title: Dietary antioxidants enhance immunocompetence in larval amphibians.
abstract: Dietary antioxidants have been shown to confer a variety of benefits through their ability to counter oxidative stress, including increased immunocompetence and reduced susceptibility to both infectious and non-infectious diseases. However, little is known about the effects of dietary antioxidants on immune function in larval amphibians, a group experiencing worldwide declines driven by factors that likely involve altered immunocompetence. We investigated the effects of dietary antioxidants (quercetin, vitamin E, and β-carotene) on two components of the immune system, as well as development and growth. Lithobates pipiens tadpoles fed diets with supplemental β-carotene or vitamin E exhibited an enhanced swelling response as measured with a phytohemagglutinin assay (PHA), but there was no induced antibody response. Effects were often dose-dependent, with higher antioxidant levels generally conferring stronger swelling that possibly corresponds to the innate immune response. Our results indicate that the antioxidant content of the larval amphibian diets not only had a detectable effect on their immune response capability, but also promoted tadpole growth (mass gain), although developmental stage was not affected. Given that many environmental perturbations may cause oxidative stress or reduce immunocompetence, it is critical to understand how nutrition may counter these effects.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada. Electronic address: dszuroczki@brocku.ca.
authors.forename: Dorina
authors.initials: D
authors.lastname: Szuroczki
authors.affiliation: Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada.
authors.forename: Janet
authors.initials: J
authors.lastname: Koprivnikar
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Baker
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D004032:Diet; D007113:Immunity, Innate / Q000187:drug effects / Q000502:physiology; D007121:Immunocompetence / Q000187:drug effects / Q000502:physiology; D007814:Larva / Q000276:immunology; D018384:Oxidative Stress; D011794:Quercetin / Q000008:administration & dosage; D011894:Rana pipiens / Q000254:growth & development / Q000276:immunology* / Q000502:physiology; D014810:Vitamin E / Q000008:administration & dosage; D019207:beta Carotene / Q000008:administration & dosage
chemical_list: D000975:Antioxidants; D019207:beta Carotene; D014810:Vitamin E; D011794:Quercetin
keywords: Algae; Amphibian; Antioxidant; Carotenoid; Diet; Immune