In Vitro Inhibitory Effect Of Lamivudine Combined With Protocatechuic Acid On Duck Hepatitis B Virus

Hepatitis B virus (HBV) infection is a serious global health problem, in addition to causing acute and chronic hepatitis, it has a close relationship with the generation of cirrhosis and hepatocellular carcinoma.Currently, lamivudine (3TC) has been used for the treatment of HBV infections as a popular drug, which exhibits a significantly inhibition effect on HBV-DNA in vivo. However, this therapy is limited in clinical application because of the unsatisfactory long-term efficacy, the recurrence of viremia after therapy and the development of mutants. Based on the preliminary study results, the combination of 3TC and protocatechuic acid (PA) reflected obvious synergistic effects against HBV-DNA, HBeAg and HBsAg in HepG 2.2.15 cell system. In addition, our results also indicated that inhibitory action of 3TC and PA combination on the activities of HBV gene promoters and the distribution of HBV X protein in cellular nucleus were the important inhibitory mechanism of 3TC and PA combination on HBV replication. Furthermore, the combination of 3TC and PA can not only slowed down the 3TC absorption rate in rats to increase their uptake, but also significantly slow down the absorption and the elimination speed of PA in rats, extended their duration of action in vivo. Moreover, PA combined with 3TC could significantly enhance the inhibitory effect of 3TC on ducklings' DHBV infected, reducing the virus' drug tolerance, and also have some protective effect for DHBV induced liver injury.To evaluate the combination of drugs 3TC and PA (3TC/PA) influence on different links of HBV infection, this paper choose duck HBV (DHBV) to infect primary duck hepatocytes(PDHs) as experimental material, in vitro to simulate virus natural infection process, give drug treatment before the virus infection, infection at the same time and after infection different times to study the influence of 3TC/PA on DHBV adsorption infection, entry and intracellular inhibition of replication and other links. Results showed that 3TC, PA and 3TC plus PA significantly inhibited DHBV both in culture supernatant and in PDHs at the different stages of DHBV life cycle, including viral attachment, entry and replication in PDHs. Although the prevention and blockade action of 3TC plus PA has no significant difference as compared with the positive control(3TC group), the inhibitory action of 3TC plus PA on viral attachment, entry and replication, as well as the inhibitory action on AST and ALT activities in viral infected PDHs, were more powerful than that of the positive control. The results indicated that 3TC plus PA had more powerful inhibitory effect on DHBV infection and more powerful hepatoprotective effect than that of 3TC or PA used alonely.