[Studies on the effects of tea catechins against hepatitis B virus infection].

OBJECTIVE: To examine the effects of tea catechins against hepatitis B virus and their roles in protecting liver damage. METHODS: A duck hepatitis B virus infection model was established by using one-day-old Beijing ducklings. The infected ducklings were divided into six groups: three treatment groups of different dosages (60, 120 and 240 mg/kg of tea catechins p.o., 93.7% total catechins and 48.7% EGCG), positive control group (Are-AMP, i.v.), model group (water, p.o.) and negative control group (no DHBV, no catechins). Serum DHBV-DNA was tested by dot blot hybridization (marked with digogenin), DHBsAg was assayed by ELISA. The morphologic changes of liver and the activities of ALT and AST were also measured. RESULTS: Levels of DHBsAg and DHBV-DNA in duck serum were significantly decreased in all the three catechin treated groups (P < 0.05, P < 0.01). Activities of ALT and AST were also significantly decreased after treatment for 25 days and 14 days after the end of the treatment (P < 0.05, P < 0.01). Results of liver pathological examinations also provided positive evidence. CONCLUSIONS: The protective effects of tea catechins against hepatitis B virus infection were significant. It protected the liver functions and reduced the pathological changes of the liver tissue.