title: Phytotoxicity of multi-walled carbon nanotubes on red spinach (Amaranthus tricolor L) and the role of ascorbic acid as an antioxidant.
abstract: Carbon nanotubes (CNTs) are a novel nanomaterial with wide potential applications; however the adverse effects of CNTs following environmental exposure have recently received significant attention. Herein, we explore the systemic toxicity and potential influence of 0-1000 mg L(-1) the multi-walled CNTs on red spinach. The multi-walled CNTs exposed plants exhibited growth inhibition and cell death after 15 days of hydroponic culture. The multi-walled CNTs had adverse effects on root and leaf morphology, as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Raman spectroscopy detected the multi-walled CNTs in leaves. Biomarkers of nanoparticle toxicity, reactive oxygen species (ROS), and cell damage in the red spinach were greatly increased 15 days post-exposure to the multi-walled CNTs. These effects were reversed when the multi-walled CNTs were supplemented with ascorbic acid (AsA), suggesting a role of ROS in the multi-walled CNT-induced toxicity and that the primary mechanism of the multi-walled CNTs' toxicity is oxidative stress.
authors.affiliation: Laboratory of Environmental Medical Chemistry, Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Parvin
authors.initials: P
authors.lastname: Begum
authors.forename: Bunshi
authors.initials: B
authors.lastname: Fugetsu
mesh_terms: D027721:Amaranthus / Q000187:drug effects* / Q000254:growth & development; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D004573:Electrolytes / Q000737:chemistry; D005070:Evans Blue; D018527:Hydroponics; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000737:chemistry; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D012639:Seeds; D013059:Spectrum Analysis, Raman
chemical_list: D000975:Antioxidants; D004573:Electrolytes; D037742:Nanotubes, Carbon; D017382:Reactive Oxygen Species; D005070:Evans Blue; D001205:Ascorbic Acid