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The quest to discover the variety of ecological niches inhabited by Saccharomyces cerevisiae has led to research in areas as diverse as wineries, oak trees and insect guts. The discovery of fungal communities in the human gastrointestinal tract suggested the host's gut as a potential reservoir for yeast adaptation. Here, we report the existence of yeast populations associated with the human gut (HG) that differ from those isolated from other human body sites. Phylogenetic analysis on 12 microsatellite loci and 1715 combined CDSs from whole-genome sequencing revealed three subclusters of HG strains with further evidence of clonal colonization within the host's gut. The presence of such subclusters was supported by other genomic features, such as copy number variation, absence/introgressions of CDSs and relative polymorphism frequency. Functional analysis of CDSs specific of the different subclusters suggested possible alterations in cell wall composition and sporulation features. The phenotypic analysis combined with immunological profiling of these strains further showed that sporulation was related with strain-specific genomic characteristics in the immune recognition pattern. We conclude that both genetic and environmental factors involved in cell wall remodelling and sporulation are the main drivers of adaptation in S. cerevisiae populations in the human gut.
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Evolução Molecular , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Insetos/microbiologia , Saccharomyces cerevisiae/genética , Animais , Variações do Número de Cópias de DNA , Genoma Fúngico , Genômica , Humanos , Microbiota , Repetições de Microssatélites , Filogenia , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/isolamento & purificaçãoRESUMO
Xanthones are specialized metabolites with antimicrobial properties, which accumulate in roots of Hypericum perforatum. This medicinal plant provides widely taken remedies for depressive episodes and skin disorders. Owing to the array of pharmacological activities, xanthone derivatives attract attention for drug design. Little is known about the sites of biosynthesis and accumulation of xanthones in roots. Xanthone biosynthesis is localized at the transcript, protein, and product levels using in situ mRNA hybridization, indirect immunofluorescence detection, and high lateral and mass resolution mass spectrometry imaging (AP-SMALDI-FT-Orbitrap MSI), respectively. The carbon skeleton of xanthones is formed by benzophenone synthase (BPS), for which a cDNA was cloned from root cultures of H. perforatum var. angustifolium. Both the BPS protein and the BPS transcripts are localized to the exodermis and the endodermis of roots. The xanthone compounds as the BPS products are detected in the same tissues. The exodermis and the endodermis, which are the outermost and innermost cell layers of the root cortex, respectively, are not only highly specialized barriers for controlling the passage of water and solutes but also preformed lines of defence against soilborne pathogens and predators.
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Vias Biossintéticas , Hypericum/anatomia & histologia , Hypericum/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/metabolismo , Xantonas/metabolismo , Acil Coenzima A/metabolismo , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Regulação da Expressão Gênica de Plantas , Lipídeos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência do Ácido Nucleico , Especificidade por Substrato , Xantonas/químicaRESUMO
The immune system is essential to maintain the mutualistic homeostatic interaction between the host and its micro- and mycobiota. Living as a commensal,Saccharomyces cerevisiaecould potentially shape the immune response in a significant way. We observed thatS. cerevisiaecells induce trained immunity in monocytes in a strain-dependent manner through enhanced TNFα and IL-6 production upon secondary stimulation with TLR ligands, as well as bacterial and fungal commensals. Differential chitin content accounts for the differences in training properties observed among strains, driving induction of trained immunity by increasing cytokine production and direct antimicrobial activity bothin vitroandin vivo These chitin-induced protective properties are intimately associated with its internalization, identifying a critical role of phagosome acidification to facilitate microbial digestion. This study reveals how commensal and passenger microorganisms could be important in promoting health and preventing mucosal diseases by modulating host defense toward pathogens and thus influencing the host microbiota-immune system interactions.
