Anti-inflammatory action of Ginkgo Biloba leaf polysaccharide via TLR4/NF-?b signaling suppression.

Ginkgo biloba is a valuable herb that has been used as traditional medicine for thousands of years. Extract of Ginkgo biloba leaves possesses several clinical beneficial effects such as antiinflammatory property. In this study, we investigated the effect of purified polysaccharides from Ginkgo biloba leaf (P-PGBL) on inflammatory reaction induced by lipopolysaccharides (LPS) in RAW264.7 mouse macrophage cells and the potential underlying mechanisms. The results showed that P-PGBL treatment significantly inhibited the LPS-induced protein and mRNA expression of Toll-like receptor 4 (TLR4) in a dose-dependent manner. P-PGBL treatment downregulated the nuclear factor-κB (NF-κB)p65 protein expression in LPS-stimulated RAW264.7 macrophage cells. Meanwhile, the levels of pro-inflammatory cytokines, such as IL-1β and IL-6 were suppressed by P-PGBL. In conclusion, P-PGBL exerts an anti-inflammatory effect by inhibiting TLR4/NF-κB signaling pathway, thereby lowering production of inflammatory cytokines