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1.
Toxicol Appl Pharmacol ; 487: 116978, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38795847

RESUMO

Non-small cell lung cancer (NSCLC) is a complex malignancy with a high degree of heterogeneity, representing approximately 85% of all lung cancer cases. The treatment landscape for NSCLC has been revolutionised by incorporating targeted and immunotherapies; however, novel therapeutic modalities are consistently needed to enhance the treatment outcomes. Indeed, alternative anti-cancer therapies involving natural products have drawn the attention of clinicians and scientists owing to their remarkable chemopreventive potential, often displaying minimal toxicity. D-carvone (CN) is one such natural product that has exhibited numerous promising therapeutic benefits, yet its efficacy against NSCLC remains enigmatic. In the present study, network pharmacological studies and molecular docking in conjunction with in-vitro validation were used to elucidate the underlying mechanism of action of CN comprehensively. Different databases revealed a total of 77 putative anti-NSCLC targets of CN. The identified core targets were utilised to construct a "Compound- Target- Disease" network by Cytoscape (v3.9.0). Further analysis identified 5 core/ hub targets of CN including JAK2, ERK1, ESR1, GSK3B and HSP90AA1. Molecular docking indicated a strong binding interaction of the compound with these core targets. Also, Gene Ontology and KEGG analysis validated the involvement of multiple biological processes. Additionally, CN significantly inhibited cell proliferation, clonogenicity, and wound healing potential while promoting apoptosis in a dose-dependent manner in H1299 and A549 cell lines as examined by flow cytometry, morphological assessment, and western blotting. In conclusion, this study delineates the therapeutic effects of CN on NSCLC, thus highlighting CN as a putative drug candidate for further analysis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Monoterpenos Cicloexânicos , Neoplasias Pulmonares , Simulação de Acoplamento Molecular , Farmacologia em Rede , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Monoterpenos Cicloexânicos/farmacologia , Células A549 , Linhagem Celular Tumoral , Transdução de Sinais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Mapas de Interação de Proteínas , Apoptose/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química
2.
Arch Microbiol ; 206(2): 88, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38305873

RESUMO

The COVID-19 pandemic caused unprecedented damage to humanity, and while vaccines have been developed, they are not fully effective against the SARS-CoV-2 virus. Limited targeted drugs, such as Remdesivir and Paxlovid, are available against the virus. Hence, there is an urgent need to explore and develop new drugs to combat COVID-19. This study focuses on exploring microbial natural products from soil-isolated bacteria Streptomyces sp. strain 196 and RI.24 as a potential source of new targeted drugs against SARS-CoV-2. Molecular docking studies were performed on holoRdRp and nsp13, two key factors responsible for virus replication factor. Our in silico studies, K-252-C aglycone indolocarbazole alkaloid (K252C) and daunorubicin were found to have better binding affinities than the respective control drugs, with K252C exhibiting binding energy of - 9.1 kcal/mol with holoRdRp and - 9.2 kcal/mol with nsp13, and daunorubicin showing binding energy at - 8.1 kcal/mol with holoRdRp and - 9.3 kcal/mol with nsp13. ADMET analysis, MD simulation, and MM/GBSA studies indicated that K252C and daunorubicin have the potential to be developed as targeted drugs against SARS-CoV-2. The study concludes that K252C and daunorubicin are potential lead compounds that might suppress the inhibition of SARS-CoV-2 replication among the tested microbial compounds and could be developed as targeted drugs against COVID-19. In the future, further in vitro studies are required to validate these findings.


Assuntos
Produtos Biológicos , COVID-19 , Humanos , SARS-CoV-2 , Produtos Biológicos/farmacologia , Simulação de Acoplamento Molecular , Pandemias , Daunorrubicina/farmacologia , Inibidores de Proteases
3.
J Fluoresc ; 33(2): 751-772, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36515760

