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1.
EXCLI J ; 23: 300-334, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38655092

RESUMO

Cutaneous Squamous Cell Carcinoma (cSCC) is a common and potentially fatal type of skin cancer that poses a significant threat to public health and has a high prevalence rate. Exposure to ultraviolet radiation on the skin surface increases the risk of cSCC, especially in those with genetic syndromes like xerodermapigmentosum and epidermolysis bullosa. Therefore, understanding the molecular pathogenesis of cSCC is critical for developing personalized treatment approaches that are effective in cSCC. This article provides a comprehensive overview of current knowledge of cSCC pathogenesis, emphasizing dysregulated signaling pathways and the significance of molecular profiling. Several limitations and challenges associated with conventional therapies, however, are identified, stressing the need for novel therapeutic strategies. The article further discusses molecular targets and therapeutic approaches, i.e., epidermal growth factor receptor inhibitors, hedgehog pathway inhibitors, and PI3K/AKT/mTOR pathway inhibitors, as well as emerging molecular targets and therapeutic agents. The manuscript explores resistance mechanisms to molecularly targeted therapies and proposes methods to overcome them, including combination strategies, rational design, and optimization. The clinical implications and patient outcomes of molecular-targeted treatments are assessed, including response rates and survival outcomes. The management of adverse events and toxicities in molecular-targeted therapies is crucial and requires careful monitoring and control. The paper further discusses future directions for therapeutic advancement and research in this area, as well as the difficulties and constraints associated with conventional therapies.

2.
PeerJ ; 12: e16746, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38562998

RESUMO

Identifying suitable habitats and conserving corridors are crucial to the long-term conservation of large and conflict-prone animals. Being a flagship species, survival of Asian elephants is threatened by human-induced mortality and habitat modification. We aimed to assess the habitat suitability and connectivity of the Asian elephant Elephas maximus Linnaeus, 1758 habitat in the state of Odisha in eastern India. We followed the ensemble of spatial prediction models using species presence data and five environmental variables. We used least-cost path and circuit theory approaches to identify the spatial connectivity between core habitats for Asian elephants. The results revealed that normalized difference vegetation index (NDVI; variable importance 42%) and terrain ruggedness (19%) are the most influential variables for predicting habitat suitability of species within the study area. Our habitat suitability map estimated 14.6% of Odisha's geographical area (c. 22,442 km2) as highly suitable and 13.3% (c. 20,464 km2) as moderate highly suitable. We identified 58 potential linkages to maintain the habitat connectivity across study area. Furthermore, we identified pinch points, bottlenecks, and high centrality links between core habitats. Our study offers management implications for long-term landscape conservation for Asian elephants in Odisha and highlights priority zones that can help maintain spatial links between elephant habitats.


Assuntos
Elefantes , Animais , Humanos , Ecossistema , Meio Ambiente , Índia
3.
Curr Microbiol ; 80(8): 265, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37393301

RESUMO

Sulfur is an important key nutrient required for the growth and development of cyanobacteria. Several reports showed the effect of sulfate limitation in unicellular and filamentous cyanobacteria, but such studies have not yet been reported in heterocytous cyanobacteria to ascribe the mechanisms of nitrogen and thiol metabolisms. Thus, the present work was carried out to appraise the impacts of sulfate limitation on nitrogen and thiol metabolisms in Anabaena sp. PCC 7120 by analyzing the contents as well as enzymes of nitrogen and thiol metabolisms. Cells of Anabaena sp. PCC 7120 were exposed to different regimes of sulfate, i.e., 300, 30, 3, and 0 µM. Application of reduced concentration of sulfate showed negative impact on the cyanobacterium. Sulfate-limiting conditions reduces nitrogen-containing compounds in the cells of Anabaena. Additionally, reduced activities of nitrogen metabolic enzymes represented the role of sulfate in nitrogen metabolism. However, decreased activities of thiol metabolic enzymes indicated that sulfate-limited cyanobacterial cells have lower amount of glutathione and total thiol contents. Reduced accumulation of thiol components in the stressed cells indicated that sulfate-limited cells have lower ability to withstand stressful condition. Hence, Anabaena displays differential response to different concentrations of sulfate, and thus, stipulated that sulfur plays an important role in nitrogen and thiol metabolisms. To the best of our knowledge, this is the first report demonstrating the impact of sulfate stress on nitrogen and redox metabolisms in heterocytous cyanobacteria. This preliminary study provides a baseline idea that may help improve the production of paddy.


