Hypertension is one of the most common worldwide diseases that afflict humans. Angiotensin-I converting enzyme (ACE) plays an important role in the regulation of blood pressure and hypertension. ACE catalyzes the conversion of inactive angiotensin-I into a potent vasoconstrictor, angiotensin-II. ACE also inactivates the vasodilator, bradykinin. Inhibitors of ACE are often used to treat myocardial infarction, hypertension, and other cardio-related diseases. Angiotensin II form by angiotensin I catalyzes by angiotensin-converting enzyme (ACE) cause vasoconstriction, and inactivation of vasodilator, bradykinin. Angiotensin II results in increases peripheral resistance, heart rate, and cardiac output. The influences of ACE on blood pressure make it an ideal target clinically and nutritionally in the treatment of hypertension. Inhibition of ACE mainly results in an overall antihypertensive effect. Several synthetic ACE inhibitors such as captopril, enalapril, lisinopril and temocapril are in clinical use for the treatment of hypertension. Synthetic ACE inhibitors are believed to have certain side effects such as cough, taste disturbances, skin rashes and high cost and drug-drug interactions. Therefore, search for non-toxic, safer, innovative and economical ACE inhibitors as alternatives to synthetic drugs. It is of great interest among researchers and many natural ACE inhibitors have been isolated from functional food and natural bio-resources. The natural ACE inhibitors are considered to be milder and safer compared with synthetic drugs. This review focuses on phytochemicals, chemistry, mechanism, and lead compounds derived from plants and use to control or in the treatment of hypertension. Detailed accounts from various natural products are study below.
