title: Effects of the antioxidant Pycnogenol on cellular redox systems in U1285 human lung carcinoma cells.
abstract: Pycnogenol, which is extracted from the bark of French maritime pine, has been shown to have antioxidant and free radical scavenging activities. Thioredoxin reductase (TrxR), glutathione peroxidase (GPx) and glutathione reductase (GR) are three central redox enzymes that are active in endogenous defence against oxidative stress in the cell. Treatment of cells with Pycnogenol decreased the activity of both TrxR and GPx in cells by more than 50%, but GR was not affected. As previously reported, both enzymes were induced after treatment with hydrogen peroxide and selenite. The presence of Pycnogenol efficiently decreased selenite-mediated reactive oxygen species (ROS) production. Addition of Pycnogenol after selenite treatment reduced the mRNA expression and activity of TrxR to basal levels. In contrast, the GPx activity was completely unaffected. The discrepancy between TrxR and GPx regulation may indicate that transcription of TrxR is induced primarily by oxidative stress. As TrxR is induced in various pathological conditions, including tumours and inflammatory conditions, decreased activity mediated by a non-toxic agent such as Pycnogenol may be of great value.
authors.affiliation: Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Valentina
authors.initials: V
authors.lastname: Gandin
authors.forename: Christina
authors.initials: C
authors.lastname: Nyström
authors.forename: Anna-Klara
authors.initials: AK
authors.lastname: Rundlöf
authors.forename: Kerstin
authors.initials: K
authors.lastname: Jönsson-Videsäter
authors.forename: Frank
authors.initials: F
authors.lastname: Schönlau
authors.forename: Jarmo
authors.initials: J
authors.lastname: Hörkkö
authors.forename: Mikael
authors.initials: M
authors.lastname: Björnstedt
authors.forename: Aristi P
authors.initials: AP
authors.lastname: Fernandes
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000235:genetics; D054477:Glutaredoxins / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts; D012333:RNA, Messenger / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D018038:Sodium Selenite / Q000494:pharmacology; D013880:Thioredoxin-Disulfide Reductase / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D054477:Glutaredoxins; D010936:Plant Extracts; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C024070:pycnogenols; D013880:Thioredoxin-Disulfide Reductase; D018038:Sodium Selenite