Allium cepa tests: A plant-based tool for the early evaluation of toxicity and genotoxicity of newly synthetized antifungal molecules.

Many fungal genera such as Aspergillus, Penicillium, Fusarium and Alternaria are able to produce, among many other metabolites, the aflatoxins, a group of toxic and carcinogenic compounds. To reduce their formation, synthetic fungicides are used as an effective way of intervention. However, the extensive use of such molecules generates long-term residues into the food and the environment. The need of new antifungal molecules, with high specificity and low off-target toxicity is worth. The aim of this study was to evaluate: i) the toxicity and genotoxicity of newly synthesized molecules with a good anti-mycotoxic activity, and ii) the suitability of the Allium cepa multi-endpoint assay as an early screening method for chemicals. Eight compounds were tested for toxicity by using the A. cepa bulb root elongation test and for genotoxicity using the A. cepa bulb mitotic index, micronuclei and chromosome aberrations tests. Three molecules showed no toxicity, while two induced mild toxic effects in roots exposed to the highest dose (100 µM). A more pronounced toxic effect was caused by the other three compounds for which the EC50 was approximately 50 µM. Furthermore, all molecules showed a clear genotoxic activity, both in terms of chromosomal aberrations and micronuclei. Albeit the known good antifungal activity, the different molecules caused strong toxic and genotoxic effects. The results indicate the suitability of experiments with A. cepa as a research model for the evaluation of the toxic and genotoxic activities of new molecules in plants before they are released into the environment.

Exploring the potential of eco-friendly silver nanoparticles to inhibit azole-resistant clinical isolates of Candida spp.

The antimicrobial activity and biological efficiency of silver nanoparticles (AgNps) have been widely described and can be modeled through stabilizing and reducing agents, especially if they exhibit biocidal properties, which can enhance bioactivity against pathogens. The selective action of AgNps remains a major concern. In this regard, the use of plant extracts for the green synthesis of nanoparticles offers advantages because it improves the toxicity of Nps for microorganisms and is harmless to normal cells. However, biological evaluations of the activity of AgNps synthesized using different reducing agents are determined independently, and comparisons are frequently overlooked. Thus, we investigated and compared the antifungal and cytotoxic effects of two ecological AgNps synthesized from Moringa oleifera aqueous leaf extract (AgNp-M) and glucose (AgNp-G) against azole-resistant clinical isolates of Candida spp. and nontumor mammalian cells. Synthesized AgNps exhibited an antifungal effect on planktonic cells of drug-resistant C. albicans and C. tropicalis (MIC 0.21-52.6 µg/mL). The toxicity was influenced by size. However, the use of M. oleifera extracts allows us to obtain AgNps that are highly selective and nongenotoxic to Vero cells due to modifications of the shape and surface. Therefore, these results suggest that AgNp-M has antimicrobial potential and deserves further investigation for biomedical applications.

Investigating the Antifungal Effect of the Essential Oil of Thymus eriocalyx on Dominant Filamentous Fungal Agents Isolated from Livestock and Poultry Feed.

BACKGROUND: One of the most important principles in disease control is the health of livestock and poultry feed. Given the natural growth of Th. eriocalyx in Lorestan province, its essential oil can be added to the livestock and poultry feed and prevent the growth of the dominant filamentous fungi. OBJECTIVE: Therefore, this study aimed to identify the dominant moldy fungal agents of livestock and poultry feed, examine phytochemical compounds and analyze antifungal effects, anti-oxidant properties, as well as cytotoxicity against human white blood cells in Th. eriocalyx. METHODS: Sixty samples were collected in 2016. The PCR test was used to amplify ITS1 and ASP1 regions. The analysis of essential oil was conducted by gas chromatography and gas chromatographymass spectrometry devices. MIC and MFC were performed using the broth micro-dilution method. For the analysis of DDPH activity, DDPH was used. Cytotoxicity effect on healthy human lymphocytes was carried out by the MTT method. RESULTS: In this study, A. niger, F. verticilloides and F. circinatum, P. oxalicum, and P. chrysogenum were the most resistant species, and A. oryzae and A. fumigatus, F. prolifratum and F. eqiseti, P. janthnellum were the most susceptible ones. IC50 value of T. daenensis Celak was 41.33 µg/ml, and 100 µl/ml of the essential oil caused slight cell lysis. CONCLUSION: Considering our results, compared with drugs and chemical additives, essential oils can be added to livestock and poultry feed to prevent the growth of filamentous fungi in the livestock and poultry feed.

Cytotoxicity and antimicrobial activity of isolated compounds from Monsonia angustifolia and Dodonaea angustifolia.

