Molecular and Human Genetics Division, Indian Institute of Chemical Biology, Kolkata, India.
Nutr Cancer. 2011;63(7):1122-32. doi: 10.1080/01635581.2011.605985. Epub 2011 Sep 15.
Antimutagenic and anticancer effects of black tea polyphenols theaflavins (TF) and thearubigins (TR) have previously been reported. TR is a complex mixture of polyphenols. In this study, our interest was to fractionate TR and to study the antimutagenic and anticancer activities of the fractions. Three fractions of TR, namely TR-1, TR-2, and TR-3, were isolated by chromatographic processes. Antimutagenic activity of these 3 fractions was carried out on 4 Salmonella strains by Ames assay. Anticancer activity was studied on human leukemic cells U937. Our findings clearly indicated antimutagenic and anticancer activities of the TR-1, TR-2, and TR-3 fractions on Salmonella strains and on U937 cells, respectively. However, all 3 fractions, at or below 100 μg/ml dose, did not show any significant toxic effects on the normal human cells (peripheral blood mononuclear cells). TR-2 was found to be the most active fraction among the 3. Flow cytometric and confocal microscopic studies further indicate that apoptosis induction could be an important mechanism behind the anticancer effects of these fractions. To our knowledge, this study is the first attempt to describe the antimutagenic and anticancer activity of TR fractions, and it also suggests that TR-2 is the most active component of TR.
先前已有报道称，红茶多酚茶黄素（TF）和茶红素（TR）具有抗突变和抗癌作用。TR 是多酚的复杂混合物。在这项研究中，我们的兴趣是对 TR 进行分段，并研究各馏分的抗突变和抗癌活性。通过色谱过程分离出 TR 的三个馏分，即 TR-1、TR-2 和 TR-3。通过 Ames 试验对这 3 个馏分在 4 种沙门氏菌菌株上的抗突变活性进行了研究。在人白血病细胞 U937 上研究了抗癌活性。我们的研究结果清楚地表明，TR-1、TR-2 和 TR-3 馏分对沙门氏菌菌株和 U937 细胞均具有抗突变和抗癌活性。然而，所有 3 个馏分在 100μg/ml 剂量以下时，对正常人外周血单个核细胞均没有明显的毒性作用。在这 3 个馏分中，TR-2 的活性最高。流式细胞术和共聚焦显微镜研究进一步表明，细胞凋亡诱导可能是这些馏分抗癌作用的重要机制。据我们所知，这项研究首次尝试描述 TR 馏分的抗突变和抗癌活性，同时也表明 TR-2 是 TR 中最活跃的成分。
