Cyto-Genotoxic Impacts of Antimony Tin Oxide (ATO) Nanoparticles on Allium cepa Root Meristem Cells: An Integrative Experimental and in Silico Approach

TL;DR

This study shows that antimony tin oxide nanoparticles harm plant cells by disrupting cell division and damaging DNA, using both experiments and computer models.

Contribution

The study introduces an integrative experimental and in silico approach to assess the genotoxicity of ATO nanoparticles in plant cells.

Findings

ATO NPs caused concentration-dependent decreases in mitotic index and increases in chromosomal aberrations and DNA damage.

ATO NPs showed higher predicted binding affinities to tubulin and DNA than colchicine and MMS, suggesting dual genotoxic pathways.

Morphological changes in root tips were observed using SEM and TEM after ATO NP exposure.

Abstract

In this study, antimony
tin oxide (ATO) nanoparticles (NPs) were
evaluated for their cyto-genotoxic effects on Allium
cepa root tips, as their widespread use in industrial
and electronic applications raises concerns about possible environmental
release and biological hazards that remain largely unexplored. The
ATO NPs were characterized using high-resolution transmission electron
microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and
X-ray diffraction (XRD), confirming high structural uniformity and
crystallinity. Root tips were exposed to 12.5, 25, 50, and 100 μg/mL
of ATO NPs for 4 h, and cyto-genotoxicity was assessed using the Allium
anaphase-telophase and alkaline comet assays. ATO NPs caused a significant
concentration-dependent decrease in mitotic index (MI) and an increase
in chromosomal aberrations (CAs) such as laggards, bridges, stickiness,
and polyploidy along with DNA damage, indicating suppressed cell division
and genotoxic potential of ATO NPs in plant cells, respectively. SEM
and TEM analysis also revealed morphological alterations in treated
roots compared to controls. In computational docking, the ATO NP showed
more favorable predicted affinities against the colchicine-binding
site of the tubulin heterodimer (ΔG = −11.06
kcal/mol) and the synthetic B-DNA dodecamer (ΔG = −12.07 kcal/mol) than colchicine and methylmethanesulfonate
(MMS), respectively, suggesting a possible dual genotoxic pathway
involving microtubule perturbation and DNA interaction. Consequently,
this study demonstrated that ATO NPs induce cyto- genotoxic effects
in A. cepa root meristematic cells,
supporting the use of this model as a reliable tool for NP toxicity
assessment.

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