ABSTRACT
0bjective To study the potency of Entecavir Maleate(ETVM),Entecavir(ETV) and Adefovir(ADV) on suppressing duck hepatitis B virus (DHBV) replication.Methods DHBV DNA positive ducks were used as experimental animal model.Ail these ducks were randomized to different arms and respectively given high,medium and low dosage of ETVM,ETV and ADV.ETVM and ETV were given orally daily respectively for six weeks and ADV orally 3 times every week for six weeks.The serum DHBV DNA levels were tested every 2 weeks at day 0 and,after that,at week 2,4.6 and 8 respectively by real-time fluorescent quantitative polymerase chain reaction(PCR).The results were analyzed by paired-samples t test.Results The treatment resulted in the reduction of viral load among all ETVM.ETV or ADV treated groups.The viral load of DHBV DNA at pretreatment and week 6 in the ETVM high dosage group were(7.34±1.33)and(2.12±2.50)lg copy/mL,respectively(P<O.01) and in the ETV high dosage group,the load of DHBV DNA were(8.02±0.56)and(4.36±1.64)lg copy/mL at pretreatment and week 6,respectively (P<0.01).DHBV DNA rebounds were observed after treatment cessation in these groups.The results showed that ETVM and ETV had superior antiviral activity compared tO ADV by rapidly and intensively inhibiting DHBV DNA replication in hepatitis B infected ducks.while the potency of ETVM was even better than ETV.Conclusions Both ETVM and ETV'S antiviral activities are much better than that of ADV while ETVM has the best antiviral efficacy.DHBV animal model is a good model tO screen and evaluate antiviral activity of different drugs and compounds.