ETHNOPHARMACOLOGICAL RELEVANCE: Monsonia angustifolia is traditionally used to treat anthrax, heartburn, diarrhea, eye infections and hemorrhoids. Dodonaea angustifolia is frequently used as a treatment for dental pain, microbial infections and jungle fever. The two plant species were selected due to the presence of secondary metabolites such as coumarins, flavonoids, terpenoids, saponins and polyphenolics from the crude extracts, which exhibit pharmacological significance. The pure isolated compounds from the crude extracts are known for their diverse structures and interesting pharmacophores. AIM: To isolate and identify antibacterial and antifungal chemical constituents from Monsonia angustifolia and Dodonaea angustifolia plant extracts and evaluate the cytotoxicity of pure compounds from the crude extracts. MATERIALS AND METHODS: Extractives from M. angustifolia and D. angustifolia plants were isolated using chromatographic techniques and structures were elucidated based on NMR, IR and MS spectroscopic techniques. A microplate serial dilution method was used to evaluate the antibacterial activity of extracts and pure compounds against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and antifungal activity against Candida albicans and Cryptococcus neoformans. The cytotoxicity was determined using the 3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The dichloromethane, ethyl acetate and methanol crude extracts from the plants exhibited significant inhibition of microbial growth. The phytochemical investigation of these active crude extracts led to the isolation of five pure active compounds, 5-methoxyjusticidin A (1), cis-phytyl diterpenoidal fatty acid ester (2), stigmasterol (3), ß-sitosterol (4) and 5-hydroxy-7,4'-dimethoxyflavone (5). Stigmasterol (3) showed good antifungal activity against Cryptococcus neoformans with a minimum inhibition concentration (MIC) of 25 µg/mL and Candida albicans (MIC = 50 µg/mL). CONCLUSION: Compounds (1-5) isolated from Monsonia angustifolia and Dodonaea angustifolia showed antibacterial and antifungal activities and were non-toxic against Madin-Darby canine kidney (MDCK) cells and VERO monkey kidney (VERO) cells.

Galloylquinic acid derivatives from Byrsonima fagifolia leaf extract and potential antifungal activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Byrsonima fagifolia Niedenzu (Malpighiaceae) and other Byrsonima species are popularly employed in Brazilian traditional medicine in the form of preparations as cicatrizing, anti-inflammatory, and antimicrobial. AIM OF THE STUDY: To characterize the phytochemical profile of the hydromethanolic extract obtained from B. fagifolia leaves (BF extract) and to evaluate the toxicity and the antifungal activity. MATERIALS AND METHODS: The compounds from BF extract were isolated by HPLC and the structures were elucidated based on extensive analyses of 1D and 2D NMR spectra (HMQC, HMBC and COSY) data. The antifungal effect was determined by the broth microdilution method and the toxicity was evaluated on erythrocytes from sheep's blood and Galleria mellonella larvae. RESULTS: Phytochemical investigation of the BF extract led to the isolation and characterization of pyrogallol, n-butyl gallate, 3,4-di-O-galloylquinic acid, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid, and 1,3,4,5-tetra-O-galloylquinic acid. The BF extract showed high content of galloylquinic acid derivatives reaching more than twenty-times the quercetin derivatives content, according to the quantification by HPLC. These galloylquinic acid derivatives, obtained during this study, and quercetin derivatives, previously isolated, were submitted to the antifungal assays. The BF extract inhibited yeast growth mainly against Cryptococcus spp., at concentrations of 1-16 µg/mL, comparable to isolated compounds galloylquinic acid derivatives. However, the quercetin derivatives as well as quinic acid, gallic acid, and methyl gallate showed lower antifungal effect compared with galloylquinic derivatives. In addition, the BF extract had no hemolytic effect and no toxicity on G. mellonella. CONCLUSION: The phytochemical analysis revealed that galloylquinic acid derivatives are the major compounds in the leaves of B. fagifolia and they are associated to anti-cryptococcal activity and presented reduced toxicity.

Synthesis of Hemiprotonic Phenanthroline-Phenanthroline+ Compounds with both Antitumor and Antimicrobial Activity.

