ABSTRACT
Medicinal plants are used in traditional medicine for the treatment of different diseases such as hypertension. Since inhibition of angiotensin converting enzyme [ACE] is one of the involved mechanisms in control of hypertension, in this study the inhibitory effect of 20 medicinal plants on ACE was investigated. The medicinal plants were collected, powdered, extracted, lyophilized and kept in -20degree C. ACE activity was assayed with hyporyl L histidine L leusine [HHL] as substrate in the micro scale. The extracts that inhibited 50% of ACE activity in comparison to control were considered as probable ACE inhibitors. From 20 medicinal plants in this study, the highest ACE inhibitory effect [100%] was related to Alcea digitata [Boiss] Alef., Rubia tinctorum L. and Cerasus avium [L.] Monech. Citrus aurantium L., Berberis integerrima Bge, Peganum harmala L. and Allium sativum L. also inhibited ACE activity equal or more than 70%. Since the highest ACE inhibitory effect was observed for Alcea digitata [Boiss.] Alef., Rubia tinctorum L. and Cerasus avium [L.] Monech, this plants can be used in further studies for separation of their active components against ACE activity