Effects of Phenanthrene and Pyrene on Cytogenetic Stability of Human Dermal Fibroblasts Using Alkaline Comet Assay Technique

Abstract

In the present study, the influence of phenanthrene and pyrene on cytogenetic stability of human dermal fibroblasts using alkaline comet assay was evaluated. The cells were isolated from foreskin samples obtained from healthy male infants and in low passages (P 1–3) were exposed to various concentrations (0.0900, 0.0625, 0.0320, and 0.0066 ppm) of phenanthrene and pyrene. Then, alkaline comet assay was performed to investigate the influence of these compounds on DNA damage and cytogenetic stability of human dermal fibroblasts. In the present work H2O2 treatment was used as a positive control of comet assay to create DNA damages. The analysis of alkaline comet assay parameters by CaspLab software showed the tail DNA% in high concentration (0.0900 ppm) of phenanthrene and pyrene in the exposed cells got increased as compared to normal cells, while head DNA% decreased. Also, similar to positive control (H2O2), DNA damage with long tail comet was observed in high concentration of these compounds as compared to normal cells. The comparison of comet assay parameters specially head DNA% and tail DNA% between each concentrations of phenanthrene and pyrene with other groups (healthy cells and H2O2 treatment) by ANOVA and post hoc Tukey test showed that these parameters were more significantly different (p < 0.05). These results indicated that phenanthrene and pyrene even in low dosage are dangerous and can increase the DNA damage and affect on cytogenetic stability of dermal fibroblasts. These findings suggested that phenanthrene and pyrene could increase the related diseases and risk of skin cancer in exposed individuals.