A morphological, enzymatic and metabolic approach to elucidate apoptotic-like cell death in fungi exposed to h- and α-molybdenum trioxide nanoparticles

Nanoscale ◽  
2018 ◽  
Vol 10 (44) ◽  
pp. 20702-20716 ◽  
Author(s):  
Clemencia Chaves-Lopez ◽  
Hang N. Nguyen ◽  
Rodrigo C. Oliveira ◽  
Enrico T. Nadres ◽  
Antonello Paparella ◽  
...  

The present study compares for the first time the effects of h-MoO3and α-MoO3against two fungal strains:Aspergillus nigerandAspergillus flavus.

Author(s):  
Mubashira Begum

Abstract: Latex is a natural plant polymer and milky white fluid distributed throughout the plant body like leaves, stems, roots and fruits of all flowering plants and consists of proteins, alkaloids, starches, sugars, oils, tannins, resins and gums that coagulate on-air exposure. It is secreted by specialized plant cells called Laticifers. Plants exude latex in response to physical damage. The present study was carried out to assess the potential antifungal activity of latex of five different plants namely Plumeria rubra, Plumeria alba, Aloe vera, Calotropis procera and Calotropis gigantea against three different pathogenic strains of fungi. All five latexes were found to show good to moderated activity against all the three fungal strains, namely Trichoderma viride, Aspergillus flavus and Aspergillus niger. The latex of each plant was tested in two volumes (i.e. 10µl & 20µl), and it was found that the antifungal activity was volume-dependent, and a significant difference was also observed in the case of different fungal strains. The antifungal activity of plant latexes was evaluated by Agar well diffusion method; results revealed that among all the five latexes, the fresh latex of Plumeria rubra (Vol: 10µl &20µl) showed excellent antifungal activity against Aspergillus niger and Aspergillus flavus, whereas fresh latex of Aloe vera (Vol: 10µl & 20µl) showed excellent antifungal activity against Trichoderma viride. The results of the current research imply that the antifungal activity of latex varies with the species of plants and the fungal strains used. The results therefore demonstrated that, the used five latexes effectively inhibited the growth of three tested fungi. Hence, these plant latexes are natural, ecofriendly and can be used as good candidates for the treatment of various fungal diseases. In further words, they can be used for therapy of antifungal-resistant fungi. Keywords: Antifungal activity, Proteins, Alkaloids, Tannins, Resins, Laticifers, Plumeria rubra, Plumeria alba, Aloe vera, Calotropis procera, Calotropis gigantea, Aspergillus flavus, Aspergillus niger, Trichoderma viride, Latex, Agar well diffusion.


2017 ◽  
Vol 12 (10) ◽  
pp. 1934578X1701201
Author(s):  
Ismail Kiran ◽  
Özge Özşena ◽  
K Hüsnü Can Başer ◽  
Fatih Demirci

Cyclademol (1) was converted for the first time to 1-(4-hydroxy-3,3-dimethylcyclohexyl) ethanone (2) and 4-(1-hydroxyethyl)-2,2-dimethylcyclohexanol (3) with 31.2 and 15.1% yields by Aspergillus niger and Neurospora crassa, respectively. The resulting metabolite structures were established by FT-IR, MS and NMR spectroscopic studies, respectively. In addition, the in vitro antimicrobial activities of the substrates and metabolites were evaluated comparatively both by using agar dilution and microdilution methods. The minimum inhibitory concentrations (MIC) of the tested compounds against a panel of pathogenic bacterial strains ranged from 1000 - 4000 μg/mL, whereas the MIC values against fungal strains were between 500 −1000 μg/mL.


2019 ◽  
Author(s):  
Chem Int

Novel acyclic and cyclic merocyanine dyes derived from the nucleu of furo [(3,2-d) pyrazole; ( d 2 , 3 )imidazole]were prepared. The electronic visible absorptionspectra of all the synthesized new cyanine dyes were examined in 95% ethanolsolution to evaluate their photosensitization properties. Antibacterial andantifungal activities for some selected dyes were tested against various bacterialand fungal strains (Escherichia coli, Staphylococcus aureus, Aspergillus flavus andCandida albicans) to evaluate their antimicrobial activity. Structural identificationwas carried out via elemental analysis, visible spectra, IR and 1H NMRspectroscopic data.


