title: Dietary intake of antioxidant supplements modulate antioxidant status and heat shock protein 70 synthesis.
abstract: The physiological effects and efficacy of dietary intake of antioxidant supplements in humans remains controversial. Experiments involving dietary, often high, intake of a single antioxidant or vitamin may be seriously flawed given the interactive nature of antioxidants in vivo. The present studies were conducted on individuals (35-60 years of age) taking a commercial antioxidant mixture in a double-blind, placebo-controlled, cross-over study. Intake was two capsules per day, for 4 weeks, with a 4-week washout period in between active dose or placebo. Intake of antioxidants was associated with little change in superoxide dismutase activity, but an increase in glutathione peroxidase was noted. Haemolysis of red blood cells (erythrocytes) induced by the free radical generator AAPH was significantly reduced in individuals on antioxidant supplements. In lymphocytes isolated from individuals taking supplements, there was a marked increase, as compared with individuals on placebo, in the synthesis of heat shock protein 70 (hsp70) following heat shock from 37 degrees C to 42.5 degrees C. We conclude that dietary intake of a mixed antioxidant supplement leads to modulation of cellular redox status resulting in decreased oxidative stress and increased ability of lymphocytes to mount a stress response.
authors.affiliation: Human Biology, School of Biological Sciences, University of New England, Armidale, New South Wales, Australia.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Howard
authors.forename: Graham L
authors.initials: GL
authors.lastname: Jones
authors.forename: Chris
authors.initials: C
authors.lastname: Oliver
authors.forename: Kenneth
authors.initials: K
authors.lastname: Watson
mesh_terms: D000328:Adult; D000367:Age Factors; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004912:Erythrocytes / Q000378:metabolism; D005609:Free Radicals; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010919:Placebos; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D018840:HSP70 Heat-Shock Proteins; D010919:Placebos; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase