RESUMO
OBJECTIVE: To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus (C. orbiculatus) extract in human hepatocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cells (HCCLM6) were treated with C. orbiculatus extract (COE) at different nontoxic concentrations (10, 20, 40, 80, and 160 microg/mL). The effect of COE on HCCLM6 viability was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Cellular apoptosis following COE treatment was assessed by flow cytometry and western blot analysis. RESULTS: COE significantly inhibited cell viability and induced apoptosis of HCCLM6 cells in a dose-dependent manner. Apoptosis was accompanied by increased Bax expression and decreased Bcl-2 expression. In addition, COE treatment led to the release of cytochrome c, activation of caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Furthermore, activation of extracellular signal-regulated kinase (ERK), p38 kinase, and c-Jun N-terminal kinase (JNK) phosphorylation, and down-regulation of Akt phosphorylation was observed. CONCLUSION: COE induces mitochondrial-mediated, caspase-dependent apoptosis in HCCLM6 cells, which might be attributed to the activation of mitogen-activated protein kinase (MAPK) and inhibition of Akt signaling pathways. These data suggest that COE may be a potential treatment for human hepatocellular carcinoma.
Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/fisiopatologia , Celastrus/química , Neoplasias Hepáticas/fisiopatologia , Mitocôndrias/metabolismo , Extratos Vegetais/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/genética , Citocromos c/metabolismo , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
<p><b>OBJECTIVE</b>Celastrus orbiculatus Thunb. has been used for thousands of years in China as a remedy against cancer and inflammatory diseases. This study aims to investigate whether C. orbiculatus extract (COE) could inhibit angiogenesis, which is the pivotal step in tumor growth, invasiveness, and metastasis.</p><p><b>METHODS</b>In this study, the extract from the stem of C. orbiculatus was used. Mouse hepatic carcinoma cells (Hepa1-6) were treated with COE in different nontoxic concentrations (10, 20, 40, 80, and 160 μg/mL). The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively; the active fractions were further tested on C57BL/6 mice and human umbilical vein endothelial cells (HUVEC) for any antiangiogenic effects.</p><p><b>RESULTS</b>COE significantly inhibited proliferation and induced apoptosis in Hepa1-6 cells and inhibited VEGF expression at both mRNA and protein levels. Furthermore, this agent inhibited the formation of the capillary-like structure in primary cultured HUVEC in a dose-dependent manner. In vivo, COE significantly reduced the volume and weight of solid tumors with low adverse effects and decreased tumor angiogenesis.</p><p><b>CONCLUSIONS</b>In summary, COE could be used to treat hepatic carcinoma. The mechanisms of the antitumor activity of COE may be due to its effects against tumor angiogenesis by targeting the VEGF protein.</p>
