The Study Of Anti-Hepatitis B Virus,Anti-Hepatoma Activities And Their Mechanisms Of The New Hepatoprotectant SY-801

SY-801, a new hepatoprotectant developed by our institute, has been shown to have hepatoprotective action and anti-cancer activity with low toxicicity. In the present study, the actions of its anti-hepatitis B virus and anti-hepatocarcinoma and their mechanisms were studied in several aspects as follows:1. Anti-hepatitis B virus effectBeijing ducklings hatched within one day were infected with duck hepatitis B virus ( DHBV ) intravenously. Seven days after the infection, the hepatocytes of a duckling were isolated and maintained in culture medium containing SY-801 for 7 days. The other ducklings were treated orally with SY-801 ( 0.2, 0.4 , 0.6 g/kg ) for ten days. The results showed that SY-801 at concentrations of 1x10-4 - 5x10-4 mol/L could inhibit the replication of duck hepatitis B virus DNA in vitro, meanwhile it had no cytotoxicity on cultured DHBV-uninfected duck hepatocytes. It appears that the action of SY-801 on DHBV is relatively selective. In in vivo, oral administration of SY-801 ( 0.4 -0.6 g/kg ) markedly reduced the level of DHBV DNA in serum of ducklings. The potency of SY-801 is coresponding to the positive control drug PFA ( 0.5 mg/kg, i.p. for 10 days ). SY-801 also reduced DHBV DNA level in the liver of ducklings. Using Southern blot analysis, it was found that SY-801 could inhibit the replication of DHBV in duck livers.The antiviral activity of SY-801 was also tested in 2.2.15 cell line, the human hepatoblastoma cell line HepG₂ which was transfected with a vector containing hepatitis B virus ( HBV ). It was found that SY-801 at concentrations of 5x10-5 - 5x10-4 mol/L significantly inhibited the replication of HBsAg and HBeAg of the cultured 2.2.15 cells, and also...