Currently, cancer patients with microbial infection are a severe challenge in clinical treatment. To address the problem, we synthesized hemiprotonic compounds based on the unique structure of hemiprotonic nucleotide base pairs in a DNA i-motif. These compounds were produced from phenanthroline (ph) dimerization with phenanthroline as a proton receptor and ammonium as a donor. The biological activity shows that the compounds have a selective antitumor effect through inducing cell apoptosis. The molecular mechanism could be related to specific inhibition of transcription factor PLAGL2 of tumor cells, assessed by transcriptomic analysis. Moreover, results show that the hemiprotonic ph-ph+ has broad-spectrum antibacterial and antifungal activities, and drug-resistant bacteria, including methicillin-resistant Staphylococcus aureus, are sensitive to the compound. In animal models of liver cancer with fungal infection, the ph-ph+ retards proliferation of hepatoma cells in tumor-bearing mice and remedies pneumonia and encephalitis caused by Cryptococcus neoformans. The study provides a novel therapeutic candidate for cancer patients accompanied by infection.

Optimization and Evaluation of Novel Antifungal Agents for the Treatment of Fungal Infection.

Due to the increased morbidity and mortality by fungal infections and the emergence of severe antifungal resistance, there is an urgent need for new antifungal agents. Here, we screened for antifungal activity in our in-house library through the minimum inhibitory concentration test and derived two hit compounds with moderate antifungal activities. The hit compounds' antifungal activities and drug-like properties were optimized by substituting various aryl ring, alkyl chain, and methyl groups. Among the optimized compounds, 22h was the most promising candidate with good drug-like properties and exhibited potent fast-acting fungicidal antifungal effects against various fungal pathogens and synergistic antifungal activities with some known antifungal drugs. Additionally, 22h was further confirmed to disturb fungal cell wall integrity by activating multiple cell wall integrity pathways. Furthermore, 22h exerted significant antifungal efficacy in both the subcutaneous infection mouse model and ex vivo human nail infection model.

Bioactivity of medicinal plant extracts against human fungal pathogens and evaluation of toxicity using Vero cells.

Medicinal plants are a potential source of new antifungal agents to combat the development of drug-resistant fungi. This study aims to investigate the aerial parts of Alternanthera sessilis (Amaranthaceae) and Ipomoea aquatica (Convolvulaceae), and the leaves of Catunaregam spinosa (Rubiaceae) and Tradescantia spathacea (Commelinaceae) for antifungal activity and cytotoxicity. The plant materials were extracted sequentially using hexane, chloroform, ethyl acetate, ethanol, methanol, and distilled water. The antifungal activity was evaluated against four species of yeasts and two species of filamentous fungi using a colorimetric broth microdilution method. The toxicity of the extracts was assessed using African monkey kidney epithelial (Vero) cells. All 24 extracts from the four medicinal plants showed inhibitory activity against all fungal species, except Aspergillus fumigatus, with a minimum inhibitory concentration range of 0.04-2.50 mg/mL. The antifungal activity of these plants was more prominent on the yeasts than the filamentous fungi. Generally, the less polar extracts (hexane, chloroform, and ethyl acetate) of the plants had stronger antifungal activity than the more polar extracts (ethanol, methanol, and water). In contrast, toxicity assessment revealed that the less polar extracts showed relatively higher toxicity towards the Vero cells than the more polar extracts. The lowest median cytotoxic concentration was shown by the chloroform extract of A. sessilis (17.4 ± 0.4 µg/mL). All water extracts, the methanol extract of I. aquatica, and the ethyl acetate, ethanol, and methanol extracts of T. spathacea did not show significant toxicity (P>0.05) towards the Vero cells. The results suggested that Tradescantia spathacea has the most promising potential for pharmaceutical developments due to its broad spectrum and selective activity against human fungal pathogens.

The Antifungal Action Mode of N-Phenacyldibromobenzimidazoles.

Our study aimed to characterise the action mode of N-phenacyldibromobenzimidazoles against C. albicans and C. neoformans. Firstly, we selected the non-cytotoxic most active benzimidazoles based on the structure-activity relationships showing that the group of 5,6-dibromobenzimidazole derivatives are less active against C. albicans vs. 4,6-dibromobenzimidazole analogues (5e-f and 5h). The substitution of chlorine atoms to the benzene ring of the N-phenacyl substituent extended the anti-C. albicans action (5e with 2,4-Cl2 or 5f with 3,4-Cl2). The excellent results for N-phenacyldibromobenzimidazole 5h against the C. albicans reference and clinical isolate showed IC50 = 8 µg/mL and %I = 100 ± 3, respectively. Compound 5h was fungicidal against the C. neoformans isolate. Compound 5h at 160-4 µg/mL caused irreversible damage of the fungal cell membrane and accidental cell death (ACD). We reported on chitinolytic activity of 5h, in accordance with the patterns observed for the following substrates: 4-nitrophenyl-N-acetyl-ß-d-glucosaminide and 4-nitrophenyl-ß-d-N,N',N″-triacetylchitothiose. Derivative 5h at 16 µg/mL: (1) it affected cell wall by inducing ß-d-glucanase, (2) it caused morphological distortions and (3) osmotic instability in the C. albicans biofilm-treated. Compound 5h exerted Candida-dependent inhibition of virulence factors.

