ALPHA-LIPOIC ACID INCREASES INTRACELLULAR GLUTATHIONE IN A HUMAN T-LYMPHOCYTE JURKAT CELL-LINE

The addition of exogenous a-lipoic acid to cellular medium causes a ra pid increase of intracellular unbound thiols in Jurkat cells, a human T-lymphocyte cell line. The rise of cellular thiols is a result of the cellular uptake and reduction of lipoic acid to dihydrolipoic acid an d a rise in intracellular glutathione. Although the level of dihydroli poic acid is 100-fold lower than glutathione, the cellular concentrati on of dihydrolipoic acid might be responsible for the modulation of to tal cellular thiol levels. Rises in glutathione correlate with the lev els of intracellular dihydrolipoic acid (p<.01). This increase in glut athione is not the result of expression of new proteins like gamma-glu tamylcysteine synthetase, since the rise in glutathione was not inhibi ted by cycloheximide, a protein synthesis inhibitor. Lipoic acid admin istration is therefore a potential therapeutic agent in an array of di seases with glutathione anomalies including HIV infection. (C) 1995 Ac ademic Press, Inc.