Anti-inflammatory and PPAR Transaetivationai Effects of Components from Ginkgo biloba Seeds

摘要

Ginkgo biloba, one of the oldest species of trees, has existed on earth for 200 million years. The G. biloba leaves and seeds have been used in traditional medicine and food for thousands of years. Although numerous pharmacological effects and chemical components of G biloba leaves extracts have been reported, few studies have been conducted on G. biloba seeds. In traditional food and medicine, G biloba seeds have been used as supplementary materials for desserts, glazed fruits and beverages.1 Some studies on the proteins of G biloba seeds showed that the protein content of dry and defatted G. biloba seed powder was about 7%, and a number of proteins with antifungal and antioxidant activities were isolated. As part of our search for bioactive components from this valuable medicinal plant, together with the methanol extract of G biloba seeds was found to be active on NF-kB and PPARs transaetivationai effects during the preliminary screening process, the present study describes the isolation and structural elucidation of 13 compounds from the methanol extract of G. biloba seeds. The effects of compounds 1-13 on TNFα-induced NF-xfi transcriptional activity in human hepatocarcinoma (HepG2) cells were evaluated using an NF-xB-luciferase assay. To confirm the inhibitory effects of the compounds on NF-kB transcriptional activity, the effects of the compounds on the upregulation of the pro-inflammatory proteins iNOS and COX-2 were assessed in TNFa-stimuIated HepG2 cells by RT-PGR. Futhermore, the effects of compounds 1-13 on the transcriptional activity of PPARs and individual PPAR subtypes in HepG2 cells were also evaluated using a PPRE-luciferase and GAL4-PPAR chimera assays.