title: Protection of human cultured cells against oxidative stress by Rhodiola rosea without activation of antioxidant defenses.
abstract: Rhodiola rosea root has been long used in traditional medical systems in Europe and Asia as an adaptogen to increase an organism's resistance to physical stress. Recent research has demonstrated its ability to improve mental and physical stamina, to improve mood, and to help alleviate high-altitude sickness. We have also recently found that R. rosea is able to extend the life span of Drosophila melanogaster. The mode of action of R. rosea is currently unknown; it has been suggested by some to act as an antioxidant, whereas others have argued that it may actually be a pro-oxidant and act through a hormetic mechanism. We found that R. rosea supplementation could protect cultured cells against ultraviolet light, paraquat, and H(2)O(2). However, it did not alter the levels of the major antioxidant defenses nor did it markedly activate the antioxidant response element or modulate heme-oxygenase-1 expression levels at relevant concentrations. In addition, R. rosea extract was not able to significantly degrade H(2)O(2) in vitro. These results suggest that in human cultured cells R. rosea does not act as an antioxidant and that its mode of action cannot be sufficiently explained through a pro-oxidant hormetic mechanism.
authors.affiliation: Department of Pharmaceutical Sciences, University of California at Irvine, Irvine, CA 92697, USA.
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Schriner
authors.forename: Agnesa
authors.initials: A
authors.lastname: Avanesian
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Liu
authors.forename: Hendrik
authors.initials: H
authors.lastname: Luesch
authors.forename: Mahtab
authors.initials: M
authors.lastname: Jafari
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism* / Q000502:physiology; D001205:Ascorbic Acid / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D019610:Cytoprotection / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008954:Models, Biological; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000009:adverse effects / Q000494:pharmacology* / Q000633:toxicity; D018517:Plant Roots / Q000737:chemistry; D020218:Response Elements / Q000187:drug effects; D029771:Rhodiola / Q000737:chemistry
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D006861:Hydrogen Peroxide; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; D001205:Ascorbic Acid