RESUMO

Compound, (E)-5-(4-((thiophen-2-ylmethylene)amino)phenyl)-1,3,4-oxadiazole-2-thiol (3) was synthesized via condensation reaction of 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol with thiophene-2-carbaldehyde in ethanol. For the synthesis and structural confirmation the FT-IR, 1H, 13C-NMR, UV-visible spectroscopy, and mass spectrometry were carried out. The long-term stability of the probe (3) was validated by the experimental as well as theoretical studies. The sensing behaviour of the compound 3 was monitored with various metal ions (Ca2+, Cr3+, Fe3+, Co2+, Mg2+, Na+, Ni2+, K+) using UV- Vis. and fluorescence spectroscopy techniques by various methods (effect of pH and density functional theory) which showing the most potent sensing behaviour with iron. Job's plot analysis confirmed the binding stoichiometry ratio 1:1 of Fe3+ ion and compound 3. The limit of detection (LOD), the limit of quantification (LOQ), and association constant (Ka) were calculated as 0.113 µM, 0.375 µM, and 5.226 × 105 respectively. The sensing behavior was further confirmed through spectroscopic techniques (FT-IR and 1H-NMR) and DFT calculations. The intercalative mode of binding of oxadiazole derivative 3 with Ct-DNA was supported through UV-Vis spectroscopy, fluorescence spectroscopy, viscosity, cyclic voltammetry, and circular dichroism measurements. The binding constant, Gibb's free energy, and stern-volmer constant were find out as 1.24 × 105, -29.057 kJ/mol, and 1.82 × 105 respectively. The cleavage activity of pBR322 plasmid DNA was also observed at 3 × 10-5 M concentration of compound 3. The computational binding score through molecular docking study was obtained as -7.4 kcal/mol. Additionally, the antifungal activity for compound 3 was also screened using broth dilution and disc diffusion method against C. albicans strain. The synthesized compound 3 showed good potential scavenging antioxidant activity against DPPH and H2O2 free radicals.


Assuntos
Corantes Fluorescentes , Bases de Schiff , Bases de Schiff/química , Espectroscopia de Infravermelho com Transformada de Fourier , Simulação de Acoplamento Molecular , Íons , Corantes Fluorescentes/química , DNA/química
4.
Chem Biodivers ; 20(5): e202300096, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37042439

RESUMO

Working principle of azoles as antifungals is the inhibition of fungal CYP51/lanosterol-14α-demethylase via selective coordination with heme iron. This interaction can also cause side effects by binding to host lanosterol-14α-demethylase. Hence, it is necessary to design, synthesize and test new antifungal agents that have different structures than those of azoles and other antifungal drugs of choice in clinical practice. Consequently, a series of steroidal 1,4-dihydropyridine analogs 16-21 were synthesized and screened for their in vitro anti-fungal activity against three Candida species as steroids-based medications have low toxicity, less vulnerability to multi-drug resistance, and high bioavailability by being capable of penetrating the cell wall and binding to specific receptors. Initially, Claisen-Schmidt condensation takes place between steroidal ketone (dehydroepiandrosterone) and an aromatic aldehyde forming steroidal benzylidene 8-13 followed by Hantzsch 1,4-dihydropyridine synthesis resulting in steroidal 1,4-dihydropyridine derivatives 16-21. The results exhibited that compound 17 has significant anti-fungal potential with an MIC value of 750 µg/ml for C. albicans and C. glabrata and 800 µg/ml for C. tropicalis. In silico molecular docking and ADMET studies were also performed for compounds 16-21.


Assuntos
Antifúngicos , Lanosterol , Simulação de Acoplamento Molecular , Lanosterol/farmacologia , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Antifúngicos/química , Azóis/química , Azóis/farmacologia , Candida albicans
5.
Bioorg Chem ; 129: 106218, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36341741

