Immunomodulation of Inflammatory Markers in Activated Macrophages by Leaf Extracts of Gingko Biloba

Much recent attention has been given to traditional medicines and natural products with potential and promising anti-inflammatory properties. Leaf extract of Ginkgo biloba GbE-761, possesses several clinical beneficial effects and is now used in a broad spectrum of pharmacological actions. However, mechanisms associated with its anti-inflammatory effect are not very much clear. Previously we established that GbE-761 exerts a neuroprotective effect against ischemic brain injury through an anti-apoptotic mechanism. In this study we investigated the anti-inflammatory effect of GbE-761 in LPS-activated murine macrophage. Our results demonstrate that GbE-761 potently inhibited LPS-induced NO and PGE2 production and these observations were consistent with the inhibition in the protein and mRNA expression levels of inducible iNOS and COX-2 enzymes in a dose dependent manner. Not only this, GbE-761 attenuated the production of pro-inflammatory cytokines like IL-1 , IL-6 and TNFin LPS-activated murine macrophages in concentration dependent manner. In addition we reported inhibition in the protein and mRNA expression levels of IL-1 , IL-6 and TNF. Furthermore, GbE-761 inhibited the NFB activation induced by LPS. Together these results suggest that anti-inflammatory properties of GbE-761 extract might be the results of inhibition of iNOS and COX-2 by upregulating anti-oxidative enzymes and inhibition of pro-inflammatory cytokines (IL-1 , IL-6 and TNF) expression through the down-regulation of NF-kB activation in murine macrophages.