Also, to examine whether the oxidative stress caused oxidative damage on the cells, membrane lipid peroxidation was quantified. The results showed that the MDA content in T. dealbata roots aqueous extract-exposure cells of M. aeruginosa increased significantly, the MDA content increased as the aqueous extract concentration increased and exposure time extended. The MDA content at 18 mL/L of the aqueous extract was 5.1 times relative to the controls (P < 0.05).