Modulatory Activity of the Copper Chelate, Copper N-(2-Hydroxy Acetophenone) Glycinate, in ABC-transporter-expressing Cell Lines.

BACKGROUND/AIM: Metal-containing compounds (e.g., platinum complexes) belong to the standard armamentarium of cancer chemotherapy. Copper N-(2-hydroxy acetophenone) glycinate (CuNG) exerts anticancer activity in vitro and in vivo and modulates drug resistance related to glutathione or P-glycoprotein. The potential of CuNG to interact with ATP-binding cassette (ABC) transporters has not been fully explored yet. This study focused on the modulatory effects of CuNG on four ABC transporters (MRP1, MRP1, BCRP, and P-glycoprotein). MATERIALS AND METHODS: Cell viability, drug uptake and ABC transporter expression were measured by resazurin assays, flow cytometry, and ELISA in HL60AR, MDCKII-hBCRP, and Caco-2 cells. RESULTS: CuNG increased doxorubicin sensitivity of MRP1-over-expressing HL60AR with a similar efficacy as the control MRP1 inhibitor MK571. CuNG also increased MRP1's efflux activity. Comparable results were obtained with MDCKII cells over-expressing hBCRP. ELISA assays revealed that the expression of MRP1 in HL60AR cells and BCRP in MDCKII- cells was predominant but other ABC-transporters were also expressed at lower levels. Caco-2 cells expressed high levels of MRP2, but MRP1, BCRP, and P-glycoprotein were also expressed. In contrast to the two former cell lines, CuNG increased doxorubicin resistance and decreased efflux activity in Caco-2 cells. CONCLUSION: CuNG exerted different modulatory activities towards ABC-transporter-expressing cells. While CuNG-mediated ABC-transporter inhibition may improve tumor chemotherapy (like in HL60AR and MDCKII-hBCRP cells), CuNG-mediated enhanced ABC-transport (like in Caco-2 cells) may be a new strategy to ameliorate inflammatory diseases associated with decreased ABC-transporter expression such as ulcerative colitis.

Unmet Need for Further LDL-C Lowering in India despite Statin Therapy: Lipid Association of India Recommendations for the Use of Bempedoic Acid.

Lipid-lowering therapy plays a crucial role in reducing adverse cardiovascular (CV) events in patients with established atherosclerotic cardiovascular disease (ASCVD) and familial hypercholesterolemia. Lifestyle interventions along with high-intensity statin therapy are the first-line management strategy followed by ezetimibe. Only about 20-30% of patients who are on maximally tolerated statins reach recommended low-density lipoprotein cholesterol (LDL-C) goals. Several factors contribute to the problem, including adherence issues, prescription of less than high-intensity statin therapy, and de-escalation of statin dosages, but in patients with very high baseline LDL-C levels, including those with familial hypercholesterolemia and those who are intolerant to statins, it is critical to expand our arsenal of LDL-C-lowering medications. Moreover, in the extreme risk group of patients with an LDL-C goal of ≤30 mg/dL according to the Lipid Association of India (LAI) risk stratification algorithm, there is a significant residual risk requiring the addition of non-statin drugs to achieve LAI recommended targets. This makes bempedoic acid a welcome addition to the existing non-statin therapies such as ezetimibe, bile acid sequestrants, and PCSK9 inhibitors. A low frequency of muscle-related side effects, minimal drug interactions, a significant reduction in high-sensitivity C-reactive protein (hsCRP), and a lower incidence of new-onset or worsening diabetes make it a useful adjunct for LDL-C lowering. However, the CV outcomes trial results are still pending. In this LAI consensus document, we discuss the pharmacology, indications, contraindications, advantages, and evidence-based recommendations for the use of bempedoic acid in clinical practice.

A novel tin based hydroxamic acid complex induces apoptosis through redox imbalance and targets Stat3/JNK1/MMP axis to overcome drug resistance in cancer.

