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<p align="left"><font face="Times New Roman">Aspalathus linearis (A. linearis), </font><font face="Times New Roman">commonly known as Rooibos tea or Red bush tea and </font><i><font face="Times New Roman">amellia sinensis (C. sinensis) </font></i><font face="Times New Roman">or Black tea are beverages that are consumed throughout the</font><font face="Times New Roman">world. These teas possess antioxidant, immunomodulating and anti-cancer actions. The aim</font> <font face="Times New Roman">of this study was to use <i>in vitro </i>assays to screen Rooibos and Black tea for endocrine</font> <font face="Times New Roman">modulation. </font><font face="Times New Roman">The immune modulating effects of Rooibos and Black tea were investigated using an <i>in vitro</i></font> <font face="Times New Roman">whole blood culture (WBC) assay. Unstimulated WBCs treated with Rooibos tea secreted</font> <font face="Times New Roman">higher levels of IL-6, IL-10 and IFN<font lang="JA">&gamma / </font>than cultures treated with DMSO control. Rooibos treatment of stimulated WBCs resulted in higher IL-6, lower IL-10 and no effect on IFN&gamma / </font><font face="Times New Roman">secretion compared to DMSO treated stimulated WBC. Black tea treatment of stimulated</font> <font face="Times New Roman">WBC resulted in decreased IL-6, IL-10 and IFN<font lang="JA">&gamma / </font>secretion compared to the DMSO treated</font> <font face="Times New Roman">stimulated WBC. </font><font face="Times New Roman">Extracts of Rooibos and Black tea were assessed for phytoestrogens using quantitative </font><font face="Times New Roman">estrogen ELISAs. Both teas contain phytoestrogens. The quantitative ELISAs showed that </font><font face="Times New Roman">Rooibos tea contained significantly lower estrone (E1), estradiol (E2) and estriol (E3) levels </font><font face="Times New Roman">than Black tea. The effects of Rooibos and Black tea on proliferation of the estrogen</font> <font face="Times New Roman">dependant MCF-7 cell line was determined to further characterise the phytoestrogenic</font> <font face="Times New Roman">properties of the teas. Both Rooibos and Black tea extracts caused a significant inhibition of</font> <font face="Times New Roman">MCF-7 proliferation. </font><font face="Times New Roman">This study shows that Rooibos tea and Black tea are beverages that can either stimulate or </font><font face="Times New Roman">suppress the immune system. Also, both teas contain significant levels of phytoestrogens as </font><font face="Times New Roman">determined by quantitative ELISAs. The current study confirms previous reports showing </font><font face="Times New Roman">inhibition of growth in breast cancer cell lines by phytoestrogens. The findings extend </font><font face="Times New Roman">related observations on the anti-carcinogenic potential of the two teas.</font></p>
Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:UWC_ETD:http%3A%2F%2Fetd.uwc.ac.za%2Findex.php%3Fmodule%3Detd%26action%3Dviewtitle%26id%3Dgen8Srv25Nme4_5859_1259070342 |
Date | January 2008 |
Creators | Hendricks, Rahzia. |
Source Sets | South African National ETD Portal |
Language | English |
Detected Language | English |
Type | Thesis and dissertation |
Format | |
Coverage | ZA |
Rights | Copyright: University of the Western Cape |
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