Namasivayam Elangovan

Specific versus Non-Specific Immune Responses in an Invertebrate Species Evidenced by a Comparative de novo Sequencing Study

Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5′-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5′-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.

Taxifolin mitigates oxidative DNA damage in vitro and protects zebrafish (Danio rerio) embryos against cadmium toxicity

Taxifolin (TAX) is a natural source of bioflavonoid found in various conifers. In this study, initially we investigated the antioxidant potential of TAX under in vitro assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), ferric-ion reducing power (FRAP) and hydroxyl radical (OH). The activities of DPPH, ABTS, FRAP and OH radical levels were significantly inhibited by TAX with an IC50 values of 16.48, 66.34, 18.17 and 11.42μg/ml, respectively. Secondly, TAX exhibited a strong protection against OH mediated DNA damage on pUC19 plasmid DNA at 1.0μg/ml. Finally, we evaluated the protective mechanism of TAX against cadmium intoxicated zebrafish embryos (Danio rerio). We found that embryos exposed to 100μM Cd exhibited significantly reduced survival, delayed hatching and phenotypic abnormalities at 24, 48, 72 and 96hours post fertilization (hpf). Similarly, Cd intoxicated embryos showed significantly increased cardiac function (131beats/min) at 60hpf. Conversely, treatment with TAX (0.1, 1.0 and 10μM) significantly enhanced the antioxidant enzyme levels (SOD, CAT, GPx and GR) by reducing the lipid peroxidation (MDA) in zebrafish embryos. Collectively, our results concluded that TAX could act as a potent redox scavenger against oxidative DNA damage and also functions as a crucial suppressor of Cd toxicity in zebrafish embryos.

Taxifolin curbs NF-κB-mediated Wnt/β-catenin signaling via up-regulating Nrf2 pathway in experimental colon carcinogenesis

Aberrations in homeostasis mechanisms including Nrf2, inflammatory, and Wnt/β-catenin signaling are the major causative factors implicated in colon cancer development. Hence blocking these pathways through natural interventions pave a new channel for colon cancer prevention. Earlier, we reported the chemopreventive effect of taxifolin (TAX) against colon carcinogenesis. In this study, we aimed to understand the ability of TAX, to modulate the Nrf2, inflammatory and Wnt/β-catenin cascades on 1, 2-dimethyl hydrazine (DMH)-induced mouse colon carcinogenesis. In addition, in silico molecular docking studies were performed to evaluate the binding affinity between TAX and target proteins (Nrf2, β-catenin, and TNF-α). We perceived that the increase of serum marker enzyme levels (CEA and LDH) and mast cell infiltration that occurs in the presence of DMH is inverted after TAX treatment. Immunoblot expression and docking analysis revealed that TAX could induce antioxidant response pathway, confirming the enhanced level of Nrf2 protein. It also inhibited NF-κB and Wnt signaling by down-regulating the levels of regulatory metabolites such as TNF-α, COX-2, β-catenin, and Cyclin-D1. Collectively, results of our hypothesis shown that TAX is an effective chemopreventive agent capable of modulating inflammatory, Wnt and antioxidant response pathway proteins in tumor microenvironment which explicating its anticancer property.

CNB-001 a Novel Curcumin Derivative, Guards Dopamine Neurons in MPTP Model of Parkinson’s Disease

Copious experimental and postmortem studies have shown that oxidative stress mediated degeneration of nigrostriatal dopaminergic neurons underlies Parkinsons disease (PD) pathology. CNB-001, a novel pyrazole derivative of curcumin, has recently been reported to possess various neuroprotective properties. This study was designed to investigate the neuroprotective mechanism of CNB-001 in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) rodent model of PD. Administration of MPTP (30 mg/kg for four consecutive days) exacerbated oxidative stress and motor impairment and reduced tyrosine hydroxylase (TH), dopamine transporter, and vesicular monoamine transporter 2 (VMAT2) expressions. Moreover, MPTP induced ultrastructural changes such as distorted cristae and mitochondrial enlargement in substantia nigra and striatum region. Pretreatment with CNB-001 (24 mg/kg) not only ameliorated behavioral anomalies but also synergistically enhanced monoamine transporter expressions and cosseted mitochondria by virtue of its antioxidant action. These findings support the neuroprotective property of CNB-001 which may have strong therapeutic potential for treatment of PD.

