Combination effects of baicalein with antibiotics against oral pathogens.
BACKGROUND
Baicalein is one of the major flavonoids in Scutellaria baicalensis Georgi, which has long been used in Asia as herbal medicine. Several biological effects of baicalein, such as antiviral, anti-inflammatiom, anti-hepatotoxicity, and anti-tumour properties, have been reported.


OBJECTIVE AND DESIGN
In this study, the antibacterial activities of baicalein were investigated in combination with ampicillin and/or gentamicin against oral bacteria.


RESULTS
Baicalein was determined with MIC and MBC values ranging from 80 to 320 and 160 to 640 μg/mL against oral bacteria. The range of MIC₅₀ and MIC₉₀ were 20-160 μg/mL and 80-320 μg/mL, respectively. The combination effects of baicalein with antibiotics were synergistic (FIC index <0.375-0.5 and FBCI <0.5) against oral bacteria. Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 1-6 h of treatment with the MIC₅₀ of baicalein, regardless of whether it was administered alone or with ampicillin or gentamicin.


CONCLUSION
These results suggest that baicalein combined with other antibiotics may be microbiologically beneficial and not antagonistic.
['Jang|Eun-Jin|EJ|', 'Cha|Su-Mi|SM|', 'Choi|Sung-Mi|SM|', 'Cha|Jeong-Dan|JD|']
D000667:Ampicillin D000900:Anti-Bacterial Agents D001419:Bacteria D004357:Drug Synergism D004791:Enzyme Inhibitors D044950:Flavanones D047309:Flavones D005839:Gentamicins D006801:Humans D008826:Microbial Sensitivity Tests D009055:Mouth
Baicalein Fractional bactericidal concentration (FBC) index Fractional inhibitory concentration (FIC) index Minimum bactericidal concentrations (MBCs) Minimum inhibitory concentrations (MICs) Synergistic effect