Liu Yun-hai

Anti-Endotoxic Effects of Syringic Acid of Radix Isatidis

SummaryThe anti-endotoxic effect of syringic acid (SA) isolated fromRadix Isatidis (Banlangen, BLG) was studied. SA was extracted and isolated from BLG and diluted into 1% solution. The content of SA-pretreated endotoxin (ET) was quantitatively determined using Limulus test. The ability of fever induction of ET pretreated with SA was measured using endotoxin-induced fever test in rabbits. The LPS-induced death in mice pretreated with and without SA was compared. Results showed that after pretreatment with SA, 83.16% of ET was destroyed, the ET-induced fever in rabbits relieved markedly and the LPS-induced death rate in mice dropped from 68 % to 20 %. It was concluded that SA isolated from BLG had anti-endotoxic effects.

Screening of anti-endotoxin components from Radix isatidis.

SummaryTo find a component with the strongest anti-endotoxin effect from the four components (F021, F022, F023, and F024) of chloroform extract (F02) ofRadix 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 F02, F022, F023, and F024. The 5 components all had inhibotory 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 F02, F0211, F022, F023, and F024 for the production of TNFα 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 F022 ofRadix Isatidis has the strongest anti-endotoxin effect.