Fig. 6

MNQ deprives the function of multidrug-resistant efflux pumps. Efflux pump activities of E. coli DH5α + pAM401-tet(X4) with the treatment of MNQ or in combination with tetracycline were determined using the fluorescence dye Rhodamine (a–b) or Ethidium bromide (EtBr) (c–d). All data were repeated three times independently. **P < 0.01; *P < 0.05