Inhibition of human glutathione S-transferase P1-1 by tocopherols and alpha-tocopherol derivatives.

: Biochim Biophys Acta 2001 Jul 9;1548(1):23-8 Related Articles, Books, LinkOut Inhibition of human glutathione S-transferase P1-1 by tocopherols and alpha-tocopherol derivatives. Van Haaften RI, Evelo CT, Penders J, Eijnwachter MP, Haenen GR, Bast A. Department of Pharmacology and Toxicology, Faculty of Medicine, Universiteit Maastricht, P.O. Box 616, 6200 MD Maastricht, Netherlands. r.vanhaaften@farmaco.unimaas.nl alpha-Tocopherol inhibits glutathione S-transferase P1-1 (GST P1-1) (R.I.M. van Haaften, C.T.A. Evelo, G.R.M.M. Haenen, A. Bast, Biochem. Biophys. Res. Commun. 280 (2001)). In various cosmetic and dietary products alpha-tocopherol is added as a tocopherol ester. Therefore we have studied the effect of various tocopherol derivatives on GST P1-1 activity. It was found that GST P1-1 is inhibited, in a concentration dependent manner, by these compounds. Of the compounds tested, the tocopherols were the most potent inhibitors of GST P1-1; the concentration giving 50% inhibition (IC(50)) is