Objective: To investigate the time-effect relationship of Shaoyao Gancao decoction on carrageenan-induced inflammatory markers. Method: Acute inflammatory model was induced by carrageenane. Time-effect relation of paw swelling inhibition ratio

myeloperoxidase(MPO)

cyclooxygenase-2(COX-2)

prostaglandin E2 (PGE2) was tested respectively at 1

2

3

4

5

6

7

8

9

10

11

12 h. Result: The result showed that Shaoyao Gancao decoction had significant efficacy of anti-inflammatory. Inflammatory markers such as paw swelling inhibition ratio

MPO

COX-2

PGE2 were inhibited at different time points obviously. High-dose Shaoyao Gancao decoction could effectively reduce carrageenan-induced paw edema at 1

2

3

4

5

6 h. It also could significantly decrease the production of MPO at 2

4

5

6 h

COX-2 at 4

5

6 h

PGE2 at 2

3

5

6 h. But low-does Shaoyao Gancao decoction could effectively reduce carrageenan-induced paw edema at 2

4

5

6 h

and decrease the production of MPO

PGE2 at 2

6 h

and COX-2 only at 6 h. Conclusion: Shaoyao Gancao decoction had significantly inhibit effects on carrageenan-induced different inflammatory markers(swelling rate

MPO

COX-2 and PEG2) in the timing relationship at different some time

and different concentration Shaoyao Gancao decoction had different action time. It shows that Shaoyao Gancao decoction have the characteristic of the time-effect relationship.