Proteomic analysis revealed ROS-mediated growth inhibition of Aspergillus terreus by shikonin

Controlled delivery of nikkomycin by PEG coated PLGA nanoparticles inhibits chitin synthase to prevent growth of Aspergillus flavus and Aspergillus fumigatus

Aspergillosis is one of the most common fungal infections that can threaten individuals with immune compromised condition. Due to the increasing resistance of pathogens to the existing antifungal drugs, it is difficult to tackle such disease conditions. Whereas, nikkomycin is an emerging safe and effective antifungal drug which causes fungal cell wall disruption by inhibiting chitin synthase. Hence, the study aims at the development of nikkomycin loaded PEG coated PLGA nanoparticles for its increased antifungal efficiency and inhibiting Aspergillus infections. The P-PLGA-Nik NPs were synthesized by w/o/w double emulsification method which resulted in a particle size of 208.3 ± 15 nm with a drug loading of 52.97 %. The NPs showed first order diffusion-controlled drug release which was sustained for 24 h. These nanoparticle's antifungal efficacy was tested using the CLSI - M61 guidelines and the MIC50 defined against Aspergillus flavus and Aspergillus fumigatus was found to be >32 μg/ml which was similar to the nikkomycin MIC. The hyphal tip bursting showed the fungal cell wall disruption. The non-cytotoxic and non-haemolytic nature highlights the drug safety profile.

Accelerating the understanding of Aspergillus terreus: Epidemiology, physiology, immunology and advances

Aspergillus species encompass a variety of infections, ranging from invasive aspergillosis to allergic conditions, contingent upon the immune status of the host. In this spectrum, Aspergillus terreus stands out due to its emergence as a notable pathogen and its intrinsic resistance to amphotericin-B. The significance of Aspergillus-associated infections has witnessed a marked increase in the past few decades, particularly with the increasing number of immunocompromised individuals. The exploration of epidemiology, morphological transitions, immunopathology, and novel treatment approaches such as new antifungal drugs (PC945, olorofim) and combinational therapy using antifungal drugs and phytochemicals (Phytochemicals: quercetin, shikonin, artemisinin), also using immunotherapies to modulate immune response has resulted in better outcomes. Furthermore, in the context COVID-19 era and its aftermath, fungal infections have emerged as a substantial challenge for both immunocompromised and immunocompetent individuals. This is attributed to the use of immune-suppressing therapies during COVID-19 infections and the increase in transplant cases. Consequently, this review aims to provide an updated overview encompassing the epidemiology, germination events, immunopathology, and novel drug treatment strategies against Aspergillus terreus-associated infections.

Natural Plant-Derived Compounds in Food and Cosmetics: A Paradigm of Shikonin and Its Derivatives

Shikonin and its derivatives are the natural naphthoquinone compounds produced in the roots of the Boraginaceae family. These red pigments have been used for a long time in coloring silk, as food colorants, and in the Chinese traditional system of medicines The resurgence of public interest in natural and plant-based products has led to this category of compounds being in high demand due to their wide range of biological activities including antioxidant, antitumor, antifungal, anti-inflammatory ones. Different researchers worldwide have reported various applications of shikonin derivatives in the area of pharmacology. Nevertheless, the use of these compounds in the food and cosmetics fields needs to be explored more in order to make them available for commercial utilization in various food industries as a packaging material and to enhance their shelf life without any side effects. Similarly, the antioxidant properties and skin whitening effects of these bioactive molecules may be used successfully in various cosmetic formulations. The present review delves into the updated knowledge on the various properties of shikonin derivatives in relation to food and cosmetics. The pharmacological effects of these bioactive compounds are also highlighted. Based on various studies, it can be concluded that these natural bioactive molecules have potential to be used in different sectors, including functional food, food additives, skin, health care, and to cure various diseases. Further research is required for the sustainable production of these compounds with minimum disturbances to the environment and in order to make them available in the market at an economic price. Simultaneous studies utilizing recent techniques in computational biology, bioinformatics, molecular docking, and artificial intelligence in laboratory and clinical trials would further help in making these potential candidates promising alternative natural bioactive therapeutics with multiple uses.