Assuntos
Anabaena , Cianobactérias , Nitrogênio , Sulfatos , Oxirredução , Compostos de Sulfidrila , Enxofre
4.
Environ Sci Pollut Res Int ; 30(18): 53424-53444, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36856995

RESUMO

The present work performs the polyphasic characterization of a novel cyanobacterial species Scytonema ambikapurensis isolated from an Indian hot spring and evaluates its wastewater bioremediation potential. While the physicochemical analyses of the wastewater indicated high load of nutrients and metals, the wastewater bioremediation experiment performed using the test cyanobacterium denoted the removal of 70 and 86% phosphate, 49 and 66% sulfate, 96 and 98% nitrate, 91 and 92% nitrite, 95 and 96% ammonia, 66 and 72% chloride, 79 and 81% zinc, 68 and 80% nickel, 81 and 90% calcium, and 80 and 90% potassium from the autoclaved and un-autoclaved wastewater, respectively, after 20 days of culturing. The kinetics study of zinc and nickel removal from wastewater revealed that the cyanobacterium employed sequential biosorption (by following pseudo-second-order kinetics model) and bioaccumulation methods to remove these two metals. The quality of the autoclaved and un-autoclaved wastewater was further improved by the cyanobacterium through reduction of hardness by 74 and 81%, respectively. In wastewater, the cyanobacterium not only enhanced its biomass, chlorophyll and carbohydrate contents, but also produced small amount of released and high capsular exopolysaccharide (EPS). The FTIR and TGA analyses of capsular EPS unraveled that it was a negatively charged sulfated biomolecule having thermostability up to 240 °C, which suggested its possible use as excellent emulsifying, viscosifying, and biosorption agent. The credibility of this EPS as biosorption agent was ascertained by evaluating its metal chelating ability. Finally, the experimental data denoting the ability of S. ambikapurensis to bioremediate wastewater and simultaneously produce EPS was statistically validated by PCA1-pollutant removal model and the PCA2-cellular constituent model, respectively. Briefly, the study discloses that the cyanobacterium has huge biotechnological and industrial importance as it bioremediates wastewater and simultaneously produces thermostable exopolysaccharide.


Assuntos
Cianobactérias , Fontes Termais , Purificação da Água , Águas Residuárias , Níquel , Biomassa , Zinco , Biodegradação Ambiental , Adsorção , Cinética
5.
Curr Drug Discov Technol ; 20(3): e210223213867, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36824006

RESUMO

INTRODUCTION: The root bark of Berberis aristata has been utilized by indigenous peoples for wound treatment for centuries. The mature root barks are crushed into a paste and applied to the wound's surface. OBJECTIVE: The focus of this research is to analyse the wound healing activities of an ethanolic extract of Berberis aristata, as well as to use molecular docking to establish the likely mechanism of the potent phytochemical. There is no scientific evidence to support the usage of root bark extract of Berberis aristata. METHODS: The Herbal ointment, which comprises (1%, 2%, and 4% w/w) ethanolic extract of root bark, was developed to test the wound healing ability of incision and excision wounds, and the molecular mechanism was established using Auto-Dock software. RESULTS: Epithelization stage, wound index, % wound contraction area, hydroxyproline content, DNA estimate, and histopathological assessments were performed on the incision wound model. Tensile strength was assessed in an excision wound model. TLC was used to identify the samples after successive extractions with different solvents based on polarity. CONCLUSION: Berberine and tetrahydropalmatine were major active phytoconstituent found in root barks of Berberis aristata as secondary metabolites. Animals treated with 4% w/w formulation demonstrated considerable wound contraction, epithelization time, and wound index in the excision model. In contrast, to control and standardize the concentrations of hydroxyproline, total amino acids, and DNA in recovering tissue were higher. At 4% w/w extract formulation, the parameters studied indicated a substantial result. Berberine and tetrahydropalmatine, active metabolites which are present in the ethanolic extract of Berberis aristata, were found to be responsible for wound healing. Based on ligand interactions, the findings verified Berberis aristata ethnomedicinal claim in a wound healing capacity.


