Genotoxic effect of saccharin on Allium cepa root tips

Saccharin has been a controversial dietary component because of its potential to aggravate a number of human health disorders. The genotoxic properties of saccharin affect the normal karyokinesis process and results in chromosomal aberrations. In this backdrop, the current study has been formulated to evaluate the genotoxic potential of aqueous saccharin solution using Allium cepa L. assay. Three different concentrations of saccharin solution (0.25%, 0.5% and 1%) and a negative control were used for the root growth inhibition assay. The root length of Allium cepa significantly reduced under saccharin treatments and the effective concentration (EC50) value of the aqueous saccharin solution was determined as 0.587%. The genotoxic effects were determined for the root tip meristematic cells through mitotic index (MI) and mitotic depression (MD) at 3, 6 and 12 h of study. The MI registered highest value without saccharin at low exposure period (17.0 ± 1.5%) while a significant reduction with saccharin application culminated in the lowest MI for 1% saccharin solution at 12 h (3.4 ± 0.4%). MD was found to have a concomitant increase regarding the exposure of the chemical. Higher dose of saccharin for longer exposure time had a gradual decrease in the prophase and simultaneous increase in metaphase and anaphase. Further microscopic observations revealed eight different types of chromosomal aberrations in the A. cepa root tip cells with Anaphase Bridge assuming the highest score. Thus the current study clearly establishes the genotoxic consequences of aqueous solution of saccharin warranting its moderate and regulated dietary intake.