Isolation Of Effective Anti-CpG DNA Fractions From Rhubarb, And Investigation On Their Biology Activities Of The Fractions

Objective: Sepsis is the most frequent cause of the death in serious patients. Although great attentions have been paid in treatment. It still keeps a high mortality about 50%-60%. CpG DNA is recognized as a key molecule during the pathophysiology of sepsis. CpG DNA can bind to TLR9(toll-like receptor 9) of monocytes and macrophages, then induces cytokines such as TNF-αand IL-6 to release, which at last lead to sepsis or even multiple organ dysfuction syndrome and death. Therefore, preventing CpG DNA from binding to its receptor is considered as the most promising strategy.Clinical experiences and studies had revealed that a lot of traditional Chinese herbs possess the anti-inflammatory effect. However, there are too complicated chemical components in the herbs, and the material bases of the anti-inflammatory effects are unclear, which limits the uses of the herbs in clinic. Therfore, targeting on CpG DNA, we screened the effective components extracted from the herbs, and investigate their pharmacologic effect to treat sepsis.Methods: (1) CpG DNA, the target, was immobilized on the biotin cuvette of biosensor. The biosensor technology was applied to screen anti-inflammatory traditional Chinese herbs targeting on CpG DNA. (2) The activites of the fractions were isolated by silica gel chromatography and high performance liquid chromatography(HPLC)from rhubarb. After the activites of the fractions were evaluated, the most active fraction was confirmed. (3) In vitro, the abilities of Fraction D binding to CpG DNA and Lipid A were measured, and its inhibition on TNF-αrelease from RAW264.7 cells induced by CpG DNA and LPS were observed, too. (4) In vivo, the protection of Fraction D on mice challenged with heat-inactived E coli was observed.Results: (1) The platform to screen the anti-inflamatory effect of traditional Chinese herbs was established. Among the seventy-eight traditional Chinese herbs, fourteen herbs possessed the higher binding ablity for CpG DNA, and nine herbs possessed larger content of effective components. (2) The active fraction D(Fraction D)from rhubarb was...