Assuntos
Berberina , Berberis , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Simulação de Acoplamento Molecular , Berberis/química , Berberina/análise , Casca de Planta/química , Hidroxiprolina/análise , Cicatrização , Etanol , DNA/análise
6.
Res Microbiol ; 174(4): 104027, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36646262

RESUMO

A moderately thermophilic, gram-positive genomospecies Anoxybacillus rupiensis TPH1 was isolated from Tatapani hot spring, Chhattisgarh, India. Genome of 3.70 Mb with 42.3% GC subsumed 4131 CDSs, 65 tRNA, 5 rRNA, 35 AMR and 19 drug target genes. Further, comparative genomics of 19 Anoxybacillus spp. exhibited an open pan genome of 13102 genes along with core (10.62%), unique (43.5%) and accessory (45.9%) genes. Moreover, phylogenomic tree displayed clustering of Anoxybacillus spp. into two distinct clades where clade A species harbored larger genomes, more unique genes, CDS and hypothetical proteins than clade B species. Further, distribution of azoreductases showed FMN-binding NADPH azoreductase (AzoRed1) presence in clade A species only and FMN-binding NADH azoreductase (AzoRed2) harboring by species of both clades. Heavy metal resistance genes distribution showed omnipresence of znuA, copZ and arsC in both clades, dispersed presence of cbiM, czcD, merA and feoB over both clades and harboring of nikA and acr3 by few species of clade A only. Additionally, molecular docking of AzoRed1, AzoRed2, ZnuA, CopZ, Acr3, CbiM, CzcD, MerA and NikA with their respective ligands indicated high affinity and stable binding. Conclusively, present study provided insight into gene repertoire of genus Anoxybacillus and a basis for the potential application of this thermophile in bioremediation of azo dyes and heavy metals.


Assuntos
Anoxybacillus , Fontes Termais , Metais Pesados , Anoxybacillus/genética , Biodegradação Ambiental , Compostos Azo/metabolismo , Simulação de Acoplamento Molecular , Metais Pesados/metabolismo , Filogenia
7.
Environ Sci Pollut Res Int ; 30(4): 9591-9608, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36057058

RESUMO

Cyanobacteria adopt a variety of changes at proteomic and metabolic levels for surviving under harmful environmental conditions including heavy metal stress. The current study investigates the impact of zinc stress on the proteome of Anabaena sphaerica to get an insight into its molecular mechanisms of zinc tolerance. The study revealed three different aspects that were associated with the zinc tolerance in A. sphaerica: (i) the reduced expression of photosynthesis, nitrogen fixation, energy metabolism, respiratory, and transcriptional/translational proteins probably to conserve energy and utilizing it to sustain growth; (ii) the enhanced expression of metallothionein and ferritin domain protein All 3940 to chelate free zinc ions whereas upregulation of antioxidative proteins for detoxifying reactive oxygen species; and (iii) the expression of large numbers of hypothetical proteins to maintain the important cellular functions. Furthermore, over expressions of sulfate adenylyl transferase and cystathionine beta synthase along with the increased synthesis of peptidases and thiolated antioxidant proteins were also noticed which denoted cysteine synthesis under sulfur deprivation possibly by mobilizing the sulfur from dead cells and its channelization towards the production of thiolated antioxidants. Besides tolerating excess amount of zinc, A. sphaerica exhibited high zinc biosorption efficiency which confirmed its outstanding zinc bioremediation potential.


