Protosappanin A (PTA), an immunosuppressive ingredient and major biphenyl compound isolated from Caesalpinia sappan L, suppresses JAK2/STAT3 -dependent inflammation pathway through down-regulating the phosphorylation of JAK2 and STAT3 In Vitro Protosappanin A (PTA: 12.5, 25, 50 μM, 24 hours) significantly inhibits the production of TNF-α and IL-1β in LPS-activated BV2 microglia. And the mRNA expressions of IL-6, IL-1β, and MCP-1 are reduced by PTA in a dose-dependent manner in BV2 microglial cell line. Protosappanin A (PTA: 12.5, 25, 50 μM, 24 hours) suppresses JAK2/STAT3-dependent inflammation pathway through down-regulating the phosphorylation of JAK2 and STAT3, as well as STAT3 nuclear translocation against LPS treatment. Protosappanin A (PTA: 12.5, 25, 50 μM, 24 hours) shows obvious effect on disturbing the interaction of transmembrane protein CD14 with Toll-like receptor-4, resulting in the inhibition of NF-κB-dependent oxidative and nitrative stress in LPS-induced BV2 microglia. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Western Blot AnalysisCell Line: Murine BV2 microglial cell line. Concentration: 12.5, 25, 50 μM. Incubation Time: 24 hours. Result: Inhibits the releases of NO, TNF-α and IL-1β in LPS-induced BV2 cells. Attenuated IL-6, IL-1β and MCP-1 gene expressions in the LPS-induced BV2 cells. Suppressed JAK2/STAT3 pathway activation in the LPS-induced BV2 cells. Form:Solid IC50& Target:JAK2 STAT3