Wang Wenqing

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.

Influence ofRadix isatidis on the endotoxin-induced release of TNF-α and IL-8 from HL-60 cells

SummaryThe effects of active antiendotoxin chemical fraction isolated fromRadix Isatidis (fraction D) on TNF-α and IL-8 secretion in HL-60 cells induced by lipopolysaccharide (LPS) were studied. The appropriate densities of cell suspension and fraction D solution were determined by MTT colorimetric method. Fraction D and LPS were added to HL-60 cell suspension with three different methods respectively. The contents of TNF-α and IL-8 in the cultured supernatant induced by LPS were detected by using ELISA method. The results showed that the absorbance (A) was directly proportional to the number of cells and the linearity was good in the range from 0.25×105 to 2×105 cell/mL cell suspension. The fraction D significantly inhibited the oversecretion of TNF-α and IL-8 in HL-60 cells induced by LPS at the concentration of 7.812 mg/mL which had no cytotoxicity. It was indicated that the antiendotoxin mechanism of the active fraction fromRadix Isatidis was contributed to the inhibition of the oversecretion of cytokines induced by LPS.