Synthesis, crystal structure, thermal stability and biological study of bis{(2-methoxy-6-[(E)-(propylimino)methyl]phenolato}nickel(II) complex

A Schiff base complex of nickel, bis{(2-methoxy-6-[(E)-(propylimino)methyl]phenolato}nickel(II) was synthesised by condensing bis(2-hydroxy-3-methoxybenzaldehyde) nickel (II) and n-propylamine in methanolic medium. Single crystal X-ray diffraction analysis of the complex revealed it to possess planar geometry with a monoclinic crystal system. The non-isothermal TG/DTA runs on this complex in a high purity (99.99 %) nitrogen environment at atmospheric pressure confirmed the absence of any coordinated water. A sharp endotherm in its DTA shows a melting temperature range of 168-171 °C. It is thermally stable up to 243 °C and decomposes in two steps, yielding NiO and carbon as residue. In addition to the methoxy group (-OCH3), infrared analysis (IR) confirmed the presence of the characteristic azomethine group (-C[bond, double bond]N-) which is also responsible for the biological action. It was further analysed by elemental analyser (C, H, N), 1H and 13C NMR as well as mass spectrometry. It showed considerable antibacterial activity towards Escherichia coli and Staphylococcus aureus when the concentration exceeds 200 μg/ml. The antifungal study shows significant inhibition with the antifungal drug imidazole as a positive control (PC). Small values of MIC, MBC/MIC indicate a lesser quantity of complex is required to inhibit the growth of micro-organisms.

Monoamine oxidase mediated oxidative stress: a potential molecular and biochemical crux in the pathogenesis of obesity

Obesity has become a global health concern with an increasing prevalence as years pass by but the researchers have not come to a consensus on the exact pathophysiological mechanism underlying this disease. In the past three decades, Monoamine Oxidases (MAO), has come into limelight for a possible involvement in orchestrating the genesis of obesity but the exact mechanism is not well elucidated. MAO is essentially an enzyme involved in the catabolism of neurotransmitters and other biogenic amines to form a corresponding aldehyde, hydrogen peroxide (H2O2) and ammonia. This review aims to highlight the repercussions of MAO's catabolic activity on the redox balance, carbohydrate metabolism and lipid metabolism of adipocytes which ultimately leads to obesity. The H2O2 produced by these enzymes seems to be the culprit causing oxidative stress in pre-adipocytes and goes on to mimic insulin's activity independent of its presence via the Protein Kinase B Pathway facilitating glucose influx. The H2O2 activates Sterol regulatory-element binding protein-1c and peroxisome proliferator activated receptor gamma crucial for encoding enzymes like fatty acid synthase, acetyl CoA carboxylase 1, Adenosine triphosphate-citrate lyase, phosphoenol pyruvate carboxykinase etc., which helps promoting lipogenesis at the same time inhibits lipolysis. More reactive oxygen species production occurs via NADPH Oxidases enzymes and is also able activate Nuclear Factor kappa B leading to inflammation in the adipocyte microenvironment. This chronic inflammation is the seed for insulin resistance.

Exploring the molecular interactions and binding affinity of resveratrol and calcitriol with RAGE and its intracellular proteins and kinases involved in colorectal cancer

Colorectal cancer (CRC) burden is progressively increasing in young population due to dietary and lifestyle pattern. Advanced glycation end products (AGEs), one of the dietary compounds, form complex aggregates with proteins, lipids, and nucleic acids distorting their structure and function. AGE's pro-tumorigenic role is mediated through the receptor for AGEs (RAGE) triggering an array of signaling pathways. The current study aimed to target AGE-RAGE axis signaling proteins and kinases at multiple levels with calcitriol (CAL) and trans-resveratrol (RES) through in silico analysis using molecular docking (MD), molecular dynamic simulation(MDS), MM-PBSA analysis, and in vitro study. In silico analysis of CAL and RES showed significant binding affinity toward RAGE and its signaling proteins such as NF-kB, PI3K/AKT, ERK1/2, and PKC compared to its reference inhibitors through better hydrogen, hydrophobic, pi-pi stacking interactions. MD and MDS studies have revealed stable and compact protein-ligand complexes. Binding free energies of protein-ligand complex were estimated using MM/PBSA analysis thatprovided an assessment of overall interacting free energies of complexes and revealed the presence of low binding energy within the active site. Furthermore, in the in vitro study, methylglyoxal (MG), an AGE-precursor showed a proliferative effect on HCT116, however, CAL and RES showed an inhibitory effect against MG induced effect with an IC50 value of 51 nM and 110 µM respectively. Thus, the study suggests the possible target binding sites of AGE-RAGE signaling proteins and kinases with CAL and RES, thereby exploiting it for developing CAL with RES as adjuvant therapy along with chemo drug for CRC.Communicated by Ramaswamy H. Sarma.

