Garlic extract reduces serum angiotensin converting enzyme (ACE) activity in nondiabetic and streptozotocin-diabetic rats

The rennin–angiotensin system (RAS) has been implicated in the development of diabetic vascular complications. Peptidyl-dipeptidase A (angiotensin converting enzyme, ACE) has a major role in this system. The aim of the present study was to clarify the effect of intraperitoneal administration of aqueous garlic extract (Allium sativum) on the serum ACE activity of streptozotocin (STZ)-diabetic and nondiabetic rats. Although garlic extract administration had no significant effect on serum glucose, it significantly strongly decreased the serum ACE activity. ACE activity was higher in diabetic than nondiabetic rats, but in diabetic animals treated with garlic extract, the elevation of ACE activity did not occur. These results suggest that garlic extract might have value as ACE inhibitor to prevent some vascular complications of diabetes mellitus.