Objective: To observe the inhibitory effect of the water extract from helicteres angustifolia on duck hepatitis B virus(DHBV) in vivo. Method: Ducks infected with DHBV were randomly divided into five groups: three dose groups of helicteres angustifolia(10

5

2.5 g·kg-1)

lamivudine group and model group.Ducks in the lamivudine group were administrated with lamivudine(50 mg·kg-1) once per day.Ducks in the three-dose groups of helicteres angustifolia were administrated with different dose of helicteres angustifolia for 14 days respectively.The serum content of DHBV-DNA was determined by FQ-PCR method before treatment and on the 7th

14th day after treatment.The pathological changes of liver were evaluated after the treatment. Result: Lamivudine showed a rapid inhibiting effect on DHBV-DNA

but this effect didn’t last long

and the serum level of DHBV-DNA increased again after treatment stopped.The serum level of DHBV-DNA dropped markedly in the high-

medium-dose groups of helicteres angustifolia on the 7th and 14th day.And the hepatic pathological changes in the high-dose helicteres angustifolia group and lamivudine group were slighter than those in the model group. Conclusion: Helicteres angustifolia could inhibit DHBV DNA significantly

and its inhibitory effect was in a dose and time dependent manner.