Undesired toxicity and emergence of multidrug resistance (MDR) are the major impediments to the successful application of organotin-based compounds against cancer. Since oxalyl-bis(N-phenyl)hydroxamic acid (OBPHA) exerts significant efficacy against cancer, we believe that derivatives of OBPHA including organotin molecule can show a promising effect against cancer. Herein, we have selected three previously characterized OBPHA derivatives viz., succinyl-bis(N-phenyl)hydroxamic acid (SBPHA), diphenyl-tin succinyl-bis(N-phenyl)hydroxamic acid (Sn-SBPHA), malonyl-bis(N-phenyl)hydroxamic acid (MBPHA) and evaluated their antiproliferative efficacy against both drug-resistant (CEM/ADR5000; EAC/Dox) and sensitive (CCRF-CEM; HeLa; EAC/S) cancers. Data revealed that Sn-SBPHA selectively targets drug-resistant and sensitive cancers without inducing any significant toxicity to normal cells (Chang Liver). Moreover, shortening of the backbone of SBPHA enhances the efficacy of the newly formed molecule MBPHA by targeting only drug-sensitive cancers. Sn-SBPHA induces caspase3-dependent apoptosis through redox-imbalance in both drug-resistant and sensitive cancer. Sn-SBPHA also reduced the activation and expression of both MMP2 and MMP9 without altering the expression status of TIMP1 and TIMP2 in drug-resistant cancer. In addition, Sn-SBPHA reduced the activation of both STAT3 and JNK1, the transcriptional modulator of MMPs, in a redox-dependent manner in CEM/ADR5000 cells. Thus, Sn-SBPHA targets MMPs by modulating STAT3 and JNK1 in a redox-dependent manner. However, MBPHA and SBPHA fail to target drug resistance and both drug-resistant and sensitive cancer respectively. Furthermore, Sn-SBPHA significantly increases the lifespan of doxorubicin-resistant and sensitive Ehrlich Ascites Carcinoma-bearing mice without inducing any significant systemic toxicity. Therefore, Sn-SBPHA has the therapeutic potential to target and overcome MDR in cancer.

A zinc Schiff base complex inhibits cancer progression both in vivo and in vitro by inducing apoptosis.

Cancer chemotherapy suffers from selectivity and undesired toxicity of the drugs. Since zinc is a biocompatible tracer element and cysteine derivatives are used in cancer chemoprevention, we intend to develop a complex of zinc and cysteine-derivatives as potent, non-toxic anticancer agents. Herein, we synthesized and characterized cysteine based ligand, 2-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-3-mercapto-propionic acid and its Zn-complex, which are found to be non-toxic towards normal human PBMC. Data also revealed that only Zn-complex exhibited remarkable apoptosis in drug-sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 cancer cells as assessed by MTT, Cell cycle and AnnexinV binding assay. Moreover, Zn-complex altered ROS and GSH level of the respective cell lines. Finally, treatment of Zn-complex in Swiss albino mice did not show any systemic toxicity in preliminary trials in normal mice and remarkably increased the life-span of EAC bearing mice. In conclusion, the synthesized Zn-complex may be developed for efficacious, multidrug resistance reversal, non-toxic chemotherapeutic agents in future.

A newly synthesized nickel chelate can selectively target and overcome multidrug resistance in cancer through redox imbalance both in vivo and in vitro.

Induction of undesired toxicity and emergence of multidrug resistance (MDR) are the major obstacles for cancer treatment. Moreover, aggressive cancers are less sensitive towards existing chemotherapeutics. Therefore, selective targeting of cancers without inducing undesired side effects and designing proper strategies to overcome MDR has utmost importance in modern chemotherapy. Previously we revealed the anticancer properties of some transition metal chelates of Schiff base, but the effectiveness of nickel complex is still unrevealed. Herein, we synthesized and characterized a Schiff base nickel chelate, nickel-(II) N-(2-hydroxyacetophenone) glycinate (NiNG), through different spectroscopic means. NiNG proves to be a broad spectrum anticancer agent with considerable efficacy to overcome MDR in cancer. Antiproliferative effects of NiNG was evaluated using drug-resistant (CEM/ADR5000; NIH-MDR-G185; EAC/Dox), drug-sensitive aggressive (Hct116; CCRF-CEM; EAC/S) and normal (NIH-3T3) cells that reveal the selective nature of NiNG towards drug resistant and sensitive cancer cells without inducing any significant toxicity in normal cells. Moreover, NiNG involves reactive oxygen species (ROS)-mediated redox imbalance for induction of caspase 3-dependent apoptosis in aggressive drug-sensitive Hct116 and drug-resistant NIH-MDR-G185 cells through disruption of mitochondrial membrane potential. Moreover, intraperitoneal (i.p.) application of NiNG at non-toxic doses caused significant increase in the life-span of Swiss albino mice bearing sensitive and doxorubicin-resistant subline of Ehrlich ascites carcinoma cells. It is noteworthy that, in vitro NiNG can only overcome P-glycoprotein-mediated MDR while in vivo NiNG can overcome MRP1-mediated MDR in cancer. Therefore, NiNG has therapeutic potential to target and overcome MDR in cancer.

