Activation of human erythrocyte glutathione - s - transferase (EC. 2.5.1.18) by caffeine (1, 3, 7 - trimethylxanthine)

Caffeine (1,3,7 - trimethylxanthine) was extracted from Nescafe\uae (product number CC5AA) a brand of "instant coffees" produced by Nestle foods, Lagos, Nigeria, using Harris method adapted from FDALS (1982) and confirmed by Wagenar test (Arnand, 1984). Various concentrations (5.0\u3bcM, 10.0\u3bcM, 15.0\u3bcM, 20.0\u3bcM, 25.0\u3bcM and 50.0\u3bcM) of the isolated caffeine were tested in-vitro on their possible effect on human erythrocyte (red cell) glutathione - S - transferase (EC. 2.5.1.18) activity. The result indicated significant (P < 0.05) activation of the erythrocyte enzyme (GST) by caffeine in a concentration - dependent manner i.e. higher concentrations produced greater activation of the enzyme. For instance at caffeine concentrations of 5.0\u3bcM, 25.0\u3bcM and 50.0\u3bcM, red cell GST activity was increased by 1.99 folds (299.43%), 4.99 folds (598.85%) and 6.98 folds (798.28%) respectively. These results may point to a possible binding - deterioration of caffeine by the human erythrocyte GST @ JASE