RESUMO
<p><b>OBJECTIVE</b>To study the anti-endotoxin activity and mechanism of F022 from Radix Isatidis.</p><p><b>METHOD</b>The production of TNF-alpha and IL-6 of murine peritoneal macrophages stimulated by LPS was measured by ELISA. The temperature in rabbits was tested after i.v. administration of LPS. The lethality of BCG-primed mice was induced by LPS.</p><p><b>RESULT</b>If F022 was added to macrophages culture simultaneously with LPS or 1 h before addition of LPS, production of TNF-alpha and IL-6 by macrophages was remarkably inhibited in vitro. F022 inhibited the fever induced by LPS in rabbits and protected BCG-primed mice from LPS induced lethality if given before administration of LPS.</p><p><b>CONCLUSION</b>The anti-endotoxin effect of F022 may inhibit LPS binding to its receptor, and it may be a LPS receptor antagonist.</p>