Cytotoxic and Genotoxic Assessment of Methylparaben on Vero Cell Line

Parabens such as methylparaben (MP) are mostly used as antimicrobial preservative in personal care products owing to their short chain length which have greater water solubility to inhibit microbial growth in an aqueous enivroment. Its ubiquitous use has raised some concerns regarding its potential health threats including breast cancer, endocrine disruption, dermatitis, female reproductive problems and male infertility. Several studies have been done on cytogenotoxicity of MP on different organisms but its cytogenotoxic potential is yet to be explored on Vero cell line. Therefore, the current study aims to assess the cytotoxic and genotoxic effects of methylparaben on vero cell line. Vero cell line can serve as a reliable invitro model due to stable growth patterns, relevancy of cellular and molecular pathways to human cells due to its mammalian nature, thereby ensuring reproducible results to aid in regulatory assessments. Cytotoxic potential of MP was evaluated by MTT assay (MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) whereas, genotoxicity was determined by comet and micronucleus assays. Vero cells were treated with nine different doses of MP (0.1, 1, 10, 20, 50, 75, 100, 150 and 200 µM) for MTT assay in order to find LD50. LD50 was determined at 100 µM dose concentration of MP whereas, sub-lethal (LD50/2) and supra-lethal (3 × LD50/2) concentrations were observed at 50 and 150 µM respectively. MTT assay showed a significant dose oriented reduction in cell viability at 100 µM (LD50) in the treated groups upon comparison with the control groups. Results of both assays showed a dose dependent increase in comet tail and micronuclei formation. Highest cytogenotoxic effects in both assays were shown by 3 × LD50/2 dose whereas, lowest cytogenotoxic effects were observed at LD50/2. The results of the study concluded that methylparaben had significant cytotoxic and genotoxic effects on Vero cell line that could aid in the optimization and imposition of regulatory measures regarding the use of MP in daily used products for public safety.