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

Abstract

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.