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Regio- and Stereoselective Synthesis of a Library of Bioactive Dispiro-Oxindolo/Acenaphthoquino Andrographolides via 1,3- Dipolar Cycloaddition Reaction Under Microwave Irradiation
No full textDispiro-pyrrolidino/pyrrolizidino fused oxindoles/acenaphthoquinones have
been derived from andrographolide via azomethine ylide cycloaddition to the conjugated
double-bond under microwave (MW) irradiation. The reactions are chemo-, stereo-, and
regioselective in nature. Change in amino acid from sarcosine/N-benzyl glycine to L-proline
changes the regiochemistry. A representative library of 40 compounds along with in vitro
anticancer evaluation is reporte
Design, Development and Analysis of two Databases: IGDD and ProHspDb
No full textDatabase is a set of systematically organized, structured storage container of indexed information, which is arranged in such a way that a computer can easily retrieve, update,
analyze, and manage the data. The data may represent any kind of information. It may be in the form of graphics, images, reports, scripts, tables, text, etc. Everyday most people use the underlying technology of databases in their daily life.Databases are a crucial component of a huge fraction of websites. It resides behind any software system that maintains some amount of persistent information. Database systems should maintain some important properties to make them exceptionally useful and convenient such as persistence, reliability, scalable concurrency control, data abstractions, and high-level query languages. There is a wide range of databases from a spreadsheet, a mail server, a word document to a relational server based database, desktop database etc. Even a book, the
World Wide Web (WWW) themselves are databases. Since the beginning of defined civilization, men kept track of information writing them down on paper indices. So a book
may be considered as the first (non-electronic) database used to track scientific knowledge, historical fact etc
Molecular Study of Micrornamediated Regulation of Mitosis and its Impact on Oral Carcinogenesis
No full textCancer is a complex disorder, a group of more than 100 diseases that develop across time and involve the uncontrolled proliferation of the body's cells. Although
cancer can develop in virtually any of the body's tissues, and each type of cancer has its unique features, the basic processes that produce cancer are quite similar in all forms of the disorder [1]. In this multistep process, cells acquire a series of mutations that eventually lead to unrestrained cell growth and division, inhibition of cell differentiation, and evasion of cell death. These cells break free from the normal restraints on cell
division and begin to follow their own agenda for proliferation (Fig. 1). A tumour, formed of these abnormal cells may remain within the tissue in which it originated (in situ cancer), or it may begin to invade nearby tissues (invasive cancer). An invasive tumour is said to be malignant, and cells shed into the blood or lymph from a malignant tumour are likely to establish new tumours (metastases) throughout the body
Adenosine Kinase Reactivation by Leishmania donovani Coded Cyclophilin and its Truncated Form
No full textTrypanosomatid parasites, that cause various neglected human diseases, have deadly effects on several million people worldwide. Visceral leishmaniasis or kala-azar, one of the disastrous trypanosomatid diseases, is spread by Leishmania donovani. L. donovani, a purine auxotroph, incapable of synthesizing purine bases de novo, fulfill the requirement of purines by salvaging purines from the host using its purine salvage pathway. Adenosine kinase, a key enzyme of this salvage pathway, phosphorylates adenosine to AMP. Previous reports from this laboratory suggested that AdK has an inherent tendency to form soluble aggregates, leading to inactivation of the enzyme. Further studies showed that a single domain cycliphilin (LdCyP) from L. donovani disrupted the aggregates with concomitant reactivation of the enzyme. The work presented in this dissertation revealed that ADP, one of the products of AdK
reaction, facilitated aggregate formation. These ADP-induced aggregates were reversible in nature and were amenable to disaggregation in presence of LdCyP. In contrast, the naturally formed AdK aggregates
were irreversible and therefore could not be reactivated by LdCyP-chaperone. Detailed structural and biochemical analysis of the two forms of aggregates revealed marked differences in the morphology between two forms of aggregates. Disaggregating and reactivating properties of LdCyP remained intact even after truncating 88-amino acids from the N-terminal end of the full-length LdCyP. A further search for smaller LdCyP fragment has resulted in identification of one LdCyP-decapeptide that appeared to
have AdK stimulating activity. Although, the physiological significance of this phenomenon in L. donovani has not yet been firmly established, it is well known that like many other developmentally regulated parasitic proteins, AdK, along with adenosine deaminase (ADA), exhibits high specific activity during transformation from promastigote to amastigote. Hence, the importance of in vivo regulation of AdK activity, responsible for Ado uptake in purine auxotrophs, during multiplication of amastigote within the
macrophage of hosts cannot be overlooked. Furthermore, in view of previous observation, that in stressed leishmanial cells retrograde translocation of LdCyP from the endoplasmic reticulum to cytoplasm is accompanied with increased uptake of Ado, makes it relevant. Hence, development of peptide-based antagonist as a tool to control the AdK activity might be a possible strategy to inhibit in vivo parasite multiplication. Studies on the molecular mechanism of AdK aggregation and the mechanism
by which LdCyP exerts its unique chaperone function to reactivate the activity by disrupting only the
ADP-induced aggregates and a detailed structural characterization and conformational analysis of the
two forms of the aggregates is therefore clearly important
Factor V Activator from Daboia russelli russelli Venom Destabilizes �-Amyloid Aggregate, the Hallmark of Alzheimer Disease*
No full textFormation of plaque by fibrils of �-amyloid (A�) peptide in
the brain is the characteristic feature of Alzheimer disease (AD).
