OBJECTIVETo explore the effects of oxymatrine (OMT) on JAK/STAT iteral in rat lung tissue with sepsis.

METHODFifty-six male SD rats were randomly divided into 6 groups: sham operation group, model (CLP) group, CLP + OMT high, middle, low-dose groups (52, 26, 13 mg x kg(-1), vena caudalis bolus), and positive control group (dexamethasone, 10 mg x kg(-1), vena caudalis bolus) to observe the effects of oxymatrine on the ratio between wet weight of the lung and dry weight of the lung (W/D) and pulmonary coefficient, gross changes and pathological changes examined with lightmicroscope in the pulmonary tissue. Changes in JAK2 and STAT3 activity in the pulmonary tissue were determined by immunohistochemical method. Tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels in pulmonary tissue were determined by radioimmunoassay.

RESULTOMT could decrease significantly the JAK2 and STAT3 positive reaction and activity in the pulmonary tissue (P < 0.05). TNF-alpha and IL-6 levels in pulmonary tissue homogenate decreased markedly (TNF-alpha decreased 36%, 26%, 16% and IL-6 decreased 46%, 39%, 24% on CLP + OMT 52, 26 mg x kg(-1) and 13 mg x kg(-1) groups. P < 0.05 or P < 0.01). OMT could decrease the ratio between wet weight of the lung and dry weight of the lung and the pulmonary coefficient, improve the condition of pulmonary hyperemia, edema, infiltrate of heterophil granulocyte and emerge of asphyxial membrane, and alleviate the inflammatory reaction. And the results were equal to those of the positive control (CLP + dexamethasone) group.

CONCLUSIONOMT can inhibit JAK/STAT iteral activity and reduce the expression of proinflammatory factor (TNF-alpha, IL-6) and antagonize the lung injury in a rat model of sepsis.