Objective:To study the effect of Gancao Xiexin decoction formula granules on model rats with recurrent oral ulcer(ROU). Method:Forty-eight Wister rats were randomly divided into six groups:normal group

model group

levamisole group (17.5 mg·kg-1)

three Gancao Xiexin decoction formula granules groups-high

medium and low (12

6

3 g·kg-1). Except the rats in the normal group

the rats in other groups were used to establish the recurrent oral ulcer model with immune method. After 20 days of continuous intragastric administration

the pain threshold in rats was tested by hot plate method

the tumor necrosis factor-α(TNF-α) and interleukin-8 (IL-8) levels in rat serum were tested by enzyme-linked immunosorbent assays (ELISA)

and T lymphocyte subsets of peripheral blood was determined by flow cytometry. Result:Compared with normal group

the pain threshold of rats in the model group was decreased

and the TNF-α and IL-8 levels in rat serum were increased

the number of CD4+ cells fell

and the number of CD8+ cells rose

CD4+/CD8+ ratio decreased(P<0.01). Compared with model group

in the high and medium Gancao Xiexin decoction formula granules groups

the pain threshold was increased:(4.1±0.7)

(9.2±2.0)

(8.5±1.4) s

the TNF-α in rat serum was decreased:(182.4±11.6)

(37.8±9.0)

(42.7±4.6) ng·L-1

and IL-8 was decreased:(870.0±42.2)

(303.7±31.7)

(331.8±18.6) ng·L-1

the number of CD4+ cells rose:(37.4±3.6)%

(48.0±1.5)%

(48.1±4.4)%

and the number of CD8+ cells fell:(32.1±3.6)%

(26.3±2.7)%

(26.8±1.2)%

leading to an increased CD4+/CD8+ratio:(1.2±0.1)

(1.8±0.2)

(1.8±0.2)(P<0.01). Conclusion:Gancao Xiexin decoction formula granules is effective in the treatment of model rats with recurrent oral ulcer

which may have something to do with its effects of analgesia

inhibiting inflammatory factors

and regulating the imbalance of T lymphocyte subgroup.