RESUMO

The use of aqueous cyanobacterial extracts for selenium nanoparticle (SeNP) synthesis is considered green, cost-effective, and eco-friendly technology that is more advanced than physical and chemical methods. In the current study, an aqueous extract of Arthrospira indica SOSA-4 was used as a reducing and stabilizing agent for the green synthesis of SeNPs. The UV-Visible absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-Ray diffraction, Raman spectroscopy, Atomic force microscopy (AFM), Scanning electron microscopy-Energy Dispersive X-Ray spectroscopy(SEM-EDX), and Transmission electron microscopy (TEM) were performed to characterize the biosynthesized SeNPs. Gas chromatography-Mass spectrometry (GC-MS) was also performed to know the composition of the cyanobacterial extract. SEM, TEM, and AFM showed the average size of SeNPs to be 8.5 nm, 9 nm, and 8.7 nm respectively. FT-IR analysis demonstrated the presence of functional groups on the SeNPs that acted as stabilizing agents. XRD pattern and Raman spectroscopy showed the amorphous nature of SeNPs. Synthesized SeNPs showed significant antioxidant activity in DPPH, FRAP, SOR, and ABTS assay. SeNPs showed good anti-microbial activity against Staphylococcus aureus, Escherichia coli, Candida albicans, Candida glabrata, and Candida tropicalis and good anti-cancer activity in MTT assay, Trypan assay, and Flow cytometry analysis against MCF-7, SiHa, and SW480 cell lines. Non-toxicity of SeNPs against normal cell line (HEK-293) was an additional property that affirmed its potential as a bio-compatible nanomaterial.


Assuntos
Cianobactérias , Selênio , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Células HEK293 , Selênio/química , Extratos Vegetais/química , Antibacterianos/farmacologia , Antibacterianos/química
6.
Luminescence ; 37(3): 408-421, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34986516

RESUMO

An oxadiazole derivative 2 was prepared by condensation reaction through cyclization of semicarbazone in the presence of bromine; the structural confirmation was supported by 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform-infrared spectroscopy, and liquid chromatography-mass spectrometry. Its sensing ability towards Ni2+ ion was examined showing a binding constant of 1.04 × 105 compared with other suitable metal cations (Ca2+ , Co2+ , Cr3+ , Ag+ , Pb2+ , Fe3+ , Mg2+ , and K+ ) using ultraviolet-visible (UV-vis) and fluorescence spectroscopic studies. The minimum concentration of Ni2+ ions and limit of detection was found to be 9.4 µM. A job's plot gave the binding stoichiometry ratio of oxadiazole derivative 2 vs Ni2+ ions as 2:1. Furthermore, the intercalative binding mode of oxadiazole derivative 2 with calf thymus DNA was supported by ultraviolet-visible (UV-vis) and fluorescent light, viscosity, cyclic voltammetry, time-resolved fluorescence, and circular dichroism measurements. The molecular docking result gave the binding score for oxadiazole derivative 2 as -6.5 kcal/mol, which further confirmed the intercalative interaction. In addition, the antifungal activity of oxadiazole derivative 2 was also screened against several fungal strains (C. albicans, C. glabrata, and C. tropicalis) by broth dilution and disc diffusion methods. In antioxidant studies, the oxadiazole derivative 2 showed potential scavenging activity against 2,2-diphenyl-1-picrylhydrazyl and H2 O2 free radicals.


Assuntos
Antifúngicos , Antioxidantes , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , DNA/química , Íons , Simulação de Acoplamento Molecular , Oxidiazóis , Espectrometria de Fluorescência
7.
Cell Microbiol ; 22(2): e13140, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31736226

RESUMO

Hypoxic adaptation pathways, essential for Candida albicans pathogenesis, are tied to its transition from a commensal to a pathogen. Herein, we identify a WW domain-containing protein, Ifu5, as a determinant of hypoxic adaptation that also impacts normoxic responses in this fungus. Ifu5 activity supports glycosylation homeostasis via the Cek1 mitogen-activated protein kinase-dependent up-regulation of PMT1, under normoxia. Transcriptome analysis of ifu5Δ/Δ under normoxia shows a significant up-regulation of the hypoxic regulator EFG1 and EFG1-dependent genes. We demonstrate physical interaction between Ifu5 by virtue of its WW domain and Efg1 that represses EFG1 expression under normoxia. This interaction is lost under hypoxic growth conditions, relieving EFG1 repression. Hypoxic adaptation processes such as filamentation and biofilm formation are affected in ifu5Δ/Δ cells revealing the role of Ifu5 in hypoxic signalling and modulating pathogenicity traits of C. albicans under varied oxygen conditions. Additionally, the WW domain of Ifu5 facilitates its role in hypoxic adaptation, revealing the importance of this domain in providing a platform to integrate various cellular processes. These data forge a relationship between Efg1 and Ifu5 that fosters the role of Ifu5 in hypoxic adaptation thus illuminating novel strategies to undermine the growth of C. albicans.