2009 ◽  
Vol 14 (8) ◽  
pp. 956-969 ◽  
Author(s):  
Christophe Antczak ◽  
Toshimitsu Takagi ◽  
Christina N. Ramirez ◽  
Constantin Radu ◽  
Hakim Djaballah

Caspases are central to the execution of programmed cell death, and their activation constitutes the biochemical hallmark of apoptosis. In this article, the authors report the successful adaptation of a high-content assay method using the DEVDNucView488™ fluorogenic substrate, and for the first time, they show caspase activation in live cells induced by either drugs or siRNA. The fluorogenic substrate was found to be nontoxic over an exposure period of several days, during which the authors demonstrate automated imaging and quantification of caspase activation of the same cell population as a function of time. Overexpression of the antiapoptotic protein Bcl-XL, alone or in combination with the inhibitor Z-VAD-FMK, attenuated caspase activation in HeLa cells exposed to doxorubicin, etoposide, or cell death siRNA. This method was further validated against 2 well-characterized NSCLC cell lines reported to be sensitive (H3255) or refractory (H2030) to erlotinib, where the authors show a differential time-dependent activation was observed for H3255 and no significant changes in H2030, consistent with their respective chemosensitivity profile. In summary, the results demonstrate the feasibility of using this newly adapted and validated high-content assay to screen chemical or RNAi libraries for the identification of previously uncovered enhancers and suppressors of the apoptotic machinery in live cells. ( Journal of Biomolecular Screening 2009:956-969)


2021 ◽  
Author(s):  
Mahdi Hosseini Bafghi ◽  
Razieh Nazari ◽  
Majid Darroudi ◽  
Mohsen Zargar ◽  
Hossein Zarrinfar

Abstract Biosynthesis of nanoparticles can stand as a replacement for the available chemical and physical methods by offering new procedures as green syntheses that have proved to be simple, biocompatible, safe, and cost-effective. Considering how nanoparticles with a size of 1 to 100 nanometers contain unique physical and chemical properties, recent reports are indicative of observing the antifungal qualities of selenium nanoparticles (Se-NPs). Recently, the observance of antifungal resistance towards different species of these fungi is often reported. Therefore, due to the antifungal effects of biological nanoparticles, this study aimed to investigate the exertion of these nanoparticles and evaluate their effects on the growth of fungal pathogens. Se-NPs were biosynthesized by the application of wet reduction method, which included specific concentrations of Aspergillus flavus and Candida albicans. The presence of nanoparticles was confirmed by methods such as UV-Vis spectroscopy, FT-IR analysis, and FESEM electron microscope that involved FESEM and EDAX diagram. The fungal strains were cultured in sabouraud dextrose agar medium to perform the sensitivity test based on the minimum inhibitory concentration (MIC) method in duplicate. The utilization of Se-NPs at concentrations of 1 µg/ ml and below resulted in zero growth of fungal agents. However, their growth was inhibited by antifungal drugs at concentrations of 2 µg/ ml and higher. Based on the obtained results, biological nanoparticles produced by fungal agents at different concentrations exhibited favorable inhibitory effects on the growth of fungal strains.


2001 ◽  
Vol 64 (5) ◽  
pp. 741-743 ◽  
Author(s):  
DANTE J. BUENO ◽  
JULIO O. SILVA ◽  
GUILLERMO OLIVER

This article reports on the identification of mycoflora of 21 dry pet foods (12 belonging to dogs and 9 to cats) that corresponded to 8 commercial brands made in Argentina and imported. The isolation frequency and relative density of the prevalent fungal genera are compared too. Ten genera and fungi classified as Mycelia sterilia were identified. The predominant genera were Aspergillus (62%), Rhizopus (48%), and Mucor (38%). The most prevalent among Aspergillus was Aspergillus flavus followed by Aspergillus niger and Aspergillus terreus. The predominant Mucor was Mucor racemosus followed by Mucor plumbeus and Mucor globosus. The moisture content of these foods ranged from 5.6 to 10.0% and from 7.2 to 9.9% for dog and cat foods, respectively. A greater moisture content in food for the senior category (9.5 ± 0.2) was observed only in comparison to adult and kitten/puppy. If the moisture content can be maintained at these levels, mold growth would be prevented or at least it would remain at an insignificant level. Some genera and species isolated and identified from the foods analyzed are potentially producing toxins, which are known as mycotoxins. This involves a risk for animal health.