Assuntos
Anabaena , Zinco , Zinco/metabolismo , Biodegradação Ambiental , Proteômica , Anabaena/metabolismo , Proteínas/metabolismo , Antioxidantes/metabolismo , Enxofre/metabolismo , Proteínas de Bactérias/metabolismo
8.
Planta ; 256(2): 37, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35819629

RESUMO

MAIN CONCLUSION: Plant responds to Agrobacterium via three-layered immunity that determines its susceptibility or resistance to Agrobacterium infection. Agrobacterium tumefaciens is a soil-borne Gram-negative bacterium that causes crown gall disease in plants. The remarkable feat of interkingdom gene transfer has been extensively utilised in plant biotechnology to transform plant as well as non-host systems. In the past two decades, the molecular mode of the pathogenesis of A. tumefaciens has been extensively studied. Agrobacterium has also been utilised as a premier model to understand the defence response of plants during plant-Agrobacterium interaction. Nonetheless, the threat of Agrobacterium-mediated crown gall disease persists and is associated with a huge loss of plant vigour in agriculture. Understanding the molecular dialogues between these two interkingdom species might provide a cure for crown gall disease. Plants respond to A. tumefaciens by mounting a three-layered immune response, which is manipulated by Agrobacterium via its virulence effector proteins. Comparative studies on plant defence proteins versus the counter-defence of Agrobacterium have shed light on plant susceptibility and tolerance. It is possible to manipulate a plant's immune system to overcome the crown gall disease and increase its competence via A. tumefaciens-mediated transformation. This review summarises the recent advances in the molecular mode of Agrobacterium pathogenesis as well as the three-layered immune response of plants against Agrobacterium infection.


Assuntos
Agrobacterium tumefaciens , Plantas , Agrobacterium tumefaciens/genética , Tumores de Planta/genética , Tumores de Planta/microbiologia , Plantas/genética , Virulência
9.
Plant Cell Rep ; 41(4): 873-891, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35067774

RESUMO

KEY MESSAGE: OsGSTU5 interacts and glutathionylates the VirE2 protein of Agrobacterium and its (OsGSTU5) overexpression and downregulation showed a low and high AMT efficiency in rice, respectively. During Agrobacterium-mediated transformation (AMT), T-DNA along with several virulence proteins such as VirD2, VirE2, VirE3, VirD5, and VirF enter the plant cytoplasm. VirE2 serves as a single-stranded DNA binding (SSB) protein that assists the cytoplasmic trafficking of T-DNA inside the host cell. Though the regulatory roles of VirE2 have been established, the cellular reaction of their host, especially in monocots, has not been characterized in detail. This study identified a cellular interactor of VirE2 from the cDNA library of rice. The identified plant protein encoded by the gene cloned from rice was designated OsGSTU5, it interacted specifically with VirE2 in the host cytoplasm. OsGSTU5 was upregulated during Agrobacterium infection and involved in the post-translational glutathionylation of VirE2 (gVirE2). Interestingly, the in silico analysis showed that the 'gVirE2 + ssDNA' complex was structurally less stable than the 'VirE2 + ssDNA' complex. The gel shift assay also confirmed the attenuated SSB property of gVirE2 over VirE2. Moreover, knock-down and overexpression of OsGSTU5 in rice showed increased and decreased T-DNA expression, respectively after Agrobacterium infection. The present finding establishes the role of OsGSTU5 as an important target for modulation of AMT efficiency in rice.


Assuntos
Agrobacterium , Oryza , Agrobacterium/genética , Agrobacterium/metabolismo , Agrobacterium tumefaciens/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Canais Iônicos/metabolismo , Oryza/genética , Oryza/metabolismo
10.
J Hazard Mater ; 426: 128100, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-34954436

