title: Cytogenetic studies of chromium (III) oxide nanoparticles on Allium cepa root tip cells.
abstract: The current study evaluates the cytogenetic effects of chromium (III) oxide nanoparticles on the root cells of Allium cepa. The root tip cells of A. cepa were treated with the aqueous dispersions of Cr2O3 nanoparticles (NPs) at five different concentrations (0.01, 0.1, 1, 10, and 100μg/mL) for 4hr. The colloidal stability of the nanoparticle suspensions during the exposure period were ascertained by particle size analyses. After 4hr exposure to Cr2O3 NPs, a significant decrease in mitotic index (MI) from 35.56% (Control) to 35.26% (0.01μg/mL), 34.64% (0.1μg/mL), 32.73% (1μg/mL), 29.6% (10μg/mL) and 20.92% (100μg/mL) was noted. The optical, fluorescence and confocal laser scanning microscopic analyses demonstrated specific chromosomal aberrations such as-chromosome stickiness, chromosome breaks, laggard chromosome, clumped chromosome, multipolar phases, nuclear notch, and nuclear bud at different exposure concentrations. The concentration-dependent internalization/bio-uptake of Cr2O3 NPs may have contributed to the enhanced production of anti oxidant enzyme, superoxide dismutase to counteract the oxidative stress, which in turn resulted in observed chromosomal aberrations and cytogenetic effects. These results suggest that A. cepa root tip assay can be successfully applied for evaluating environmental risk of Cr2O3 NPs over a wide range of concentrations.
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: A
authors.initials: A
authors.lastname: Rajeshwari
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Pradeep Singh
authors.initials: PS
authors.lastname: Jadon
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Gouri
authors.initials: G
authors.lastname: Chaudhuri
authors.affiliation: Centre of Advanced Study, Department of Botany, University of Calcutta, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Mukherjee
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Chandrasekaran
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
mesh_terms: D002857:Chromium / Q000737:chemistry* / Q000633:toxicity*; D002869:Chromosome Aberrations; D032461:Chromosomes, Plant / Q000187:drug effects / Q000235:genetics; D053758:Nanoparticles / Q000737:chemistry*; D019697:Onions / Q000737:chemistry* / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D018517:Plant Roots / Q000166:cytology* / Q000187:drug effects*
chemical_list: D002857:Chromium
keywords: A. cepa; Bio-uptake; Chromosomal aberration; Cr(2)O(3) nanoparticles; Mitotic index; SOD