Fisetin upregulates anti-oxidants levels in lipopolysaccharide (LPS)-exposed mice with acute otitis media. (A) SOD activity, and (B) MDA levels in serum were measured. (C) SOD activity and (D) MDA levels in the middle ear tissues were analyzed. Western blot analysis was included to detect SOD1, SOD2, HO-1 and Nrf2 protein expression levels in the middle ear tissue of mice with LPS induction in the presence or absence of fisetin at different doses. (E) Representative images of western blot analysis are displayed. (F) SOD1, SOD2, HO-1 and Nrf2 protein levels were quantified following western blot results. Data are expressed as the mean ± SEM (n=10). *p<0.05, **p<0.01 and ***p<0.001 vs. the control (Con) group; +p<0.05, ++p<0.01 and +++p<0.001 vs. the LPS group.