Assuntos
Candida albicans/patogenicidade , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Virulência/metabolismo , Regulação Fúngica da Expressão Gênica , Hifas , Virulência , Domínios WW
8.
Med Mycol ; 58(1): 93-106, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30843057

RESUMO

The pathogenicity of Candida albicans, an opportunistic human fungal pathogen, is attributed to several virulence factors. ß-citronellol is a monoterpenoid present in several plant essential oils. The present study explores the antifungal potential and mode of action of ß-citronellol against C. albicans ATCC 90028 (standard), C. albicans D-27 (FLC-sensitive), and C. albicans S-1 (FLC-resistant). Anti-Candida potential was studied by performing MIC, MFC, growth curves, disc diffusion, spot assay, and WST1 cytotoxic assay. Morphological transition was monitored microscopically in both solid and liquid hyphae inducing media. ß-citronellol inhibits yeast to hyphal transition in both liquid and solid hyphae inducing media. It had a significant inhibitory effect on biofilm formation and secretion of extracellular proteinases and phospholipases. We showed that it has an adverse effect on membrane ergosterol levels and modulates expression of related ERG genes. Expression profiles of selected genes associated with C. albicans pathogenicity displayed reduced expression in treated cells. This work suggests that ß-citronellol inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as modulates the expression of associated genes. Pleiotropic phenotype shown by ß-citronellol treated Candida cells suggests various modes of action. Further studies will assess the clinical application of ß-citronellol in the treatment of fungal infections.


Assuntos
Monoterpenos Acíclicos/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Óleos Voláteis/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/genética , Candida albicans/patogenicidade , Proteínas Fúngicas/genética , Hifas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Fenótipo , Virulência , Fatores de Virulência/genética
9.
Org Biomol Chem ; 14(45): 10599-10619, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27735963

RESUMO

The increasing incidence of human candidiasis and the tendency of Candida species to become resistant to existing chemotherapies are well-recognized health problems. The present study demonstrates the successful synthesis of novel triazole-amino acid hybrids with potent in vitro and in vivo inhibitory activity against Candida species. Particularly, compounds 68 and 70 showed potent in vitro activity against fluconazole (FLC) resistant as well as sensitive clinical isolates of Candida albicans. Time kill curve analysis of lead inhibitors 68 and 70 showed their fungistatic nature. Secretion of hydrolytic enzymes, mainly proteinases and phospholipases, decreased considerably in the presence of 68 and 70 indicating their interference in fungal virulence. TEM analysis of Candida cells exposed to compounds 68 and 70 clearly showed morphological changes and intracellular damage as their possible mode of action. A preliminary mechanistic study carried out on the two most effective inhibitors (68 and 70) revealed the inhibition of ergosterol biosynthesis thereby causing the cells to lose their integrity and viability. The selected compounds did not show significant cytotoxicity up to a concentration of 200 µg mL-1 in the HEK293 cell line. An in silico analysis of 68 and 70 binding to a modeled C. albicans CYP51 showed critical H-bonding as well as hydrophobic interactions with the important active site residues indicating the basis of their anti-Candida role. Studies on the larvae of Galleria mellonella showed that the selected inhibitors (68 and 70) were non-toxic, did not provoke an immune response and significantly reduced Candida proliferation in vivo.


Assuntos
Aminoácidos/química , Aminoácidos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Triazóis/química , Triazóis/farmacologia , Candida/crescimento & desenvolvimento , Candida/metabolismo , Candida/patogenicidade , Candidíase/tratamento farmacológico , Fluconazol/farmacologia , Células HEK293 , Humanos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Esterol 14-Desmetilase/metabolismo , Virulência/efeitos dos fármacos
10.
Microb Pathog ; 80: 50-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25681060

