Abstract: 【Objective】 The present study was aimed at the effects of compound ammonium glycyrrhizin soluble powder (CAG) on proinflammatory cytokines production and T-cell subsets deviation in peripheral blood in chicken liver injury induced by enrofloxacin and lipopolysaccharide crude extract(LPS).【Method】A total of 104 animals were allocated randomly into 5 groups named I- V: I normal group, II liver injury group(model group), III prevention group, IV high dosage treatment group and V low dosage treatment group. Group II- IV were administered with enrofloxacin(100 mg•kg-1) once a day for three days and on the third day administered with LPS (4 mL•kg-1) at the same time. Group III received prior administration of CAG at the dosage of 40 mg•L-1 ( by ammonium glycyrrhizin, the same as follows) in drinking water for three days before establishment of liver injury model. Groups IV and V received CAG at a dosage of 22.5 and 7.5 mg•kg-1 twice a day for three days after LPS treatment. Every eight chickens were sacrificed at 6, 24 and 48 h following post-treatment with LPS and their blood samples were collected for detection.【Result】Compared with group I, the group II levels of serum ALT, AST, TNF-α, IL-1 and IL-6 were significantly higher at 6, 24, 48 h post-treatment with LPS and CD3(+), CD4(+) and CD8(+) T-lymphocytes were significantly lower at 6 and 24 h higher at 48 h post-treatment with LPS. When compared with group II , there existed a significant fall in the levels of serum ALT ,TNF-α, IL-6 at 6 h, AST at 6 h and 24 h and the number of CD3(+), CD4(+) and CD8(+) T-lymphocytes at 48 h in group III. In group IV, the levels of ALT, AST, TNF-α, IL-6 at 6 h and 24 h , IL-1 and CD3(+) , CD4(+) and CD8(+) T-lymphocytes at 48 h decreased significantly and CD3(+) T-lymphocytes at 6 h and 24 h , CD4(+) T-lymphocytes at 24 h increased obviously. In group V, there was a significant fall in CD8(+) T-lymphocytes at 48 h and no obvious other differences were detected. The liver histopathological changes got a better improvement in group IV than others.【Conclusion】The novel liver injury induced by enrofloxacin and LPS effects might be related to TNF-α, IL-1 and IL-6 production and CD3(+), CD4(+) and CD8(+) T-cell deviation in peripheral blood. CAG prevents the liver injury through inhibiting TNF-α, IL-1 and IL-6 production and regulating the number of T-cell subsets in peripheral blood by bi-directional regulation and the efficacy might be related to dosage and treatment time.

Key words: compound ammonium glycyrrhizin soluble powder , LPS , enrofloxacin , liver injury , cytokines , T-cell subsets