Potential of Ageratum conyzoides in Inhibiting Nitric Oxide Synthase

lbgBackground and Objective:l/bg Inflammation occurs ligvial/ig several mechanisms, one of which includes the production of Nitric Oxide (NO) catalyzed by inducible nitric oxide synthase (iNOS), which is inhibited selectively by isothioureas. ligAgeratum conyzoidesl/ig L. has shown activity in reducing pain and inflammation, although the molecular mechanism had not been undertaken. The objectives of this work were (1) to study the mechanism of anti-inflammatory activity of ligA. conyzoidesl/ig through inhibition of iNOS, (2) to correlate the iNOS inhibitory activity of the plant with the total flavonoid content of the plants and (3) to identify the flavonol synthase (FLS), an enzyme that catalyzes the production of quercetin. lbgMaterials and Methods:l/bg The inhibitory activity against iNOS was assayed by ligin vitrol/ig method. The total flavonoids (calculated as quercetin) of ligA. conyzoidesl/ig were determined by fluorometry. The protein extraction of the leaves was carried out by employing Laing and Christeller's (2004) method, followed with SDS-PAGE. lbgResults:l/bg The inhibitory activity (IClsubg50l/subg) of ethanol extract and ethyl acetate fraction of ligA. conyzoidesl/ig against iNOS was 92.05 and 4.78 μg mLlsupgl/supglsupg1l/supg, respectively. Pearson correlation analysis resulted in 0.548 (ethanol extract) and 0.696 (ethyl acetate fraction). The total flavonoids (calculated as quercetin) contained in the ethanol extract and ethyl acetate fraction of ligA. conyzoidesl/ig were 0.71 and 7.65%, respectively. The FLS in ligA. conyzoidesl/ig leaves was identified at 31 kDa. lbgConclusion:l/bg ligA. l/igcligonyzoidesl/ig L. is potential in inhibiting iNOS due to quercetin contained in the leaves. This report will add a scientific insight of ligA. conyzoidesl/ig for biological sciences.