Table 4.

Antibacterial actions of flavonoids.

Flavonoid	Experimental Model	MIC	Mechanism of action or main results	Author/year
3′,3′,4-trihydroxyflavone	In vitro Pathogens: E. faecalis, S. aureus, E. coli, E. aerogenes, S. epidermidis, K. pneumoniae S. haemolyticus, and P. aeruginosa	32 μg/mL (E. faecalis and S. aureus) 64 and 128 μg/mL (K. pneumoniae, E. aerogenes, and E. coli)	(i)Killing bacteria from diabetic wounds	[153]
3′,4′,7-trihydroxyflavone	In vitro Pathogens: E. coli, E. aerogenes, K. pneumoniae, P. stuartii, and P. aeruginosa	MIC values ranging from 4 to 128 μg/mL	(i)Antibacterial and antibiotic sensitizing activity against MDR gram-negative enteric bacteria Substrates for efflux pump	[166]
Isoquercitrin	In vitro Pathogen: E. coli	MIC 4.64 μg/mL MBC 18.56 μg/mL	Membrane alterations, a rapid increase in DNA fragmentation, and caspase activation	[167]
Baicalin	In vitro Broth-microdilution method	Sub-MIC 256 μg/mL	(i)Anti-QS activity against P. aeruginosa (ii)Marked reduction in inflammation indicated by reduced accumulation of cellular infiltration in peritoneal tissue Significant decrease in IL-4 in the peritoneal flushing fluid Significant increase in INF-γ production	[160]
	In vivo Mouse intraperitoneal foreign-body biofilm infection model	100 mg/kg subcutaneous
Rutin	In vitro AI-2 bioluminescence assay APEC-O78 strain (CVCC141)	12.5, 25 and 50 μg/mL	(i)Inhibition of QS gene expression in P. aeruginosa (ii)Decreased production of the signaling molecule AHL by P. aeruginosa (iii)Reduction in CFU count of P. aeruginosa	[162]