植多酚之抗癌活性與神經保護作用機制之探討

Studies on the anti-cancer and neuroprotective effects of phytopolyphenols

華國泰(Kuo-Tai Hua)

指導教授 ： 林仁混

國立臺灣大學/醫學院/生物化學暨分子生物學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00265

摘要

茶自古以來被視為是一種具保健效果的飲料，其中所富含的兒茶素經研究證實具有抗癌、抗氧化、抗發炎、抗菌等弁遄C一直以來，茶樹（Camellia sinesis）的栽培即是為了取其葉進一步烘焙成具高度經濟價值的各式茶葉。本實驗室過去發現除葉子外，茶花當中也具有高量的兒茶素。同時，茶花萃取物亦具有不錯的抗氧化及抗發炎能力，唯一缺點是其花朵較小且採收不易。在本實驗中，我們選取了六種屬於Camellia japonica的園藝種山茶樹與用於搾油的兩種油茶樹(Camellia olefera and Camellia tenuifolia)以及兩種香茶樹與台茶十二號比較，試圖找尋花朵大且生物活性高的茶種。以HPLC分析茶多酚含量發現, 所分析的茶花中僅偵測出咖啡因(caffeine)，兒茶素(catechin, C)與表兒茶素 (epicatechin , EC)，而在兒茶素總量方面，亦較台茶十二號少。進一步作活性分析後發現，在抑制乳癌細胞生長及誘發細胞凋亡方面，茶花萃取物仍具有程度不等的活性。值得一提的是，由於過去研究證實表沒食子兒茶素沒食子酸酯(epigallocatechin-3-gallate, EGCG)及表沒食子兒茶素(epigallocatechin, EGC)是茶葉中最具生物活性的成分，而本實驗發現儘管不含上述二成分，少數茶種如小葉種油茶的茶花萃取液仍具有抑制乳癌細胞生長及誘發乳癌細胞凋亡的能力，顯示在這些茶花中可能存在其它不同於兒茶素的活性物質，值得進一步的研究。

關鍵字

茶葉 ； 乳癌 ； 茶花 ； 咖啡因 ； 抗細胞增生 ； 兒茶素

並列摘要

Tea is a popular beverage with health benefits. The enriched tea polyphenols including catechins have been reported to perform anti-cancer, anti-oxidant, anti-inflammation and anti-bacteria activity. At all times, tea trees are cultivated to obtain leaves and further manufacture to different kinds of Cha. Previously, we demonstrated that the amount of tea polyphenols and caffeine in tea flowers from different species of Camellia sinensis was equally to that in old leaves. The anti-oxidant and anti-inflammation activity was also noted. But the flowers of Camellia sinensis were relatively small and difficult to harvest. In this study, we compared the levels of catechins and caffeine in tea flowers from 6 different species of Camellia japonica, Camellia tenuifolia, Camellia oleifera, 2 savoury camellias and TTES #12 (Camellia sinensis). Only (+)-catechin and (-)-epicatechin can be detected by the isocratic HPLC system in tea flowers besides TTES #12, and total catechins were also lower in these tea flowers. In addition, the water extracts of tea flowers were used to test the biological functions including anti-proliferous and apoptotic effects in human breast cancer MCF-7 cells. TTES #12 remained the most active either examined by MTT assay or the cleavage of apoptotic related molecules, PARP and Bid. Although the most actived catechins, (-)-epigallocatechin-3-gallate and (-)-epigallocatechin, were not detectable in these flowers, some tea flowers like Camellia tenuifolia still have potent bioactivity. It is likely that bioactived molecules other than catechins exist in these tea flowers.

並列關鍵字

tea leaves ； caffeine ； bid ； MCF-7 ； Tea flowers ； antiproliferation ； PARP ； catechins

參考文獻

3. Lin, J. K., Liang, Y. C., Lin-Shiau, S. Y. (1999) Biochem. Pharmacol. 58, 911-915

7. Lin, J. K.; Chen, P. C.; Ho, C. T.; Lin-Shiau, S. Y. (2000) J. Agric. Food Chem. 48, 2736-2743

5. Liang, Y. C.; Chen, C. F.; Lin, Y. L.; Lin-Shiau, S. Y.; Lin, J. K. (1999) Carcinogenesis, 20, 733-736

6. Liang, Y. C.; Lin-Shiau, S. Y.; Chen, C. F.; Lin, J. K. (1999) J. Cell. Biochem. 75, 1-12

1. Weisburger, J. H. (1998) Cancer Res. 58, Cover legend (September issue)