The concentrations of TNF-α and IL-6 in the supernatant of cells pretreated with 2.5 or 25 mg/L of Schisantherin A are significantly decreased compared to the LPS control group (p<0.05, p<0.01). The potential cytotoxicity of Schisantherin A is evaluated by the MTT assay after incubating cells for 24 h in the absence or presence of LPS, result shows cell viabilities are not affected by the cytokines at concentrations used (0.5, 2.5, 25 mg/L). RAW 264.7 murine macrophage cells are pre-incubated with Schisantherin A for 1 h and then stimulated with 1 mg/L LPS for 12 h. Both LPS and samples are untreated in control group. After the cell culture media are collected, nitrite and PGE ₂ levels are determined, and Schisantherin A is found to reduce NO and PGE ₂ production in a dose-dependent manner.

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.