CNB-001, a novel pyrazole derivative mitigates motor impairments associated with neurodegeneration via suppression of neuroinflammatory and apoptotic response in experimental Parkinson’s disease mice

Parkinsons disease (PD) is characterized by the progressive degeneration via apoptosis of nigrostriatal dopaminergic neurons associated with inflammation, resulting in behavioral anomalies. Therefore, an anti-apoptotic and anti-inflammatory regimen may be useful in treatment of PD. CNB-001, a novel pyrazole derivative of curcumin and cyclohexyl bisphenol A has superior biological properties than its parental compounds. The present study utilizes a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD to investigate anti-inflammatory and anti-apoptotic mediated neuroprotection of CNB-001. The administration of MPTP (30 mg/kg for four successive days) significantly induced motor impairments as determined by behavioral studies (narrow beam test, catalepsy and akinesia), lowered dopamine levels and up-regulated the expressions of the inflammatory and apoptotic markers (tumor necrosis factor-alpha, interleukin-1β, interleukin-6, inducible nitric oxide synthase, glial fibrillary acidic protein, cyclooxygenase-2 and Bax). Moreover, MPTP treatment attenuated Bcl-2 and nigrostriatal dopamine transporter expression and also increased total nitrite and citrulline levels in comparison to the control group. However, co-treatment with CNB-001 significantly attenuated motor impairments and pathological changes caused by MPTP administration. Collectively, our results demonstrate that CNB-001 is neuroprotective through its anti-inflammatory and anti-apoptotic properties. Thus, CNB-001 has potential to be further developed as a therapeutic candidate for treatment of PD.

Characterization of multifarious plant growth promoting traits of rhizobacterial strain AR6 under Chromium (VI) stress

Plant growth promoting rhizobacteria (PGPR) can increase the host plant tolerance to cope up with heavy metal induced stress, which can be improve plant growth. Thus, the present study was designed to isolate Cr(VI) tolerant PGPR strain and evaluate its plant growth promoting (PGP) properties under Cr(VI) stress. Rhizobacterial strain AR6 was isolated from the rhizosphere of Phaseolus vulgaris L. and showed 99% homology with Cellulosimicrobium funkei (KM032184) in BLASTn analysis. Strain AR6 was specifically selected due to its high Cr(VI) tolerance (1200μg/ml) and substantial production of PGP substances. Strain AR6 produced 36.75μg/ml of indole acetic acid (IAA), 60.40μg/ml of ammonia and 14.23μg/ml of exopolysaccharide (EPS). Moreover, strain AR6 showed positive results for catalase, protease, amylase, lipase production and phosphate solubilization. A trend of Cr(VI) concentration dependent progressive decline for PGP traits of strain AR6 was observed excluding EPS which was regularly increased on increasing concentrations of Cr(VI). Among the four tested Cr(VI) concentrations, 250μg/ml showed the maximum toxicity to PGP activities of strain AR6. Inoculation of rhizobacterial strain AR6 significantly increased the root length of test crops in the presence of Cr(VI) and produced a considerable number of colonizes on the root of versatile dicot and monocot plants. Moreover, strain AR6 exhibited strong antagonistic activity against phytopathogen Aspergillus niger. Thus, the present study suggests that metal tolerant and PGP activities of the rhizobacterial strain AR6 could be exploited for environmental and agricultural issues.

Waste-to-biofuel: production of biobutanol from sago waste residues

ABSTRACT The main concern of extensive production of biobutanol has been associated with the high cost of the substrate and the relatively low tolerance of Clostridia to biobutanol production. In this study, the use of fermentable cassava waste residue (CWR) as substrate for biobutanol production was investigated using solvent-tolerant Clostridium sp. Four of obligatory, solvent-producing bacteria were isolated from sago industry waste sites. The NSW, PNAS1, SB5 and SBI4 strains showed identical profiles of 16S rRNA gene sequence similarity of Bacillus coagulans, Clostridium bifermentans and Clostridium sp. (97% similarity) and a wide range of carbohydrate substrate; however, the CWR was found to be suitable for the production of biobutanol considerably. Batch culture study was carried out using parameters such as time and temperature and carbon sources have been studied and optimized. Using pre-optimized CWR medium, significant amount of solvent production was observed in NSW, PNAS1, SB5 and SBI4 with 1.53, 3.36, 1.56 and 2.5 g L−1of butanol yield and 6.84, 9.012, 8.32 and 8.22 g L−1of total solvents, respectively. On the basis of these studies, NSW is proposed to represent the B. coagulans for butanol production directly from sago waste residues.