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Quitina/imunologia , Imunidade Inata , Monócitos/microbiologia , Saccharomyces cerevisiae/imunologia , Animais , Parede Celular/imunologia , Humanos , Interleucina-6/imunologia , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Fagocitose , Fator de Necrose Tumoral alfa/imunologiaRESUMO
This study aimed to evaluate the rheological properties of doughs with 50% brewers' spent grain (BSG) derived from a rye-based (RBSG) and barley-based (BBSG) beer added, and the textural profile of the related baked products. Simple model systems using BSG flour mixed with water were studied. Two bakery products, focaccia and cookies, were made as food systems using BSG in a 1:1 ratio with wheat flour (WF). Their rheological properties and texture after baking were characterized. BSG-added dough exhibited viscoelastic properties with a solid gel-like behavior. The addition of BSG increased G' > Gâ³ and decreased the dough flexibility. BSG addition in baked RBSG focaccia increased the hardness, gumminess, and chewiness by 10%, 9%, and 12%, respectively. BBSG cookies had a 20% increase in fracturability. A positive correlation was found between the rheological metrics of the dough and the textural parameters of BBSG-added cookies. PCA analysis revealed that complex viscosity, G', Gâ³, and cohesiveness separated BBSG focaccia from RBSG focaccia and the control. Therefore, the rheological properties of BSG dough will have industrial relevance for 3D-printed customized food products with fiber. Adding RBSG and BBSG to selected foods will increase the up-cycling potential by combining techno-functional properties.
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Hypericum perforatum is a well-known medicinal plant which contains a wide variety of metabolites, including xanthones, which have a wide range of biological properties, including antifungal activity. In the present study, we evaluated the capability of roots regenerated from calli of H. perforatum subsp. angustifolium to produce xanthones. Root biomass was positively correlated with the indole-3-butyric acid concentration, whereas a concentration of 1 mg l(-1) was the most suitable for the development of roots. High auxin concentrations also inhibited xanthone accumulation. Xanthones were produced in large amounts, with a very stable trend throughout the culture period. When the roots were treated with chitosan, the xanthone content dramatically increased, peaking after 7 days. Chitosan also induced a release of these metabolites into the culture. The maximum accumulation (14.26 ± 0.62 mg g(-1) dry weight [DW]) and release (2.64 ± 0.13 mg g(-1) DW) of xanthones were recorded 7 days after treatment. The most represented xanthones were isolated, purified, and spectroscopically characterized. Antifungal activity of the total root extracts was tested against a broad panel of human fungal pathogen strains (30 Candida species, 12 Cryptococcus neoformans, and 16 dermatophytes); this activity significantly increased when using chitosan. Extracts obtained after 7 days of chitosan treatment showed high antifungal activity (mean minimum inhibitory concentration of 83.4, 39.1, and 114 µg ml(-1) against Candida spp., C. neoformans, and dermatophytes, respectively). Our results suggest that root cultures can be considered as a potential tool for large-scale production of extracts with stable quantities of xanthones.
Assuntos
Antifúngicos/farmacologia , Quitosana/metabolismo , Hypericum/crescimento & desenvolvimento , Hypericum/metabolismo , Extratos Vegetais/farmacologia , Xantonas/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Arthrodermataceae/efeitos dos fármacos , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Indóis/metabolismo , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Fatores de Tempo , Xantonas/química , Xantonas/isolamento & purificaçãoRESUMO
Fungal infections represent a global problem, notably for immunocompromised patients in hospital, COVID-19 patient wards and care home settings, and the ever-increasing emergence of multidrug resistant fungal strains is a sword of Damocles hanging over many healthcare systems. Azoles represent the mainstay of antifungal drugs, and their mode of action involves the binding mode of these molecules to the fungal lanosterol 14α-demethylase target enzyme. In this study, we have prepared and characterized four novel organometallic derivatives of the frontline antifungal drug fluconazole (1a-4a). Very importantly, enzyme inhibition and chemogenomic profiling demonstrated that lanosterol 14α-demethylase, as for fluconazole, was the main target of the most active compound of the series, (N-(ferrocenylmethyl)-2-(2,4-difluorophenyl)-2-hydroxy-N-methyl-3-(1H-1,2,4-triazol-1-yl)propan-1-aminium chloride, 2a). Transmission electron microscopy (TEM) studies suggested that 2a induced a loss in cell wall integrity as well as intracellular features ascribable to late apoptosis or necrosis. The impressive activity of 2a was further confirmed on clinical isolates, where antimycotic potency up to 400 times higher than fluconazole was observed. Also, 2a showed activity towards azole-resistant strains. This finding is very interesting since the primary target of 2a is the same as that of fluconazole, emphasizing the role played by the organometallic moiety. In vivo experiments in a mice model of Candida infections revealed that 2a reduced the fungal growth and dissemination but also ameliorated immunopathology, a finding suggesting that 2a is active in vivo with added activity on the host innate immune response.
