Screening of Extracts from Red Algae in Jeju for Potentials MarineAngiotensin - I Converting Enzyme (ACE) Inhibitory Activity

This study was conducted to screen in vitro angiotensin -I converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts at 20C and 70C, respectively, prepared from twenty-six red algae obtained from the coast of Jeju Island in Korea. Among aqueous extracts at 20C (20AE) from red algae Lomentaria catenata showed the strongest ACE inhibitory activity and Lithophyllum okamurae recorded the second highest activity. From MeOH extract at 20C (20ME) Ahnfeltiopsis flabelliformis possessed the strongest ACE inhibitory activity. Remarkable activities from MeOH extracts at 70C (70ME) were observed in Grateloupia filicina, Sinkoraena lancifolia and Grateloupia lanceolata. However, no significant activity was found in aqueous extracts at 70C (70AE). The IC 50 values, which are concentrations required to inhibit 50% activity of ACE, for ACE inhibitory activities of 20AE from Lithophyllum okamurae and L. catenata were 13.78 and 12.21 g mL -1 , respectively. The IC 50 values of 20ME from A. flabelliformis and Laurencia okamurae were 13.84 and 106.15 g mL -1 . Those of the 70ME from Bonnemaisonia hamifera, Grateloupia filicina, Sinkoraena lancifolia, G. lanceolata, Gracilaria vermiculophylla and L. okamurae ranged from 25.82 to 124.69 g mL -1 .