Catechins in green tea have various useful features including antioxidant activity and preventive effects on metabolic syndrome. Various beverages that are enriched with tea catechins are marketed as Foods for Specifi...Catechins in green tea have various useful features including antioxidant activity and preventive effects on metabolic syndrome. Various beverages that are enriched with tea catechins are marketed as Foods for Specified Health Uses (FOSHU) in Japan. However, recent reports have indicated that excessive consumption of green tea extracts as a dietary supplement are associated with adverse health effects such as liver disorders. Various catechins and caffeine are constituents of FOSHU tea-based beverages. The amount of catechins in FOSHU products is displayed on labels as total catechin content, but the content of individual catechins are not provided. Although health hazards of FOSHU products have rarely been reported, precise information about the content and types of catechins in FOSHU products is needed to ensure safety. We used high-performance liquid chromatography with a photodiode array (HPLC/PDA) to simultaneously identify and quantify catechins and caffeine in green tea-based popular beverages and FOSHU beverages. This technique allowed simultaneous quantitation of five types of catechins and caffeine in green tea without complicated sample preparation. Epigallocatechin gallate (EGCG) and epigallocatechin EGC were the main catechins in various FOSHU beverages and the concentrations of almost all catechins were higher in FOSHU, than in popular green tea-based beverages. The concentrations of EGCG in green tea-based popular beverages and in FOSHU beverages were 5.4 - 7.3 and 10.2 - 41.9 mg/100mL, respectively, with the highest concentration being in a product named Healthya (approximately 147 mg/bottle). The simultaneous determination of compounds such as catechins and caffeine in FOSHU beverages can help to estimate beneficial and adverse effects to prevent deleterious effects on health and the excessive consumption of FOSHU beverages containing high concentrations of tea catechins should be avoided.展开更多
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 specif...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.展开更多
文摘Catechins in green tea have various useful features including antioxidant activity and preventive effects on metabolic syndrome. Various beverages that are enriched with tea catechins are marketed as Foods for Specified Health Uses (FOSHU) in Japan. However, recent reports have indicated that excessive consumption of green tea extracts as a dietary supplement are associated with adverse health effects such as liver disorders. Various catechins and caffeine are constituents of FOSHU tea-based beverages. The amount of catechins in FOSHU products is displayed on labels as total catechin content, but the content of individual catechins are not provided. Although health hazards of FOSHU products have rarely been reported, precise information about the content and types of catechins in FOSHU products is needed to ensure safety. We used high-performance liquid chromatography with a photodiode array (HPLC/PDA) to simultaneously identify and quantify catechins and caffeine in green tea-based popular beverages and FOSHU beverages. This technique allowed simultaneous quantitation of five types of catechins and caffeine in green tea without complicated sample preparation. Epigallocatechin gallate (EGCG) and epigallocatechin EGC were the main catechins in various FOSHU beverages and the concentrations of almost all catechins were higher in FOSHU, than in popular green tea-based beverages. The concentrations of EGCG in green tea-based popular beverages and in FOSHU beverages were 5.4 - 7.3 and 10.2 - 41.9 mg/100mL, respectively, with the highest concentration being in a product named Healthya (approximately 147 mg/bottle). The simultaneous determination of compounds such as catechins and caffeine in FOSHU beverages can help to estimate beneficial and adverse effects to prevent deleterious effects on health and the excessive consumption of FOSHU beverages containing high concentrations of tea catechins should be avoided.
文摘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.