Induction of apoptosis in human colorectal cancer cell line, HCT-116 by a vanadium- Schiff base complex.

Vanadium compounds are well known for their therapeutic interventions against several diseases. Various biochemical attributes of vanadium complexes inspired us to evaluate the cancer cell killing efficacy of the vanadium complex, viz., vanadyl N-(2-hydroxyacetophenone) glycinate [VO(NG)2]. Previously we showed that VO(NG)2 is an effective anticancer agent in in vitro and in vivo cancer models and imposed miniscule side effects. Herein we report that VO(NG)2 is significantly cytotoxic to various cancer cell lines. Furthermore, this redox active vanadyl complex altered the redox homeostatsis of many human cancer cell lines significantly. VO(NG)2 actuates programmed cell death in human colorectal carcinoma cells(HCT-116) through mitochondrial outer membrane permeabilization but in caspase independent manner, possibly by altering cellular redox status and by inflicting DNA damage. Thus, the present work is an attempt to provide many evidences regarding the potent and selective chemotherapeutic efficacy of the novel VO(NG)2.

A Novel Approach of Synthesizing and Evaluating the Anticancer Potential of Silver Oxide Nanoparticles in vitro.

BACKGROUND: Development of novel strategies to kill cancer by sparing normal cells is of utmost importance. Apart from their known antimicrobial activity, only limited information has been recorded regarding the antitumor potential of biocompatible silver oxide nanoparticles (AgONPs). There is a need to evaluate the anticancer potential of biocompatible AgONPs in vitro. METHODS: A new approach of utilizing the leaf extract of Excoecaria agallocha was used to synthesize AgONPs. This was then characterized by ultraviolet-visible spectrophotometry, nanoparticle-tracking analysis, and ζ-potential analysis. Cytotoxicity and apoptotic potential were evaluated with an MTT assay and an annexin V-binding assay against the murine melanoma (B16F10), murine colon cancer (CT26), murine lung adenocarcinoma (3LL), and murine Ehrlich ascites carcinoma (EAC) cell lines. Cellular localization of AgONPs was evaluated on fluorescence microscopy. RESULTS: UV peaks at 270 and 330 nm indicated the formation of nanoparticles (NPs) and the NP-tracking analyzer revealed them to have a size of 228 nm. AgONPs exerted initial cytotoxicity, specifically against all the experimental malignant cells by sparing the normal cell lines. Moreover, AgONPs exert apoptosis equally on all the malignant cells in vitro and ex vivo. This cytotoxicity possibly occurs via the nuclear translocation of AgONPs as analyzed in B16F10 cells. CONCLUSIONS: AgONPs utilizing natural sources would be a new medicinal approach against a broad spectrum of malignancy.

Modulation of cell death in human colorectal and breast cancer cells through a manganese chelate by involving GSH with intracellular p53 status.