RESUMO

Arsenic (As) considered as one of the hazardous metalloid that hampers various physiological activities in rice. To study the mechanism of As tolerance in rice, one differentially expressed tau class glutathione-S-transferase (OsGSTU5) has been selected and transgenic rice plants with knockdown (KD) and overexpressing (OE) OsGSTU5 were generated. Our results suggested that KD lines became less tolerant to As stress than WT plants, while OE lines showed enhanced tolerance to As. Under As toxicity, OE and KD lines showed enhanced and reduced antioxidant activities such as, SOD, PRX and catalase, respectively indicating its role in ROS homeostasis. In addition, higher malondialdehyde content, poor photosynthetic parameters and higher reactive oxygen species (ROS) in KD plant, suggests that knockdown of OsGSTU5 renders KD plants more susceptible to oxidative damage. Also, the relative expression profile of various transporters such as OsABCC1 (As sequestration), Lsi2 and Lsi6 (As translocaters) and GSH dependent activity of GSTU5 suggests that GSTU5 might help in chelation of As with GSH and sequester it into the root vacuole using OsABCC1 transporter and thus limits the upward translocation of As towards shoot. This study suggests the importance of GSTU5 as a good target to improve the As tolerance in rice.


Assuntos
Arsênio , Oryza , Antioxidantes , Arsênio/toxicidade , Glutationa , Glutationa Transferase/genética , Oryza/genética , Raízes de Plantas
11.
Biol Trace Elem Res ; 200(8): 3594-3607, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34705190

RESUMO

Hepatocellular carcinoma is among the leading causes of cancer-related deaths worldwide and needs efficient and feasible approach of treatment. Present study focuses on exploring the anticancer activity of a secondary metabolite called siderophore of Aspergillus nidulans against hepatocellular carcinoma cell line HepG2. These small peptides are produced by microorganisms including fungi for scavenging iron from its surroundings. Fungi including Aspergillus spp. are known to produce siderophores under iron-limited conditions. Siderophores have high affinity towards iron and are classified into various types. In the present study, siderophore isolated and purified from fungal cultures was confirmed to be of hydroxamate type by chrome azurol sulfonate and Atkin's assay. HPLC analysis confirmed purity while LC-ESI-MS revealed that the siderophore is triacetyl fusigen. Cancerous cells, HepG2, grown under siderophore treatment showed inhibition in growth and proliferation in a dose- and time-dependent manner. Reduction in viability and metabolic activity was evident upon treatment as seen in trypan blue, MTT and WST assay. Fluorescent staining using PI and DAPI confirmed the same while DCFDA staining revealed increased reactive oxygen species production which might have led to cell death and deterioration. Such increase in ROS has been correlated with iron accumulation by assessing intracellular iron level through ICP-MS. To assess the effect of siderophore treatment on normal cells, WRL-68, same assays were carried out but the effect was mostly non-significant up to 48 h. Thus, present work suggests that an optimum dose of siderophore purified from A. nidulans culture might prove a useful anticancer agent.


Assuntos
Aspergillus nidulans , Carcinoma Hepatocelular , Neoplasias Hepáticas , Aspergillus nidulans/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular , Humanos , Ferro/metabolismo , Ferro/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Sideróforos/farmacologia
12.
J Environ Sci Health B ; 56(11): 962-968, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34693893

RESUMO

To test the tolerance and degradation potential of the cyanobacterium Fischerella sp. lmga1 for surfactant, sodium dodecyl sulfate (SDS), different doses of SDS (10, 30, 40, 50, 70 and 100 µM) were used for the growth. The lower doses of SDS supported the growth of cyanobacterium whereas the higher doses were found to be inhibitory but the cyanobacterium somehow managed its survival up to 100 µM SDS. However, a significant reduction was observed in the pigment and protein content. A substantial accumulation of carbohydrate at 70 µM SDS may act as an osmoprotectant for the survival of the cyanobacterium. The higher doses of SDS also triggered the ROS generation and lipid peroxidation which showed negative impact on the PSII efficiency. Simultaneously, an efficient ROS mitigation system (SOD and CAT activity) has also been worked up to 70 µM SDS while APX was enhanced only up to 50 µM SDS. Furthermore, the SDS degrading potential was investigated and almost 80% of the SDS was degraded after 6th days of treatment in the cyanobacterium. Hence, the results suggested that due to robust antioxidative defence system and ability to degrade the surfactant this cyanobacterium showed significant tolerance toward SDS.


