Schisantherin A, a dibenzocyclooctadiene lignan isolated from the fruit of Schisandra sphenanthera, has been reported to possess varied beneficial pharmacological effects. Schisantherin A protects lipopolysaccharide-induced acute respiratory distress syndrome in mice through inhibiting NF-κB and MAPKs signaling pathways. Pretreatment with Schisantherin A markedly ameliorates LPS-induced histopathologic changes and decreases the levels of TNF-α, IL-6 and IL-1β in the BALF. In addition, the phosphorylation of NF-κB p65, IκB-α, JNK, ERK and p38 induced by LPS are suppressed by Schisantherin A. The lung wet/dry weight ratio is evaluated at 7 h after the intranasal instillation of LPS. The results show that there are no differences between control group and Schisantherin A (40 mg/kg) group (p>0.05). LPS causes a significant increase in lung wet/dry weight ratio (p<0.01) compared with the control group. Schisantherin A dose-dependently decreases the lung wet/dry weight ratio (p<0.05) compared to those in the LPS group[1].