Abstract
The present study was carried out to evaluate the effects of the water extract of Chinese medicine "Pingliu Keli" (PK) on human glioma cell viability and apoptosis and to investigate its mechanisms of action in SHG-44 cells. MTT assay showed that PK had a strong cytotoxic effect on SHG-44 cells. The number of live cells was less than 20% after exposure to 90 μg/mL PK for 24 h. PK increased cytotoxicity of SHG-44 cells in a dose-dependent manner. PK caused arrest of SHG-44 cells in G1 phase at low concentration and in G2 phase at high concentration. The percentage of apoptotic cells by flow cytometric analysis of the DNA-stained cells increased to 38% and 52% after treatment with 72 and 108 μg/mL PK, respectively. In addition, PK increased the expression of proapoptotic protein (Bax) and decreased antiapoptotic protein (Bcl-2), with a concomitant increase in the levels of cleaved caspase-3, cleaved caspase-9 and cleaved poly-ADP-ribose polymerase (PARP). These results suggest that PK has a significant apoptosis inducing effect on SHG-44 glioma cells in vitro and caspase-3 may act as a potential mediator in the process.