Objective      To isolate and identify the anti-lipopolysaccharide (LPS) components from Densefruit pittany root-bark and investigate its potential anti-LPS activities in vitro and in vivo.       Methods      The components were isolated by macroporous adsorptive resins

ion exchange

polyamide and silica gel column chromatography from the aqueous extract of Densefruit pittany root-bark

and identified by tube test. The neutralization of LPS was assayed by Limulus Amebocyte Lysate (LAL) test. The inhibition o

f tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) release from RAW264.7 cells induced by LPS was assessed by enzyme-linked immunosorbent assay (ELISA). The protective effect was observed in mice challenged by lethal dose of heat-killed Escherichia coli.       Results      The alkaloids components with anti-LPS activity

BXP-A

were isolated and identified from Densefruit pittany root-bark. In vitro

BXP-A (0.5 to 1.0 mg/L) inhibited the coagulation of LAL induced by LPS (0.2 μg/L)（P0.05）

and it (100 to 200 mg/L） significantly suppressed the release of TNF-α and IL-6 induced by LPS (100 μg/L) in RAW264.7 cells（P0.05 or 0.01）. In vivo

BXP-A (40 mg/kg) improved the survival rate of mice challenged by lethal dose of heat-killed Escherichia coli (1.3×10

11

CFU/kg).       Conclusion      BXP-A neutralizes LPS and inhibits the overproduction of cytokines in cells

and has protective effect against sepsis in a heat-killed Escherichia coli-induced mouse model of sepsis.