To evaluate whether hordenine incre

To evaluate whether hordenine increased the susceptibility ofantibiotics against biofilms, biofilms were treated with hordenineand netilmicin for 24 h. Results indicated that hordenine significantlyenhanced the effect of netilmicin on P. aeruginosa PAO1biofilms in a concentration-dependent manner (Figure 3A). Atconcentrations of 0.5, 0.75, and 1.0 mg mL−1, hordenine reducedbiofilms by approximately 35%, 52%, and 88%, respectively, withthe addition of 0.4 μg mL−1 of netilmicin (MIC, 1.0 μg mL−1).When used alone, netilmicin resulted in a minor reduction inthe biofilms (P > 0.05). Cell survival determination indicatedthat hordenine (0.5 and 0.75 mg mL−1) coupled with netilmicinhad no effect on the viability of planktonic cells, though at1.0 mg mL−1, planktonic cells were reduced by 10% (Figure 3B).