| Popis: |
Antimicrobial and DPPH-scavenging assay were analyzed on nine Asteraceae species collected from Southest in Vietnam. Crude extracts from Taraxacum officinale, Chrysanthemum morifolium, Ageratum conyzoides, Tagetes erecta and essential oils from Ageratum conyzoides, Helianthus annuus, Artemisia vulgaris have antimicrobial activity on tested microorganisms. The essential oils of displayed effect on Candida spp. and Gram possitive bacteria, meanwhile, crude extracts expressed the inhibitory ability on bacteria. Ethyl acetate fraction from Ageratum conyzoides showed the most potent effect on urinary clinical strains ( E. coli and K. pneumoniae) with MIC at 1.25-10 mg/ml and 5-12.5 mg/ml, respectively. All ethanol crude extracts exhibited strong reducing power indicating on the TLC plate. The results of the DPPH scavenging assay showed that Tagetes erecta extract had the lowest IC 50 (17.280 μg/ml) and 2.5 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae , and could therefore be applicable of prophylactic urinary tract infection. |
