Flavonoids from Praxelis clematidea R.M. King and Robinson modulate bacterial drug resistance

• Published in: Molecules (Basel, Switzerland) Switzerland), 2011-06, Vol.16 (6), p.4828-4835
• Main Authors: Maia, Gabriela Lemos de Azevedo, Falcão-Silva, Vivyanne dos Santos, Aquino, Pedro Gregório Vieira, de Araújo-Júnior, João Xavier, Tavares, Josean Fechine, da Silva, Marcelo Sobral, Rodrigues, Luis Cezar, de Siqueira-Júnior, José Pinto, Barbosa-Filho, José Maria
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; antibacterial activity; Antibiotics; Asteraceae; Asteraceae - chemistry; bacterial resistance; Drug resistance; Drug Resistance, Bacterial - drug effects; efflux pump; Flavonoids; Flavonoids - chemistry; Flavonoids - pharmacology; Pharmaceuticals; Praxelis clematidea; Staphylococcus aureus - drug effects
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules16064828

Chemical studies of Praxelis clematidea R.M. King & Robinson resulted in the isolation of six flavones: Apigenine, genkwanine, 7,4'-dimethylapigenin, trimethylapigenin, cirsimaritin and tetramethylscutellarein, which were tested for their toxicity against Staphylococcus aureus SA-1199B, a strain possessing the NorA efflux pump. Efflux pumps are integral proteins of the bacterial membrane and are recognized as one of the main causes of bacterial drug resistance, since they expel antibiotics from the cell. The inhibition of this transporter is one form of modulating bacterial resistance to antimicrobial drugs. The flavones tested did not show any significant antibacterial activity against the Staphylococcus aureus strain used, but were able to modulate bacterial drug resistance. This property might be related to the degree of lipophilicity of the flavones conferred by the methoxyl groups, since 4',5,6,7 tetramethoxyflavone the most methoxylated compound, reduced the minimal inhibitory concentration of the drug 16-fold.