Chemotherapy is central to current treatment modality especially for advanced and metastatic colorectal and breast cancers. Targeting the key molecular events of the neoplastic cells may open a possibility to treat cancer. Although some improvements in understanding of colorectal and breast cancer treatment have been recorded, the involvement of glutathione (GSH) and dependency of p53 status on the modulation of GSH-mediated treatment efficacy have been largely overlooked. Herein, we tried to decipher the underlying mechanism of the action of Mn-N-(2-hydroxyacetophenone) glycinate (MnNG) against differential p53 status bearing Hct116, MCF-7, and MDA-MB-468 cells on the backdrop of intracellular GSH level and reveal the role of p53 status in modulating GSH-dependant abrogation of MnNG-induced apoptosis in these cancer cells. Present study discloses that MnNG targets specifically wild-type-p53 expressing Hct116 and MCF-7 cells by significantly depleting both cytosolic, mitochondrial GSH, and modulating nuclear GSH through Glutathione reductase and Glutamate-cysteine ligase depletion that may in turn induce p53-mediated intrinsic apoptosis in them. Thus GSH addition abrogates p53-mediated apoptosis in wild-type-p53 expressing cells. GSH addition also overrides MnNG-induced modulation of phase II detoxifying parameters in them. However, GSH addition partially replenishes the down-regulated or modulated GSH pool in cytosol, mitochondria, and nucleus, and relatively abrogates MnNG-induced intrinsic apoptosis in p53-mutated MDA-MB-468 cells. On the contrary, although MnNG induces significant cell death in p53-null Hct116 cells, GSH addition fails to negate MnNG-induced cell death. Thus p53 status with intracellular GSH is critical for the modulation of MnNG-induced apoptosis.

A copper chelate induces apoptosis and overcomes multidrug resistance in T-cell acute lymphoblastic leukemia through redox imbalance and inhibition of EGFR/PI3K/Akt expression.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive form of cancer and the therapeutic outcome for T-ALL patients remains poor. Thus innovative therapeutic strategies with less toxic drugs are of immense need. Moreover combinational effect of redox imbalance with modulated EGFR/PI3K/Akt axis in T-ALL is still elusive. To explore more effective drugs we developed and characterized 5-SMAG, Cu-5-SMAG and Cu-OBPHA complexes by different spectroscopic methods and revealed that introduction of methoxy group and copper to the previously synthesized Schiff base ligand, NG can efficiently target leukemia by sparing the normal cells and overcomes MDR in T-ALL through induction of caspase3 dependent apoptosis as assessed by MTT, Cell-cycle, Annexin-V and caspase3 activation assay. However the ligand 5-SMAG fails to exert significant cytotoxicity. Moreover introduction of copper does not increase the efficacy of the drug molecule as Cu-OBPHA fails to exert significant effect compared to Cu-5-SMAG. Moreover Cu-5-SMAG targets T-ALL cells more than Cu-OBPHA because Cu-5-SMAG generates greater extent of redox imbalance compared to Cu-OBPHA and when this redox imbalance is reduced by application of NAC and PEG-Catalase, highest abrogation of apoptosis is observed following Cu-5-SMAG treatment In addition, Cu-5-SMAG significantly down-regulates the activation and expression of EGFR1, Akt and PI3K in drug-resistant T-ALL cells. Furthermore Cu-5-SMAG significantly increases the life-span of doxorubicin resistant and sensitive Ehrlich ascites carcinoma bearing Swiss albino mice without inducing any significant systemic toxicity compared to 5-SMAG and Cu-OBPHA treatment. Therefore typical architect of Cu-5-SMAG made it a promising new anti-leukemic agent irrespective of the MDR phenotype.

Marker-free transgenic rice expressing the vegetative insecticidal protein (Vip) of Bacillus thuringiensis shows broad insecticidal properties.

MAIN CONCLUSION: Genetically engineered rice lines with broad insecticidal properties against major lepidopteran pests were generated using a synthetic, truncated form of vegetative insecticidal protein (Syn vip3BR) from Bacillus thuringiensis. The selectable marker gene and the redundant transgene(s) were eliminated through Cre/ lox mediated recombination and genetic segregation to make consumer friendly Bt -rice. For sustainable resistance against lepidopteran insect pests, chloroplast targeted synthetic version of bioactive core component of a vegetative insecticidal protein (Syn vip3BR) of Bacillus thuringiensis was expressed in rice under the control of green-tissue specific ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit gene promoter. The transgenic plants (in Oryza sativa indica Swarna cultivar) showed high insect mortality rate in vitro against major rice pests, yellow stem borer (Scirpophaga incertulas), rice leaf folder (Cnaphalocrocis medinalis) and rice horn caterpillar (Melanitis leda ismene) in T1 generation, indicating insecticidal potency of Syn vip3BR. Under field conditions, the T1 plants showed considerable resistance against leaf folders and stem borers. The expression cassette (vip-lox-hpt-lox) as well as another vector with chimeric cre recombinase gene under constitutive rice ubiquitin1 gene promoter was designed for the elimination of selectable marker hygromycin phosphotransferase (hptII) gene. Crossing experiments were performed between T1 plants with single insertion site of vip-lox-hpt-lox T-DNA and one T1 plant with moderate expression of cre recombinase with linked bialaphos resistance (syn bar) gene. Marker gene excision was achieved in hybrids with up to 41.18 % recombination efficiency. Insect resistant transgenic lines, devoid of selectable marker and redundant transgene(s) (hptII + cre-syn bar), were established in subsequent generation through genetic segregation.

