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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 glutathi-one reductase (GR) are three central redox enzymes that are active in endogenous defence against oxidative stress in the cell. | Effects of the antioxidant Pycnogenol on cellular redox systems in U1285 human lung carcinoma cells Valentina Gandin1 Christina Nystrom1 Anna-Klara Rundlof1 Kerstin Jonsson-Videsater2 Frank Schonlau3 Jarmo Horkko4 Mikael Bjornstedt1 and Aristi P. Fernandes1 1 Division of Pathology Department of Laboratory Medicine Karolinska Institutet Karolinska University HospitalHuddinge Stockholm Sweden 2 Division of Haematology and Oncology Department of Medicine Karolinska University HospitalHuddinge Stockholm Sweden 3 Department of PharmaceuticalChemistry University of Munster Germany 4 Almado Turku Finland Keywords antioxidant glutathione peroxidise oxidative stress Pycnogenol thioredoxin reductase Correspondence A. P. Fernandes Division of Pathology Department of Laboratory Medicine Karolinska Institutet Karolinska University HospitalHuddinge SE-14186 Stockholm Sweden Fax 46 8 58581020 Tel 46 8 58582926 E-mail aristi.fernandes@ki.se Permanent address Department of Pharmaceutical Sciences University of Padova Italy Received 29 August 2008 revised 15 October 2008 accepted 13 November 2008 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
