Objective    To investigate to the role of Angelica sinensis polysaccharides (ASP) against hepatic encephalopathy and explore the probable mechanism.     Methods    Sprague-Dawley rats were established into carbon tetrachloride (CCl

4

)-induced liver cirrhosis

then treated with distilled water (negative control)

lactulose (positive control)

ASP solution (10

20 and 40 g/L respectively

intragastrically at dose of 10 ml·kg

-1

·d

-1

) for 14 days. On 15th day

all the survival rats were intraperitoneally injected with endotoxin (3 mg/kg) once

then in t

he following 12 h

the rats that fall into coma were counted and the time period of coma was recorded. The blood plasma concentrations of ammonia

serum glutamate-pyruvate transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) were determined. The apoptotic cerebral cells were dyed in situ by TUNEL. Glial fibrillary acidic protein (GFAP) in astrocytes was determined by immunohistochemical method. Then we counted the apoptotic cerebral cells and GFAP positive cells under light microscope.     Results    The survival rats in distilled water group were highest in the concentrations of ammonia

GPT and GOT

the amount of apoptotic cerebral cells

and coma rate than the rats in other groups. The rats in 40 g/L ASP group had the higher ammonia level

GOT concentration

coma rate than those in lactulose group. The rats in 3 ASP groups all had less apoptotic cerebral cells than those in lactulose group. As to GFAP

distilled water group had the lowest immunological activity

and the GFAP immunological positive cells of 3 ASP groups were all more than those in lactulose group.     Conclusion    ASP

even more effective than lactulose

can protect rat brain function and delay the occurrence of hepatic encephalopathy

whose effects may be related to the decrease of blood ammonia

the amelioration of liver function as well as the protection of astrocyte function and neuronic activity.