Abstract: To investigate the influence of volatile oil of Piper puberulum from Guizhou in oleic acid-induced acute lung injury and its mechanism.Healthy adult male SD rats were randomly divided into three equal groups:normal control group,oleic acid model group and volatile oil group (0.125 mL/kg,0.25 mL/kg and 0.5 mL/kg).Oleic acid model group was administered oleic acid(0.2 mL/kg) via right jugular vein;In volatile oil group,volatile oil group was injected via jugular vein,followed 30min before by oleic acid infusion;At the 4 hours animals were sacrificed,pathological changes of the lung tissue were examined with light microscope.Arterial blood gas,the wet/dry weight (W/D) of the right lower lung were examined,lung index,LPI and Levels of TNF-α,IL-6 and IL-1β in BALF were examined.The expression conditions of p38MAPK and p-p38MAPK were determined by Western blot and immunohistochemical method.The results show that compared to control group,PaO2 and PaO2/FiO2 declined in the animals of oleic acid model group,while right lower lung wet/dry ratio,lung index,LPI and Levels of TNF-α,IL-6 and IL-1β in BALF were increased obviously.Pulmonary edema was observed in injured lung pathology.Compared to oleic acid model group,those indexes were improved in volatile oil group.The lung tissue levels of p-p38MAPK expressions were markedly higher in oleic acid model group compared to control group.Compared to oleic acid model group,the expression of p-p38MAPK was reduced in volatile oil group.Experiments have proved that volatile oil of Piper puberulum from Guizhou has a better protection effect to acute lung injury and reduces the cytokine production and it can exert its action by inhibiting p38MAPK pathway.

Key words: volatile oil of Piper puberulum from Guizhou, oleic acid, acute lung injury, inflammation, p38MAPK