Houttuynia cordata Thunb extract induces apoptosis through mitochondrial-dependent pathway in HT-29 human colon adenocarcinoma cells.
The Houttuynia cordata Thunb (HCT) extract has been used as a traditional Chinese herb medicine and as well as an effective drug for treating allergic inflammation for thousands of years. In this study, we investigated the anti-cancer activity of HCT and its molecular mechanisms in the human colon adenocarcinoma cell line HT-29. HCT inhibited HT-29 cell viability in a dose- and time-dependent manner by MTT assay. Treatment with 450 microg/ml of HCT for 48 and 72 h led to DNA damage and apoptosis by DAPI staining and comet assay. HCT increased reactive oxygen species production and decreased the levels of mitochondria membrane potential (MMP) in HT-29 cells by flow cytometry analysis. HCT caused the release of cytochrome c, Apaf-1, pro-caspase-9 and AIF from mitochondria via a decrease of the MMP. The decrease of MMP was then associated with a decrease in the ratio of Bax/Bcl-2 and activation of caspase-9 and -3 by Western blotting and caspase activity assay. Caspase-9 and -3 inhibitors almost completely suppressed HCT-induced caspase-9 and -3 activities. Our results demonstrated that the HCT-induced apoptosis in human colon adenocarcinoma cell line HT-29 might be related to a mitochondrial-dependent pathway.
Department of Family Medicine, Taichung Veterans General Hospital, School of Medicine, Chung-Shan Medical University, Taichung, Taiwan, ROC.
Yih-Jing
YJ
Tang
Jai-Sing
JS
Yang
Chin-Fen
CF
Lin
Woei-Cherng
WC
Shyu
Minoru
M
Tsuzuki
Chi-Cheng
CC
Lu
Yuh-Fung
YF
Chen
Kuang-Chi
KC
Lai
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005434:Flow Cytometry; D052859:Houttuynia; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014407:Tumor Cells, Cultured
D004365:Drugs, Chinese Herbal; C442781:Houttuynia cordata extract; D017382:Reactive Oxygen Species; D020169:Caspases; D020780:Matrix Metalloproteinase 9