Inhibition of the process of aggregate formation from A�-monomer
and destabilization of the aggregate could be useful for
prevention and propagation of the disease respectively. Russell’s
viper venom (RVV) contains protein(s) that destabilize A�
aggregates as revealed from the thioflavin T assay. The active
component was identified as factor V activator (RVV-V). Among
the possible mechanisms of destabilization, RVV-V-mediated proteolysis
was ruled out from mass spectrometric data and the thioflavinTassay.
The alternate hypothesis that small peptides derived
fromRVV-Vdestabilize the aggregate is better supported by experimental
results. Six small peptides were synthesized using RVV-V
as the template, and three unrelated peptides were synthesized to
serve as controls. Destabilization ofA� aggregate by these peptides
was studied using spectrofluorometric assays, atomic force
microscopy, transmission electron microscopy, and confocal
microscopy. Among the peptides, CTNIF and the mixture of
the six peptides were most potent in converting the aggregates
to the monomeric state and thus, preventing cytotoxicity
in SH-SY5Y human neuroblastoma cells. The control peptides
failed to show similar effects. Moreover, some of these
peptides are stable in blood for 24 h. Therefore, these venomderived
peptides offer an encouraging opportunity to prevent
amyloidosis and may provide information to combat A
Melatonin synergizes with low doses of L-DOPA to improve dendritic spine density in the mouse striatum in experimental Parkinsonism
No full textThe dopamine precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), is the preferred drug for Parkinson’s disease, but long-term treatment results in the drug-induced dyskinesias and other side effects. This study was
undertaken to examine whether melatonin could potentiate low dose L-DOPA effects in 1-methyl-4 phenyl-1,2,3,6- tetrahydropyridine (MPTP)-induced experimental parkinsonism. Mice were treated with the parkinsonian
neurotoxin, MPTP, and different doses of melatonin and low doses of L-DOPA. Behavior, striatal histology, and dopamine metabolism were evaluated on the 7th day. MPTP-induced striatal dopamine loss was not modified by melatonin administration (10–30 mg/kg; i.p. at 10-hr intervals, 6
times; or at 2-hr intervals, by day). However, low doses of L-DOPA (5 mg/kg, by oral gavage) administered alone or along with melatonin (10 mg/kg, i.p.) twice everyday for 2 days, 10 hr apart, after two doses of MPTP significantly
attenuated striatal dopamine loss and provided improvements in both catalepsy and akinesia. Additionally, Golgi-impregnated striatal sections showed preservation of the medium spiny neurons, which have been damaged
in MPTP-treated mouse. The results demonstrated that melatonin, but not L-DOPA, restored spine density and spine morphology of medium spiny neurons in the striatum and suggest that melatonin could be an ideal adjuvant
to L-DOPA therapy in Parkinson’s disease, and by the use of this neurohormone, it is possible to bring down the therapeutic doses of L-DOPA
Functional compensation of glutathione S-transferase M1 (GSTM1) null by another GST superfamily member,GSTM2
Get PDFThe gene for glutathione-S-transferase (GST) M1 (GSTM1), a member of the GST-superfamily, is widely studied in cancer risk with regard to the homozygous deletion of the gene (GSTM1 null), leading to a lack of corresponding enzymatic activity. Many of these studies have reported inconsistent findings regarding its association with cancer risk. Therefore, we employed in silico, in vitro, and in vivo approaches to investigate whether the absence of a functional GSTM1 enzyme in a null variant can be compensated for by other family members. Through the in silico approach, we identified maximum structural homology between GSTM1 and GSTM2. Total plasma GST enzymatic activity was similar in recruited individuals, irrespective of their GSTM1 genotype (positive/null). Furthermore, expression profiling using real-time PCR, western blotting,
and GSTM2 overexpression following transient knockdown of GSTM1 in HeLa cells confirmed that the absence of GSTM1 activity can be compensated for by the overexpression of GSTM
Delineation of Innate Immune Response of Vibrio Cholerae and its Outer Membrane Vesicles in an Epithelial Cell-Dendritic Co-Culture Model
No full textCholera remains a devastating bacterial cause of human morbidity and mortality in India and other developing countries. The disease is produced by a Gram-negative,
motile organism Vibrio cholerae that colonizes in the human intestine and secretes a potent cholera toxin, which ultimately stimulates cellular adenylate cyclase to cause
