title: Inhibitory Effects of the Four Main Theaflavin Derivatives Found in Black Tea on Ovarian Cancer Cells.
abstract: BACKGROUND
  Some polyphenols induce apoptosis and inhibit angiogenesis. Consumption of black tea, rich in polyphenols, has been found to reduce ovarian cancer risk. Theaflavin (TF1), theaflavin-3-gallate (TF2a), theaflavin-3'-gallate (TF2b) and theaflavin-3, 3'-digallate (TF3) are four main theaflavin derivatives found in black tea.
  
  
  METHODS
  Cell proliferation assay, Hoechst 33342 staining assay, Caspase-Glo Assay, western blot, human umbilical vein endothelial cell tube formation assay and vascular endothelial growth factor (VEGF) enzyme-linked immunosorbent assay were performed.
  
  
  RESULTS
  All four theaflavin derivatives reduced viability of ovarian cancer cells at lower concentrations than with normal ovarian cells. TF1 mainly mediated apoptosis via the intrinsic pathway, while the others via the intrinsic and extrinsic pathways. TF1 inhibited tube formation via reducing VEGF secretion in a hypoxia-inducible factor 1α-independent manner, while the others in a HIF1α-dependent way.
  
  
  CONCLUSIONS
  All four theaflavin derivatives inhibited ovarian cancer cells. Some of the effects and mechanisms of TF1 are different from those of the other three theaflavin derivatives.
authors: Department of Tea Science, Zhejiang University, Hangzhou, P.R. China College of Science, Technology and Mathematics, Alderson Broaddus University, Philippi, WV, U.S.A.
authors: Ying
authors: Y
authors: Gao
authors: Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, U.S.A.
authors: Gary O
authors: GO
authors: Rankin
authors: Department of Tea Science, Zhejiang University, Hangzhou, P.R. China chenyc@ab.edu youytu@zju.edu.cn.
authors: Youying
authors: Y
authors: Tu
authors: College of Science, Technology and Mathematics, Alderson Broaddus University, Philippi, WV, U.S.A. chenyc@ab.edu youytu@zju.edu.cn.
authors: Yi Charlie
authors: YC
authors: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D044946:Biflavonoids / Q000494:pharmacology*; D015153:Blotting, Western; D002392:Catechin / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects*; D006801:Humans; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D013662:Tea / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D044946:Biflavonoids; D013662:Tea; C056068:theaflavin; D002392:Catechin
keywords: Theaflavins; angiogenesis; apoptosis; ovarian cancer