To find a component with the strongest anti-endotoxin effect from the four components (F_ 021 , F_ 022 , F_ 023 , and F_ 024 ) of chloroform extract (F_ 02 ) of Radix Isatidis, the protective effects of the five components on endotoxin-challenged mice and their effects on the production of TNFα and IL-6 by macrophages from the endotoxin-challenged mice were compared. It was found that the five components all had protective effects on endotoxin-challenged mice in terms of mortality. The mortalities of the mice challenged by 2.42 mg/kg endotoxin were 30 %, 50 %, 20 %, 50 % and 60 % after treatment with F_ 02 , F_ 021 , F_ 022 , F_ 023 , and F_ 024 . The 5 components all had inhibitory effects on the production of TNFα and IL-6 by macrophages from the mice. At a concentration of LPS of 50 ng/mL, the inhibitory rates of F_ 02 , F_ 021 1, F_ 022 , F_ 023 , and F_ 024 for the production of TNF_α and IL-6 were 76.54 %, 30.86 %, 78.60 %, 36.63 %, 2.06 % and 75.85 %, 18.45 %, 77.68 %, 24.41 %, 3.64% and at the dose of 100 ng/mL, the inhibitory rates were 49.65 %, 16.86 %, 66.97 %, 13.39 %, 7.16 % and 59.78 %, 1.28 %, 61.86 %, 2.08 %, 1.44 %, respectively. It is concluded that the component F_ 022 of Radix Isatidishas the strongest anti-endotoxin effect.
