title: Innocuity and anti-Newcastle-virus-activity of Cladosiphon okamuranus fucoidan in chicken embryos.
abstract: This study evaluated the potential toxicity and antiviral activity of fucoidan from Cladosiphon okamuranus against Newcastle disease virus (NDV), one of the most serious threats to the poultry industry in the world. Toxicity was assayed on chicken embryo fibroblast (CEF) secondary cultures at concentrations ranging from 0.1 to 1500 μg per mL culture medium, assessing the cell viability by the yellow tetrazolium MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay, and on 9-day-old embryonated chicken eggs by inoculation of 2 to 500 μg doses in the allantoic cavity, assessing the embryos morphology and liver histology. At 48 h post-inoculation, viability of CEF exposed to concentrations up to 10 μg/mL was not significantly affected, and the 50% cytotoxic concentration was estimated as of 1062 μg/mL; after exposure in ovo, some chick embryos showed liver steatosis when treated with fucoidan doses over 20 μg per egg (15 to 28% at 200 μg, 27 to 56% at 500 μg), but no change was detected in their size or aspect. Antiviral activity was tested by treating 9-day-old embryos via the allantoic route with 0.25 to 16 μg fucoidan doses that were applied at different times (-1, 0 and +1 h) relative to the inoculation of 10,000 folds the 50% Tissue Culture Infective Dose (TCID50) of the NDV, La Sota strain. At 72 h post infection, virus titration in the allantoic fluid by hemagglutination assay (HA) showed a considerable and significant inhibition of infectivity for all doses, the best result (a 90% decrease) being obtained in embryos treated with 1 μg fucoidan one hour before infection. Viral RNA semi-quantification in pooled liver and small intestine of embryos that had been treated with 4 and 16 μg fucoidan 1 h before the infection showed reductions of the virus replication by 60 and 99.8%, respectively. Since this high anti-NDV activity in ovo was obtained with quite innocuous doses, fucoidan from C. okamuranus could be a potential low-toxicity antiviral compound to be used in areas exposed to NDV.
authors.affiliation: Laboratorio de Inmunología y Virología.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Trejo-Avila
authors.affiliation: Laboratorio de Inmunología y Virología.
authors.forename: Regina
authors.initials: R
authors.lastname: Elizondo-Gonzalez
authors.affiliation: Laboratorio de Inmunología y Virología.
authors.forename: Patricia
authors.initials: P
authors.lastname: Rodriguez-Santillan
authors.affiliation: Laboratorio de Inmunología y Virología.
authors.forename: Jose Alberto
authors.initials: JA
authors.lastname: Aguilar-Briseño
authors.affiliation: Programa Maricultura, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Manuel L. Barragán y Av. Pedro de Alba s/n, Cd. Universitaria, C.P. 66455, San Nicolás de los Garza, N.L., México.
authors.forename: Denis
authors.initials: D
authors.lastname: Ricque-Marie
authors.affiliation: Laboratorio de Inmunología y Virología.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodriguez-Padilla
authors.affiliation: Laboratorio de Inmunología y Virología lucia.cruzsr@uanl.edu.mx.|Programa Maricultura, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Manuel L. Barragán y Av. Pedro de Alba s/n, Cd. Universitaria, C.P. 66455, San Nicolás de los Garza, N.L., México.
authors.forename: L Elizabeth
authors.initials: LE
authors.lastname: Cruz-Suarez
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use* / Q000633:toxicity; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects / Q000821:virology; D006386:Hemagglutination Tests; D009521:Newcastle Disease / Q000188:drug therapy*; D009522:Newcastle disease virus; D000459:Phaeophyceae / Q000737:chemistry; D011134:Polysaccharides / Q000627:therapeutic use* / Q000633:toxicity
chemical_list: D000998:Antiviral Agents; D011134:Polysaccharides; C007789:fucoidan
keywords: Cladosiphon okamuranus, citotoxicity; NDV; antiviral; fucoidan