Protective Role of Curcumin against N-Nitrosodiethylamine (NDEA)-Induced Toxicity in Rats

The present investigation was aimed at studying the possible role of curcumin against N-nitrosodiethylamine (NDEA)-induced toxicity in albino rats. Administration of NDEA to rats at a concentration of 0.1 mg/ml in drinking water ad libitum for 21 days produced toxicity in them, which was evident from histopathological changes in the rat livers, and increased levels of blood serum enzyme markers, i.e. aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase. In addition, the levels of oxidative stress markers like lipid peroxidation (LPO), protein carbonyl (PCC), and glutathione-S-transferase (GST) activity were elevated and the total glutathione (GSH) content was reduced in the livers. The administration of curcumin to rats at concentrations of 10, 20, and 40 mg/ml in drinking water along with 0.1 mg/ml of NDEA for 21 days effectively suppressed NDEA-induced toxicity and also resulted in a dose-dependent reduction in the levels of blood serum enzyme markers (AST, ALT, ALP, and LDH). Moreover, LPO, PCC, and GST activity were reduced and the GSH level was increased upon the administration of curcumin along with NDEA. The results obtained for the comet assay in rat hepatocytes and blood lymphocytes showed a significant dose-dependent decrease in the mean tail length. The micronucleus assay performed on rat hepatocytes also showed a dose-dependent reduction in the frequency of micronucleated cells along with curcumin administration. These results suggest that curcumin has a protective role against NDEA-induced toxicity in albino rats.     

Synthesis, Raman, FT-IR, NMR spectroscopic characterization, antimicrobial activity, cytotoxicity and DNA binding of new mixed aza-oxo-thia macrocyclic compounds

Series of new mixed aza-oxo-thia macrocyclic ligands 1,9(2,6)-ditriazina-2,8,10,16-tetraaza-3,7,11,15-tetraoxo-5,13-dithia-cyclohexadecaphan-1⁴,9⁴-diphenyl (L₁); 1,10(2,6)-ditri azina-2,9,11,18-tetraaza-3,8,12,17-tetraoxo-5,6,14,15-tetrathia-cyclooctadecaphan-1⁴,10⁴-diphenyl (L₂); 1,11(2,6)-ditriazina-2,10,12,20-tetraaza-3,9,13,19-tetraoxo-6,16-dithia-cyclocosa-phan-1⁴,11⁴-diphenyl (L₃); 1,12(2,6)-ditriazina-2,11,13,22-tetraaza-3,10,14,21-tetraoxo-6,7,17,18-tetrathia-cyclodocosaphan-1⁴,12⁴-diphenyl (L₄) were synthesised. The structural features of the compounds have been studied by elemental analyses, Mass, FT-Raman, FT-IR, ¹H and ¹³C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against several bacteria and yeast cultures. The obtained results from both methods were assessed in side-by-side comparison with commercial antibacterial and antifungal agents. In most cases, the compounds show strong antifungal activity in the comparison tests. Cytotoxic activities of the ligands against two different human cancer cell lines, stomach (23132/87) and lung (A549) were determined by MTT assay. DNA fragmentation assay tested cell lines were used to analyze the DNA ladder formation which is a characteristic of apoptotic cell death. The binding of the ligands with calf thymus DNA (CT-DNA) has also been investigated by absorption spectroscopy.     

Molecular cloning of a ligand for the inducible T cell gene 4-1BB: a member of an emerging family of cytokines with homology to tumor necrosis factor

4-1BB is an inducible T cell antigen that shows sequence homology to members of an emerging family of cytokine receptors, including those for tumor necrosis factor and nerve growth factor. To aid in the analysis of the function of 4-1BB we have utilized a soluble form of the molecule as a probe to identify and clone the gene which encodes its ligand. The ligand for 4-1BB is a type II membrane glycoprotein that has homology to tumor necrosis factor, lymphotoxin, and the ligands for CD40 and CD27, all of which are themselves ligands to receptors in this superfamily. The gene for 4-IBB is on mouse chromosome 4 and maps close to the p80 form of the tumor necrosis factor receptor as well as the gene for CD30. The gene for 4-IBB ligand maps to mouse chromosome 17, but considerably distal to the tumor necrosis factor and lymphotoxin genes. Interaction of 4-1BB with its ligand induces the proliferation of activated thymocytes and splenic T cells, a response which is mimicked on similar cell populations stimulated with an antibody to 4-1BB.     

Development and application of monoclonal antibodies for specific detection of human enteric adenoviruses.