Integrated genomics and proteomics analysis of Paenibacillus peoriae IBSD35 and insights into its antimicrobial characteristics

Antimicrobial resistance has been developing fast and incurring a loss of human life, and there is a need for new antimicrobial agents. Naturally occurring antimicrobial peptides offer the characteristics to counter AMR because the resistance development is low or no resistance. Antimicrobial peptides from Paenibacillus peoriae IBSD35 cell-free supernatant were salted out and purified using chromatography and characterized with liquid chromatography-tandem-mass spectrometry. The extract has shown a high and broad spectrum of antimicrobial activity. Combining the strain IBSD35 genome sequence with its proteomic data enabled the prediction of biosynthetic gene clusters by connecting the peptide from LC-MS/MS data to the gene that encode. Antimicrobial peptide databases offered a platform for the effective search, prediction, and design of AMPs and expanded the studies on their isolation, structure elucidation, biological evaluation, and pathway engineering. The genome-based taxonomy and comparisons have shown that P. peoriae IBSD35 is closely related to Paenibacillus peoriae FSL J3-0120. P. peoriae IBSD35 harbored endophytic trait genes and nonribosomal peptide synthases biosynthetic gene clusters. The comparative genomics revealed evolutionary insights and facilitated the discovery of novel SMs using proteomics from the extract of P. peoriae IBSD35. It will increase the potential to find novel bio-molecules to counter AMR.

MTA1-TJP1 interaction and its involvement in non-small cell lung cancer metastasis

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MTA1 was highly expressed in NSCLC tissues and was associated with tumor progression.

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MTA1 promoted NSCLC cell invasion and migration in vitro and in vivo.

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TJP1 was found to be an interacting protein of MTA1 involved in cell adhesion.

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MTA1 promoted NSCLC invasion and metastasis by inhibiting TJP1 protein expression and attenuating intercellular tight junctions.

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Targeting the MTA1-TJP1 axis may be a promising strategy for inhibiting NSCLC metastasis.

Distant metastasis is the main cause of death in non-small cell lung cancer (NSCLC) patients. The mechanism of metastasis-associated protein 1(MTA1) in NSCLC has not been fully elucidated. This study aimed to reveal the mechanism of MTA1 in the invasion and metastasis of NSCLC.

Bioinformatics analysis and our previous results showed that MTA1 was highly expressed in NSCLC tissues and correlated with tumor progression. Knockout of MTA1 by CRISPR/Cas9 significantly inhibited the migration and invasion of H1299 cells, but enhanced cell adhesion. Stable overexpression of MTA1 by lentivirus transfection had opposite effects on migration, invasion and adhesion of A549 cells. The results of in vivo experiments in nude mouse lung metastases model confirmed the promotion of MTA1 on invasion and migration. Tight junction protein 1 (TJP1) was identified by immunoprecipitation and mass spectrometry as an interacting protein of MTA1 involved in cell adhesion. MTA1 inhibited the expression level of TJP1 protein and weakened the tight junctions between cells. More importantly, the rescue assays confirmed that the regulation of MTA1 on cell adhesion, migration and invasion was partially attenuated by TJP1.

In Conclusion, MTA1 inhibits the expression level of TJP1 protein co-localized in the cytoplasm and membrane of NSCLC cells, weakens the tight junctions between cells, and changes the adhesion, migration and invasion capabilities of cells, which may be the mechanism of MTA1 promoting the invasion and metastasis of NSCLC. Thus, targeting the MTA1-TJP1 axis may be a promising strategy for inhibiting NSCLC metastasis.

Review of Shikonin and Derivatives: Isolation, Chemistry, Biosynthesis, Pharmacology and Toxicology

Shikonin and its derivatives, isolated from traditional medicinal plant species of the genus Lithospermum, Alkanna, Arnebia, Anchusa, Onosma, and Echium belonging to the Boraginaceae family, have numerous applications in foods, cosmetics, and textiles. Shikonin, a potent bioactive red pigment, has been used in traditional medicinal systems to cure various ailments and is well known for its diverse pharmacological potential such as anticancer, antithrombotic, neuroprotective, antidiabetic, antiviral, anti-inflammatory, anti-gonadotropic, antioxidants, antimicrobial and insecticidal. Herein, updated research on the natural sources, pharmacology, toxicity studies, and various patents filed worldwide related to shikonin and approaches to shikonin’s biogenic and chemical synthesis are reviewed. Furthermore, recent studies to establish reliable production systems to meet market demand, functional identification, and future clinical development of shikonin and its derivatives against various diseases are presented.

