Antimicrobial activity of Baccharis species

FAVIER, LAURA; CIANCHINO, VALERIA; GOMEZ, MARÍA ROXANA; LACIAR, ANALIA; ALCARAZ, L.; TONN, CARLOS

Mendoza

Congreso; XXVIII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2010

Sociedad de Biología de Cuyo

In Argentina folk medicine Baccharis species such as B. articulata (Lam.) Persoon, B. trimera (Less) DC, and B. crispa Sprengel are used due to its digestive, choleretic, diuretic, anti-inflammatory, and antiseptic properties. The objective of the present study was to test the antimicrobial activity of both aqueous and ethanolic extracts. Microbiological assay: the minimum inhibitory concentration (MIC) of the extracts against Staphylococcus aureous, Pseudomona aeruginosa, Listeria monocytogene and Klebsiella pneumoniae was determined. Broth microdilution test using 96-well microplates was employed. In each well 95 μl Mueller Hinton broth, supplemented with 0.01% 2,3,5,-trifenyltetrazolium as visual indicator of bacterial growth, 5 μl of a suspension of 10 7 UFC/ml strains and 100 μl serial dilution in base two (2500 to 156.25 μg/ml) of different extracts were added. Media, extract and strains controls were included. The test was performed in triplicate. The plates were incubated at 37°C 24 h, and read visually. The results showed antimicrobial activity of all extracts against S. aureus and L. monocytogene. The range of MIC values was 1250 to 2500 μg/ml. The ethanolic extracts were most active and any particular action against gramnegative bacteria was no observed. The antibacterial activity found can be attributed to flavonoids. Furthermore, flavonoids of these species could be considered the main responsible of their popular use for healing and treating wounds and microbial infections.