ORIGINAL CONTRIBUTION Vitamin C levels in blood are influenced by polymorphisms in glutathione S-transferases Alexandra Horska • Csilla Mislanova • Stefano Bonassi • Marcello Ceppi • Katarina Volkovova • Maria Dusinska Received: 23 June 2010 / Accepted: 8 November 2010 / Published online: 9 December 2010 Ó Springer-Verlag 2010 Abstract Purpose Glutathione S-transferases (GSTs) are inti- mately involved in combating oxidative stress and in detoxifying xenobiotics. Our objective was to examine possible interactions between polymorphisms in GST genes and plasma vitamin C, tocopherols and carotenoids in 149 reference subjects and 239 subjects occupationally exposed to mineral fibres (asbestos, rock wool, glass fibre), agents that induce oxidative stress. Methods Deletion of GSTM1 and GSTT1, and substitu- tion 105Ile/Val in GSTP1 genes were determined by PCR, antioxidants in plasma were measured by HPLC. Results Tocopherols and carotenoids were affected by age, sex, smoking, occupational exposure to fibres, but not by GST polymorphisms. Vitamin C level was influenced by sex, smoking and occupational exposure. Subjects with deletion of GST had lower vitamin C levels compared with subjects carrying the functional gene variant. Vitamin C levels varied according to GSTM1 polymorphism in the whole group (p \ 0.05), in all reference subjects (p \ 0.05), in the asbestos factory reference group (p \ 0.05), and according to GSTT1 polymorphism in reference group of the rock wool plant (p \ 0.05). Vitamin C levels were approximately 20% lower in subjects with both functionally deficient genes in the whole group (p \ 0.01) and in all non-exposed subjects (p \ 0.05). Conclusions The correspondence of lower vitamin C levels with non-functional GST isoenzymes may indicate a causal connection between two antioxidant defence path- ways, also the underlying mechanism is not yet clear. It seems that supplementation by natural antioxidants is particularly important for subjects with unfavourable genetic makeup and in those exposed to oxidative stress. Keywords GST polymorphisms Á Antioxidants Á Vitamin C Á Oxidative stress Á Exposure to mineral fibres Á Individual susceptibility Introduction Oxidative stress occurs due to imbalance between cellular oxidants and antioxidant compounds, and it has been implicated in the pathogenesis of number of diseases. Reactive oxygen species (ROS) can damage nucleic acids, proteins and lipids and induce cellular dysfunctions. To prevent free radical-induced cellular damage, organisms have developed the complex antioxidant defence mecha- nism consisted of antioxidant enzymes, GSH/GSSG redox system with low-molecular antioxidants and some plasma proteins. The major exogenous antioxidants are represented by vitamin E, vitamin C and carotenoids [1]. The general defence network is completed by cooperation of immune system, repair and biotransformation machinery. A. Horska Á C. Mislanova Á K. Volkovova Á M. Dusinska (&) Department of Experimental and Applied Genetics, Slovak Medical University, Limbova 12, 833 03 Bratislava, Slovakia e-mail: mdu@nilu.no; maria.dusinska@szu.sk S. Bonassi Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Rome, Italy M. Ceppi Unit of Molecular Epidemiology, National Cancer Research Institute, Genoa, Italy M. Dusinska CEE-Health Effects Group, Norwegian Institute for Air Research (NILU), Kjeller, Norway 123 Eur J Nutr (2011) 50:437–446 DOI 10.1007/s00394-010-0147-2