massive intestinal fluid loss leading to profuse watery diarrhea. To combat the disease from newly emerging threats, besides the study of organisms V. cholerae, a thorough understanding of the host response following V. cholerae infection and the response generated by bacterial components such as lipopolysaccharide, flagellar proteins, CT as well as outer membrane vesicles (OMVs) is indispensable. Such findings will eventually improve the present vaccine strains as well as design drugs for appropriate targets. Vibrio cholerae induces acute inflammatory response at intestinal epithelial surface; the underlying cellular immune mechanisms for such effects are largely unexplored. Mucosal immune response is controlled by the crosstalk between the intestinal epithelial cells (ECs) and dendritic cells (DCs). ECs act as a sensor for
current environmental conditions and release a variety of mediators which instruct nearby DCs accordingly. The present study has established for the first time an ECDC
co-culture model for V. cholerae infection. Our studies revealed that an ECderived cytokine thymic stromal lymphopoietin (TSLP) is highly elevated in ECs stimulated with V. cholerae and its recombinant flagellin (rFlaA). V. cholerae treated human ECs produce DC-attracting chemokine MIP-3α (CCL20). Flagellin, a potent V. cholerae factor was responsible for maximum stimulation of epithelial CCL20
production and subsequent DC activation. Activated DCs express high levels of costimulatory molecules and secrete inflammatory cytokines TNF-α, IL-6 and IL-1β. Bacteria stimulated ECs conditioned DCs to produce Th2 cell-attracting chemokines CCL17 and CCL22. TSLP and other mediators present in the V. cholerae stimulated
EC-culture filtrate potently activated DCs, which subsequently primed CD4+T cells to differentiate into T helper type 2 (Th2) cells that produce high amounts of IL-4, IL-13 and TNF-α and low IFN-γ. TSLP-induced proinflammatory response in DCs involved the transcriptional mechanisms, MAPKs (ERK1/2, p38 and JNK) and STAT3 activation. This study suggests TSLP and other mediators released from ECs in response to V. cholerae colonization actively influence DCs in initiating inflammatory
response. Another important component of V. cholerae is outer membrane vesicles or OMVs which are naturally produced bacterial vesicles. They are discrete, closed outer
membrane blebs having an average diameter of 10-300 nm with a bilayer membrane and electron-dense luminal content and consist only of the protein and lipids of OM and periplasm. The existence of OMVs has been demonstrated in a variety of Gramnegative bacteria. Our study for the first time demonstrates that a fraction of cholera toxin (CT), the major virulence factor of pathogenic V. cholerae is associated with the outer membrane vesicles (OMVs). Atomic force microscopy (AFM) and also transmission electron microscopy (TEM) of purified OMVs from toxigenic V.
cholerae O395 strain revealed spherical shaped vesicles of size range 20–200 nm. Immunoblotting of purified OMVs with polyclonal anti-CT antibody and GM1 ganglioside dependent ELISA suggests that CT is associated with OMVs. CHO cell
assay indicated that OMV associated CT is physiologically active. OMVs labelled with fluorescent dye interacted with intestinal epithelial cells via the CT-receptor and
were internalized increasing the cAMP level. Thus OMVs may represent an important vehicle in delivering CT to epithelial cells. In pathogenic bacteria, as OMVs are associated with a mixture of different pathogen associated molecular patterns (PAMPs) like LPS, peptidoglycan and with
toxins as in V. cholerae, these OMVs are expected to elicit host immune response.The present study evaluated the interaction of OMVs with intestinal epithelial cells
and with EC-DC co-culture. It was observed that, cytosolic pattern recognition receptor (PRR) NOD1 significantly upregulated in epithelial cells during OMV stimulation. In contrast, another PRR NOD2 expression was constitutive in nature and not up regulated upon OMV treatment. Therefore we sought to investigate the production of proinflammatory cytokines in response to V. cholerae O395 OMV stimulation in NOD1 dependent manner. We observed that vesicles induced
expression of proinflammatory cytokines such as IL-8 and GM-CSF, chemokines like CCL2, CCL20 and also TSLP in ECs through activation of ERK1/2 and p38 MAPK and NF-kB pathways in NOD1 dependent manner. ECs stimulated with OMVs
activate DCs in a direct co-culture system. DC activation was indicated by an increased number of cells expressing high levels of the activation markers HLA-DR,
Synopsis CD80 and CD83. Activated DCs express high levels of costimulatory molecules and released inflammatory cytokines IL-1β, IL-6, TNF-α, IL-23 and chemokines CCL22,
CCL17 and subsequently primed CD4+T cells leading to IL-4, IL-13 and IL-17 expression. It was observed that neutralizing of IL-23p19 caused a significant decrease in IL-17 production. These results suggest that V. cholerae O395 OMVs modulate the epithelial pro-inflammatory response and activate DCs which promoted the T cells polarization towards an inflammatory Th2/Th17 response. Thus the overall