Expression of an engineered synthetic cry2Aa (D42/K63F/K64P) gene of Bacillus thuringiensis in marker free transgenic tobacco facilitated full-protection from cotton leaf worm (S. littoralis) at very low concentration.

Emergence of resistant insects limits the sustainability of Bacillus thuringiensis (Bt) transgenic crop plants for insect management. Beside this, the presence of unwanted marker gene(s) in the transgenic crops is also a major environmental and health concern. Thus, development of marker free transgenic crop plants expressing a new class of toxin having a different mortality mechanism is necessary for resistance management. In a previous study, we generated an engineered Cry2Aa (D42/K63F/K64P) toxin which has a different mortality mechanism as compared to first generation Bt toxin Cry1A, and this engineered toxin was found to enhance 4.1-6.6-fold toxicity against major lepidopteran insect pests of crop plants. In the present study, we have tested the potency of this engineered synthetic Cry2Aa (D42/K63F/K64P) toxin as a candidate in the development of insect resistant transgenic tobacco plants. Simultaneously, we have eliminated the selectable marker gene from the Cry2Aa (D42/K63F/K64P) expressing tobacco plants by exploiting the Cre/lox mediated recombination methodology, and successfully developed marker free T2 transgenic tobacco plants expressing the engineered Cry2Aa toxin. Realtime and western blot analysis demonstrated the expression of engineered toxin gene in transgenic plants. Insect feeding assays revealed that the marker free T2 progeny of transgenic plants expressing Cry2Aa (D42/K63F/K64P) toxin showed 82-92 and 52-61 % mortality to cotton leaf worm (CLW) and cotton bollworm (CBW) respectively. Thus, this engineered Cry2Aa toxin could be useful for the generation of insect resistant transgenic Bt lines which will protect the crop damages caused by different insect pests such as CLW and CBW.

Induction of intrinsic and extrinsic apoptosis through oxidative stress in drug-resistant cancer by a newly synthesized Schiff base copper chelate.

Multidrug resistance (MDR) in cancer represents a variety of strategies employed by tumor cells to evade the beneficial cytotoxic effects of structurally different anticancer drugs and thus confers impediments to the successful treatment of cancers. Efflux of drugs by MDR protein-1, functional P-glycoprotein and elevated level of reduced glutathione confer resistance to cell death or apoptosis and thus provide a possible therapeutic target for overcoming MDR in cancer. Previously, we reported that a Schiff base ligand, potassium-N-(2-hydroxy 3-methoxy-benzaldehyde)-alaninate (PHMBA) overcomes MDR in both in vivo and in vitro by targeting intrinsic apoptotic/necrotic pathway through induction of reactive oxygen species (ROS). The present study describes the synthesis and spectroscopic characterization of a copper chelate of Schiff base, viz., copper (II)-N-(2-hydroxy-3-methoxy-benzaldehyde)-alaninate (CuPHMBA) and the underlying mechanism of cell death induced by CuPHMBA in vitro. CuPHMBA kills both the drug-resistant and sensitive cell types irrespective of their drug resistance phenotype. The cell death induced by CuPHMBA follows apoptotic pathway and moreover, the cell death is associated with intrinsic mitochondrial and extrinsic receptor-mediated pathways. Oxidative stress plays a pivotal role in the process as proved by the fact that antioxidant enzyme; polyethylene glycol conjugated-catalase completely blocked CuPHMBA-induced ROS generation and abrogated cell death. To summarize, the present work provides a compelling rationale for the future clinical use of CuPHMBA, a redox active copper chelate in the treatment of cancer patients, irrespective of their drug-resistance status.