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The success of antifungal therapies is often hindered by the limited number of available drugs. To close the gap in the antifungal pipeline, the search of novel leads is of primary importance, and here the exploration of neglected plants has great promise for the discovery of new principles. Through bioassay-guided isolation, uliginosin B and five new dimeric acylphloroglucinols (uliginosins C-D, and 3'prenyl uliginosins B-D), besides cembrenoids, have been isolated from the lipophilic extract of Hypericum mexicanum. Their structures were elucidated by a combination of Liquid Chromatography - Mass Spectrometry LC-MS and Nuclear Magnetic Resonance (NMR) measurements. The compounds showed strong anti-Candida activity, also against fluconazole-resistant strains, with fungal growth inhibition properties at concentrations ranging from 3 to 32 µM, and reduced or absent cytotoxicity against human cell lines. A chemogenomic screen of 3'prenyl uliginosin B revealed target genes that are important for cell cycle regulation and cytoskeleton assembly in fungi. Taken together, our study suggests dimeric acylphloroglucinols as potential candidates for the development of alternative antifungal therapies.
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Investigation of the fungal communities in animal models of Inflammatory Bowel Diseases (IBD) showed a controversial role of Saccharomyces cerevisiae and Candida spp. In health and disease. These conflicting observations could be ascribed to immunogenic differences among co-specific strains. To assess the relevance of intra-strains differences on yeast immunogenicity and impact on the microbiota, we screened S. cerevisiae and Candida spp. Strains isolated from fecal samples of IBD patients. We compared the cytokine profiles, obtained upon stimulation of Peripheral Blood Mononuclear Cells (PBMCs) and Dendritic Cells with different yeast strains, and evaluated the relationship between strain's cell wall sugar amount and immune response. Moreover, the gut microbiota composition was explored in relation to fungal isolation from fecal samples by metabarcoding analysis. The comparison of cytokine profiles showed strain dependent rather than species-dependent differences in immune responses. Differences in immunogenicity correlated with the cell wall composition of S. cerevisiae intestinal strains. Stimulation of human healthy PBMCs with different strains showed a pro-inflammatory IL-6 response counterbalanced by IL-10 production. Interestingly, Crohn's (CD) patients responded differently to "self" and "non-self" strains, eliciting pure Th1 or Th17 cytokine patterns. The differences observed in vitro were recapitulated in vivo, where different strains contributed in dramatically different ways to local epithelial activity and to the inflammation of wild type and Interleukin-deficient mice. Furthermore, we observed that the gut microbiota profiles significantly differentiated according to the presence of Saccharomyces or Candida spp. or the absence of fungal isolates in fecal samples. Our results show the importance to deepen metagenomics and immunophenotyping analyses to the strain level, to elucidate the role of fungal and bacterial communities in health and disease.
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The increasing popularity of "Mirto" liqueur, produced from Myrtus communis berries, has led to the planting of domesticated cultivars, expanding myrtle berry production. To promote the use of cultivated berries, the content in the nutraceutical compounds ellagitannins has been investigated both in spontaneous and cultivated fruits. Oenothein B and eugeniflorin D2, characterized by 1H and 13C NMR, were isolated and quantified using ultrahigh-performance liquid chromatography-diode array detector-tandem mass spectrometry (UPLC-DAD-MS/MS). The antifungal and anti-inflammatory activities of oenothein B were assayed in vitro. Large amounts of oenothein B and eugeniflorin D2 were detected in seeds (12 ± 2.4 and 5.8 ± 1.2 mg/g). The oenothein B concentration in liqueurs was 194 ± 22 mg/L. This macrocyclic ellagitannin dimer showed anti-Candida (minimal inhibitory concentration <8-64 µg/mL) and anti-inflammatory properties. Cultivated myrtle berries are a source of nutraceutical compounds. The high concentration of oenothein B in liqueur suggests a possible contribution to the organoleptic and biological properties of the beverage.
