Abstract: The objective was to investigate the immunomodulatory effect of catechu extract with the infectious animal model, which were measured by delayed type hypersensitivity (DTH) and the neutralizing antibody level. The animal model of virus infection of respiratory tract was established by primed influenza virus strain A/FM/1/47(H1N1). The results showed the catechu extract could markedly intensify DTH caused by DNFB. It could also increase ear swelling and spleen index in the group of catechu extract and virus infection and the group only treated by catechu extract, compared with the control group (P<0.05). The average titer of neutralizing antibody of the group treated by catechu extract was 1:203. It had significantly increased compared with the control group without catechu extract (1:104.2)(P<0.01). The finding suggests that the catechu extract could markedly intensify the cell immunological function and the humoral immunological function in mice infected by influenza virus.

Key words: catechu extract, influenza virus, delayed type hypersensitivity, neutralizing antibody