Inhibition of angiotensin converting enzyme activity by reduced glutathione: A dose dependent invitro study.

The Angiotensin converting enzyme (ACE) is a dipeptidyl carboxypeptidase and plays an important role in the regulation of blood pressure. Several potent inhibitors of this enzyme have been reported to be active antihypertensive agents. Sulfhydryl (SH) group containing ACE inhibitors used as a antihypertensive agents. Reduced glutathione (GSH) as antioxidant play an important role in reducing the blood pressure. Several recent studies have shown that reduced glutathione enhance nitric oxide pathway and increases the bioavailability of nitric oxide resulting in vasodilatation. In this study reduced glutathione and oxidized glutathione (GS-SG) were investigated for inhibition against ACE using Hip-His-Leu (HHL) as substrate. The inhibition of ACE by different concentrations of reduced glutathione was much more than that of oxidized glutathione. The inhibition of ACE by reduced glutathione ranges from 12.5% to 60%. Oxidized glutathione shows less than 5% of inhibition. This study shows that apart from the antioxidant role, reduced glutathione inhibits ACE activity which plays a crucial role in the regulation of blood pressure.