Enhancement of α-linolenic acid content in transgenic tobacco seeds by targeting a plastidial ω-3 fatty acid desaturase (fad7) gene of Sesamum indicum to ER.

KEY MESSAGE: Expression of sesame plastidial FAD7 desaturase modified with the endoplasmic reticulum targeting and retention signals, enhances the α-linolenic acid accumulation in seeds of Nicotiana tabacum. In plants, plastidial ω-3 fatty acid desaturase-7 (FAD7) catalyzes the formation of C16 and C18 trienoic fatty acids using organellar glycerolipids and participate in the membrane lipid formation. The plastidial ω-3 desaturases (FAD7) share high sequence homology with the microsomal ω-3 desaturases (FAD3) at the amino acid level except the N-terminal organelle transit peptide. In the present study, the predicted N-terminal plastidial signal peptide of fad7 gene was replaced by the endoplasmic reticulum signal peptide and an endoplasmic reticulum retention signal was placed at the C-terminal. The expression of the modified sesame ω-3 desaturase increases the α-linolenic acid content in the range of 4.78-6.77 % in the seeds of transgenic tobacco plants with concomitant decrease in linoleic acid content. The results suggested the potential of the engineered plastidial ω-3 desaturase from sesame to influence the profile of α-linolenic acid in tobacco plant by shifting the carbon flux from linoleic acid, and thus it can be used in suitable genetic engineering strategy to increase the α-linolenic acid content in sesame and other vegetable oils.

Simple Detection Methods for Antinutritive Factor ß-ODAP Present in Lathyrus sativus L. by High Pressure Liquid Chromatography and Thin Layer Chromatography.

Lathyrus sativus L. (Grass pea) is the source for cheap and nutritious food choice in drought and famine susceptible zones in greater part of North India and Africa. The non-protein amino acid ß-N-oxalyl-L-α,ß-diaminopropionic acid (ß-ODAP) has been known for decades for its potent neurotoxic effect, causing irreversible neurodegenerative disease "neurolathyrism", present in both seed and leaf of Lathyrus sativus L. and other species in varying proportions. It is crucial to establish a rapid as well as reliable detection methodology for ß-ODAP content in various Lathyrus plants. Currently available HPLC based methods involve multi-step derivatization of the sample. To overcome this, we have developed ß-ODAP analysis method by HPLC without any prior derivatization. This method is statistically significant in the range of 2 to 100µg/ml and exhibited linear response with r2 > 0.99. Limit of detection and quantitation of the later method was determined to be 5.56 µg/ml and 16.86 µg/ml, respectively. In addition to this, a TLC based method has also been developed. The limit of detection of ß-ODAP is 0.6µg and for its substrate, L-1,2-diaminopropionic acid is 5µg. Both HPLC and TLC methods were validated by conducting in-vitro bioconversion test to detect the presence of biocatalyst in plant extract. This method is economical, rapid and simple.

A deletion mutant ndv200 of the Bacillus thuringiensis vip3BR insecticidal toxin gene is a prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insect damage.

MAIN CONCLUSION: Ectopic expression of a deletion mutant ( ndv200 ) of Bacillus thuringiensis vip3BR gene in tobacco plant provided almost complete protection against major crop pests cotton boll worm ( Helicoverpa armigera ), black cut worm ( Agrotis ipsilon ) and cotton leaf worm ( Spodoptera littoralis ). Whereas vip3BR transgenic tobacco plant failed to protect themselves from these insects and showed resistance towards cotton leaf worm only. An analogous form of the Bacillus thuringiensis vip3Aa insecticidal toxin gene, named vip3BR, was identified and characterized, and exhibited similar attributes to the well-known Vip3Aa toxin. Vip3BR possessed broad-spectrum lepidopteran-specific insecticidal properties effective against most major crop pests of the Indian subcontinent. A Vip3BR toxin protein N-terminal deletion mutant, Ndv200, showed increased insecticidal potency relative to the native toxin, which conferred efficacy against four major crop pests, including cotton boll worm (Helicoverpa armigera), black cut worm (Agrotis ipsilon), cotton leaf worm (Spodoptera littoralis), and rice yellow stem borer (Scirpophaga incertulas). Ligand blot analysis indicated the Ndv200 toxin recognized the same larval midgut receptors as the native Vip3BR toxin, but differed from receptors recognized by Cry1A toxins. In the present study, we tested the prospect of the vip3BR and ndv200 toxin gene as candidate in development of insect-resistant genetically engineered crop plants by generating transgenic tobacco plant. The study revealed that the ndv200 mutant of vip3BR insecticidal toxin gene is a strong and prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insects.

