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
Oligonol is a lychee fruit-derived functional food that contains oligomerized polyphenol compounds. Oligonol exhibits a number of beneficial biological effects, primarily due to its antioxidant activity. Retinitis pig...Oligonol is a lychee fruit-derived functional food that contains oligomerized polyphenol compounds. Oligonol exhibits a number of beneficial biological effects, primarily due to its antioxidant activity. Retinitis pigmentosa (RP) is an inherited chronic degenerative disease affecting retinal photoreceptor cells. There is currently no effective therapy capable of stopping or reversing the progression of the disease. In RP, apoptosis of photoreceptor cells resulting from oxidative damage is considered to be the final common pathway. In this report, we present an evaluation of the suppressive activity of Oligonol against N-methyl-N-nitrosourea (MNU)-induced retinal damage in mice, which is a commonly used animal model of RP. Both intraperitoneal and oral administration of Oligonol reduced the loss of photoreceptor cells 7 days after MNU injection, as evaluated by histological staining. Photoreceptor cells derived from MNU-treated mice exhibited increased TUNEL-positive staining, suggesting increased DNA fragmentation, a hallmark of apoptosis. Oligonol treatment reduced the number of TUNEL-positive cells. Additionally, Oligonol suppressed MNU-induced retinal production of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative stress. Moreover, Oligonol attenuated the MNU-induced decrease in the visual activity of mice, as evaluated by the visual cliff test. Oligonol, therefore, effectively suppresses NMU-induced retinal degeneration.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Oligonol is a lychee fruit-derived functional food that contains oligomerized polyphenol compounds. Oligonol exhibits a number of beneficial biological effects, primarily due to its antioxidant activity. Retinitis pigmentosa (RP) is an inherited chronic degenerative disease affecting retinal photoreceptor cells. There is currently no effective therapy capable of stopping or reversing the progression of the disease. In RP, apoptosis of photoreceptor cells resulting from oxidative damage is considered to be the final common pathway. In this report, we present an evaluation of the suppressive activity of Oligonol against N-methyl-N-nitrosourea (MNU)-induced retinal damage in mice, which is a commonly used animal model of RP. Both intraperitoneal and oral administration of Oligonol reduced the loss of photoreceptor cells 7 days after MNU injection, as evaluated by histological staining. Photoreceptor cells derived from MNU-treated mice exhibited increased TUNEL-positive staining, suggesting increased DNA fragmentation, a hallmark of apoptosis. Oligonol treatment reduced the number of TUNEL-positive cells. Additionally, Oligonol suppressed MNU-induced retinal production of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative stress. Moreover, Oligonol attenuated the MNU-induced decrease in the visual activity of mice, as evaluated by the visual cliff test. Oligonol, therefore, effectively suppresses NMU-induced retinal degeneration.
