Anti-inlfammatory Activity And Anti-inflammatiory Signal Transduction Mechanism Of Polysacchairdes From Ginkgo Biloba Leaf

Ginkgo biloba extract is one of the most important part of active ingredient intraditional Chinese dedicine, in clinical, it showed anti-fatigue, anti-oxidation, protectliver, improving blood circulation and a variety of other pharmacological effects. LPSis the main component of the cell wall of Gram-negative bacteria, LPS-mediatedactivation of macrophages leads to the production of various cytokines such as tumournecrosis factor-α (TNF-α), interleukin-6(IL-6) and inflammation mediators such asnitric oxide (NO) and prostaglandin E2(PGE2). The production of these cytokinesmay result in the systemic inflammatory response syndrome (SIRS), severe tissuedamage, and septic shock. So lipopolyssacharide (LPS)-activated macrophages havetypically been used to evaluate the anti-inflammatory effects of various materials.In order to improve the medicinal value of Ginkgo biloba， and further expandthe scope of application of ginkgo biloba in clinical. In this paper, we study theanti-inflammatory activity of PGBL deeply. We built in vitro inflammatory model byLPS-stimulated murine RAW264.7macrophages, and further exploredanti-inflammatory molecular mechanism of PGBL by inflammatory signaltransduction pathway. The results showed that the range of concentrations tested(1.5mg-4.5mg/mL) PGBL can not strongly increased RAW264.7cell activity (p>0.05vs.control). When the concentration of PGBL is greater than5.50mg/mL can inhibitedthe RAW264.7cell activity （p<0.05vs. control）.24h, the different concentrations ofPGBL can inhibit the activity of inflammatory cells, and show dose-dependent, Whichthe concentration higher than4.5mg/mL of PGBL can inhibit the inflammatory cellline of RAW264.7(p<0.05vs. LPS-stimulated).48h the concentration higher than3.5mg/mL of PGBL can inhibit the inflammatory cell line of RAW264.7(p<0.05vs.LPS-stimulated).72h the activity of inflammatory cells RAW264.7cells had noinhibitory effect, the other groups inhibited RAW264.7cell activity of inflammatorycells (p<0.05vs.LPS-stimulated). LPS with different concentrations of the PGBL common incubated RAW264.7cells, the cell supernatants of TNF-α levels decreasedsignificantly after24h (p<0.05vs. LPS-stimulated). After48h of TNF-α only greaterthan the3.5mg/mL the PGBL group decreased significantly (p<0.05vs.LPS-stimulated). RNA was extracted at6h, determined by RT-PCR results showedthat different concentrations the PGBL can inhibit the mRNA expression of TNF-αgene (p<0.05vs. LPS-stimulated). In addition, PGBL can inhibit IL-6mRNAexpression in6h. In vitro, PGBL can play an anti-inflammatory effect by regulatingthe secretion of cytokines. In order to found the LPS-induced cytokine productionmechanism in inflammatory signaling pathway, we further investigated the effect ofPGBL on NF-κB signal transduction pathways in LPS-stimulated murine RAW264.7macrophages. The result showed that PGBL inhibited NF-κB activity in adose-dependent manner. It suggested that PGBL inhibited cytokine TNF-α secretionand TNF-α IL-6mRNA expression by regulating both NF-κB pathways.This is the first discovery and proof of PGBL anti-inflammatory molecularmechanism of inflammatory cytokines. This not only provided for PGBL theanti-inflammatory applications of molecular evidence, but also provides a newapproach for the study of polysaccharide anti-inflammatory molecular mechanism,also laid a theoretical foundation for the development of anti-inflammatory drugcandidate for Traditional Chinese medicine.