Nitro and dinitroamino N-oxides of octaazaanthracene as high energy materials.

The present study undertook the design of nitro and dinitroamino compounds from the skeleton of isomeric N-oxides of octaazanaphthalene, using computational methods to predict their degradation and explosive characteristics. The atom equivalent method was employed to evaluate the gas phase heats of formation of the designed species. Condensed phase heats of formation were also determined and found to be in the range of 220-286 kcal mol(-1). Crystal densities of all the designed molecules were calculated and found to be in the range of 1.91-1.98 g cm(-3). Detonation pressure (P) and detonation velocity (D) determined using the Kamlet-Jacobs equation showed that the performance of nitro-substituted compounds was comparable to that of RDX while that of dinitroamino compounds (P ≈ 43.4-43.7 GPa; D ≈ 9.6-9.7 km s(-1)) showed their superiority over HMX (P ≈ 39.3 GPa and D ≈ 9.10 km s(-1)). Impact sensitivity (h 50) of the designed molecules was compared with nitro- and nitramino-based commercial explosives on the basis of the available free space (∆V) per molecule in their crystal lattice estimated using wave function analysis. The study showed that dinitroamino compounds were more sensitive compared to their nitro analogs. Reactivity or chemical stability of the designed molecules were measured in terms of charge distribution, molecular electrostatic potential and frontier molecular orbital energy. The nitro compounds of N-oxides of octaazaanthracene were found to be more stable than their dinitroamino analogs.

Co-administration of glycyrrhizic acid with the antileishmanial drug sodium antimony gluconate (SAG) cures SAG-resistant visceral leishmaniasis.

Since there are very few affordable antileishmanial drugs available, antimonial resistance has crippled antileishmanial therapy, thereby emphasising the need for development of novel therapeutic strategies. This study aimed to evaluate the antileishmanial role of combined therapy with sodium antimony gluconate (SAG) and the triterpenoid glycyrrhizic acid (GA) against infection with SAG-resistant Leishmania (GE1F8R). Combination therapy with GA and SAG successfully limited infection with SAG-resistant Leishmania in a synergistic manner (fractional inhibitory concentration index <1.0). At the same time, mice infected with SAG-resistant Leishmania and co-treated with GA and SAG exhibited a significant reduction in hepatic and splenic parasite burden. In probing the mechanism, it was observed that GA treatment suppressed the expression and efflux activity of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1), two host ABC transporters responsible for antimony efflux from host cells infected with SAG-resistant parasites. This suppression correlated with greater intracellular antimony retention during SAG therapy both in vitro and in vivo, which was reflected in the reduced parasite load. Furthermore, co-administration of GA and SAG induced a shift in the cytokine balance towards a Th1 phenotype by augmenting pro-inflammatory cytokines (such as IL-12, IFNγ and TNFα) and inducing nitric oxide generation in GE1F8R-infected macrophages as well as GE1F8R-infected mice. This study aims to provide an affordable leishmanicidal alternative to expensive antileishmanial drugs such as miltefosine and amphotericin B. Furthermore, this report explores the role of GA as a resistance modulator in MRP1- and P-gp-overexpressing conditions.

Mn complex-mediated enhancement of antitumor response through modulating myeloid-derived suppressor cells in drug-resistant tumor.

