title: Lipid peroxidation and cytotoxicity induced by respirable volcanic ash.
abstract: This paper reports that the main component of respirable volcanic ash, allophane, induces lipid peroxidation (LP), the oxidative degradation of lipids in cell membranes, and cytotoxicity in murin monocyle/macrophage cells. Naturally-occurring allophane collected from New Zealand, Japan, and Ecuador was studied. The quantification of LP was conducted using the Thiobarbituric Acid Reactive Substances (TBARS) assay. The cytotoxic effect was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide colorimetric assay. Electron-Paramagnetic Resonance (EPR) determinations of naturally-occurring allophane confirmed the incorporation in the structure and clustering of structural Fe(3+), and nucleation and growth of small-sized Fe (oxyhydr)oxide or gibbsite. LP induced by allophane varied with time, and solid concentration and composition, reaching 6.7 ± 0.2 nmol TBARS mg prot(-1). LP was surface controlled but not restricted by structural or surface-bound Fe(3+), because redox processes induced by soluble components other than perferryl iron. The reactivity of Fe(3+) soluble species stemming from surface-bound Fe(3+) or small-sized Fe(3+) refractory minerals in allophane surpassed that of structural Fe(3+) located in tetrahedral or octahedral sites of phyllosilicates or bulk iron oxides. Desferrioxamine B mesylate salt (DFOB) or ethylenediaminetetraacetic acid (EDTA) inhibited LP. EDTA acted as a more effective inhibitor, explained by multiple electron transfer pathways. Registered cell-viability values were as low as 68.5 ± 6.7%.
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana Unidad Cuajimalpa, México City, Mexico; Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. Electronic address: jcervini@correo.cua.uam.mx.
authors.forename: Javiera
authors.initials: J
authors.lastname: Cervini-Silva
authors.affiliation: Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City, Mexico.
authors.lastname: Antonio-Nieto-Camacho
authors.affiliation: Laboratorio de Resonancia Paramagnética Electrónica, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City, Mexico.
authors.forename: Virginia
authors.initials: V
authors.lastname: Gomez-Vidales
authors.affiliation: Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City, Mexico.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Ramirez-Apan
authors.affiliation: Dirección de Investigación y Posgrado, Instituto Mexicano del Petróleo, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Palacios
authors.affiliation: Dirección de Investigación y Posgrado, Instituto Mexicano del Petróleo, Mexico.
authors.forename: Ascención
authors.initials: A
authors.lastname: Montoya
authors.affiliation: BGR Bundesansaltfür Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kaufhold
authors.affiliation: Applied Chemistry for Environmental Industry Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan; Department of Chemistry, Faculty of Science and Mathematics, Bogor Agriculture University, Kampus Darmaga, JL Meranti, Bogor West of Java, Indonesia.
authors.forename: Zeanal
authors.initials: Z
authors.lastname: Abidin
authors.affiliation: Landcare Research, Private Bag 11052, Palmerston North 4442, New Zealand.
authors.forename: Benny K G
authors.initials: BK
authors.lastname: Theng
mesh_terms: D000538:Aluminum Silicates / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D051379:Mice; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D018707:Volcanic Eruptions
chemical_list: D000538:Aluminum Silicates; D017392:Thiobarbituric Acid Reactive Substances
keywords: Mineral Fe(3+); Naturally-occurring allophane; Oxidative stress; Redox