Sinapic acid prevents adipogenesis by regulating transcription factors and exerts an anti-ROS effect by modifying the intracellular anti-oxidant system in 3T3-L1 adipocytes

Objectives

In this study, we tested the hypothesis that sinapic acid (SA), a naturally occurring hydroxycinnamic acid found in vegetables, cereal grains, and oilseed crops with various biological activities suppresses adipogenesis in 3T3-L1 adipocytes by down-regulating adipogenesis transcription factor.

Materials and Methods

3T3-L1 adipocytes were treated with SA and evaluated by Oil Red O staining, triglyceride estimation, lipolysis, and reverse transcription-polymerase chain reaction. 3T3-L1 adipocytes were treated with various concentrations of SA (100 to 1000 μmol) during differentiation.

Results

SA prevented an increase in adipocytes by reducing preadipocyte clonal expansion. ORO staining analyses revealed that SA reduced cytoplasmic lipid droplet accumulation in 3T3-L1 by 57% at the highest concentration of 1000 μmol without affecting cell viability. Furthermore, SA down-regulated the expression of peroxisome proliferator-activated receptor-gamma, CCAAT/enhancer-binding protein alpha, sterol regulatory element-binding protein 1c, and fatty acid synthase. ROS generated during adipogenesis was also attenuated by SA treatment by increasing antioxidant enzymes superoxide dismutase, catalase, and the cellular antioxidant glutathione. SA demonstrated no in vivo toxicity in the Drosophila melanogaster model.

Conclusion

These results suggest that SA exerts anti-oxidant and anti-adipogenic effects and could be used as a functional nutraceutical ingredient in combatting obesity-related diseases.

Genotyping by sequencing-based linkage map construction and identification of quantitative trait loci for yield-related traits and oil content in Jatropha (Jatropha curcas L.)

BACKGROUND

Jatropha (Jatropha curcas L.) has been considered as a potential bioenergy crop and its genetic improvement is essential for higher seed yield and oil content which has been hampered due to lack of desirable molecular markers.

METHODS AND RESULTS

An F₂ population was created using an intraspecific cross involving a Central American line RJCA9 and an Asiatic species RJCS-9 to develop a dense genetic map and for Quantitative trait loci (QTL) identification. The genotyping-by-sequencing (GBS) approach was used to genotype the mapping population of 136 F₂ individuals along with the two parental lines for classification of the genotypes based on single nucleotide polymorphism (SNPs). NextSeq 2500 sequencing technology provided a total of 517.23 million clean reads, with an average of ~ 3.8 million reads per sample. We analysed 411 SNP markers and developed 11 linkage groups. The total length of the genetic map was 4092.3 cM with an average marker interval of 10.04 cM. We have identified a total of 83 QTLs for various yield and oil content governing traits. The percentage of phenotypic variation (PV) was found to be in the range of 8.81 to 65.31%, and a QTL showed the maximum PV of 65.3% for a total seed number on the 6th linkage group (LG).

CONCLUSIONS

The QTLs detected in this study for various phenotypic traits will lay down the path for marker-assisted breeding in the future and cloning of genes that are responsible for phenotypic variation.

Enhanced Inhibition of Adipogenesis by Chrysin via Modification in Redox Balance, Lipogenesis, and Transcription Factors in 3T3-L1 Adipocytes in Comparison with Hesperidin

OBJECTIVE

The present study was conducted to elucidate the in-vitro anti-oxidant and anti-adipogenic effect of the flavone, chrysin in comparison with the citrus bioflavonoid, hesperidin during adipogenic differentiation in 3T3-L1 mouse preadipocytes.

METHODS

The effect of chrysin and hesperidin on adipogenic differentiation was evaluated using Oil red-O staining, triglyceride estimation, free glycerol release, and ROS accumulation. The expression of adipogenesis-related genes was evaluated in real time-polymerase chain reaction.