The aflatoxin inhibitors capsaicin and piperine from Capsicum chinense and Piper nigrum fruits modulate the antioxidant system in Aspergillus parasiticus

Several aflatoxin inhibitors can modulate the antioxidant system in fungi. In this work, the effect of the ethanolic extract of Capsicum chinense and Piper nigrum fruits, capsaicin, and piperine on the expression of the aflE, aflG, aflH, aflI, aflK, aflL, aflO, aflP, and aflQ genes involved in the aflatoxin biosynthetic pathway in Aspergillus parasiticus were studied by qRT-PCR analysis. As well as, the effect on the expression of fungal antioxidant genes (sod1, catA, and cat2) and enzymatic activity of catalase (CAT) and superoxide dismutase (SOD). Results reveal that the highest (p < 0.05) radial growth inhibition (68 and 86%) and aflatoxins production inhibition (73 and 80%) was observed with capsaicin and piperine respectively, at 300 µg/mL, instead of the ethanolic extract at the same concentration. The qRT-PCR analysis showed that compounds and extracts at 300 µg/mL induced a down-regulation of aflatoxin genes and an up-regulation on the fungal antioxidant genes. CAT activity increased by 23.15, 36.65, 51.40, and 65.50%, in the presence of C. chinense and P. nigrum extract, capsaicin, and piperine exposure, respectively. While SOD activity was not significantly impacted (p > 0.05). In conclusion, the capsaicin and piperine, two antifungal and anti-aflatoxigenic compounds produce an up-regulation of antioxidant defense genes accompanied by an enhancement of catalase enzymatic activity in A. parasiticus.

Shikonin, a naphthalene ingredient: Therapeutic actions, pharmacokinetics, toxicology, clinical trials and pharmaceutical researches

BACKGROUND

Shikonin is one of the major phytochemical components of Lithospermum erythrorhizon (Purple Cromwell), which is a type of medicinal herb broadly utilized in traditional Chinese medicine. It is well established that shikonin possesses remarkable therapeutic actions on various diseases, with the underlying mechanisms, pharmacokinetics and toxicological effects elusive. Also, the clinical trial and pharmaceutical study of shikonin remain to be comprehensively delineated.

PURPOSE

The present review aimed to systematically summarize the updated knowledge regarding the therapeutic actions, pharmacokinetics, toxicological effects, clinical trial and pharmaceutical study of shikonin.

METHODS

The information contained in this review article were retrieved from some authoritative databases including Web of Science, PubMed, Google scholar, Chinese National Knowledge Infrastructure (CNKI), Wanfang Database and so on, till August 2021.

RESULTS

Shikonin exerts multiple therapeutic efficacies, such as anti-inflammation, anti-cancer, cardiovascular protection, anti-microbiomes, analgesia, anti-obesity, brain protection, and so on, mainly by regulating the NF-κB, PI3K/Akt/MAPKs, Akt/mTOR, TGF-β, GSK3β, TLR4/Akt signaling pathways, NLRP3 inflammasome, reactive oxygen stress, Bax/Bcl-2, etc. In terms of pharmacokinetics, shikonin has an unfavorable oral bioavailability, 64.6% of the binding rate of plasma protein, and enhances some metabolic enzymes, particularly including cytochrome P450. In regard to the toxicological effects, shikonin may potentially cause nephrotoxicity and skin allergy. The above pharmacodynamics and pharmacokinetics of shikonin have been validated by few clinical trials. In addition, pharmaceutical innovation of shikonin with novel drug delivery system such as nanoparticles, liposomes, microemulsions, nanogel, cyclodextrin complexes, micelles and polymers are beneficial to the development of shikonin-based drugs.

CONCLUSIONS

Shikonin is a promising phytochemical for drug candidates. Extensive and intensive explorations on shikonin are warranted to expedite the utilization of shikonin-based drugs in the clinical setting.

Analysis of Antimicrobial Peptide Metabolome of Bacterial Endophyte Isolated From Traditionally Used Medicinal Plant Millettia pachycarpa Benth

Increasing prevalence of antimicrobial resistance (AMR) has posed a major health concern worldwide, and the addition of new antimicrobial agents is diminishing due to overexploitation of plants and microbial resources. Inevitably, alternative sources and new strategies are needed to find novel biomolecules to counter AMR and pandemic circumstances. The association of plants with microorganisms is one basic natural interaction that involves the exchange of biomolecules. Such a symbiotic relationship might affect the respective bio-chemical properties and production of secondary metabolites in the host and microbes. Furthermore, the discovery of taxol and taxane from an endophytic fungus, Taxomyces andreanae from Taxus wallachiana, has stimulated much research on endophytes from medicinal plants. A gram-positive endophytic bacterium, Paenibacillus peoriae IBSD35, was isolated from the stem of Millettia pachycarpa Benth. It is a rod-shaped, motile, gram-positive, and endospore-forming bacteria. It is neutralophilic as per Joint Genome Institute’s (JGI) IMG system analysis. The plant was selected based on its ethnobotany history of traditional uses and highly insecticidal properties. Bioactive molecules were purified from P. peoriae IBSD35 culture broth using 70% ammonium sulfate and column chromatography techniques. The biomolecule was enriched to 151.72-fold and the yield percentage was 0.05. Peoriaerin II, a highly potent and broad-spectrum antimicrobial peptide against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 was isolated. LC-MS sequencing revealed that its N-terminal is methionine. It has four negatively charged residues (Asp + Glu) and a total number of two positively charged residues (Arg + Lys). Its molecular weight is 4,685.13 Da. It is linked to an LC-MS/MS inferred biosynthetic gene cluster with accession number A0A2S6P0H9, and blastp has shown it is 82.4% similar to fusaricidin synthetase of Paenibacillus polymyxa SC2. The 3D structure conformation of the BGC and AMP were predicted using SWISS MODEL homology modeling. Therefore, combining both genomic and proteomic results obtained from P. peoriae IBSD35, associated with M. pachycarpa Benth., will substantially increase the understanding of antimicrobial peptides and assist to uncover novel biological agents.