Assuntos
Antioxidantes , Cianobactérias , Dodecilsulfato de Sódio , Tensoativos
13.
3 Biotech ; 11(7): 354, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34249595

RESUMO

The biosynthesis of cysteine is crucial and critically regulated by two enzymes. i.e., serine acetyl transferase (SAT) and O-acetyl serine (thiol) lyase (OAS-TL). A descriptive account on the activity and regulatory mechanism of the enzyme is available in bacteria and plants. But no such studies yet performed in cyanobacteria, to understand the evolutionary aspect of cysteine biosynthesis and its regulation. Therefore, in our study a detailed bioinformatic analysis has been performed to understand all the possible features of cyanobacterial SATs and OAS-TLs. The analysis of SAT and OAS-TL sequences from cyanobacteria depicted that the large genome and morphological complexities favoured acquisition of these genes. Besides, conserved function of these enzymes was presumed by their sequence similarity. Further, the phylogenetic tree consisted of distinct clusters for unicellular, filamentous, and heterocytous strains. Nevertheless, the specificity pocket, SVKDR for OAS-TL having K as catalytic residue was also identified. Additionally, in silico protein modelling of SAT (SrpG) and OAS-TL (SrpH) of Synechococcus elongatus PCC 7942 was performed to gain insight into the structural attributes of the proteins. Finally, here we showed the possibility of hetero-oligomeric bi-enzyme cysteine synthase complex formation upon interaction of SAT and OAS-TL through protein-protein docking analysis thus provides a way to understand the regulation of cysteine biosynthesis in cyanobacteria. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02899-1.

14.
Front Microbiol ; 12: 682306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276616

RESUMO

The functionality of caspase homologs in prokaryotic cell execution has been perceived, yet the dimensions of their metabolic pertinence are still cryptic. Here, a detailed in silico study on putative cyanobacterial caspase homologs, termed orthocaspases, in a sequenced genome of 132 strains was performed. We observed that 473 putative orthocaspases were distributed among 62% cyanobacterial strains subsumed within all the taxonomical orders. However, high diversity among these orthocaspases was also evident as the conventional histidine-cysteine (HC) dyad was present only in 72.03% of orthocaspases (wild-type), whereas the rest 28.18% were pseudo-variants having substituted the catalytic dyad. Besides, the presence of various accessory functional domains with Peptidase C14 probably suggested the multifunctionality of the orthocaspases. Moreover, the early origin and emergence of wild-type orthocaspases were conferred by their presence in Gloeobacter; however, the complex phylogeny displayed by these caspase-homologs perhaps suggested horizontal a gene transfer for their acquisition. However, morpho-physiological advancements and larger genome size favored the acquisition of orthocaspases. Moreover, the conserved caspase hemoglobinase fold not only in the wild-type but also in the pseudo-orthocaspases in Nostoc sp. PCC 7120 ascertained the least effect of catalytic motifs in the protein tertiary structure. Further, the 100-ns molecular dynamic simulation and molecular mechanics/generalized born surface area exhibited stable binding of arginylarginine dipeptide with wild-type orthocaspase of Nostoc sp. PCC 7120, displaying arginine-P1 specificity of wild-type orthocaspases. This study deciphered the distribution, diversity, domain architecture, structure, and basic substrate specificity of putative cyanobacterial orthocaspases, which may aid in functional investigations in the future.

