| Background A lot of laboratory experiments and epedemiologic studies have suggested that the consumption of green tea may reduce the risk of a variety of human cancers,including cancers of the lung, skin, stomach and mammary glands etc. The main chemical components of green tea are green tea polyphenols (GTP), which are responsible for the anticancer activity of green tea. There are many mechanisms concerning GTP' s effects, but none of them could completely explain GTP' s wide anticancer activities. It is well known that the growths of all solid tumors are depended on angiogenesis, without neovascularization, the primary tumor would not reach the size of l-2mm3.GTP' s antiangiogenesis activity has been demonstrated in vitro.So it is reasonable to surmise that GTP may inhibit tumor angiogenesis in vivo.Objective To study the antiangiogenesis activity of GTP in vivo. Methods Lewis lung cancinoma was employed as the model to study the antiangiogenesis activity of GTP by using the methods of immunohistochemstry. C57BL/6J mouse were divided into six groups randomly, two control groups and four treatment groups.The latter were orally administered GTP 62.5, 125, 250, 125mg/kg ?d" respectively 24 hours after implantation. At day 13 and 23, mouse were killed seperately to study tumors' angiogenesis and metastasis. VEGF, C-Jun, PCNA and MVD were measured immunohistochemically. The metastatic foci on the lung surface were counted under a magnifying glass. Result Lewis lung carcinomas were greatly inhibited,with aninhibitory rate of 27.2% by GTP (125mg/kg ?d') and MVDS weredecreased by 29.5% correspondingly. GTP also lowered the expressionof VEGF, PCNA and C-Jun, the inhibitory rates were 46.2%, 15.6%,and 12% respectively. The average number of metastatic foci on lungsurface was decreased from 13.17 to 5.17 after three-week treatment ofGTP(125mg/kg ?d').Conclusion GTP may exert at least part of its anticancer effect byinhibiting angiogenesis through blocking the expression of C-Jun andVEGF.
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