Preventive Effect of Ginkgo biloba Extract (GBB) on the Lipopolysaccharide-Induced Expressions of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 via Suppression of Nuclear Factor-κB in RAW 264.7 Cells(Pharmacognosy)

概要

論文の詳細を見る
During our ongoing efforts to identify bioactive natural products with anti-inflammatory activity, we produced an extract from Ginkgo biloba (GBB) which contains higher levels of the active principles terpene and bi-flavonoid than EGb, the standard commercially available extract. In the present study, we examined and compared the effects of these two extracts on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E_2 (PGE_2) production by the RAW 264.7 macrophage cell line. Our data indicate that GBB is a more potent inhibitor of NO and PGE_2 production than EGb 761, and it also significantly decreased tumor necrosis factor (TNF)-α release. Consistent with these observations, the protein and mRNA expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) were found to be inhibited by GBB in a dose-dependent manner. Furthermore, GBB inhibited the LPS-induced DNA binding activity of nuclear factor-KB (NF-KB), which was associated with the prevention of IKB degradation, and subsequently with decreased p65 protein level in the nucleus. These results suggest that GBB inhibits LPS-induced iNOS, COX-2 and TNF-α expressions through the down-regulation of NF-KB-DNA binding activity.
社団法人日本薬学会の論文
2006-05-01