Objective: To investigate the effect of Chaihu Shugan Tang on EEG and expression of multidrug resistance protein P-gp of refractory epilepsy rats induced by licl-pilocarpine. Method: Except for blank control group(A)

50 Sprague-Dawley refractory epilepsy rats were randomly divided into five groups: model group(B group)

VPA group(C group)

low

middle

high dose of Chaihu Shugan Tang groups (D

E

F group). Chaihu Shugan Tang was decocted and concentrated into 1g crude drug/mL. C group is administrated for 0.2 g ·kg-1

D

E

F group is 4.5

9

18 g ·kg-1

the same amount of saline was given to A

B group. After the intragastirc administration for 8 weeks each group

EEG was recorded and the protein P-gp was detected in rat hippocampus and temporal cortex in each group. Result: There was no epileptic wave in A group

but much more epileptic wave in B group. Epileptic wave were decreased in C

D

E

F groups compared with B group. Expression of P-gp by Western blotting was different in each group ( P <0.01). Conclusion :VPA increases expression of multidrug resistance protein P-gp in rat hippocampus and temporal cortex. Chaihu Shugan Tang decreases expression of P-gp and epileptic wave. High dose of Chaihu Shugan Tang is the most efficient.