Ammonium Hydroxide Extracts from Black Tea Inhibit Growth, Migration and Invasion of Colon Cancer Cells

In this study, the effects of ammonium hydroxide extracts from black tea on colon cancer cells were analyzed. Here we showed that black tea extracts decreased the growth of SW480 and HCT116 cells in a dose-dependent manner. The increase of subG1 population indicated that the black tea extracts induced cancer cell death. In addition, cell migration and invasion were significantly inhibited by the black tea extracts. We also found that tyrosine phosphorylation of focal adhesion kinase and paxillin was decreased in these cells, suggesting that integrin signaling pathways were affected by the extracts. In addition, decreased phosphorylation of extracellular signal7 Corresponding author. Dr. Min-Chuan Huang, Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, No. 1, Sec. 1 Ren-Ai Road, Taipei 100, Taiwan. TEL: 886-2-23123456, Ext. 8177; FAX: 886-2-23915292; EMAIL: [email protected] Journal of Food Biochemistry 32 (2008) 201–215. All Rights Reserved. © 2008, The Author(s) Journal compilation © 2008, Blackwell Publishing 201 regulated kinase and increased phosphorylation of p38 and c-Jun N-terminal kinase were observed, indicating that the extracts can modulate mitogenactivated protein kinase (MAPK) signaling pathways. These results suggest that the crude ammonium hydroxide extracts from black tea can significantly inhibit malignant phenotypes of colon cancer cells and that integrin and MAPK signaling pathways could be involved. PRACTICAL APPLICATIONS Ammonium hydroxide extracts of black tea can significantly suppress colon cancer cell growth, migration and invasion in vitro. These findings suggest that the ammonium hydroxide extracts of black tea may be applied for cancer treatment and prevention.