RESUMO

Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps and restore antifungal susceptibility to fluconazole in resistant Candida strains. Exposure to these natural compounds induces a cascade of stress responses, which are important to comprehend their microbicidal mechanisms. This study evaluates the antioxidant defense response to lower concentrations of thymol and carvacrol in Candida albicans. The antioxidant defense responses in C. albicans are important for developmental mechanisms pertaining to resistance against the immune system, infection establishment and drug resistance. In this view, primary and secondary antioxidant defense enzymes, and oxidative stress markers including glutathione and lipid peroxidation were determined in C. albicans cells exposed to lower concentrations of thymol and carvacrol. These compounds were found to induce oxidative stress and compromised the antioxidant defense system in C. albicans at lower concentrations. This study helps in understanding the 'in cell' antifungal mechanisms of natural monoterpene phenols originating from oxidative stress. Thymol and carvacrol induced membrane deterioration reported earlier, is further explained as a result of a toxic radical cascade mediated by lipid peroxidation. Findings reinforce the observed toxic oxidizing effects of these compounds as a consequence of direct damage to antioxidant components and not to their genetic manipulations.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/metabolismo , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Monoterpenos/farmacologia , Estresse Oxidativo , Timol/farmacologia , Candida albicans/fisiologia , Cimenos , Glutationa/análise , Peroxidação de Lipídeos
11.
Bioprocess Biosyst Eng ; 38(9): 1773-81, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26017756

RESUMO

Biomimetic and economic method for the synthesis of silver nanoparticles (AgNPs) with controlled size has been reported in presence of shape-directing cetlytrimethylammonium bromide (CTAB). Biochemical reduction of Ag(+) ions in micellar solution with an aqueous lemon extract produced spherical and polyhedral AgNPs with size ranging from 15 to 30 nm. The influence of [CTAB] and [lemon extract] on the size of particles, fraction of metallic silver and their antimicrobial properties is discussed. The AgNPs were evaluated for their antimicrobial activities (antibacterial and antifungal) against different pathogenic organisms. For this purpose, AgNPs were tested against two model bacteria (Staphylococcus aureus (MTCC3160) and Escherichia coli (MTCC405)) and three species of Candida fungus (Candida albicans (ATCC90028), Candida glabrata (ATCC90030) and Candida tropicalis (ATCC750). AgNPs were found to be highly toxic towards both bacteria. The inhibition action was due to the structural changes in the protein cell wall.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Candida/classificação , Candida/fisiologia , Nanopartículas Metálicas/administração & dosagem , Prata/administração & dosagem , Antibacterianos/administração & dosagem , Antibacterianos/síntese química , Antifúngicos/administração & dosagem , Antifúngicos/síntese química , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Candida/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Prata/química , Especificidade da Espécie
12.
Pharm Biol ; 53(10): 1496-504, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25853964

RESUMO

CONTEXT: Mentha piperita L. (Lamiaceae) has been used in folk medicine since antiquity. Its essential oil (mint EO) and major bioactive components have antimicrobial properties but their mechanism of action is still not clear. OBJECTIVE: The present work aims to elucidate M. piperita's anti-Candida activity and mode of action. MATERIALS AND METHODS: Chemical constituents of mint EO were identified by GC-MS by injecting 0.1 ml sample in a splitless mode. MIC was determined by the broth dilution method. Synergy with fluconazole (FLC) was evaluated by checkerboard assay and FICI. Mid log phase cells harvested from YPD media were used for proton extrusion measurement and the rate of glucose-induced H(+) efflux gives PM-ATPase activity. Cell membrane integrity was estimated by total ergosterol content and scanning microscopy at respective MIC and sub-MIC values. In vitro hemolytic activity was performed to rule out possible cytotoxicity of the test compounds. RESULTS: The MIC value of mint EO, carvone, menthol, and menthone was 225, 248, 500, and 4200 µg/ml, respectively. At their respective MICs, these compounds showed 47, 42, 35, and 29% decrease in PM-ATPase activity besides showing synergy with FLC. In case of FLC-resistant strains, the decrease in H(+) efflux was by 52, 48, 32, and 30%, a trend similar to the susceptible cases. Exposed Candida cells showed a 100% decrease in the ergosterol content, cell membrane breakage, and alterations in morphology. DISCUSSION AND CONCLUSION: Our studies suggest that mint EO and its lead compounds exert antifungal activity by reducing ergosterol levels, inhibiting PM-ATPase leading to intracellular acidification, and ultimately cell death. Our results suggest that mint EO and its constituents are potential antifungal agents and need to be further investigated.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Mentha piperita , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Antifúngicos/isolamento & purificação , Candida/isolamento & purificação , Candida/fisiologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/isolamento & purificação , Óleos de Plantas/isolamento & purificação
13.
J Antimicrob Chemother ; 69(11): 2935-41, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25074855

