Figure 4.

EEC protects mice from lethal influenza virus infection. Six-week-old female BALB/c mice weighing 16–18 g were infected with 4 LD₅₀ of H1N1 PR8 virus intranasally. Three hours after infection, four groups of mice (10 mice in each group) were treated intraperitoneally with 60, 30, 15 mg/kg/d of EEC or placebo solution respectively for five consecutive days. Survival rate (A) and body weight loss (B–D) were monitored daily until day 18 post-infection. Lung lavage fluids (BALFs) from the infected mice treated with 60 mg/kg/d of EEC were collected on days 3 and 7 post-infection to monitor virus titers (E), and total cell counts (F) (mean ±SEM). The data are representative of three independent experiments. (n = 3 per group at each time point). * p < 0.05; ** p < 0.01; *** p < 0.001. Sections from lungs of PR8-infected BALB/c mice treated with 60 mg/kg/d of EEC or placebo solution at day 3 and 7 post-infection were H&E-stained (scale bar 200 μm) (G).