title: Physiological and biochemical responses of two keystone polychaete species: Diopatra neapolitana and Hediste diversicolor to Multi-walled carbon nanotubes.
abstract: Multi-walled carbon nanotubes (MWCNTs) are one of the most important carbon Nanomaterials (NMs). The production and use of these carbon NMs is increasing rapidly and, therefore, the need to assess their presence in the environment and associated risks has become increasingly important. However, limited literature is available regarding the impacts induced in aquatic organisms by this pollutant, namely in invertebrate species. Diopatra neapolitana and Hediste diversicolor are keystone polychaete species inhabiting estuaries and shallow water bodies intertidal mudflats, frequently used to evaluate the impact of environmental disturbances in these systems. To our knowledge, no information is available on physiological and biochemical alterations on these two species due to MWCNTs exposure. Thus, the present study aimed to assess the toxic effects of different MWCNTs concentrations (0.01; 0.10 and 1.00mg/L) in both species physiological (regenerative capacity and respiration rate) and biochemical (energy reserves, metabolic activities, oxidative stress related biomarkers and neurotoxicity markers) performance, after 28 days of exposure. The results obtained revealed that exposure to MWCNTs induced negative effects on the regenerative capacity of D. neapolitana. Additionally, higher MWCNTs concentrations induced increased respiration rates in D. neapolitana. MWCNTs altered energy-related responses, with higher values of electron transport system activity, glycogen and protein concentrations in both polychaetes exposed to this contaminant. Furthermore, when exposed to MWCNTs both species showed oxidative stress with higher lipid peroxidation, lower ratio between reduced and oxidized glutathione, and higher activity of antioxidant (catalase and superoxide dismutase) and biotransformation (glutathione-S-transferases) enzymes in exposed organisms.
authors.affiliation: Departamento de Biologia & CESAM, University of Aveiro, 3810-193, Portugal; Center for Mechanical Technology and Automation (TEMA), University of Aveiro, 3810-193, Portugal.
authors.forename: Lucia
authors.initials: L
authors.lastname: De Marchi
authors.affiliation: Center for Mechanical Technology and Automation (TEMA), University of Aveiro, 3810-193, Portugal.
authors.forename: Victor
authors.initials: V
authors.lastname: Neto
authors.affiliation: Department of Veterinary Sciences, University of Pisa, San Piero a Grado, PI 56122, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pretti
authors.affiliation: Departamento de Biologia & CESAM, University of Aveiro, 3810-193, Portugal.
authors.forename: Etelvina
authors.initials: E
authors.lastname: Figueira
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa 56126, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Chiellini
authors.affiliation: Departamento de Biologia & CESAM, University of Aveiro, 3810-193, Portugal.
authors.forename: Amadeu M V M
authors.initials: AMVM
authors.lastname: Soares
authors.affiliation: Departamento de Biologia & CESAM, University of Aveiro, 3810-193, Portugal. Electronic address: rosafreitas@ua.pt.
authors.forename: Rosa
authors.initials: R
authors.lastname: Freitas
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002802:Cholinesterases / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism; D015999:Multivariate Analysis; D037742:Nanotubes, Carbon / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D011077:Polychaeta / Q000187:drug effects* / Q000502:physiology*; D012038:Regeneration / Q000187:drug effects; D015996:Survival Rate; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D004798:Enzymes; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D002802:Cholinesterases
keywords: Body regeneration; Invertebrates; Multi-walled carbon nanotubes; Neurotoxicity; Oxidative stress; Respiration rate