Swagatika Dash

Dielectric and impedance spectroscopy of (Bi0.5Li0.5)(Fe0.5Nb0.5)O3 multiferroics

The polycrystalline sample of (Bi0.5Li0.5)(Fe0.5Nb0.5)O3 was prepared by a solid-state reaction method. Preliminary X-ray structural analysis of the sample suggests the formation of a tetragonal phase with a new unit cell configuration. Dielectric, electrical, impedance and modulus properties of the material were investigated in a wide range of temperature (25–500 °C) and frequency (1 kHz–1 MHz). Two dielectric anomalies observed at 295 °C and 400 °C clearly suggest the existence of magnetic phase transition and two relaxation processes in the system. Dielectric properties have greatly been improved on addition of LiNbO3 to BiFeO3. The appearance of a hysteresis loop at room temperature confirms the ferroelectric properties of the material. The nature of the Nyquist plot confirms the presence of both bulk and grain boundary effects in the material. The ac conductivity was found to obey Jonschers power law. The dc conductivity variation with temperature follows the Arrhenius equation. The induced voltage changes with the applied magnetic field, showing that the sample is multiferroic.

Drug Targets for Cardiovascular-Safe Anti-Inflammatory: In Silico Rational Drug Studies

Cyclooxygenase-2 (COX-2) plays an important role in memory consolidation and synaptic activity, the most fundamental functions of the brain. It converts arachidonic acid to prostaglandin endoperoxide H2. In contrast, if over-expressed, it causes inflammation in response to cytokine, pro-inflammatory molecule, and growth factor. Anti-inflammatory agents, by allosteric or competitive inhibition of COX-2, alleviate the symptoms of inflammation. Coxib family drugs, particularly celecoxib, are the most famous anti-inflammatory agents available in the market showing significant inhibitory effect on COX-2 activity. Due to high cardiovascular risk of this drug group, recent researches are focused on the investigation of new safer drugs for anti-inflammatory diseases. Natural compounds, particularly, phytochemicals are found to be good candidates for drug designing and discovery. In the present study, we performed in silico studies to quantitatively scrutinize the molecular interaction of curcumin and its structural analogs with COX-2, COX-1, FXa and integrin αIIbβIII to investigate their therapeutic potential as a cardiovascular-safe anti-inflammatory medicine (CVSAIM). The results of both ADMET and docking study indicated that out of all the 39 compounds studied, caffeic acid had remarkable interaction with proteins involved in inflammatory response. It was also found to inhibit the proteins that are involved in thrombosis, thereby, having the potential to be developed as therapeutic agent.

Structural and electrical properties of NaNbO 3 modified BiFeO 3

Polycrystalline (Bi 0.5 Na 0.5 )(Fe 0.5 Nb 0.5 )O 3 material has been prepared using a mixed-oxide route at 800°C. The preliminary structural analysis shows that addition of equal amount of NaNbO 3 into BiFeO 3 induces a structural phase transformation from rhombohedral (BiFeO 3 ) to orthorhombic. X-ray peak broadening analysis was used to evaluate the crystalline sizes and lattice strain by the Williamson-Hall (W-H) analysis. The appearance of P-E hysteresis loop confirms the ferroelectric properties of the new system with remnant polarization (2P r ) of 3.58 µC/cm2 and coercive field (2E c ) of 42.8 kV/cm. The remnant polarization and coercive fields are found to be strongly field and frequency dependent. The electrical behaviour of the material was studied over a wide frequency (1 kHz–1MHz) and temperature (25°C–500°C) ranges. The activation energy calculated from dc conductivity signifies the conduction behaviour due to Bi cation and oxygen vacancies. Frequency dependence of ac conductivity suggests that that the material obeys Jonschers power law. The linear variation of the conductivity pattern is attributed to Arrhenius type thermally activated electrical transport phenomena. Addition of NaNbO 3 causes appearance of weak ferromagnetic moment.