The Roads to Mitochondrial Dysfunction

Mitochondria are the major site of ATP production in animal cells. The proton gradient obtained via electron transport and proton pumping in the electron transport chain is utilized by complex V to produce ATP. However, this elaborated system is prone to the electron leak that serves as the main source of superoxide anion radical (O2−∙). Additionally, other reactive species and free radicals may be produced through reactions catalyzed by antioxidant enzymes, such as superoxide dismutase, which produces H2O2 from O2−∙. An intrinsic way that leads to mitochondrial dysfunction is an increased production of reactive oxygen or nitrogen species and free radicals within this organelle. Also, other stimuli, such as presence of toxicants, protein aggregates, and stress on other organelles (as, for instance, endoplasmic reticulum stress), affect mitochondrial function and may induce mitochondrial swelling and/or mitochondrial permeability transition pore formation, which is an initial step to apoptosis. In fact, mitochondrial dysfunction at high rates is the major cause of cell death in a myriad of diseases and during aging. In this special issue, the details of the dysfunction in electron transport chain and/or respiration are analyzed in three studies. V. Jeger et al. looked at the effects of an exposure to bacterial endotoxin, also known as lipopolysaccharide in hepatic cell line HepG2 and in primary hepatocytes, as well as on mitochondria isolated from quadriceps muscle of pigs. Interestingly, the effects of LPS varied depending on the biological system analyzed. In any case, it seems that LPS is capable of affecting mitochondrial function through altering either mitochondrial membrane potential or respiration. T. Boczek et al. studied the effects of silencing plasma membrane Ca2+-ATPase isoforms 2 and 3 on energy metabolism in PC12 cells during differentiation. The researchers found that alterations in the amounts of these types of the protein pump perturb energy-generating pathways and mitochondrial activity. The researchers found that alterations in the level of such protein pump altered energy-generating pathways in order to maintain ATP homeostasis. This may be linked to the role of such proteins in controlling Ca2+ ions concentration within a physiological range during neuronal differentiation. J. R. Macarini et al. investigated the effects of carnosine on mitochondrial function isolated from rat skeletal muscle. They found that only acute carnosine exposition altered mitochondrial function. This is an important finding since there is accumulation of carnosine in carnosinase deficiency, a disease that affects several human tissues. Z. Hu and J. Tu investigated mitochondrial function in an experimental model of posttraumatic syringomyelia. The researchers found that the decrease in mitochondrial ATP outputs and other metabolic scores associated with the degree of mitochondrial impairment are the primary contributors to glutamate neurotoxicity that, in turn, may lead to necrosis and enlargement of the cavity in the model of posttraumatic syringomyelia. Importantly, if the mitochondrial damage was reversible, as it was observed in mechanical laminectomy model, the neuronal cell death was reversible as well. This observation explains why no cavity forms after laminectomy and places mitochondrial dysfunction at the heart of the posttraumatic neuronal recovery. In their review paper, J. Su et al. analyzed the crosstalk between endoplasmic reticulum stress and mitochondrial dysfunction in tumors during the development of chemotherapy resistance and provided systematic evidence that this crosstalk is mediated by activities of Bcl-2 family of the proteins. Two papers of this special issue deal with the variation of mitochondrial function in human populations. D. A. Chistiakov et al. performed a thorough review of mitochondrial aging and mitochondrial dysfunction in elderly age and the strategies of attenuating the age-related phenotype in humans, while I. A. Sobenin et al. reviewed techniques that help to reliably investigate levels of heteroplasmy of mitochondrial mutations in a variety of diseases, including those associated with aging. Finally, A. Panov et al. point that the neuronal mitochondria that are capable of simultaneous utilization of several substrates, including various neuromediators, in particular, glutamate and GABA, supplied neurons with astroglia. Authors reconcile β-oxidation of fatty acids by astrocytic mitochondria with the regulation of aerobic glycolysis and provided experimental evidence that isolated neuronal mitochondria may oxidize palmitoyl carnitine in the presence of other mitochondrial substrates. Altogether, this eclectic collection of papers reflects various aspects of the current understanding of the interplay between the functioning of the mitochondrial genome, the components of respiratory chain it encodes, and the mutual influences of the mitochondria and the cell and discusses potential impact of the mitochondrial dysfunction on some health conditions. There is a hope that an increase in understanding of molecular mechanisms of mitochondrial dynamics may lead to new therapeutic approaches for the prevention or amelioration of the diseases associated with ailing mitochondria. Marcos Roberto de Oliveira Namasivayam Elangovan Marko Ljubkovic Ancha Baranova

