Paper Title
In Vitro Inhibition Of Water Extract Of Kumis Kucing And Tempuyung Towards Angiotensin Converting Enzyme Activity

Angiotensin Converting Enzyme (ACE) has an important role in increasing blood pressure (hypertension). ACE works with the mechanism of the conversion inactive decapeptide angiotensin I to angiotensin II as its active form. With the formation of angiotensin II, there will be a narrowing of the blood vessels which can lead to hypertension. Kumis kucing (Orthosiphon aristatus (Blume) Miq.) and tempuyung (Sonchus arvensis) plant were extracted through maceration method using water and yield respectively 10.7% and 8.63%. Based on shrimp larvae toxicity test with BSLT methods, Extract of kumis kucing and tempuyung had LC50 values at 1789.06 and 1657.44 ppm. ACE inhibitory activity were tested with ACE Kit-WST method and obtained respectively 69.20% for single extract of kumis kucing, 39.67% for single extract of tempuyung, and 88.34% for captopryl at concentration 25 ppm. Based on the results, a single extract of kumis kucing have a higher power inhibition than tempuyung but lower than captopryl as a positive control. While the combination of the two extracts did not yield a good inhibition power. The inhibition power of kumis kucingļæ½s single extract at a concentration of 50 ppm is high enough to be a natural ACE inhibitors and may potentially as an antihypertensive. Keywords - kumis kucing (Orthosiphon aristatus (Blume) Miq.), tempuyung (Sonchus arvensis), Angiotensin Converting Enzyme (ACE), inhibition, in vitro.