Glutathione is the most abundant intracellular tripeptide thiol and acts as a reducing agent and an antioxidant. Glutathione may regulate many enzymatic and pharmacological activities by changing the intracellular redox condition. Recent studies have accumulated evidence for important roles of glutathione in full competence of lymphocytes for such as activation, proliferation and induction of cytotoxicity. A decrease in intracellular glutathione may cause malfunction of lymphocytes, immunosuppression and apoptosis. A variety of immunological functions are determined on the basis of the balance between synthesis and con-sumption of intracellular glutathione