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During the last two decades incidences of fungal infections dramatically increased and the often accompanying failure of available antifungal therapies represents a substantial clinical problem. The urgent need for novel antimycotics called particular attention to the study of natural products. The genus Hypericum includes many species that are used in the traditional medicine to treat pathological states like inflammations and infections caused by fungi. However, despite the diffused use of Hypericum-based products the antifungal potential of the genus is still poorly investigated. In this study five Hypericum species autochthonous of Central and Eastern Europe were evaluated regarding their polyphenolic content, their toxicological safety and their antifungal potential against a broad panel of clinical fungal isolates. LC-MS analysis led to the identification and quantification of 52 compounds, revealing that Hypericum extracts are rich sources of flavonols, benzoates and cinnamates, and of flavan-3-ols. An in-depth screen of the biological activity of crude extracts clearly unveiled H. hircinum subsp. majus as a promising candidate species for the search of novel antifungals. H. hircinum is diffused in the Mediterranean basin from Spain to Turkey where it is traditionally used to prepare a herbal tea indicated for the treatment of respiratory tract disorders, several of which are caused by fungi. Noteworthy, the infusion of H. hircinum subsp. majus excreted broad antifungal activity against Penicillium, Aspergillus and non-albicans Candida isolates comprising strains both sensitive and resistant to fluconazole. Additionally, it showed no cytotoxicity on human cells and the chemical characterization of the H. hircinum subsp. majus infusion revealed high amounts of the metabolite hyperoside. These results scientifically support the traditional use of H. hircinum extracts for the treatment of respiratory tract infections and suggest the presence of exploitable antifungal principles for further investigations aimed at developing novel antifungal therapies.
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The composition and changes of the fungal population and of the metabolites present in grapes and in ferments of Vitis vinifera L. cv. Corvina, one of the major components of the Amarone musts, were dissected aiming at the identification of constant characteristics possibly influenced by the productive process. The fungal populations and metabolomic profiles were analyzed in three different vintages. 454-pyrosequencing on the ribosomal ITS1 region has been used to identify the fungal population present in Corvina grapes and fresh must. Samples were also subjected to metabolomics analysis measuring both free volatile compounds and glycosylated aroma precursors through an untargeted approach with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry. Albeit strongly dependent on the climate, both the mycobiota and metabolome of Corvina grapes and fresh musts show some characteristics recursive in different vintages. Such persistent characteristics are likely determined by the method adopted to produce Amarone or other dry wines made from partially dried grapes. In particular, the harsh conditions imposed by the prolonged withering appear to contribute to the shaping of the fungal populations. The fungal genera and metabolites present in different vintages in V. vinifera L. cv. Corvina grapes and fresh musts represent core components of the peculiar technique of production of Amarone. Their identification allows the in-depth understanding and improved control of the process of production of this economically and culturally relevant wine.
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Regulated erroneous protein translation (adaptive mistranslation) increases proteome diversity and produces advantageous phenotypic variability in the human pathogen Candida albicans. It also increases fitness in the presence of fluconazole, but the underlying molecular mechanism is not understood. To address this question, we evolved hypermistranslating and wild-type strains in the absence and presence of fluconazole and compared their fluconazole tolerance and resistance trajectories during evolution. The data show that mistranslation increases tolerance and accelerates the acquisition of resistance to fluconazole. Genome sequencing, array-based comparative genome analysis, and gene expression profiling revealed that during the course of evolution in fluconazole, the range of mutational and gene deregulation differences was distinctively different and broader in the hypermistranslating strain, including multiple chromosome duplications, partial chromosome deletions, and polyploidy. Especially, the increased accumulation of loss-of-heterozygosity events, aneuploidy, translational and cell surface modifications, and differences in drug efflux seem to mediate more rapid drug resistance acquisition under mistranslation. Our observations support a pivotal role for adaptive mistranslation in the evolution of drug resistance in C. albicans. IMPORTANCE Infectious diseases caused by drug-resistant fungi are an increasing threat to public health because of the high mortality rates and high costs associated with treatment. Thus, understanding of the molecular mechanisms of drug resistance is of crucial interest for the medical community. Here we investigated the role of regulated protein mistranslation, a characteristic mechanism used by C. albicans to diversify its proteome, in the evolution of fluconazole resistance. Such codon ambiguity is usually considered highly deleterious, yet recent studies found that mistranslation can boost adaptation in stressful environments. Our data reveal that CUG ambiguity diversifies the genome in multiple ways and that the full spectrum of drug resistance mechanisms in C. albicans goes beyond the traditional pathways that either regulate drug efflux or alter the interactions of drugs with their targets. The present work opens new avenues to understand the molecular and genetic basis of microbial drug resistance.
