Screening of Russian medicinal and edible plant extracts for angiotensin I-converting enzyme (ACE I) inhibitory activity

The angiotensin I-converting enzyme (ACE I) inhibitory activities of 108 aqueous ethanol extracts obtained from Russian plants were evaluated in vitro. Activity was assessed with a two-stage colorimetric assay using N-[3-(2-furyl)acryloyl]-L-phenylalanyl-glycyl-glycine (FA-PGG) as a substrate and 2,4,6-trinitrobenzenesulfonic acid (TNBS) as a coloring reagent for the enzymatic cleavage product glycylglycine (GG). Extracts from eleven plants, seven of which belong to the family Rosaceae, were found to inhibit ACE I with an IC50 < 0.3 mg/mL. Among these, the Geranium pratense extract was the most active and had an IC50 value of 81 mu g/mL.