Anticancerous and Immunomodulatory Activities of Alpinia nigra (Gaertn.) Burtt

Abstract The anticancerous and immunomodulatory activities of Alpinia nigra essential oils and extracts were evaluated in the present study. Besides, volatile constituents of essential oils were also analysed by GC/MS. β-pinene (56.27±2.5%), α-Humulene (13.70±1.55%) were found to be the major constituents in the leaf oil whereas rhizome oil contained β-pinene (38.03± 0.25%), myrtenol (9.35±0.3%) as the main compounds. MCF-7 and HeLa human cancer cell lines were used for evaluation of anticancerous activity. The immunomodulatory activities were examined using human peripheral blood mononuclear cells (PBMC) emphasizing on Th1 and Th2 cytokines. Our results showed that the oil significantly inhibited proliferation of cancer cells in dose-dependent manner. Rhizome oil of Alpinia nigra showed highest percent of inhibition (79 % ± 2.6 for HeLa and 70.9% ± 5.34 for MCF7) at 20 μg/ml concentration. Human PBMC treated with leaf oil showed highest secretion of IFN-γ (102.39 pg/ml) at 40 μg/ml concentration as compared to control (64.56 pg/ ml). The study implies the potential use of oil and extract of A. nigra as potent immunomodulating agent and a therapeutic supplement for breast and cervical cancer treatment. The anti-cancerous and immunomodulatory activities of both oil and extract of A. nigra were shown for the first time in this report.

Development and evaluation of polyclonal antibodies for detection of Pythium aphanidermatum and Fusarium oxysporum in ginger

ABSTRACT Polyclonal antibodies against Pythium aphanidermatum and Fusarium oxysporum proteins were developed for the detection of rhizome rot in ginger using serological assays. Under optimal experimental conditions, the detection limit of P. aphanidermatum by indirect ELISA was 10 µg/ml with a linear working range from 5 to 100 µg/ml (R2 = 0.994). In case of F. oxysporum, the linear working range was 5–100 µg/ml (R2 = 0.991) and the limit of detection was 25 µg/ml. The developed antibodies showed the highest titer in ELISA at 1:2000 dilutions. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis identified proteins ranging from molecular weights 15–97 kDa and 14–116 kDa of P. aphanidermatum and F. oxysporum isolates, respectively. In Western blot analysis, the developed antisera gave positive reactions against the isolated antigens of the fungi. The antibodies revealed immune-reactive bands of molecular weights 59 and 65 kDa in P. aphanidermatum and 44 and 75 kDa in F. oxysporum. The results suggest that the developed antibodies could be successfully applied for the specific immunodetection of P. aphanidermatum and F. oxysporum at an early stage of rhizome rot disease.

Edible plant-derived essential oils synergistically enhance the Th1, Th2 and anti-inflammatory cytokines in neonatal cord blood monocytic cell line

ABSTRACT Edible medicinal plants Curcuma longa, Kaempferia galanga and Zingiber officinale are considered to be suitable for pregnant mother and neonates. Their essential oils are claimed to have therapeutic effects, yet its immunomodulatory activities need to be investigated. To validate the immunomodulatory effect, cord blood monocyte cells (CBMCs) treated with different concentrations of essential oils ranging from 0 to 40 µg/ml. K. galanga oil at 40 µg/ml concentrations upregulated IFN-γ at 49.23 pg/ml, while C. longa oil downregulated the IL-10 at 10.45 pg/ml showing immunostimulant activity on CBMCs. However, Z. officinale oil showed no significant result at any concentration. K. galanga and C. longa oils also showed an increase in lymphocyte proliferation in a dose-dependent manner. The present study was aimed to evaluate the immunomodulatory potentialities of essential oils which will attract the interest of researchers and pharmaceutical industries for clinical studies and other applications in the therapy of diseases related to neonatal infections. GRAPHICAL ABSTRACT