RESUMO

OBJECTIVES: To evaluate gidB alterations for possible impact on the cumulative mechanism underlying the acquisition of high-level streptomycin resistance in Mycobacterium tuberculosis. METHODS: Fifty-two isolates with high streptomycin resistance and 23 isolates with low streptomycin resistance were sequenced for mutational analysis in the rpsL, rrs and gidB region. As the gidB protein has a complex substrate and no activity assay has yet been formulated, mutants of interest were subjected to in silico modelling and were structurally mapped together with active-site amino acid residues for assessment of the relevance to activity of the mutations found. RESULTS: Eight novel sense mutations and four novel mis-sense mutations in gidB were identified. Findings showed that active-site morphology is not only greatly affected by mutants lying in close proximity to the active-site pocket, but also by other mutations altering secondary-structure motifs and having an overall effect on protein structure. CONCLUSIONS: We conclude that gidB mutations address many unanswered questions and explain the whole story behind phenotypic streptomycin-resistant strains exhibiting no mutation in rpsL or rrs. They also validate the hypothesis of sequential progression of resistance from low to high due to the existence of gidB alterations in the genetic background.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Mycobacterium tuberculosis/genética , Estreptomicina/farmacologia , Proteínas de Bactérias/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana/métodos , Mutação/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Estrutura Secundária de Proteína
14.
Natl J Maxillofac Surg ; 15(1): 47-54, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38690249

RESUMO

Background: Cleft lip and palate (CLP) patients are prone to Candida infections (oral thrush) mainly due to poor oral hygiene, repetitive surgeries, and orthodontic procedures. Aim: This study was undertaken to evaluate the antifungal efficacy of limonene against clinical Candida isolates from CLP patients. Materials and Methods: The antifungal efficacy of limonene was studied alone and in combination with fluconazole (FLC) against six standards, twenty nine FLC sensitive, and three FLC resistant clinical strains using broth dilution, checkerboard microdilution, agar disk diffusion, growth curves, and spot assays. Results: This nontoxic monoterpene gave low minimum inhibitory concentration (MIC) values of 300-375 µg/mL and 500-520 µg/mL for FLC susceptible and FLC resistant strains, respectively. It showed synergistic interaction with FLC in all clinical and standard Candida strains (fractional inhibitory concentration (FIC) index ≤0.5). Conclusion: Significant chemosensitization of FLC was observed even against resistant clinical isolates. Complete suppression of fungal growth was observed when using combinations. Negligible toxicity, easy availability, and potent antifungal properties suggest that limonene and FLC combinations in appropriate doses can make excellent antifungal mouthwashes during CLP treatment pre and post surgery. Impending in vivo studies are needed to validate the present data.

15.
Int J Biol Macromol ; 265(Pt 2): 130826, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484813

RESUMO

This study examines cellulose films reinforced with spun cotton thread and their antifungal properties. The morphology and structure of the cellulose film are analyzed using various techniques, including X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) Spectroscopy, Field Emission Scanning Electron Microscope (FE-SEM), Atomic Force Microscope (AFM), UV-Visible Spectroscopy (UV-Vis), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). The XRD pattern confirms the crystalline nature of the spun cotton-reinforced cellulose film. UV absorption analysis shows activity in the UV region of the optical spectrum. The reinforced cellulose film shows a band gap of 4.7 eV by employing the Wood and Tauc equation. FTIR spectroscopy confirms the film's structural formation. Morphological analysis reveals a random distribution of numerous pore structures on the material's surface. Thermalgravimetric Analysis indicates the material's stability at elevated temperatures, suggesting versatile applications. The film also exhibits antifungal activity against Candida albicans. This research highlights the potential of reinforced cellulose film in various applications, such as food and non-food packaging, offering enhanced UV protection and strength for heavy goods transport. The study emphasizes the multifunctional properties of the material, showcasing its promising role as a polymer in various practical applications.


