inflammation in workers in the automotive industry

“…2). Our observations conformed to the data reviewed by Møller et al [38,39], but conflicting findings have shown an age-dependent sensitivity of populations to chromosomal breakage [40] and DNA damage [41]. Nevertheless, a three-to eightfold increase in the percentage of sensitive individuals, associated with accumulation of unrepaired H 2 O 2 -induced lesions, was observed in the subgroup of elderly workers ( Table 2).…”

Cytogenetic status of healthy children assessed with the alkaline comet assay and the cytokinesis-block micronucleus cytome assay

“…Hazane et al [43] and Sauvaigo et al [44], using also the comet assay, found that aging was associated with decreased DNA-repair capacity. Piperakis et al [45] demonstrated that older persons have increased levels of DNA damage and a less efficient DNA-repair system in comparison with young persons. Increased DNA damage by older age as detected by the comet assay was also reported in other studies [46][47][48][49][50][51].…”

Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay

“…Hydrogen peroxide (H 2 O 2 ), one of the main ROS, is known to cause DNA damage in various cell types (7). Also, Caspase-3, a cysteine protease that is one of the effectors of apoptosis and necrosis, is activated by H 2 O 2 (8). …”