Aspergillus Metabolome Database for Mass Spectrometry Metabolomics

The Aspergillus Metabolome Database is a free online resource to perform metabolite annotation in mass spectrometry studies devoted to the genus Aspergillus. The database was created by retrieving and curating information on 2811 compounds present in 601 different species and subspecies of the genus Aspergillus. A total of 1514 scientific journals where these metabolites are mentioned were added as meta-information linked to their respective compounds in the database. A web service to query the database based on m/z (mass/charge ratio) searches was added to CEU Mass Mediator; these queries can be performed over the Aspergillus database only, or they can also include a user-selectable set of other general metabolomic databases. This functionality is offered via web applications and via RESTful services. Furthermore, the complete content of the database has been made available in .csv files and as a MySQL database to facilitate its integration into third-party tools. To the best of our knowledge, this is the first database and the first service specifically devoted to Aspergillus metabolite annotation based on m/z searches.

Effects of antifungal agents on the fungal proteome: informing on mechanisms of sensitivity and resistance

INTRODUCTION

Antifungal agents are essential in the fight against serious fungal disease, however emerging resistance is threatening an already limited collection of therapeutics. Proteomic analyses of effects of antifungal agents can expand our understanding of multifactorial mechanisms of action and have also proven valuable to elucidate proteomic changes associated with antifungal resistance.

AREAS COVERED

This review covers the application of proteomic techniques to examine sensitivity and resistance to antifungals including commonly used therapeutics, amphotericin B, echinocandins and the azoles, based predominantly on studies involving Aspergillus fumigatus, Candida albicans and Candida glabrata from the last 10 years. In addition, non-clinical antimicrobial agents are also discussed, which highlight the potential of proteomics to identify new antifungal targets.

EXPERT COMMENTARY

Fungal proteomics has evolved in the last decade with increased genome availability and developments in mass spectrometry. Collectively, these have led to the advancement of proteomic techniques, allowing increased coverage of the proteome. Gel-based proteomics laid the foundation for these types of studies, which has now shifted to the more powerful gel-free proteomics. This has resulted in the identification of key mediators and potential biomarkers of antifungal resistance, as well as elucidating the mechanisms of action of novel and established antifungal agents.

Identification of Genes Involved in Antifungal Activity of Burkholderia seminalis Against Rhizoctonia solani Using Tn5 Transposon Mutation Method

Rhizoctonia solani is the causative agent of rice sheath blight disease. In a previous study, we found that the growth of R. solani was inhibited by Burkholderia seminalis strain R456. Therefore, the present study was conducted to identify the genes involved in the antifungal activity of B. seminalis strain R456 by using a Tn5 transposon mutation method. Firstly, we constructed a random insertion transposon library of 997 mutants, out of which 11 mutants showed the defective antifungal activity against R. solani. Furthermore, the 10 antagonism-related genes were successfully identified based on analysis of the Tn5 transposon insertion site. Indeed, this result indicated that three mutants were inserted on an indigenous plasmid in which the same insertion site was observed in two mutants. In addition, the remaining eight mutants were inserted on different genes encoding glycosyl transferase, histone H1, nonribosomal peptide synthetase, methyltransferase, MnmG, sulfate export transporter, catalase/peroxidase HPI and CysD, respectively. Compared to the wild type, the 11 mutants showed a differential effect in bacteriological characteristics such as cell growth, biofilm formation and response to H₂O₂ stress, revealing the complexity of action mode of these antagonism-related genes. However, a significant reduction of cell motility was observed in the 11 mutants compared to the wild type. Therefore, it can be inferred that the antifungal mechanism of the 10 above-mentioned genes may be, at least partially, due to the weakness of cell motility. Overall, the result of this study will be helpful for us to understand the biocontrol mechanism of this bacterium.