Crude extracts of Solanum lyratum induced cytotoxicity and apoptosis in a human colon adenocarcinoma cell line (colo 205).
The effects of the crude extract of Solanum lyratum (SLE) on human colon cancer colo 205 cells were investigated. The cell viability, morphological changes of the cells, cell cycle arrest, apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential (deltapsi(m)) and cell cycle- and apoptosis-associated protein levels and gene expressions were examined in colo 205 cells after exposure to various concentrations of SLE for different time periods. The results indicated that SLE decreased the percentage of viable colo 205 cells accompanied by morphological changes. The most effective concentration of SLE was 300 pg/ml (SLE 300) and this concentration was used for further investigations. SLE induced S-phase arrest and apoptosis (sub-G1) in the colo 205 cells and those effects were dose- and time-dependent. DAPI staining and DNA gel electrophoresis confirmed that SLE induced apoptosis in colo 205 cells. Flow cytometric analysis also showed that SLE 300 promoted ROS production and decreased the deltapsi(m). Western blotting analysis indicated that SLE 300 increased Bax levels and decreased Bcl-2 levels, which caused the loss of deltapsi(m) followed by cytochrome c release and caspase-9 and -3 activation, finally leading to apoptosis. SLE 300 also promoted p53 and p27, but decreased the levels of cyclin B1 thus causing S-phase arrest. The gene expression associated with those proteins was also confirmed by PCR methods. The findings show that SLE might be used as a colon cancer therapeutic agent in the future.
Hsu
Shu-Chun
SC
Graduate Institute of Chinese Pharmaceutical Sciences, , China Medical University, Taichung 404, Taiwan, ROC.
Lu
Jih-Hung
JH
Kuo
Chao-Lin
CL
Yang
Jai-Sing
JS
Lin
Meng-Wei
MW
Chen
Guang-Wei
GW
Su
Chin-Cheng
CC
Lu
Hsu-Fung
HF
Chung
Jing-Gung
JG
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy*; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D017382:Reactive Oxygen Species; D032322:Solanum / Q000737:chemistry*
D010936:Plant Extracts; D017382:Reactive Oxygen Species