Crude extract of Rheum palmatum L induced cell death in LS1034 human colon cancer cells acts through the caspase-dependent and -independent pathways.

Abstract

Crude extract of Rheum palmatum L (CERP) has been used to treat different diseases in the Chinese population for decades. In this study, we investigated the effects of CERP on LS1034 human colorectal cancer cells in vitro and also examined possible mechanisms of cell death. Flow cytometric assays were used to measure the percentage of viable cells, cell cycle distribution including the sub-G1 phase (apoptosis), the activities of caspase-8, -9, and -3, reactive oxygen species (ROS) and Ca(2+) levels, and mitochondrial membrane potential (ΔΨm). DNA damage, nuclei condensation, protein expression, and translocation were examined by Comet assay, 4'-6-diamidino-2-phenylindole (DAPI) staining, Western blotting, and confocal laser system microscope, respectively. CERP induced apoptosis as seen by DNA fragmentation and DAPI staining in a concentration- and time-dependent manner in cancer cells. CERP was associated with an increase in the Bax/Bcl-2 protein ratio and CERP promoted the activities of caspase-8, -9, and -3. Both ROS and Ca(2+) levels were increased by CERP but the compound decreased levels of ΔΨm in LS1034 cells. Laser confocal microscope also confirmed that CERP promoted the expressions of AIF, Endo G, cytochrome c, and GADD153 to induce apoptosis through mitochondrial-dependent pathway.

• Authors: Yi-Shih Ma, Shu-Chun Hsu, Shu-Wen Weng, Chien-Chih Yu, Jai-Sing Yang, Kuang-Chi Lai, Jing-Pin Lin, Jaung-Geng Lin, Jing-Gung Chung
• Journal: Environmental toxicology (Environ Toxicol) Vol. 29 Issue 9 Pg. 969-80 (Sep 2014) ISSN: 1522-7278 [Electronic] United States
• PMID: 23315830 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

Chemical References

• Indoles
• Plant Extracts
• Reactive Oxygen Species
• bcl-2-Associated X Protein
• DAPI
• Cytochromes c
• Caspases
• Calcium

Topics

• Apoptosis (drug effects)
• Calcium (metabolism)
• Caspases (metabolism)
• Cell Cycle (drug effects)
• Cell Line, Tumor
• Colonic Neoplasms (enzymology, pathology)
• Comet Assay
• Cytochromes c (metabolism)
• DNA Damage
• Humans
• Indoles (chemistry)
• Membrane Potential, Mitochondrial (drug effects)
• Plant Extracts (pharmacology)
• Protein Transport
• Reactive Oxygen Species (metabolism)
• Rheum (chemistry)
• bcl-2-Associated X Protein (metabolism)