cytochrome-c-t and ethyl-acetate

Exposure of electrospray droplets to organic vapors was shown to dramatically reduce alkali-metal adduction on protein ions and shift protein charge states. Since DESI-MS is affected by similar adduct species as ESI-MS and shares similar ionization mechanisms, polar organic vapor additives should likewise also improve the DESI-MS analysis of proteins. Here the DESI spray was exposed to a variety of polar organic vapor additives. Head space vapors of polar organic solvents were entrained in nitrogen gas and delivered to the atmosphere inside a semi-enclosed plastic enclosure surrounding the spray plume. The vapors of acetone, acetonitrile, ethyl acetate, methanol, and water were investigated. Vapor dependent effects were observed with respect to changes in protein charge state distributions and signal intensities. With ethyl acetate vapor addition, the signal intensities of all proteins investigated were significantly increased, including proteins larger than 25 kDa such as carbonic anhydrase II and bovine serum albumin.

Topics: Acetates; Acetone; Acetonitriles; Animals; Carbonic Anhydrase II; Cattle; Cytochromes c; Equipment Design; Horses; Methanol; Proteins; Serum Albumin, Bovine; Solvents; Spectrometry, Mass, Electrospray Ionization; Volatilization; Water

Ethylacetate extract of Tetrastigma hemsleyanum (EET) has a potent antitumor activity in vitro and in vivo. However, the molecular mechanism underlying EET-induced apoptosis remains elusive. As part of our continuing studies, we investigated the apoptosis mechanism of HepG2 cells exposed to different concentrations of EET in vitro. Confocal laser scanning was used to detect the apoptotic morphological changes. Flow cytometer and inverted fluorescence microscope were used to detect the mitochondrial membrane potential and cytosolic Ca(2+) level. Western blotting analysis was used to evaluate the expression of the apoptosis-related proteins. Annexin V/PI staining was used to investigate cell apoptosis. Spectrophotometry was used to detect the activity of caspase family. The results showed that distinct apoptotic morphological changes occurred in HepG2 cells treated by EET. EET caused collapse of mitochondrial membrane potential, elevation of cytosolic Ca(2+) level, and evoked release of cytochrome c from mitochondria in a concentration-dependent manner. The apoptosis was accompanied by a significant activation of caspase-3, caspase-9, and the cleavage of poly (ADP-ribose) polymerase, but there was no significant change in either the activity or the expression level of caspase-8. Furthermore, EET-induced apoptosis could be inhibited by caspase-9 inhibitor Z-LEHD-FMK but not by caspase-8 inhibitor Z-IETD-FMK. Taken together, these overall results demonstrated that EET-induced apoptosis of HepG2 cells was mediated by the mitochondrial caspase-dependent intrinsic pathway rather than the death receptor/caspase-8-mediated signaling route.

Topics: Acetates; Apoptosis; Calcium; Caspase 3; Caspase 8; Caspase 9; Caspases; Cytochromes c; Fluorescent Dyes; Hep G2 Cells; Humans; Membrane Potential, Mitochondrial; Mitochondria; Plant Extracts; Vitaceae

Many studies have shown that glutamate-induced oxidative stress can lead to neuronal cell death involved in the development of neurodegenerative diseases. In this work, protective effects of ethyl acetate extract (EAE) of Arctium lappa L. roots against glutamate-induced oxidative stress in PC12 cells were evaluated. Also, the effects of EAE on antioxidant system, mitochondrial pathway, and signal transduction pathway were explored. Pretreatment with EAE significantly increased cell viability, activities of GSH-Px and SOD, mitochondrial membrane potential and reduced LDH leakage, ROS formation, and nuclear condensation in a dose-dependent manner. Furthermore, western blot results revealed that EAE increased the Bcl-2/Bax ratio, and inhibited the up-regulation of caspase-3, release of cytochrome c, phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK 1/2). Therefore, our results indicate that EAE may be a promising neuroprotective agent for the prevention and treatment of neurodegenerative diseases implicated with oxidative stress.

Topics: Acetates; Animals; Arctium; bcl-2-Associated X Protein; Caspase 3; Cytochromes c; Glutamic Acid; Glutathione Peroxidase; Malondialdehyde; Mitogen-Activated Protein Kinases; Neuroprotective Agents; Oxidative Stress; PC12 Cells; Phosphorylation; Plant Extracts; Plant Roots; Proto-Oncogene Proteins c-bcl-2; Rats; Reactive Oxygen Species; Solvents; Superoxide Dismutase

An extract of artichoke Cynara cardunculus L. (CCE) has been shown to exhibit antioxidant and antigenotoxic properties. In this study, the ability of CCE to inhibit the growth of L1210 and HL-60 leukemia cells was studied. Treatment of leukemia cells with a variety of concentrations of CCE (500-2500 microg/microL) for 24 h resulted in dose-dependent inhibition of leukemia cell growth. The cell growth inhibition was accompanied by G(0)/G(1) cell cycle arrest and by a loss of cells in S phase. Futhermore, apoptosis detected as a sub-G(0) cell population and apoptotic DNA fragmentation was observed. More detailed analyses of apoptosis induced by CCE in HL-60 cells revealed that apoptosis progressed through the caspase-9/-3 pathway, as release of cytochrome c, caspase-9/-3 activations and specific proteolytic cleavage of poly(ADP-ribose) polymerase. Taken together, the results suggest that CCE exerts an antiproliferative activity on leukemia cells and induces apoptosis of these cells through a mitochondrial/caspase dependent pathway.

Topics: Acetates; Animals; Blotting, Western; Caspases; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cynara; Cytochromes c; HL-60 Cells; Humans; Leukemia; Plant Extracts; Solubility