Supercritical carbon dioxide extraction of aromatic turmerone from Curcuma longa Linn. induces apoptosis through reactive oxygen species-triggered intrinsic and extrinsic pathways in human hepatocellular carcinoma HepG2 cells.

Abstract

The mechanisms underlying the antiproliferative and antitumor activities of aromatic turmerone (ar-turmerone), a volatile turmeric oil isolated from Curcuma longa Linn., have been largely unknown. In this study, 86% pure ar-turmerone was extracted by supercritical carbon dioxide and liquid-solid chromatography and its potential effects and molecular mechanisms on cell proliferation studied in human hepatocellular carcinoma cell lines. Ar-turmerone exhibited significant antiproliferative activity, with 50% inhibitory concentrations of 64.8 ± 7.1, 102.5 ± 11.5, and 122.2 ± 7.6 μg/mL against HepG2, Huh-7, and Hep3B cells, respectively. Ar-turmerone-induced apoptosis, confirmed by increased annexin V binding and DNA fragmentation, was accompanied by reactive oxygen species (ROS) production, mitochondrial membrane potential dissipation, increased Bax and p53 up-regulated modulator of apoptosis (PUMA) levels, Bax mitochondrial translocation, cytochrome c release, Fas and death receptor 4 (DR4) augmentation, and caspase-3, -8, and -9 activation. Exposure to caspase inhibitors, Fas-antagonistic antibody, DR4 antagonist, and furosemide (a blocker of Bax translocation) effectively abolished ar-turmerone-triggered apoptosis. Moreover, ar-turmerone stimulated c-Jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK) phosphorylation and activation; treatment with JNK and ERK inhibitors markedly reduced PUMA, Bax, Fas, and DR4 levels and reduced apoptosis but not ROS generation. Furthermore, antioxidants attenuated ar-turmerone-mediated ROS production; mitochondrial dysfunction; JNK and ERK activation; PUMA, Bax, Fas, and DR4 expression; and apoptosis. Taken together, these results suggest that ar-turmerone-induced apoptosis in HepG2 cells is through ROS-mediated activation of ERK and JNK kinases and triggers both intrinsic and extrinsic caspase activation, leading to apoptosis. On the basis of these observations, ar-turmerone deserves further investigation as a natural anticancer and cancer-preventive agent.

• Authors: Shao-Bin Cheng, Li-Chen Wu, Yun-Chih Hsieh, Chi-Hao Wu, Yu-Ju Chan, Li-Hsun Chang, Chieh-Ming J Chang, Shih-Lan Hsu, Chieh-Lin Teng, Chun-Chi Wu
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 60 Issue 38 Pg. 9620-30 (Sep 26 2012) ISSN: 1520-5118 [Electronic] United States
• PMID: 22946656 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Phytogenic
• Apoptosis Regulatory Proteins
• BAX protein, human
• BBC3 protein, human
• FASLG protein, human
• Fas Ligand Protein
• Ketones
• Proto-Oncogene Proteins
• Reactive Oxygen Species
• Sesquiterpenes
• bcl-2-Associated X Protein
• Carbon Dioxide
• ar-turmerone
• Cytochromes c
• Extracellular Signal-Regulated MAP Kinases
• MAP Kinase Kinase 4
• Caspases

Topics

• Antineoplastic Agents, Phytogenic (pharmacology)
• Apoptosis (drug effects)
• Apoptosis Regulatory Proteins (metabolism)
• Carbon Dioxide (chemistry)
• Carcinoma, Hepatocellular (drug therapy, metabolism, pathology)
• Caspases (metabolism)
• Cell Line, Tumor
• Chromatography, Supercritical Fluid (methods)
• Curcuma (chemistry)
• Cytochromes c (metabolism)
• Drug Screening Assays, Antitumor
• Extracellular Signal-Regulated MAP Kinases (metabolism)
• Fas Ligand Protein (metabolism)
• Hep G2 Cells (drug effects, metabolism)
• Humans
• Ketones (pharmacology)
• Liver Neoplasms (drug therapy, metabolism, pathology)
• MAP Kinase Kinase 4 (metabolism)
• Membrane Potential, Mitochondrial (drug effects)
• Proto-Oncogene Proteins (metabolism)
• Reactive Oxygen Species (metabolism)
• Sesquiterpenes (pharmacology)
• Signal Transduction (drug effects)
• bcl-2-Associated X Protein (metabolism)