RESULTS

50 µmol chrysin or hesperidin did not affect the cell viability of 3T3-L1 preadipocytes and adipocytes, but significantly reduced preadipocyte clonal population, accumulation of intracellular lipid and ROS and consequently increased lipolysis and antioxidant enzyme defence. It also decreased the expression of major adipogenic transcription factors, CCAAT/enhancer-binding protein-β, peroxisome proliferator activated receptor-γ, sterol regulatory element binding protein 1c, fatty acid synthase and hormone sensitive lipase.

CONCLUSION(S)

Herein we have indicated, for the first time, the effective anti-adipogenic mechanism of chrysin by down-regulating adipogenesis, lipogenesis and ROS and up-regulating lipolysis and antioxidant enzyme in differentiated 3T3-L1 adipocytes. As a nutritional bioflavonoid, chrysin with its more effective inhibition on adipogenesis than hesperidin has the potential to be developed as an anti-adipogenic nutraceutical agent.

Attenuation of tacrolimus induced oxidative stress, mitochondrial damage, and cell cycle arrest by Boerhavia diffusa root fraction in mdck cell lines

OBJECTIVES

The protective effect of ethyl acetate fraction (EAF) of Boerhavia diffusa roots against Tacrolimus (TAC) induced nephrotoxicity was studied using MDCK cell lines.

MATERIALS AND METHODS

Ethanolic root extract of B. diffusa was fractionated using the liquid-liquid partition method. The cytotoxic effect of TAC and protective effect of EAF co-treatment were studied in MDCK cell lines by measuring ROS, LPO, and NO levels; collagen accumulation, effect on mitochondrial membrane integrity and cell cycle analysis were studied. The active component in EAF was quantified by HPLC analysis.

RESULTS

TAC induced toxicity, leading to apoptosis and necrosis, was significantly reduced (P<0.001) in EAF co-treatment, with reversal of cell cycle arrest and reduced cell population at sub G0/G1 phase. Further, ROS (P<0.05), LPO and NO (P<0.001), were significantly reduced with EAF co-treatment compared with TAC individually treated cells. TAC induced mitochondrial membrane integrity loss was found to be significantly reduced in co-treated cells, as measured by rhodamine123 (P<0.05) and translocation of cytochrome c (P<0.001) from nucleus to cytoplasm, and caspase 3 release (P<0.001). The same was confirmed through annexin-FITC and PI staining (P<0.05) with reduced apoptotic and necrotic death in co-treated population. Interestingly, EAF co-treatment decreased collagen accumulation (P<0.001) with significant increase in the cell survival of tubular epithelial cells. HPLC analysis showed the presence of Quercetin (87.5 mg/g) in EAF, which may be responsible for the nephroprotective role.

CONCLUSION

Thus, these results provide sound evidence that EAF may be an effective adjuvant therapy to prevent nephrotoxicity induced by TAC.

3,5-Dimethoxy-4-benzoic acid (syringic acid) a natural phenolic acid reduces reactive oxygen species in differentiated 3T3-L1 adipocytes

Preadipocytes under nutrient excess mature to lipid-laden adipocytes that are hotspots for generation of reactive oxygen species (ROS) imbalance and oxidative stress. Syringic acid (SA), a natural phenolic acid, was evaluated for its in vitro antioxidant and ROS modulation during in matured 3T3-L1 adipocytes. Following 10 d, the SA-treated adipocytes were evaluated for the levels of glutathione (GSH) and antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT). The levels of peroxides in mature adipocytes were estimated using dichlorofluorescein (DCF) cleavage fluorescence. The level of NADPH oxidase 4 (NOX4) expression was also investigated following 10-d differentiation period. SA significantly improved the levels of GSH, SOD, and CAT in matured adipocytes. Reduction in ROS production levels was also witnessed by decrease in DCF cleavage. SA showed concentration-dependent inhibition of NOX4 by day 7 of adipogenesis when compared with differentiated and undifferentiated cells. Moreover, SA exhibited effective antioxidant and anti-radical scavenging activity. These results suggest that SA in addition to inhibiting adipogenesis can strongly reduce ROS stress in mature adipocytes by upregulating levels of intracellular antioxidants and decreasing levels of NOX4 in 3T3-L1 adipocytes.

