engleski

Standard versus Fpg-modified comet assay revealing mechanism of DNA damage induced by atorvastatin

Although benefits of atorvastatin therapy are great in treatment of patients at high risk for atherosclerotic cardiovascular disease, the aim of this study was assessment of possible DNA damage induced by therapeutical concentration of this drug with the alkaline comet assay. In addition to the standard protocol for the comet assay, Fpg-modified protocol was also used to test whether DNA damage is produced by reactive oxygen species (ROS) in lymphocytes treated with 80 mg/day atorvastatin in different time periods. Introduction of Fpg enzyme (formamidopyrimidine DNA-glycosylase), a restriction enzyme that recognizes and removes oxidized purines and some alkylate DNA products makes it possible to detect oxidative DNA damage induced by certain types of chemical and physical mutagens. The difference in measured DNA damage between the standard and Fpg-modified comet assay indicates the presence of 8-oxodG as the result of oxidative DNA damage. All parameters obtained with the standard and Fpg-modified comet assay were significantly higher in the treated than in control lymphocytes. The Fpg-modified comet assay showed a significantly greater tail length, tail intensity, and tail moment in all treated lymphocytes than did the standard comet assay, which suggests that oxidative stress is likely to be responsible for DNA damage. DNA damage detected by the standard protocol indicates that some other mechanism is also involved. These findings also suggest that the Fpg-modified comet assay is more sensitive to atorvastatine than the standard comet assay. Our study is the first to report atorvastatin-induced DNA damage and oxidative stress in vitro using the Fpg-modified comet assay. A combination of both versions of the comet assay, detecting DNA damage and repair have proven usefulness in detecting genotoxicity of this type of drug. Present study has also confirmed the need for further cytogenetic research and regular patient monitoring to minimise the risk of adverse events.

atorvastatin; DNA damage; alkaline comet assay; fpg-comet assay

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