Bullatacin, a potent antitumor annonaceous acetogenin, inhibits proliferation of human hepatocarcinoma cell line 2.2.15 by apoptosis induction

Bullatacin, isolated from the fruit of Annona atemoya, is one of the most potentially effective antitumor annonaceous acetogenins. Bullatacin was studied here for its ability to inhibit the proliferation of 2.2.15 cells, hepatitis B virus (HBV) DNA transfected human hepatocarcinoma cell line. It was found that bullatacin induced cytotoxicity of 2.2.15 cells in a time- and dose-dependent manner. Fifty percent effective dose (ED50) on day 1 of exposure to bullatacin were 7.8 +/- 2.5 nM for 2.2.15 cells. [3H]-Thymidine incorporation assays showed almost the same results. Bullatacin-treatment also reduced concentrations of hepatitis B surface antigen (HBsAg) in the cultured medium released from 2.2.15 cells, coincident with the decrease in the cell proliferation. Analysis of mophological changes of bullatacin-treated 2.2.15 by inverted phase-contrast microscope and eletron microscopy revealed a possible model of action for bullatacin to inhibit proliferation of 2.2.15 cells by inducing apoptosis. Most of the bullatacin-induced cell death was found to be due to apoptosis, as determined by double staining with fluorescein-isothiocyanate (FITC)-labeled annexin V and propidium iodide (PI).     

The formulation of life cycle impact assessment framework for Malaysia using Eco-indicator

Background, aim, and scope  

Life Cycle Assessment (LCA) is an emerging supporting tool designed to help practitioner in systematically assessing the environmental performance of selected product’s life cycle. A product’s life cycle includes the extraction of raw materials, production, and usage, and ends with waste treatment or disposal. Life cycle impact assessment (LCIA) as a part of LCA is a method used to derive the environmental burdens from selected product’s stages. LCIA is structured in classification, characterization, normalization and weighting. Presently most of the LCIA practices use European database to establish the characterization, normalization and weighting value. However, using these values for local LCA practice might not be able to reflect the actual Malaysian’s environmental scenario. The aim of this study is to create a Malaysian version of normalization and weighting value using the pollution database within Malaysia.     

Investigation of the effect of hyperglycemia on intracerebral hemorrhage by proteomic approaches

Intracerebral hemorrhage (ICH) is associated with high mortality and disability, and hyperglycemia worsens the clinical and neurological outcomes of patients with ICH. In this study, we utilized proteomic approaches to investigate the role of hyperglycemia in ICH. Hyperglycemia was induced by intraperitoneal injection of streptozotocin (STZ) in adult Sprague-Dawley male rats; ICH was induced by stereotaxic infusion of collagenase/heparin into the right striatum. It was observed that the size of induced hemorrhage was significantly larger in the hyperglycemic group (n=6 in each group). On the first day after ICH, an apparent decrease in the bilateral grasp was also observed for the lesioned hyperglycemic rats compared with normoglycemic ones. When employing 2-DE and MS to examine the proteomes of perihematomal and control regions in individual hyperglycemic and normoglycemic rats, eight differentially expressed protein targets were identified. Most noteworthy, in response to ICH significant increase of albumin was ubiquitously observed in the brains of normoglycemic rats but not in the brains of hyperglycemic rats. Coincidentally, more significant neuronal apoptosis were found in the perihematomal regions of hyperglycemic rats. These observations described suggest the protection role of albumin in acute stage of ICH, which may be dependent on different blood sugar levels.     

Epirubicin induces apoptosis in osteoblasts through death-receptor and mitochondrial pathways

Epirubicin is an anthracycline and is widely used in tumor treatment, but has toxic and undesirable side effects on wide range of cells and hematopoietic stem cells (HSC). Osteoblasts play important roles in bone development and in supporting HSC differentiation and maturation. It remains unknown whether epirubicin-induced bone loss and hematological toxicity are associated with its effect on osteoblasts. In primary osteoblast cell cultures, epirubicin inhibited cell growth and decreased mineralization. Moreover, epirubicin arrested osteoblasts in the G2/M phase, and this arrest was followed by apoptosis in which both the extrinsic (death receptor-mediated) and intrinsic (mitochondrial-mediated) apoptotic pathways were evoked. The factors involved in the extrinsic apoptotic pathway were increased FasL and FADD as well as activated caspase-8. Those involved in the intrinsic apoptotic pathway were decreased Bcl-2; increased reactive oxygen species, Bax, cytochrome c; and activated caspase-9 and caspase-3. These results demonstrate that epirubicin induced osteoblast apoptosis through the extrinsic and intrinsic apoptotic pathways, leading to the destruction of osteoblasts and consequent lessening of their functions in maintaining bone density and supporting hematopoietic stem cell differentiation and maturation.     

Increased oxidazability of plasma low density lipoprotein from patients with coronary artery disease

Oxidative modification of lipoproteins may play a crucial role in the pathogenesis of atherosclerosis. This study was designed to examine whether increased lipid peroxides and/or oxidative susceptibility of plasma lipoproteins occur in patients with coronary artery disease. The levels of lipid peroxides, estimated as thiobarbituric acid-reactive substances (TBARS), were significantly greater in the plasma and very low density lipoprotein (VLDL) of symptomatic patients with coronary artery disease than in those of healthy persons, but the TBARS levels of low density lipoprotein (LDL) and high density lipoprotein (HDL) showed insignificant difference between patients and normals. To evaluate the oxidative susceptibility of lipoproteins, we employed in vitro Cu²⁺ oxidation of lipoproteins monitored by changes in fluorescenece, TBARS level, trinitrobenzene sulfonic acid (TNBS) reactivity, apolipoprotein immunoreactivity and agarose gel electrophoretic mobility. While VLDL and LDL of normal controls were oxidazed at 5–10 μM Cu²⁺, pooled VLDL and LDL of patients with coronary artery disease were oxidized at 1–2.5 μM Cu²⁺, i.e., at relatively lowver oxidative stress. At 5 μM Cu²⁺, VLDL and LDL of patients with coronary artery disease still showed at faster oxidation rate, judged by the rate of fluorescence increase, higher TBARS level, less TNBS reactivity, greater change in apo B immunoreactivity and higher electrophoretic mobility than those of normal controls. However, the difference on the oxidizability of HDL was insignificant for patients vs. normals. In conclusion, we have shown that plasm VLDL and LDL of patients with coronary artery disease are more susceptible to in vitro oxidative modification than those of health persons. The data suggest that enhanced oxidizability of plasma lipoproteins may be important factor influencing the development of coronary artery disease.     

1H and 15N resonance assignments and secondary structure of the carbon monoxide complex of sperm whale myoglobin

Summary Sequence-specific backbone ¹H and ¹⁵N resonance assignments have been made for 95% of the amino acids in sperm whale myoglobin, complexed with carbon monoxide (MbCO). Many assignments for side-chain resonances have also been obtained. Assignments were made by analysis of an extensive series of homonuclear 2D spectra, measured with unlabeled protein, and both 2D and 3D ¹H-¹⁵N-correlated spectra obtained from uniformly ¹⁵N-labeled myoglobin. Patterns of medium-range NOE connectivities indicate the presence of eight helices in positions that are very similar to those found in the crystal structures of sperm whale myoglobin. The resonance assignments of MbCO form the basis for determination of the solution structure and for hydrogen-exchange measurements to probe the stability and folding pathways of myoglobin. They will also form a basis for assignment of the spectra of single-site mutants with altered ligand-binding properties.