title: Effect of sub-acute exposure to nickel nanoparticles on oxidative stress and histopathological changes in Mozambique tilapia, Oreochromis mossambicus.
abstract: The aim of the present study was to assess the oxidative stress, antioxidant response and histopathological changes of nickel nanoparticles (Ni NPs) exposure (14 days) in Mozambique tilapia, Oreochromis mossambicus. Ni NPs were synthesized by metal salt reduction method and characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The XRD peaks at 44°, 51° and 76° were indexed to the (111), (200) and (220) Bragg's reflections of cubic structure of Nickel, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 56nm. TEM images showed that the synthesized Ni NPs are spherical in shape. Biochemical analysis indicated that the superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity was significantly affected by Ni NPs treated O. mossambicus. Reduced antioxidant enzymes and the contents of antioxidants were lowered in the liver and gills of fishes treated with Ni NPs. After 14 days of exposure, a significant accumulation of Ni in the Ni NPs in experimental group was observed in the gill and skin tissues, with the highest levels found in the liver. Ni NPs exposed fish showed nuclear hypertrophy (NH), nuclear degeneration (ND), necrosis (NC) and irregular-shaped nuclei were observed in liver tissue. The hyperplasia of the gill epithelium (GE), lamellar fusion of secondary lamellae (LF), dilated marginal channel (MC), epithelial lifting (EL) and epithelial rupture were observed in gill tissue. Degeneration in muscle bundles (DM), focal area of necrosis (NC) vacuolar degeneration in muscle bundles (VD), edema between muscle bundles (ED) and splitting of muscle fibers were noticed in skin tissue. Further ecotoxicological evaluation will be made concerning the risk of Ni NPs on aquatic environment.
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India.
authors.forename: Chidambaram
authors.initials: C
authors.lastname: Jayaseelan
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India. Electronic address: abdulrahuman6@hotmail.com.
authors.forename: Abdul
authors.initials: A
authors.lastname: Abdul Rahuman
authors.affiliation: Department of Biotechnology, Periyar University, Salem-636 011, Tamil Nadu, India.
authors.forename: Rajendiran
authors.initials: R
authors.lastname: Ramkumar
authors.affiliation: Department of Biotechnology, Periyar University, Salem-636 011, Tamil Nadu, India.
authors.forename: Pachiappan
authors.initials: P
authors.lastname: Perumal
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India.
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Rajakumar
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India.
authors.forename: Arivarasan
authors.initials: A
authors.lastname: Vishnu Kirthi
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India.
authors.forename: Thirunavukkarasu
authors.initials: T
authors.lastname: Santhoshkumar
authors.affiliation: Unit of Nanotechnology and Bioactive Natural Products, Post Graduate and Research Department of Zoology, C. Abdul Hakeem College, Melvisharam-632 509, Vellore District, Tamil Nadu, India.
authors.forename: Sampath
authors.initials: S
authors.lastname: Marimuthu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005880:Gills / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D009532:Nickel / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D017210:Tilapia / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D000975:Antioxidants; D009532:Nickel; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Histopathological changes; Nickel nanoparticles; Oreochromis mossambicus; Oxidative stress