Inhibitory effects of andrographis paniculata and silybum marianum on the efflux pump of MRSA 41577 / 中国生化药物杂志

ABSTRACT

Objective To study the inhibitory effects of andrographis paniculata and silybum marianum on the efflux system of MRSA 41577. Methods Inhibitory effects of andrographis paniculata and silybum marianum on efflux system of MRSA 41577 was evaluated using fluorescence spectrophotometry.PCR was applied to detect the norA efflux gene.By RT-PCR method for detection of andrographis paniculata and silybum marianum influence of the expression of norA efflux gene.Results Andrographis paniculata and silybum marianum significantly increased the accumulation of ciprofloxacin in MRSA 41577 in a time-dependent manner.At 12 minute, andrographis paniculata and silybum marianum respectively increased ciprofloxacin in MRSA41577 by 49% and 76%( P <0.05 ) , which is superior to that of reserpine. Further mechanism studies indicated that andrographis paniculata and silybum marianumcould reduce the expression of norA in MRSA 41577.After incubated with andrographis paniculata and silybum marianum for 16 h, the relative expression of norA of MRSA41577 was respectively reduced by 35% and 42% ( P <0.05 ). Conclusion Andrographis paniculata and silybum marianumcould inhibit MRSA efflux system through reducing pathogen ’s expression of norA and NorA protein.