FIGURE 1.

The antiviral activity of anthralin in vitro and in vivo. (A) Chemical structures of anthralin. (B) The antiviral effects of anthralin on the production of infectious virions on two cell lines. The supernatants were harvested and the virus titers were determined by TCID₅₀ assay. Virus titers were calculated according to Spearman–Karber method as described in methods. The values represent the means ± S.D. of duplicate samples from three independent experiments. (C) Effect of anthralin administration on survival rates in the infected mice. BALB/c mice were infected with 1000 TCID₅₀ of PR8 and treated with anthralin or PBS control (n = 10). **P < 0.01 with respect to PBS controls. (D) Weight loss of mice infected with lethal influenza virus and treated with or without anthralin. *P < 0.05, **P < 0.01 and ***P < 0.001 with respect to PBS controls. (E) Virus titers in BALFs taken on the third day after infection were measured by TCID₅₀ assay determined on MDCK cells. (F) Haematoxylin & Eosin-stained sections from lungs of non-infected and PR8-infected BALB/c mice treated with anthralin or PBS at 3 dpi (day post infection) (scale = 200 μm).