title: In vitro effects of plant essential oils on non-specific immune parameters of red drum, Sciaenops ocellatus L.
abstract: Phytochemicals such as plant essential oils (EOs) have been reported to favour various activities in the innate immune system of fish. Thus, the aim of this study was to verify the in vitro effect of three different plant EOs (Ocimum americanum, Cymbopogon flexuosus and Melaleuca alternifolia) on non-specific immune parameters and erythrocyte osmotic fragility of red drum, Sciaenops ocellatus. Concentrations of each plant EO evaluated in preparations of head-kidney macrophages, blood leucocytes and blood plasma were as follows: 0.0 (control), 1.0, 2.0, 4.0, 8.0, and 16.0 μg/ml. Red drum head-kidney macrophages significantly increased extracellular superoxide anion production when exposed (20 h) to O. americanum EO (1.0-8.0 μg/ml) and C. flexuosus EO (2.0 and 4.0 μg/ml). The respiratory burst of blood leucocytes (NBT test) significantly increased in all concentrations when compared to the respective control group, for all EOs. At the highest concentration (16.0 μg/ml), C. flexuosus EO significantly inhibited the haemolytic activity of complement system in red drum blood after 1 h exposure. None of the tested concentrations significantly altered plasma lysozyme activity or erythrocyte osmotic fragility after exposing (1 h) red drum whole blood to each EO. This study demonstrated that these plant EOs are capable of triggering superoxide anion production in red drum leucocytes (head-kidney macrophages and/or blood leucocytes). In vivo studies are warranted to address their potential as immunostimulants in the diet of red drum and other aquacultured species.
authors.affiliation: CAPES Foundation, Ministry of Education of Brazil, Brasília, DF, Brazil.|Department of Physiology and Pharmacology, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: F J
authors.initials: FJ
authors.lastname: Sutili
authors.affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University System College Station, TX, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Gatlin
authors.affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University System College Station, TX, USA.
authors.forename: W
authors.initials: W
authors.lastname: Rossi
authors.affiliation: Department of Industrial Pharmacy, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: B M
authors.initials: BM
authors.lastname: Heinzmann
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: B
authors.initials: B
authors.lastname: Baldisserotto
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D031743:Cymbopogon / Q000737:chemistry; D004032:Diet / Q000662:veterinary*; D004912:Erythrocytes / Q000502:physiology; D005399:Fishes / Q000276:immunology*; D060226:Head Kidney / Q000166:cytology; D008264:Macrophages / Q000187:drug effects / Q000502:physiology; D031650:Melaleuca / Q000737:chemistry; D031339:Ocimum / Q000737:chemistry; D009822:Oils, Volatile / Q000008:administration & dosage / Q000494:pharmacology*; D009996:Osmotic Fragility / Q000187:drug effects; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D009822:Oils, Volatile; D010938:Plant Oils
keywords: complement system; erythrocyte osmotic fragility; lysozyme; phytochemical; superoxide anion