BACKGROUND: The tumor microenvironment (TME) renders tumor cells more resistant to chemotherapy. However, effective immunomodulators for cancer therapy are still elusive. We hypothesized that Mn-N-(2-hydroxyacetophenone) glycinate (MnNG), reported to be an antitumor agent, can modulate the TME. MATERIALS AND METHODS: Immunomodulatory effects of MnNG were performed through assessing Myeloid Derived Suppressor Cells (MDSCs), Interferon-γ (Ifnγ)- and Interleukin-4 (Il4)-secreting Cluster of Differentiation 4 (Cd4)(+) T-cells by annexin V-binding assay in drug-resistant TME and T-cell proliferation following in vitro co-culture assay by flow cytometry. RESULTS: MnNG induced infiltration of Ifnγ-secreting Cd4(+) T-cells and reduces MDSC numbers in vivo. Furthermore, it modulated differentiation of MDSCs towards dendritic cells with up-regulation of co-stimulatory molecules and reversed the suppressive function of MDSC's that enhances T-helper cell 1 (Th1) response. MnNG treatment resulted in reduced expression of IL4, but enhanced expression of Ifnγ when Cd4(+) T-cells were co-cultured with MDSCs. CONCLUSION: MnNG modulates MDSCs differentiaton towards dendritic cells and enhances Th1 response in drug-resistant TME, leading to immunomodulatory efficacy.

Seed-specific increased expression of 2S albumin promoter of sesame qualifies it as a useful genetic tool for fatty acid metabolic engineering and related transgenic intervention in sesame and other oil seed crops.

The sesame 2S albumin (2Salb) promoter was evaluated for its capacity to express the reporter gusA gene encoding ß-glucuronidase in transgenic tobacco seeds relative to the soybean fad3C gene promoter element. Results revealed increased expression of gusA gene in tobacco seed tissue when driven by sesame 2S albumin promoter. Prediction based deletion analysis of both the promoter elements confirmed the necessary cis-acting regulatory elements as well as the minimal promoter element for optimal expression in each case. The results also revealed that cis-regulatory elements might have been responsible for high level expression as well as spatio-temporal regulation of the sesame 2S albumin promoter. Transgenic over-expression of a fatty acid desaturase (fad3C) gene of soybean driven by 2S albumin promoter resulted in seed-specific enhanced level of α-linolenic acid in sesame. The present study, for the first time helped to identify that the sesame 2S albumin promoter is a promising endogenous genetic element in genetic engineering approaches requiring spatio-temporal regulation of gene(s) of interest in sesame and can also be useful as a heterologous genetic element in other important oil seed crop plants in general for which seed oil is the harvested product. The study also established the feasibility of fatty acid metabolic engineering strategy undertaken to improve quality of edible seed oil in sesame using the 2S albumin promoter as regulatory element.

Theoretical studies on benzo[1,2,4]triazine-based high-energy materials.

Density functional theory calculations of 13 aminonitro compounds based on the benzo[1,2,4]triazine fused-ring system were performed. The geometries of all 13 species were optimized at the B3LYP/6-31G(d) level of theory. In order to refine the energy values, single-point energy calculations of the species were made at the B3LYP/6-311++G(2df,2p) level. The gas-phase heats of formation of the species considered were calculated using the atom equivalent method. Condensed-phase heats of formation were calculated utilizing the heats of sublimation of the designed molecules, as evaluated during the present study. With the help of the WFA program, crystal densities of the designed compounds were predicted using the geometry of the molecule optimized at the B3PW91/6-31G(d,p) level. The stabilities and impact sensitivities of all of the compounds are discussed in the present paper in terms of the bond dissociation energy (BDE) of the trigger linkage (the longest C-NO2 bond) and the available free space per molecule (∆V) in the unit cell of each compound. A nucleus-independent chemical shift (NICS) study was performed to assess the aromaticities of the designed molecules, and the NICS(1) values determined 1 Å above and below the plane of the ring were found to be -7.9 to -10.5, respectively, for the benzene ring and -10.7 to -11.4, respectively, for the triazine ring in the designed fused-ring molecules, showing that both rings retain their aromaticities when undergoing substitution by nitro groups. Detonation parameters of the species were calculated, and the results suggest that the designed compounds possess comparable values to those of the commercial explosives TNT and RDX. Furthermore, results suggest that the designed compounds may be less sensitive than many nitroaromatic and nitramine explosives. Thus, the results obtained during the present study imply that the designed compounds may be used as safe explosive materials, and could be potential alternatives to TNT and RDX.