Abstract: AIM: To investigate the effects of two types of schisandra preparations,WZ capsules and bicyclol,on the plasma concentrations of immunosuppressant tacrolimus in rats with liver injury.METHODS: 55 rats were randomly divided into four groups: control group(n=10), the other three groups(n=15, in each case) only FK506 treatment group (1 mg/kg), FK506+WZ co-treatment group group(capsules 11.25 mg/kg), FK506+bicyclol combination group(bicyclol 200 mg/kg).once every day for 21 successive days,after 8 h fasting at 7,14,21 d the administration,the concentrations of FK506 and the liver function were detected. After the experiment the rats were killed,the changes of livers of rats in each group were observed.RESULTS: Plasma concentrations of FK506 in FK506 treatment group were increased slowly without schisandra preparations, the plasma concentrations of FK506 were increased in FK506+WZ co-treatment group and FK506+bicyclol combination group.The plasma concentrations of FK506 in FK506+WZ co-treatment group were increased fastly,compared with the control group, there was statistically significant difference in FK506+WZ co-treatment group,7 d after administration (F=11.043, P=0.002), 14 d (F=98.167, P=0.000) and 21 d (F=57.457, P=0.000). Compared with the FK506+WZ co-treatment group,there was no statistically significant difference in FK506+bicyclol combination group at each time point. Compared with the control group,bicyclol had liver protection obviously,the level of ALT was decreased 7 d after administration(F=12.83,P=0.001),14 d(F=11.58,P=0.002),21 d(F=22.27,P=0.000),there was statistically significant difference.The effect of on reducing ALT was weak and work slowly in FK506+WZ co-treatment group, which had no statistical significance,compared with the control group in 7 d,14 d,21 d after administration. Compared with control group,bicyclol group could keep ALB at a higher level,there was statistically significant difference at each time point(P＜0.05). The damage of FK506 to hepatocyte occurred early after administration, histologically characterized by edema, degeneration of liver cells and inflammatory cell infiltration.CONCLUSION: The WZ capsules and high-dose of bicyclol can rapidly increase the plasma concentrations of FK506,the damage of FK506 to hepatocyte occurs early after administration. Bicyclol can prevent liver from the damage of FK506.

Key words: schisandra preparation, bicyclol, WZ capsule, tacrolimus, drug interaction