2012 ◽  
Vol 56 (5) ◽  
pp. 2598-2603 ◽  
Author(s):  
Wei Liu ◽  
Yi Sun ◽  
Wei Chen ◽  
Weixia Liu ◽  
Zhe Wan ◽  
...  

ABSTRACTWith voriconazole (VRC) being approved as the first choice in treating invasive aspergillosis (IA) and its increasing use in treatment, a VRC-resistant strain ofAspergillus flavus, the second leading cause of IA afterAspergillus fumigatus, has emerged. The VRC-resistant strain ofA. flavuswas isolated for the first time from the surgical lung specimen of an IA patient with no response to VRC therapy. In order to ascertain the mechanism of VRC resistance, the azole target enzyme genes in this strain ofA. flavuswere cloned and sequenced, and 4 mutations generating amino acid residue substitutions were found in thecyp51Cgene. To further determine the role of this mutated gene for VRC resistance inA. flavus, anAgrobacterium tumefaciens-mediated gene replacement approach was applied. Consequently, the mutatedcyp51Cgene from thisA. flavusstrain was proven to confer the VRC resistance. Finally, to discern the one out of the four mutations in thecyp51Cgene that is responsible for contributing to VRC resistance, a site-directed gene mutagenesis procedure combined with a gene replacement method was performed. As a result, the T788G missense mutation in thecyp51Cgene was identified as responsible for VRC resistance inA. flavus. These findings indicated that the detection of this mutation inA. flavuscould serve as an indicator for physicians to avoid the use of VRC during IA treatment. Further comprehensive surveillance for antifungal susceptibility, as well as intensive study on the mechanism of azole resistance inA. flavuscausing IA, would be required to fully understand this mechanism.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ida Perrotta ◽  
Valentina Carito ◽  
Emilio Russo ◽  
Sandro Tripepi ◽  
Saveria Aquila ◽  
...  

The word autophagy broadly refers to the cellular catabolic processes that lead to the removal of damaged cytosolic proteins or cell organelles through lysosomes. Although autophagy is often observed during programmed cell death, it may also serve as a cell survival mechanism. Accumulation of reactive oxygen species within tissues and cells induces various defense mechanisms or programmed cell death. It has been shown that, besides inducing apoptosis, oxidative stress can also induce autophagy. To date, however, the regulation of autophagy in response to oxidative stress remains largely elusive and poorly understood. Therefore, the present study was designed to examine the ratio between oxidative stress and autophagy in macrophages after oxidant exposure (AAPH) and to investigate the ultrastructural localization of beclin-1, a protein essential for autophagy, under basal and stressful conditions. Our data provide evidence that oxidative stress induces autophagy in macrophages. We demonstrate, for the first time by immunoelectron microscopy, the subcellular localization of beclin-1 in autophagic cells.


2009 ◽  
Vol 76 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Dominik Mojzita ◽  
Marilyn Wiebe ◽  
Satu Hilditch ◽  
Harry Boer ◽  
Merja Penttilä ◽  
...  

ABSTRACT d-Galacturonic acid can be obtained by hydrolyzing pectin, which is an abundant and low value raw material. By means of metabolic engineering, we constructed fungal strains for the conversion of d-galacturonate to meso-galactarate (mucate). Galactarate has applications in food, cosmetics, and pharmaceuticals and as a platform chemical. In fungi d-galacturonate is catabolized through a reductive pathway with a d-galacturonate reductase as the first enzyme. Deleting the corresponding gene in the fungi Hypocrea jecorina and Aspergillus niger resulted in strains unable to grow on d-galacturonate. The genes of the pathway for d-galacturonate catabolism were upregulated in the presence of d-galacturonate in A. niger, even when the gene for d-galacturonate reductase was deleted, indicating that d-galacturonate itself is an inducer for the pathway. A bacterial gene coding for a d-galacturonate dehydrogenase catalyzing the NAD-dependent oxidation of d-galacturonate to galactarate was introduced to both strains with disrupted d-galacturonate catabolism. Both strains converted d-galacturonate to galactarate. The resulting H. jecorina strain produced galactarate at high yield. The A. niger strain regained the ability to grow on d-galacturonate when the d-galacturonate dehydrogenase was introduced, suggesting that it has a pathway for galactarate catabolism.


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