Monoclonal antibodies were prepared against enteric adenovirus by fusing P3-NS1/-Ag4-1 mouse myeloma cells with lymphocytes from BALB/c mice immunized with enteric adenovirus 40 (Ad40) G2297. Of the several putative clones secreting antibodies to adenovirus, five were found to react specifically to the enteric adenovirus. The specificity of two of these monoclones which recognize a single antigen of a molecular size of 17 kilodaltons was evaluated against 78 clinical isolates. One monoclone (5D8/2C2) reacted with both Ad40 and Ad41, and the other monoclone (2H6/C11) recognized Ad40 only in an enzyme-linked immunosorbent assay (ELISA). These ELISA results correlated well with those of the specific neutralization test or DNA restriction endonuclease analysis or both. The use of this rapid ELISA with these monoclones will find applications in the diagnosis of enteric adenovirus and should facilitate the epidemiologic studies of enteric adenovirus gastroenteritis.     

Antibodies to human sperm YLP12 peptide that is involved in egg binding inhibit human sperm capacitation/acrosome reaction

Recently, the authors reported a novel dodecamer peptide sequence, designated as YLP12 on human sperm, that is involved in binding to zona pellucida (ZP) of human oocyte [10]. This unique sequence is present on the acrosomal region of the human sperm cell and is expressed only in human testis/ sperm. The aim of the present study was to examine whether YLP12 sequence is involved in capacitation/acrosome reaction. Swim-up sperm were capacitated with anti-YLP12 Fab' antibodies or control Fab's (40 and 85 microg/mL) and then the acrosome reaction was induced with calcium ionophore. An average of 64-73% sperm underwent acrosome reaction when they were capacitated in the presence of 40-85 microg/mL of bovine serum albumin or control Fab's. A significant (p < .01 to < .001) reduction (58-75%) in the percentage of acrosome-reacted sperm was observed when the sperm were capacitated in the presence of YLP12 Fab's. These data indicate that the YLP12 peptide sequence is involved in sperm capacitation / acrosome reaction, and may find clinical applications in the diagnosis and treatment of male infertility and immunocontraception.     

Nanoparticles as potential clinical therapeutic agents in Alzheimer’s disease: focus on selenium nanoparticles

Introduction: In etiology of Alzheimer’s disease (AD), involvement of amyloid β (Aβ) plaque accumulation and oxidative stress in the brain have important roles. Several nanoparticles such as titanium dioxide, silica dioxide, silver and zinc oxide have been experimentally using for treatment of neurological disease. In the last decade, there has been a great interest on combination of antioxidant bioactive compounds such as selenium (Se) and flavonoids with the oxidant nanoparticles in AD. We evaluated the most current data available on the physiological effects of oxidant and antioxidant nanoparticles.

Areas covered: Oxidative nanoparticles decreased the activities of reactive oxygen species (ROS) scavenging enzymes such as glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase in the brain of rats and mice. However, Se-rich nanoparticles in small size (5–15 nm) depleted Aβ formation through decreasing ROS production. Reports on low levels of Se in blood and tissue samples and the low activities of GSH-Px, catalase and SOD enzymes in AD patients and animal models support the proposed crucial role of oxidative stress in the pathogenesis of AD.

Expert commentary: In conclusion, present literature suggests that Se-rich nanoparticles appeared to be a potential therapeutic compound for the treatment of AD.     

Construction of 0D/2D Schottky Heterojunctions of ZnO and Ti3C2 Nanosheets with the Enriched Transfer of Interfacial Charges for Photocatalytic Hydrogen Evolution

The development of cost-effective co-catalysts of high photocatalytic activity and recyclability is still a challenge in the energy transformation domain. In this study, 0D/2D Schottky heterojunctions, consisting of 0D ZnO and 2D Ti₃C₂, were successfully synthesized by the electrostatic self-assembling of ZnO nanoparticles on Ti₃C₂ nanosheets. In constructing these heterojunctions, Ti₃C₂ nanosheets acted as a co-catalyst for enhancing the transfer of excitons and their separation to support the photocatalytic response of ZnO. The as-prepared ZnO/Ti₃C₂ composites demonstrate an abbreviated charge transit channel, a huge interfacial contact area and the interfacial electrons’ transport potential. The extended optical response and large reactive area of the ZnO/Ti₃C₂ composite promoted the formation of excitons and reactive sites on the photocatalyst’s surface. The ZnO/Ti₃C₂ Schottky heterojunction showed significantly high photocatalytic activity for hydrogen production from a water–ethanol solution under the light illumination in the visible region. The hydrogen evolution overoptimized the ZnO/Ti₃C₂ composition with 30 wt.% of Ti₃C₂, which was eight times higher than the pristine ZnO. These findings can be helpful in developing 0D/2D heterojunction systems for photocatalytic applications by utilizing Ti₃C₂ as a low-cost co-catalyst.