| Summary: | 博士 === 國立臺灣大學 === 生化學研究所 === 85 === The polyphenols in ten eifferent types of commercial tea
(manufactured tea) were analyzed by HPLC. Ten different types of
commercial tea, includiogunfermented, semifermented and
fermented tea, were analyzed for theirpolyphenol compounds, and
it was foynd that both yields of solids in teawater extracts
(TWEs), and the amount of EGCG in these products, variedwith
different tea leaves and processiog methods. Longjing tea
(unfermentedgreen tea) contained the highest concentration of
EGCG and polyphenols,whereas Assam black tea (most fermented)
contained the least. We also foundthat green tea polyphenols
(GTPs) and EGCG strongly inhibited peroxyl- radical generation.
The evidence suggests that the strong antioxidativeactivity of
Longjing TWEs and GTPs are mainly due to the higher contents
oftea polyphenols. In the animal study, Wistar rats were fed
2.5% green tea leaves (Longjingtea). At the 27 and 63 weeks, the
change of AST, ALT, r-GT, and creatinine were not significant in
treated group as compared with control group. Thesesuggested
that eating of green tea leaves were not damage to the liver and
kidney. Serum triglyceride, total-cholesterol, and LDL-C were
decreased.Interesting, the dieatry intake of the two group were
similary, but the bodyweight of green tea leaves group were
decreased 10%~18% than the controlgroup. Additionally, the
superoxide dismutase (SOD) activity in the serumwas increased in
treated group. The activities of antioxidant enzyme (SODand
catalase) and phase 2 enzyme (GST) and glutathione concentration
in theliver of Wistar rats were higher in treated group than in
control group. Thesignificance of these resylts can be
implicated in relation to the cancerchemopreventive effects of
green tea against the induction of tumors.
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