Comparative cytotoxic and genotoxic potential of benzyl-butyl phthalate and di-n-butyl phthalate using Allium cepa assay

The colossal applications of phthalates make them ubiquitous. Several studies reported toxicity and ecological effects of phthalates. However, toxicological studies using Allium cepa assay are not well explored. Therefore, the current study envisages the morphological toxicity, cytotoxicity, and genotoxicity of two phthalates using Allium cepa assay. To study the effects of phthalates on roots length, the plant was subjected to different concentrations of benzyl-butyl phthalate (BBP) and di-n-butyl phthalate (DBP) for 24 and 120 h. After 120 h treatment, the effect was > 50%; therefore, for further investigations, the treatment durations were set at 24 and 48 h. The roots length was significantly declined with increase in phthalates concentrations. From microscopic studies, it was observed that phthalates significantly decreased mitotic index (MI) after 24 and 48 h exposure. After 24 h exposure, the decline in MI was maximum with BBP treatment, while after 48 h, it was maximum with DBP treatment. On the other hand, a significant increase in percent chromosomal anomalies was induced by phthalates and the maximum increase was with DBP treatment under both exposure durations. The changes in root surface morphology were observed using scanning electron microscope. The loss in cell viability was also observed in treated and untreated root samples using laser confocal scanning microscopy. UHPLC was used to analyze the accumulation of phthalates in the roots. It can be concluded that phthalates cause deleterious effects on A. cepa and extent depends on their concentrations and treatment durations. Graphic abstract

Automated summary

The study evaluates the toxic effects of two phthalates using Allium cepa assay, finding that phthalates significantly decrease root length, reduce mitotic index, induce chromosomal anomalies, and impact root surface morphology and cell viability.