15.
Artigo em Inglês | MEDLINE | ID: mdl-33638788

RESUMO

The current study describes the mechanisms of zinc toxicity in the cyanobacterium Anabaena sphaerica after eight days treatment with 10 mg L-1 ZnCl2. The application of zinc not only showed elevated accumulation of the metal inside the cells but also exhibited devastating impacts on the cell numbers, morphology, and ultrastructure of A. sphaerica. The effects of zinc on the pigments contents, oxygen evolution rate, Fv/Fm, electron transport rate, and carbohydrate content were also evaluated in A. sphaerica. Moreover, zinc adversely affected nutrient uptake and the cellular energy budget in the test cyanobacterium which in turn hampered heterocyst development and nitrogen fixation. Alongside, the cyanobacterium experienced zinc-mediated non-competitive inhibition of glutamine synthetase activity, curtailed synthesis of amino acids and proteins. Furthermore, drastically reduced total lipid and increased unsaturated lipid contents were also the prominent characteristics of zinc stressed A. sphaerica. Most importantly, zinc stress caused severe damages to the protein, lipid, and DNA by triggering hydrogen peroxide generation and accumulation of oxidized glutathione. Therefore, excess zinc is highly toxic to the cyanobacterium A. sphaerica, and the mechanisms of its toxicity followed a cascade of events including oxidative stress mediated geopardisation of growth and ultrastructure, metabolic derangements, and macromolecular damages.

16.
Appl Biochem Biotechnol ; 193(5): 1447-1468, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33484449

RESUMO

The wide applications, uniqueness, and high quality of cyanobacterial exopolysaccharides (EPSs) have attracted many biotechnologists. Despite it, the inducers and molecular determinants of EPS biosynthesis in cyanobacteria are lesser known. Although, studies revealed that environmental cues especially C/N ratio as the prime modulator, the factors like light, temperature, moisture, and nutrient availability, etc. have been overlooked. Due to this, the possibilities to modify cyanobacterial system for achieving higher quantity of EPS either by modifying growth medium or metabolic engineering are restricted to few optimisations. Therefore, the present work describes the impact of sulfate limitations on the EPS production and compositions in the cyanobacterium Anabaena sp. PCC 7120. Increased EPS production with enhanced expression of alr2882 was observed in lower sulfate supplementations; however, FTIR analysis depicted an altered composition of supramolecule. Furthermore, in silico analysis of Alr2882 depicted the presence of ExoD domain and three transmembrane regions, thereby indicating its membrane localisation and role in the EPS production. Additionally, the phylogeny and multiple sequence alignment showed vertical inheritance of exoD and conservation among cyanobacteria. The meta-threading template-based modelling and ab initio full atomic relaxation by LOMET and ModRefiner servers, respectively, also exhibited helical topology of Alr2882, with nine α-helices arranged antiparallel to the preceding one. Moreover, post-translational modifications predicted in Alr2882 indicated high order of molecular regulation underlining EPS production in Anabaena sp. PCC 7120. This study provides a foundation for understanding the EPS biosynthesis mechanism under sulfur limitation and the possible role of ExoD in cyanobacteria.


Assuntos
Anabaena/metabolismo , Proteínas de Bactérias/metabolismo , Anabaena/genética , Proteínas de Bactérias/genética , Cianobactérias/genética , Cianobactérias/metabolismo , Processamento de Proteína Pós-Traducional , Análise de Sequência de DNA , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Curr Drug Discov Technol ; 18(1): 120-126, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-31994466

RESUMO

AIMS: The aim of present investigation was to evaluate the traditional claim of Ficus retusa as an anti-diarrheal and anti-spasmodic agent using different pharmacological models. BACKGROUND: Diarrhea is considered as major cause of mortality, especially in children and aged persons. Because of diarrhoea, 17% of admitted children get die. In order to treat the diarrhea, natural drugs may be useful. OBJECTIVE: In order to prove the traditional claim of Ficus retusa, present work was undertaken with objective to prove antidiarrheal and antispasmodic activity. METHODS: The anti-diarrhoeal activity was evaluated by magnesium sulphate induced diarrhea and 5-hydroxy tryptamine(5HT) induced diarrhea. Further, the exact were subjected to gastrointestinal motility test using standard procedure. RESULT: Finding of the present study suggested that significant response was exhibited by ethanolic extract (400mg/kg bw.) of Ficus retusa. CONCLUSION: The response towards bioactivity was dose dependent. It was concluded that 400mg/kg bw of ethanolic extract is most potent in antidiarrhoeal and antispasmodic activity.


