Abstract: AimTo study the effects of ginkgolide B on lipopolysaccharide (LPS)–induced TNFα production in mouse peritoneal macrophages and NF-κB activation in rat pleural polymorphonuclear leukocytes. MethodsL929 crystal violet staining assay was used to show the level of TNFα released from mouse peritoneal macrophages induced by LPS. Electrophoretic mobility shift assay (EMSA) was used to determine NF-κB binding activities. ResultsGinkgolide B (1, 10 μmol·L^-1) was shown to significantly inhibit LPS (10 mg·L^-1 )-induced TNFα production in mouse peritoneal macrophages, the IC₅₀ was 0.26 μmol·L^-1; LPS (1 mg·L^-1) and PAF (1 nmol·L^-1) were shown to increase the NF-κB binding activities in rat pleural polymorphonuclear leukocytes; ginkgolide B (10 μmol·L^-1) was found to inhibit LPS (1 mg·L^-1 )-induced NF-κB activation in rat pleural polymorphonuclear leukocytes; ginkgolide B (1, 10 μmol·L^-1) was shown to inhibit PAF (1 nmol·L^-1 )-induced NF-κB activation in rat pleural polymorphonuclear leukocytes. ConclusionThe inhibition of NF-κB activation and TNFα production might be considered to be part of the mechanisms underlying the antiinflammatory action of ginkgolide B; PAF is involved in activation of the NF-κB pathway stimulated with LPS.