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The transition from commensalism to pathogenicity of Candida albicans reflects both the host inability to mount specific immune responses and the microorganism's dimorphic switch efficiency. In this study, we used whole genome sequencing and microarray analysis to investigate the genomic determinants of the phenotypic changes observed in two C. albicans clinical isolates (YL1 and YQ2). In vitro experiments employing epithelial, microglial, and peripheral blood mononuclear cells were thus used to evaluate C. albicans isolates interaction with first line host defenses, measuring adhesion, susceptibility to phagocytosis, and induction of secretory responses. Moreover, a murine model of peritoneal infection was used to compare the in vivo pathogenic potential of the two isolates. Genome sequence and gene expression analysis of C. albicans YL1 and YQ2 showed significant changes in cellular pathways involved in environmental stress response, adhesion, filamentous growth, invasiveness, and dimorphic transition. This was in accordance with the observed marked phenotypic differences in biofilm production, dimorphic switch efficiency, cell adhesion, invasion, and survival to phagocyte-mediated host defenses. The mutations in key regulators of the hyphal growth pathway in the more virulent strain corresponded to an overall greater number of budding yeast cells released. Compared to YQ2, YL1 consistently showed enhanced pathogenic potential, since in vitro, it was less susceptible to ingestion by phagocytic cells and more efficient in invading epithelial cells, while in vivo YL1 was more effective than YQ2 in recruiting inflammatory cells, eliciting IL-1ß response and eluding phagocytic cells. Overall, these results indicate an unexpected isolate-specific variation in pathways important for host invasion and colonization, showing how the genetic background of C. albicans may greatly affect its behavior both in vitro and in vivo. Based on this approach, we propose that the co-occurrence of changes in sequence and expression in genes and pathways driving dimorphic transition and pathogenicity reflects a selective balance between traits favoring dissemination of the pathogen and traits involved in host defense evasion. This study highlights the importance of investigating strain-level, rather than species level, differences, when determining fungal-host interactions and defining commensal or pathogen behavior.
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Xanthone-rich extracts from Hypericum perforatum root cultures grown in a Mist Bioreactor as antifungal agents against Malassezia furfur. Extracts of Hypericum perforatum roots grown in a bioreactor showed activity against planktonic cells and biofilm of Malassezia furfur. Dried biomass, obtained from roots grown under controlled conditions in a ROOTec mist bioreactor, has been extracted with solvents of increasing polarity (i.e. chloroform, ethyl acetate and methanol). The methanolic fraction was the richest in xanthones (2.86 ± 0.43 mg g(-1) DW) as revealed by HPLC. The minimal inhibitory concentration of the methanol extract against M. furfur planktonic cells was 16 µg mL(-1). The inhibition percentage of biofilm formation, at a concentration of 16 µg mL(-1), ranged from 14% to 39%. The results show that H. perforatum root extracts could be used as new antifungal agents in the treatment of Malassezia infections.
Assuntos
Antifúngicos/farmacologia , Hypericum/química , Malassezia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Reatores Biológicos , Cromatografia Líquida de Alta Pressão , Testes de Sensibilidade Microbiana , Raízes de Plantas/química , Espectrofotometria Ultravioleta , Xantonas/química , Xantonas/farmacologiaRESUMO
An increasing body of literature is addressing the immuno-modulating functions of miRNAs which include paracrine signaling via exosome-mediated intercellular miRNA. In view of the recent evidence of intake and bioavailability of dietary miRNAs in humans and animals we explored the immuno-modulating capacity of plant derived miRNAs. Here we show that transfection of synthetic miRNAs or native miRNA-enriched fractions obtained from a wide range of plant species and organs modifies dendritic cells ability to respond to inflammatory agents by limiting T cell proliferation and consequently dampening inflammation. This immuno-modulatory effect appears associated with binding of plant miRNA on TLR3 with ensuing impairment of TRIF signaling. Similarly, in vivo, plant small RNAs reduce the onset of severity of Experimental Autoimmune Encephalomyelities by limiting dendritic cell migration and dampening Th1 and Th17 responses in a Treg-independent manner. Our results indicate a potential for therapeutic use of plant miRNAs in the prevention of chronic-inflammation related diseases.