Assuntos
Antifúngicos , Celulose , Celulose/química , Antifúngicos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Polímeros/química
16.
ACS Appl Bio Mater ; 7(5): 3164-3178, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38722774

RESUMO

Microbial biofilm accumulation poses a serious threat to the environment, presents significant challenges to different industries, and exhibits a large impact on public health. Since there has not been a conclusive answer found despite various efforts, the potential green and economical methods are being focused on, particularly the innovative approaches that employ biochemical agents. In the present study, we propose a bio-nanotechnological method using magnetic cross-linked polyphenol oxidase aggregates (PPO m-CLEA) for inhibition of microbial biofilm including multidrug resistant bacteria. Free PPO solution showed only 55-60% biofilm inhibition, whereas m-CLEA showed 70-75% inhibition, as confirmed through microscopic techniques. The carbohydrate and protein contents in biofilm extracellular polymeric substances (EPSs) were reduced significantly. The m-CLEA demonstrated reusability up to 5 cycles with consistent efficiency in biofilm inhibition. Computational work was also done where molecular docking of PPO with microbial proteins associated with biofilm formation was conducted, resulting in favorable binding scores and inter-residual interactions. Overall, both in vitro and in silico results suggest that PPO interferes with microbial cell attachment and EPS formation, thereby preventing biofilm colonization.


Assuntos
Antibacterianos , Biofilmes , Catecol Oxidase , Tamanho da Partícula , Biofilmes/efeitos dos fármacos , Catecol Oxidase/metabolismo , Catecol Oxidase/química , Catecol Oxidase/antagonistas & inibidores , Antibacterianos/farmacologia , Antibacterianos/química , Teste de Materiais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Testes de Sensibilidade Microbiana , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/farmacologia , Simulação de Acoplamento Molecular , Escherichia coli/efeitos dos fármacos
17.
J Biomol Struct Dyn ; : 1-19, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38319066

RESUMO

Streptomyces spp. are considered excellent reservoirs of natural bioactive compounds. The study evaluated the bioactive potential of secondary metabolites from Streptomyces sp. strain 130 through PKS-I and NRPS gene-clusters screening. GC-MS analysis was done for metabolic profiling of bioactive compounds from strain 130 in the next set of experiments. Identified antifungal compounds underwent ADMET analyses to screen their toxicity. All compounds' molecular docking was done with the structural gene products of the aflatoxin biosynthetic pathway of Aspergillus flavus. MD simulations were utilized to evaluate the stability of protein-ligand complexes under physiological conditions. Based on the in-silico studies, compound 2,4-di-tert butyl-phenol (DTBP) was selected for in-vitro studies against Aspergillus flavus. Simultaneously, bioactive compounds were extracted from strain 130 in two different solvents (ethyl-acetate and methanol) and used for similar assays. The MIC value of DTBP was found to be 314 µg/mL, whereas in ethyl-acetate extract and methanol-extract, it was 250 and 350 µg/mL, respectively. A mycelium growth assay was done to analyze the effect of compounds/extracts on the mycelium formation of Aspergillus flavus. In agar diffusion assay, zone of inhibitions in DTBP, ethyl-acetate extract, and methanol extract were observed with diameters of 11.3, 13.3, and 7.6 mm, respectively. In the growth curve assay, treated samples have delayed the growth of fungi, which signified that the compounds have a fungistatic nature. Spot assay has determined the fungal sensitivity to a sub-minimum inhibitory concentration of antifungal compounds. The study's results suggested that DTBP can be exploited for antifungal-drug development.Communicated by Ramaswamy H. Sarma.