Cellular growth factors as prospective therapeutic targets for combination therapy in androgen independent prostate cancer (AIPC)

Cancer is the second leading cause of death worldwide, with prostate cancer, the second most commonly diagnosed cancer among men. Prostate cancer develops in the peripheral zone of the prostate gland, and the initial progression largely depends on androgens, the male reproductive hormone that regulates the growth and development of the prostate gland and testis. The currently available treatments for androgen dependent prostate cancer are, however, effective for a limited period, where the patients show disease relapse, and develop androgen-independent prostate cancer (AIPC). Studies have shown various intricate cellular processes such as, deregulation in multiple biochemical and signaling pathways, intra-tumoral androgen synthesis; AR over-expression and mutations and AR activation via alternative growth pathways are involved in progression of AIPC. The currently approved treatment strategies target a single cellular protein or pathway, where the cells slowly develop resistance and adapt to proliferate via other cellular pathways over a period of time. Therefore, an increased research aims to understand the efficacy of combination therapy, which targets multiple interlinked pathways responsible for acquisition of resistance and survival. The combination therapy is also shown to enhance efficacy as well as reduce toxicity of the drugs. Thus, the present review focuses on the signaling pathways involved in the progression of AIPC, comprising a heterogeneous population of cells and the advantages of combination therapy. Several clinical and pre-clinical studies on a variety of combination treatments have shown beneficial outcomes, yet further research is needed to understand the potential of combination therapy and its diverse strategies.

In silico docking of phytocompounds to identify potent inhibitors of signaling pathways involved in prostate cancer

Androgens and androgen receptors (AR) are the master regulators in the development of prostate cancer. Majority of the patients show positive response to surgical or medical castration, while many patients show disease relapse after the treatment. Genomic profiling has proven that the deregulated PI3K, Ras/Raf, MAPK and EGFR signaling pathways confer survival and invasion advantage to the cancer cells. Thus, modulation of these interlinked growth pathways along with androgen ablation may provide attractive therapeutic benefits. The current research is focused to identify the inhibitors of these pathways with bacosides and Piperine. The quantitative estimation of bacosides enriched standard extract of Bacopa monnieri by HPTLC showed 59.38% of Bacoside A and various active compounds with anti-oxidant, anti-cancer, anti-microbial, anti-inflammatory properties were also analyzed by GC-MS analysis. The in-vitro cytotoxic study against PC3 cell lines showed dose-dependent effect of Piperine and the extract. Further, in silico docking has shown bacosides with significant molecular interactions and binding score with growth factor receptors such as EGFR, PI3K, Akt and ERK, whereas Piperine exhibited interactions with AR. Hence, a simultaneous downregulation of interlinked signaling pathways of growth factors and AR with bacosides and Piperine may produce effective cytotoxic potential against the androgen-independent prostate cancer. Further in-vitro and in-vivo experimental investigations are necessary to determine the ultimate therapeutic utility. Communicated by Ramaswamy H. Sarma.

Phytofabricated silver nanoparticles: Discovery of antibacterial targets against diabetic foot ulcer derived resistant bacterial isolates

The present study selected the predominant multi antibiotic-resistant diabetic foot ulcer (DFU) derived bacterial isolates such as Pseudomonas aeruginosa (PA), Escherichia coli (EC), Staphylococcus aureus (SA) and Bacillus subtilis (BS) and evaluated their response against the well-characterized Aerva lanata (AL) reduced multiple phytochemicals fabricated silver nanoparticles (AL-AgNPs). The overnight culture of DFU isolates was processed and subjected to various studies such as antimicrobial activity, growth kinetics, biofilm disruption, reactive oxygen species (ROS), membrane leakage, membrane permeability, and damage and genotoxicity. The molecular docking of AL phytochemicals was also performed with bacterial enzyme DNA gyrase. Interestingly, AL-AgNPs were produced the remarkable antibacterial effect against the resistant DFU isolates, which was closely similar to the effect of AL-AgNPs observed against the reference strains. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AL-AgNPs against the DFU isolates were found to be 5-15 μg/mL and 10-20 μg/mL, respectively. The AL-AgNPs were depicted a concentration-dependent growth inhibition of DFU bacterial isolates. The MIC and MBC of AL-AgNPs were effectively destroyed the preformed biofilms of DFU isolates. Furthermore, the MBC of AL-AgNPs was displayed the increased intracellular ROS accumulation, membrane leakage, permeability and damage, and genotoxicity in the DFU isolates. Additionally, the in silico study revealed that the AL phytochemicals were fitted over the binding pocket of the DNA gyrase B subunit. The observed results were confirmed that the negative impacts of the AL-AgNPs at the level of the membrane and intracellular components of DFU isolates.

Development of genome wide transposable elements based repeat junction markers in Jatropha (Jatropha curcas L.)

