Poster Topical Area: Dietary Bioactive Components
Location: Hall D
Poster Board Number: 271
Objectives: Multiple lines of evidence, including population-based studies, demonstrate that tea consumption, especially green tea, is associated with reduced risk of cancer and other chronic diseases. One mechanism for the biological effects of Camellia sinensis is attributable to polyphenols that suppress tumor angiogenesis, the process of blood vessel formation that drives tumor progression. It is unknown, however, if there are differences in potency among teas. We studied Chinese, Japanese, and English teas for their antiangiogenic activity using standard in vitro methods in drug discovery and compared their potency.
Methods: Loose leaf teas were prepared by conventional hot water seeping, cooling, then filter-sterilized. Teas examined were: Chinese Dragon Pearl Jasmine, Chinese Dragonwell Lung Jing, Japanese Sencha, English Earl Grey, and a blend of teas. Human umbilical vein endothelial cells (HUVECs) were grown on monolayers in Matrigel, and incubated with tea extracts. Image analysis of capillary tubes was performed and capillary tubes, tube length, tube area, and branch point nodes were quantified. An angiogenesis metric was devised based on IC50 and level of suppression of capillary tubes, which allowed comparison of bioactivity among the teas.
Results: Conventionally, green teas are thought to possess greater bioactivity than black teas, but we found all tea types tested possessed a significant amount of antiangiogenic activity, including Earl Grey. Lung Jing tea had greater bioactivity than Sencha. A custom-blended tea composition had greater synergistic activity than its individual constituents.
Conclusions: Tea possesses differential antiangiogenic bioactivity that has potential to suppress tumor angiogenesis through dietary intake. Different tea varieties, including both green and black teas, possess a spectrum of bioactivity as quantified by the Angiogenesis Potency Index. This study also revealed the existence of bioactive synergies in certain combinations of tea varieties.
The Angiogenesis Foundation