18.
Antimicrob Agents Chemother ; 57(11): 5580-99, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23979757

RESUMO

Mitochondrial dysfunction in Candida albicans is known to be associated with drug susceptibility, cell wall integrity, phospholipid homeostasis, and virulence. In this study, we deleted CaFZO1, a key component required during biogenesis of functional mitochondria. Cells with FZO1 deleted displayed fragmented mitochondria, mitochondrial genome loss, and reduced mitochondrial membrane potential and were rendered sensitive to azoles and peroxide. In order to understand the cellular response to dysfunctional mitochondria, genome-wide expression profiling of fzo1Δ/Δ cells was performed. Our results show that the increased susceptibility to azoles was likely due to reduced efflux activity of CDR efflux pumps, caused by the missorting of Cdr1p into the vacuole. In addition, fzo1Δ/Δ cells showed upregulation of genes involved in iron assimilation, in iron-sufficient conditions, characteristic of iron-starved cells. One of the consequent effects was downregulation of genes of the ergosterol biosynthesis pathway with a commensurate decrease in cellular ergosterol levels. We therefore connect deregulated iron metabolism to ergosterol biosynthesis pathway in response to dysfunctional mitochondria. Impaired activation of the Hog1 pathway in the mutant was the basis for increased susceptibility to peroxide and increase in reactive oxygen species, indicating the importance of functional mitochondria in controlling Hog1-mediated oxidative stress response. Mitochondrial phospholipid levels were also altered as indicated by an increase in phosphatidylserine and phosphatidylethanolamine and decrease in phosphatidylcholine in fzo1Δ/Δ cells. Collectively, these findings reinforce the connection between functional mitochondria and azole tolerance, oxidant-mediated stress, and iron homeostasis in C. albicans.


Assuntos
Candida albicans/genética , Ergosterol/metabolismo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Ferro/metabolismo , Proteínas de Membrana Transportadoras/genética , Mitocôndrias/metabolismo , Antifúngicos/farmacologia , Azóis/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Farmacorresistência Fúngica/efeitos dos fármacos , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/metabolismo , GTP Fosfo-Hidrolases/deficiência , GTP Fosfo-Hidrolases/genética , Deleção de Genes , Perfilação da Expressão Gênica , Genoma Mitocondrial , Homeostase/genética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Membrana Transportadoras/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Proteínas Mitocondriais/deficiência , Proteínas Mitocondriais/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Oxidativo , Transdução de Sinais
19.
Steroids ; 193: 109186, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36736803

RESUMO

A series of steroidal thiazolopyrimidine derivatives were developed and evaluated for their antifungal properties against Candida species using steroid as the basic skeletonand a thiazolopyrimidine heterocycle as a pharmacophore in the D-ring. Dehydroepiandrosterone, aromatic aldehydes, and 2-aminothiazole were used in a one-pot multicomponent reaction with silica sulphuric acid to generate the target molecules. Additionally, molecular docking studies were conducted to determine how synthesized steroidal derivatives interacted with the amino acid residues of CYP51 ofCandida albicans.


Assuntos
Antifúngicos , Candida albicans , Antifúngicos/química , Candida , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Esteroides/química , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Candidíase/tratamento farmacológico
20.
Natl J Maxillofac Surg ; 14(1): 72-78, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37273448

RESUMO

Aims and Objectives: This study aims to assess and compare the incidence and rate of oral candidal colonization in patients with cleft lip and palate and collate it with healthy individuals. The objectives of this study were to evaluate the factors that may affect the incidence, rate, and polycolonity of colonization of oral Candida species in patients with cleft lip and palate (CLP) as compared to healthy individuals. Materials and Methods: The current prospective study involved the collection and assessment of oral samples from 50 CLP patients and compared it with oral samples from 50 healthy individuals. Colonies of Candida albicans and other Candida species were identified by using germ tube test and differential chromogenic media. Assessment of the distribution trend of various Candida species and their variation based on age, gender, type of cleft, number of surgeries, and oral hygiene status were recorded. Results: A highly significant (P value < 0.001) statistical difference was seen in the oral carriage rate of Candida species between the two groups with values more in the study group (60.75 ± 71.43) than in controls (1.62 ± 2.22). Individually comparing the different Candida species, significant difference in presence of C albicans (P value = 0.004), C parapsilosis (P value = 0.015), and C dubliensis (P value = 0.027) was seen as compared to other species. In the context of the type of cleft and the presence of Candida species Candida albicans was the most prevalent in patients with the cleft alveolus (60.0% n = 15), unilateral CLP (66.7% n = 8), and bilateral CLP (100.0% n = 3) respectively. Nonsignificant variation in prevalence was seen in the various fungal species based on an individual's gender and oral hygiene and the number of surgeries status was observed. Conclusion: The anatomical alteration in the oral cavity of patients with CLP contributes to the high incidence and prevalence of Candida species.

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