Assuntos
Fragaria/genética , Fatores Imunológicos/uso terapêutico , MicroRNAs/uso terapêutico , RNA de Plantas/uso terapêutico , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Sequência de Bases , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , Feminino , Humanos , Fatores Imunológicos/farmacologia , Inflamação/patologia , Metilação , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Receptor 3 Toll-Like/metabolismoRESUMO
The responses of Hypericum perforatum root cultures to chitosan elicitation had been investigated through (1)H-NMR-based metabolomics associated with morpho-anatomical analyses. The root metabolome was influenced by two factors, i.e., time of culture (associated with biomass growth and related "overcrowding stress") and chitosan elicitation. ANOVA simultaneous component analysis (ASCA) modeling showed that these factors act independently. In response to the increase of biomass density over time, a decrease in the synthesis of isoleucine, valine, pyruvate, methylamine, etanolamine, trigonelline, glutamine and fatty acids, and an increase in the synthesis of phenolic compounds, such as xanthones, epicatechin, gallic, and shikimic acid were observed. Among the xanthones, brasilixanthone B has been identified for the first time in chitosan-elicited root cultures of H. perforatum. Chitosan treatment associated to a slowdown of root biomass growth caused an increase in DMAPP and a decrease in stigmasterol, shikimic acid, and tryptophan levels. The histological analysis of chitosan-treated roots revealed a marked swelling of the root apex, mainly due to the hypertrophy of the first two sub-epidermal cell layers. In addition, periclinal divisions in hypertrophic cortical cells, resulting in an increase of cortical layers, were frequently observed. Most of the metabolic variations as well as the morpho-anatomical alterations occurred within 72 h from the elicitation, suggesting an early response of H. perforatum roots to chitosan elicitation. The obtained results improve the knowledge of the root responses to biotic stress and provide useful information to optimize the biotechnological production of plant compounds of industrial interest.
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The aim of this study was to individuate, by bioassay-guided fractionation, promising antifungal fractions and/or constituents from Hypericum perforatum subsp. angustifolium in vitro roots. Treatments with chitosan, O-carboxymethylchitosan (CMC) and its derivatives were used to improve xanthone production in the roots. The bioassay-guided fractionation of CMC-treated roots led to the individuation of an ethyl acetate fraction, containing the highest amount of xanthones (6.8%) and showing the best antifungal activity with minimal inhibitory concentration (MIC) values of 53.82, 14.18, and 36.52 µg/ml, against Candida spp., Cryptococcus neoformans and dermatophytes, respectively. From this fraction the prenylated xanthone, biyouxanthone D has been isolated and represented the 44.59% of all xanthones detected. For the first time in the present paper biyouxanthone D has been found in H. perforatum roots and tested against C. neoformans, dermatophytes, and Candida species. The xanthone showed the greatest antifungal activity against C. neoformans and dermatophytes, with MIC values of 20.16, 22.63 µg/ml. In conclusion, the results obtained in the present study demonstrated that CMC-treated Hpa in vitro root extracts represent a tool for the obtainment of promising candidates for further pharmacological and clinical studies.
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Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Quitosana/análogos & derivados , Cryptococcus neoformans/efeitos dos fármacos , Hypericum/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Xantonas/farmacologia , Antifúngicos/isolamento & purificação , Quitosana/farmacologia , Humanos , Hypericum/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Raízes de Plantas/efeitos dos fármacos , Prenilação , Xantonas/isolamento & purificaçãoRESUMO
Hypericum perforatum is a well-known medicinal plant. Among all secondary metabolites produced by this species, xanthones are very interesting for their antifungal activity. In the present study, with the aim to improve xanthone production and antifungal activity of H. perforatum subsp. angustifolium (sin. Fröhlich) Borkh in vitro roots, a new methodology consisting of a three-step culture system, has been developed. Regenerated roots of H. perforatum were cultured in a three-step culture system: in the first step, to increase biomass, the roots were cultured in half-strength liquid Murashige and Skoog (MS) medium supplemented with 1 mg L(-1) indole butyric acid (IBA) and 1.5% sucrose. In the second and third steps, to stimulate secondary metabolism, the roots were cultured with 1.1 mg L(-1) 2,4-dichlorophenoxyacetic acid (2,4-D), 0.215 mg L(-1) kinetin (KIN), and 0.186 mg L(-1) 1-naphthalenacetic acid (NAA). In the third step, some of the roots were treated with chitosan. Xanthone production increased 2.7 times following the three-step method. The mean minimal inhibitory concentration (MIC) values were of 36.9, 26.7, and 65 µg mL(-1), against Candida species, Cryptococcus neoformans and dermatophytes, respectively. A positive correlation between xanthone accumulation and antifungal activity has been shown.