2,6-Dimethoxy-1,4-benzoquinone, isolation and identification of anti-carcinogenic, anti-mutagenic and anti-inflammatory component from the juice of Vitis coignetiae

Previously we demonstrated the anti-tumorigenic, anti-mutagenic and anti-inflammatory effects of the juice of Vitis coignetiae (yamabudo), and identified caftaric acid as an anti-mutagenic component from the juice. In the present study, we investigated the isolation of anti-inflammatory components in yamabudo juice supposing that the anti-inflammatory components in yamabudo are also responsible for the anti-tumorigenic activity. The suppressing effect on nitric oxide production in mouse leukemic monocyte with LPS was used as a separation marker. Three components comprising 2,6-dimethoxy-1,4-benzoquinone (DBQ), fertaric acid and caftaric acid were isolated and identified from the juice of V. coignetiae as anti-inflammatory ingredients. Inhibitory effects were found of DBQ on the mutagenicity of dimethylbenzo[a]anthracene, aflatoxin B1, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the Ames test. Topical application of DBA significantly inhibited TPA-induced edema of mouse ears. The anti-tumorigenic effect of DBQ on the promotion and initiation stages of mouse skin tumorigenesis was investigated, and topical administration of DBQ on the promotion stage significantly decreased tumor development in mice skin. DBQ is a potential candidate for the chemopreventive effect of V. coignetiae.