Background: Acute respiratory distress syndrome (ARDS) is a severe and complicated lung inflammation. Intravenous injection of oleic acid has been accepted as a laboratory model for this disease. Shoseiryuto is a herbad compound, which is used for the treatment of several inflammatory diseases including asthma. The aim of this study was to evaluate the possible preventive effect of shoseiryuto on oleic acid-induced hypoxemia.

Materials and methods: Suspension of shoseiryuto powder in water was used acutely (intraperitoneal injection) and chronically (oral) in four groups of guinea pigs (n=8). The animals were anesthetized by pentobarbital and after cataterization of axillary arteries and vein the possible preventive effect of shoseiryuto on oleic acid induced hypoxemia was evaluated.

Results: Intravenous injection of oleic acid caused a significant decrease in PaO2, 6 and 10 minutes after injection (P<0.05). Acute and chronic administration of shoseiryuto powder showed a significant preventive effect on oleic acid induced hypoxemia (P<0.05).

Conclusion: Shoseiryuto showed a significant effect in prevention of oleic acid induced hypoxemia. Based on the various properties of this herb, several different mechanisms can be proposed.