Physiological activities of S-(1,2-dicarboxyethyl)glutathione as an intrinsic tripeptide present in liver, heart and lens.

S-(1,2-Dicarboxyethyl)glutathione (DCE-GS, CAS 1115-52-2) found in rat liver, heart and lens in considerable amounts, showed an anti-inflammatory effect, which was evaluated by testing the inhibition of the experimental conjunctival edema of rats. An intravenous injection (3 mg/kg) prior to the carrageenan injection prevented the conjunctive edema formation by up to 30%. This peptide also inhibited the histamine release from rat mast cells induced by the compound 48/80. The peptide was added to the mast cells before addition of the compound 48/80 and an inhibition of the histamine release up to 96% at a 1 mmol/l concentration occurred. Furthermore, it displayed an antianaphylactic effect in rats using antibody against chicken egg albumin. An injection of the peptide (30 mg/kg) prior to the antigen administration inhibited color deposition up to 43%. Analogues or derivatives of DCE-GS were synthesized and tested for those inhibitory activities. However, there was no other peptide having stronger effects than DCE-GS and little structure-activity relationship among them.