Jatropha curcas is a potential biodiesel crop and a highly adaptable species to various agro-climatic conditions. In this study, we have utilized transposable elements' (TE) repeat junctions (RJs) which are an important constituent of the genome, used to form a genome-wide molecular marker platform owing to its use in genomic studies of plants. We screened our previously generated Jatropha hybrid genome assembly of size 265 Mbp using RJPrimers pipeline software and identified a total of 1274 TE junctions. For the predicted RJs, we designed 2868 polymerase chain reaction (PCR) based RJ markers (RJMs) flanking the junction regions. In addition to marker design, the identified RJs were utilized to detect 225,517 TEs across the genome. The different types of transposable repeat elements mainly were scattered into Retro, LTR, Copia and Gypsy categories. The efficacy of the designed markers was tested by utilizing a subset of RJMs selected randomly. We have validated 96 randomly selected RJ primers in a group of 32 J. curcas genotypes and more than 90% of the markers effectively intensified as amplicons. Of these, 10 primers were shown to be polymorphic in estimating genetic diversity among the 32 Jatropha lines. UPGMA cluster analysis revealed the formation of two clusters such as A and B exhibiting 85.5% and 87% similarity coefficient respectively. The various RJMs identified in this study could be utilized as a significant asset in Jatropha functional genomics including genome determination, mapping and marker-assisted selection.

Regeneration of transgenic plants from two indica rice (Oryza sativa L.) cultivars using shoot apex explants

We have established a reproducible procedure for transformation of shoot apices and regeneration of transgenic plants for two indica rice cultivars, white ponni (WP) and Pusa Basmathi 1 (PB 1). Four-day-old shoot apex explants were transformed by cocultivation with Agrobacterium tumefaciens strain EHA 101 harbouring a binary plasmid pRIT1. The vector contained an improved hygromycin phosphotransferase (hpt) gene for hygromycin resistance driven by actin 1 promoter and the reporter gene beta-glucuronidase intron (INT-GUS) controlled by CaMV 35S promoter. Rice shoots were induced on media containing 0.1 mg/l napthalene acetic acid (NAA), 1.0 mg/l kinetin (kn), 1.0 mg/l N(6)-benzyleaminopurin (BAP), 300 mg/l casaminoacid, 500 mg/l proline, 50 mg/l hygromycin and 500 mg/l cefotaxime. Transgenic plants were raised in pots and seeds were collected. Histochemical and polymerase chain reaction (PCR) analyses of field established transgenic rice plants and their offsprings confirmed the presence of GUS gene. Integration of T-DNA into the genome of putative transgenics was further confirmed by southern analysis. The transformation efficiency of WP was found to be ranging from 5.6 to 6.2% whereas in the case of PB1, it was from 7 to 8%. Progeny analysis of these plants showed a pattern of classical Mendelian inheritance for both hpt and GUS gene.

Efficient protocols for in vitro regeneration of Pennisetum glaucum (L) Br

A system was developed for in vitro regeneration of Pennisetum glaucum through organogenesis and somatic embryogenesis. Mature embryo and leaf base explants of Pennisetum glaucum (L) Br. cv HH B60 (Poaceae) were cultured on Murashige and Skoog agar medium supplemented with 11.3 microM of 2,4-D for callus induction. Embryogenic calli were induced within eight weeks. Percentage of callus induction and somatic embryogenesis was significantly higher in mature embryo than leaf base explants. Maximum shoot regeneration was obtained via organogenesis on MS medium supplemented with 4.43 microM of BAP and 4.64 microM of kinetin from the calli of both the explants. The frequency of plant regeneration through somatic embryogenesis was comparatively lower than organogenesis. Regeneration frequency was higher in mature embryo explants than leaf base explants. The shoots regenerated via organogenesis were elongated and rooted efficiently on MS medium supplemented with IBA (0.49 microM). The rooted plantlets were hardened and transferred to soil.

Influence of growth regulators and explant type on in vitro shoot propagation and rooting of red sandal wood (Pterocarpus santalinus L.)

In vitro shoot regeneration in Pterocarpus santalinus L. was achieved when detached cotyledons from in vitro germinated seedlings were cultured on MS medium containing NAA (0.1 mg/L), BA (1 mg/L) and kinetin (1 mg/L). The regenerated shoots rooted on 1/4 strength MS medium with IAA (1 mg/L) and the fully developed plantlets were successfully established in the soil.