摘要：Kurozu is a traditional black rice vinegar in Japan. Kurozu-moromi is the solid sediment that arises during the production of Kurozu. Kurozu is thought to have blood thinning and antithrombotic activities but a specific effect has not been proven. Plasma plasminogen activator inhibitor 1 (PAI-1) inhibits fibrinolysis and when elevated, it is a risk factor for the development of thrombotic diseases. Here, we examined the effects of a diet containing Kurozu and Kurozu-moromi on LPS (lipopolysaccharide)-induced increases in plasma PAI-1 levels in mice and on TNF-α (tumor necrosis factor α) increased PAI-1 production in the medium of a cultured endothelial cell line. Mice were fed with a diet containing 0.25% (w/w) concentrated Kurozu or 0.5% (w/w) Kurozu-moromi for four weeks, and then subcutaneously injected with 0.015 mg/kg of LPS in saline and sacrificed three hours later. Orally administered concentrated Kurozu and Kurozu-moromi significantly suppressed the LPS-induced increase in PAI-1 antigen and its activity in mouse plasma. The ethanol extract of Kurozu-moromi inhibited TNF-α induced increases of PAI-1 in the culture medium of the EA.hy926 endothelial cell line. The present findings showed that Kurozu and Kurozu-moromi contain natural products that decrease thrombotic tendencies by decreasing PAI-1 production in inflammatory states and have potential as antithrombotic foodstuffs.
