In

China, NCTD has been used in traditional Chinese medicine for more than two thousand years. Currently it is used as an anticancer drug to treat breast cancer, lung cancer, leukemia, colon cancer, etc[2–6]. However, the signaling pathways governing apoptosis in human HepG2 cells remains unclear. Apoptosis is an important phenomenon in cytotoxicity induced by anticancer drugs. The execution of apoptosis, or programmed cell death[7], is associated with buy HKI-272 characteristic morphological and biochemical changes mediated by a series of gene regulation and cell-signaling pathways. Recently, perturbation of mitochondrial selleck chemicals function has been shown to be a key event in the CB-839 datasheet apoptotic cascade[8]. Anticancer drugs may damage the mitochondria by increasing the permeability of the outer mitochondrial membrane, which is associated with the collapse of the mitochondrial membrane potential (Δφm), because a decline in Δφm can disturb intracellular ATP synthesis, generation of reactive oxygen species (ROS), altered mitochondrial redox ratio, translocation of cyto c to the cytosol, and degradation of caspase-3/PARP[9–12]. In this

regard, we have initiated experiments aimed at characterizing the mitochondrial function of NCTD on human HepG2 cells, a rapidly proliferating and malignant cell line. Materials and methods Chemicals and Reagents NCTD of analytical grade purity were purchased from Sigma Chemical Co.(St. Louis, USA); a stock solution (5 mg/ml) in RPMI1640(HyClone, USA) was prepared and stored at 4°C. D-Hanks’ solution, penicillin, streptomycin, fetal bovine serum, and EDTA,3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), propidium iodide in this study were purchased from Sigma Chemical Co(St. Louis, USA). Anti-rabbit Bcl-2, Bid, Bax, cytochrome c, and β-actin antibodies and HRP-conjugated goat anti-rabbit Ig were

from R&D Systems Inc (Minneapolis, USA). Anti-caspase-3, -8, -9 and anti-PARP were purchased from blue sky Chemical Co, LTD (Nantong, China). Dichlorodihydrofluorescein diacetate (DCHF-DA), N-acetyl- L -cysteine (NAC) and JC-1 kit were purchased from keygen Biotechnology Co., LTD(Nanjing, China). Caspase apoptosis detection kit and Annexin V-FITC kit were obtained from IKBKE Beijing Biosea Biotechnology Co, LTD (Beijing, China). Cell Line and Cell Culture The human hepatoma cell lines HepG2 was obtained from department of oncology, Zhongnan Hospital of Wuhan University (Wuhan, China), cells were cultivated in 5% CO2 at 37°C in RPMI1640 medium supplemented with 10% heat-inactivated fetal bovine serum, glutamine (2 mmol/L), and antibiotics (100 U/ml penicillin, 100 mg/ml streptomycin). Cell Viability Assay The inhibition of cell proliferation by NCTD was determined by assaying the reduction of MTT to formazan.