study suggest that V. cholerae and its component outer membrane vesicle modulate epithelial function and induce dendritic cell mediated Th2/Th17 proinflammatory response and OMV act as a potent vehicle in delivering a percentage of cholera toxin to intestinal epithelial cells
Molecular Effects of Fatty Acid uptake and Regulatory Gene Products on Survival, Virulence and Motility of the Enteric Pathogen
No full textVibrio cholerae is the etiological agent of the diarrheal disease cholera. Expression of the major virulence factors of V. cholerae is controlled by the hierarchical expression of several regulatory proteins comprising the ToxR regulon which in turn is influenced by environmental parameters that promote optimal virulence induction in the pathogen. The objective of the present study was to elucidate the molecular basis for the hypo virulent phenotype of the fadD mutant. In this study we present evidence that a mutation in the fadD gene encoding a fatty acyl CoA ligase responsible for uptake and acylation of exogenous
fatty acids, has profound effects on the expression of virulence genes, motility and in vivo lethality of the human pathogen. The expression of major virulence genes ctxAB and tcpA was drastically repressed and a significant reduction in the expression of toxT, encoding a
cytoplasmic transcriptional activator of ctxAB and TCP operon was observed. Expression of toxT is activated by the synergistic effect of two membrane bound transcription factors ToxR and TcpP. Western blot analysis indicated that although ToxR production and membrane localisation remains unaltered in the V. cholerae fadD mutant, membrane localisation of TcpP is severely impaired, suggesting a direct correlation between reduced toxT expression
and defective membrane localisation of TcpP. In response to the extracytoplasmic stress, the integral membrane protease RseP is known to be activated and degrades TcpP. Indeed,
disruption of the rseP gene in a fadD mutant background restored membrane localization of TcpP and expression of the downstream virulence genes toxT, ctxA, and tcpA in addition to increased expression of σE regulon genes. Increased expression of the σE regulon genes in
ethanol-treated wild-type V. cholerae indicated that ethanol exposure could induce an extracytoplasmic stress response in V. cholerae. Ethanol treatment also led to activation of the RseP protease activity and resulted in degradation of membrane localized TcpP and
subsequent reduction in expression of the virulence genes. Taken together, these results suggest that extracytoplasmic stress response per se reduces virulence of V. cholerae by
impairing membrane localization of TcpP
A Biophysical Approach To Identify Active Sites Of Isolated Pure Herbal Compounds And Cell Signaling In Cancers
No full textNatural compounds have exerts promising outcomes in cancer therapy for decades.
These compounds provided several leads molecule, which are subsequently used in the
blueprint of drug development in cancer treatment. For the search of lead compounds, we have
selected a few medicinal plants from the various parts of our country. Barringtonia Racemosa
has been used as traditional medicine for the treatment of various diseases. Anti-tumor
property of the seed extract in mice model prompted us to search for the active component
present in fruit extract. Quercetin 3-O-rutinoside (QOR) was isolated from the fruits of this
plant and quantified by HPLC method. The compound was identified by IR, Mass, NMR (1D, 2D)
spectral data analysis. QOR showed dose and time dependent anti-proliferative activity in
several leukemic cell lines with negligible effect on normal human PBMC.
Additionally, another Indian medicinal plant, curcuma caesia was selected for the
identification of the active compound present in the plant material. Bio-active guided
fractionation helped us in identification of an active compound present as (1s, 4s, 5s, 10R)-
Zedoarondiol in the root extract. It showed cytotoxicity against different cancer cell lines.
Next, Mahanine isolated from Murraya Koengii has been established as a potent anticancer
molecule against different cancer including NSCLC. Even at early dose, mahanine
inhibited phosphorylation of mTOR and also the total protein effectively in lower dose and as
consequent events, inhibition of p70S6K and AKT were observed in NSCLC. To identify the
active functional groups of mahanine responsible for biological activity, structure-activity
relation was determined. Accordingly, -OH at C-7 and -NH were chemically modified. The
concentration dependent anti-proliferative activity of mahanine and its four derivatives in an
array of nineteen different cell lines from seven different types of cancers revealed that both C-
7-OH and NH groups are active functional groups responsible for its biological activity. Using
several biophysical techniques we established that complexation of mahanine with DNA is
minor groove bound conformation with high binding efficacy. These findings will help to design
potent anti-cancer agent, which may be helpful for the development of target specific efficient
drug