In vitro antioxidant potential and deoxyribonucleic acid protecting activity of CNB-001, a novel pyrazole derivative of curcumin

Background: Free radicals are underpinned to initiate cascade of toxic events leading to oxidative stress and resultant cell death in many neurodegenerative disorders. Now-a-days antioxidants have become mandatory in the treatment of various diseases apart from the drugs modes of action. CNB-001, a novel hybrid molecule synthesized by combining curcumin and cyclohexyl bisphenol A is known to possess various biological activities, but the antioxidative property of the compound has not yet been elucidated. Aim: The present study is aimed to analyze various free radicals scavenging by employing in vitro antioxidant assays and to evaluate the deoxyribonucleic acid (DNA) protecting the ability of CNB-001 against hydroxyl radicals. Materials and methods: The in vitro antioxidant potential of CNB-001 was evaluated by analyzing its ability to scavenge DPPH, ABTS, nitric oxide, superoxide, hydrogen peroxide, superoxide anion, hydroxyl, hydrogen peroxide radicals and reducing power using spectroscopic method. The DNA protecting activity of CNB-001 was also evaluated on pUC19 plasmid DNA subjected to hydroxyl radicals using standard agarose gel electrophoresis. Results: From the assays, it was observed that CNB-001 scavenged free radicals effectively in a dose dependent manner. CNB-001 scavenged 2,2-diphenyl-1-picrylhydrazyl (IC50 = 44.99 μg/ml), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 17.99 μg/ml), nitric oxide (IC50 = 1.36 μg/ml), superoxide radical (IC50 = 77.17 μg/ml), hydrogen peroxide (IC50 = 492.7 μg/ml), superoxide (IC50 = 36.92 μg/ml) and hydroxyl (IC50 = 456.5 μg/ml) radicals effectively and the reducing power was found to be 11.53 μg/ml. CNB-001 showed considerable protecting activity against plasmid DNA (pUC19) strand scission by •OH at dose dependent manner. Conclusion: Results from these assays concluded that CNB-001 has a good antioxidant potential by reducing reactive oxygen and reactive nitrogen radicals and it showed significant protecting activity against DNA scission by hydroxyl radicals. Hence, CNB-001 can be further developed as potential drug for free radical induced neurodegenerative disorders.

Isolongifolene Attenuates Oxidative Stress and Behavioral Impairment in Rotenone-Induced Rat Model of Parkinson’s Disease

Introduction: Parkinson’s disease (PD) is a progressive age-related disease, in which dopaminergic neurons in the nigrostriatal pathway are destroyed, resulting in movement and behavioral impairment. Oxidative stress and the generation of reactive oxygen species play a key role in the progression and pathology of neurodegenerative diseases such as PD. Rotenone is a common pesticide that induces PD through the generation of oxidative stress. Isolongifolene (ILF), a tricyclic sesqueterpene of Murraya koenigii, has antioxidant and neuroprotective effects. The current study was aimed to investigate the effect of ILF against oxidative stress and movement impairment on rotenone-induced rat model of PD. Materials and Methods: Biochemical measures, including the activities of catalase, glutathione peroxidase (GPx), superoxide dismutase (SOD) and the levels of reduced glutathione (GSH) and lipid peroxidation products [thiobarbituric acid reactive substances (TBARS) and behavioral analysis (hang and catalepsy test) were performed. Results: The muscle strength and cataleptic score of the ILF co-treated groups were significantly improved. Treatment with ILF prevented the increases in the levels of TBARS, significantly improved the SOD, catalase, GPx activities, and GSH levels. Conclusion: These findings suggested that ILF has neuroprotective properties through its potent antioxidant activities.