Assuntos
Antidiarreicos/farmacologia , Diarreia , Ficus , Parassimpatolíticos/farmacologia , Animais , Diarreia/tratamento farmacológico , Diarreia/fisiopatologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos/métodos , Fármacos Gastrointestinais/farmacologia , Motilidade Gastrointestinal/efeitos dos fármacos , Fitoterapia/métodos , Extratos Vegetais/farmacologia , Folhas de Planta , Ratos , Ratos Wistar , Resultado do Tratamento
18.
Mini Rev Med Chem ; 21(3): 314-335, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32819243

RESUMO

Benzothiazole is a heterocyclic aromatic and bicyclic compound in which, benzene ring is attached with thiazole ring. This nucleus is established in marine as well as terrestrial natural compounds. The benzothiazole skeleton is established in a broad variety of bioactive heterocycles and natural products. The benzothiazole nucleus is considered as the principle moiety in several biologically active compounds. Over the decade, chemists are paying more attention towards the revision of the biological and therapeutic activities such as antimicrobial, analgesic, antiinflammatory, antitubercular, antiviral and antioxidant of benzothiazole containing compounds. The molecular structures of a number of potent drugs including Frentizole, Pramipexole, Thioflavin T and Riluzole etc., are based on benzothiazole skeleton. The present work is the compilation and presentation of all available information in a systematic manner with an aim to present the findings in a way, which may be beneficial for future research.


Assuntos
Benzotiazóis/química , Benzotiazóis/farmacologia , Animais , Descoberta de Drogas , Humanos
19.
J Exp Bot ; 71(16): 4639-4657, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32369588

RESUMO

Programmed cell death (PCD), a genetically orchestrated mechanism of cellular demise, is paradoxically required to support life. As in lower eukaryotes and bacteria, PCD in cyanobacteria is poorly appreciated, despite recent biochemical and molecular evidence that supports its existence. Cyanobacterial PCD is an altruistic reaction to stressful conditions that significantly enhances genetic diversity and inclusive fitness of the population. Recent bioinformatic analysis has revealed an abundance of death-related proteases, i.e. orthocaspases (OCAs) and their mutated variants, in cyanobacteria, with the larger genomes of morphologically complex strains harbouring most of them. Sequence analysis has depicted crucial accessory domains along with the proteolytic p20-like sub-domain in OCAs, predicting their functional versatility. However, the cascades involved in sensing death signals, their transduction, and the downstream expression and activation of OCAs remain to be elucidated. Here, we provide a comprehensive description of the attempts to identify mechanisms of PCD and the existence and importance of OCAs based on in silico approaches. We also review the evolutionary and ecological significance of PCD in cyanobacteria. In the future, the analysis of cyanobacterial PCD will identify novel proteins that have varied functional roles in signalling cascades and also help in understanding the incipient mechanism of PCD morphotype(s) from where eukaryotic PCD might have originated.


Assuntos
Apoptose , Cianobactérias , Evolução Biológica , Caspases/genética , Caspases/metabolismo , Cianobactérias/genética , Cianobactérias/metabolismo , Proteólise
20.
3 Biotech ; 10(3): 84, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32089979

RESUMO

Glutathione-S-transferase (GST) is an important defense gene that confers resistance against several abiotic and biotic stresses. The present study identifies a tau class GST in rice (Oryza sativa L.), OsGSTU5 (Os09g20220), which provided tolerance against sheath blight (SB) disease, caused by a necrotrophic fungus, Rhizoctonia solani (RS). Overexpression and knockdown rice transgenic lines of OsGSTU5 were generated and tested for the severity of infection during sheath blight disease. The results obtained after RS infection showed that the lesion cover area and hyphal penetration were more in knockdown line and lesser in the overexpression line. Analysis of reactive oxygen species (ROS) accumulation showed more spots of H2O2 and O2- in knockdown lines compared to overexpressed lines. Later, RS transcript level was analyzed in RS-infected transgenic lines, which manifested that the knockdown line had higher RS transcripts in comparison to the control line and least RS transcripts were observed in the overexpressed line. In conclusion, rice transgenic lines overexpressing OsGSTU5 were found to be more tolerant, while the knockdown lines were more prone to Rhizoctonia infection compared to control lines.

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