title: MWCNT uptake in Allium cepa root cells induces cytotoxic and genotoxic responses and results in DNA hyper-methylation.
abstract: Advances in nanotechnology have led to the large-scale production of nanoparticles, which, in turn, increases the chances of environmental exposure. While humans (consumers/workers) are primarily at risk of being exposed to the adverse effect of nanoparticles, the effect on plants and other components of the environment cannot be ignored. The present work investigates the cytotoxic, genotoxic, and epigenetic (DNA methylation) effect of MWCNT on the plant system- Allium cepa. MWCNT uptake in root cells significantly altered cellular morphology. Membrane integrity and mitochondrial function were also compromised. The nanotubes induced significant DNA damage, micronucleus formation and chromosome aberration. DNA laddering assay revealed the formation of internucleosomal fragments, which is indicative of apoptotic cell death. This finding was confirmed by an accumulation of cells in the sub-G0 phase of the cell cycle. An increase in CpG methylation was observed using the isoschizomers MspI/HpaII. HPLC analysis of DNA samples revealed a significant increase in the levels of 5-methyl-deoxy-cytidine (5mdC). These results confirm the cyto-genotoxic effect of MWCNT in the plant system and simultaneously highlight the importance of this epigenetic study in nanoparticle toxicity.
authors.affiliation: Cell Biology and Genetic Toxicology Laboratory, Centre of Advanced Study -Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India. Electronic address: gmanosij@gmail.com.
authors.forename: Manosij
authors.initials: M
authors.lastname: Ghosh
authors.affiliation: Centre of Advanced Study -Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India.
authors.forename: Sreetama
authors.initials: S
authors.lastname: Bhadra
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Orita UI, Ibadan, Nigeria.
authors.forename: Aremu
authors.initials: A
authors.lastname: Adegoke
authors.affiliation: Centre of Advanced Study -Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India.
authors.forename: Maumita
authors.initials: M
authors.lastname: Bandyopadhyay
authors.affiliation: Cell Biology and Genetic Toxicology Laboratory, Centre of Advanced Study -Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India. Electronic address: anitamukherjee28@gmail.com.
authors.forename: Anita
authors.initials: A
authors.lastname: Mukherjee
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D059447:Cell Cycle Checkpoints / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002869:Chromosome Aberrations / Q000187:drug effects; D020552:Comet Assay; D018899:CpG Islands / Q000235:genetics; D004249:DNA Damage; D019175:DNA Methylation / Q000187:drug effects* / Q000235:genetics; D018744:DNA, Plant / Q000032:analysis / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity* / Q000648:ultrastructure; D019697:Onions / Q000187:drug effects* / Q000235:genetics / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D037742:Nanotubes, Carbon; D017382:Reactive Oxygen Species
keywords: Cell cycle; Cell viability; DNA damage; DNA methylation; MWCNT; Nanotoxicology