Phytochemical composition, antifungal activity, in vitro and in vivo toxicity of Syzygium cumini (L) Skeels leaves extract / Composición fitoquímica, actividad antifúngica, toxicidad in vitro e in vivo del extracto de hojas de Syzygium cumini (L) Skeels

This study determined phytochemical composition, antifungal activity and toxicity in vitro and in vivo of Syzygium cumini leaves extract (Sc). Thus, was characterized by gas chromatography coupled to mass spectrometry and submitted to determination of Minimum Inhibitory (MIC) and Fungicidal concentrations (MFC) on reference and clinical strains of Candida spp. and by growth kinetics assays. Toxicity was verified using in vitro assays of hemolysis, osmotic fragility, oxidant and antioxidant activity in human erythrocytes and by in vivo acute systemic toxicity in Galleria mellonella larvae. Fourteen different compounds were identified in Sc, which showed antifungal activity (MIC between 31.25-125µg/mL) with fungistatic effect on Candida. At antifungal concentrations, it demonstrated low cytotoxicity, antioxidant activity and neglible in vivotoxicity. Thus, Sc demonstrated a promising antifungal potential, with low toxicity, indicating that this extract can be a safe and effective alternative antifungal agent.

Este estudio determinó la composición fitoquímica, la actividad antifúngica y la toxicidad in vitro e in vivo del extracto de hojas de Syzygium cumini (Sc). Así, se caracterizó mediante cromatografía de gases acoplada a espectrometría de masas y se sometió a determinación de Concentraciones Mínimas Inhibitorias (CMI) y Fungicidas (MFC) sobre cepas de referencia y clínicas de Candida spp. y mediante ensayos de cinética de crecimiento. La toxicidad se verificó mediante ensayos in vitro de hemólisis, fragilidad osmótica, actividad oxidante y antioxidante en eritrocitos humanos y por toxicidad sistémica aguda in vivo en larvas de Galleria mellonella. Se identificaron catorce compuestos diferentes en Sc, que mostraron actividad antifúngica (CMI entre 31.25-125 µg/mL) con efecto fungistático sobre Candida. En concentraciones antifúngicas, demostró baja citotoxicidad, actividad antioxidante y toxicidad in vivo insignificante. Por lo tanto, Sc demostró un potencial antifúngico prometedor, con baja toxicidad, lo que indica que este extracto puede ser un agente antifúngico alternativo seguro y eficaz.

Agarose oligosaccharide- silver nanoparticle- antimicrobial peptide- composite for wound dressing.

Marine polysaccharides or oligosaccharides have potential to promote wound healing due to their biocompatibility and physicochemical properties. However, microbial infection delays wound healing process, and novel antimicrobial wound dressings are urgently needed. Here, agarose oligosaccharides (AGO) obtained from marine red algae were used as a reducing and stabilizer for green synthesis of silver nanoparticles (AgNPs), and further successfully connected with odorranain A (OA), one of antimicrobial peptides (AMPs), to obtain a novel composite nanomaterial (AGO-AgNPs-OA). Transmission electron microscopy (TEM) and Malvern particle size analyzer showed that AGO-AgNPs-OA was spherical or elliptic with average size of about 100 nm. Circular dichroism (CD) spectroscopy showed that AGO-AgNPs stabilized the α-helical structure of OA. AGO-AgNPs-OA showed stronger anti-bacterial activities than AGO-AgNPs, and had good biocompatibility and significant promoting effect on wound healing. Our data suggest that AMPs conjugated marine oligosaccharides and AgNPs may be effective and safe antibacterial materials for wound therapy.

Surface Characterization, Biocompatibility and Antifungal Efficacy of a Denture-Lining Material Containing Cnidium officinale Extracts.

Herein, we investigated the surface characterization and biocompatibility of a denture-lining material containing Cnidium officinale extracts and its antifungal efficacy against Candida albicans. To achieve this, a denture-lining material containing various concentrations of C. officinale extract and a control group without C. officinale extract were prepared. The surface characterization and biocompatibility of the samples were investigated. In addition, the antifungal efficacy of the samples on C. albicans was investigated using spectrophotometric growth and a LIVE/DEAD assay. The results revealed that there was no significant difference between the biocompatibility of the experimental and control groups (p > 0.05). However, there was a significant difference between the antifungal efficiency of the denture material on C. albicans and that of the control group (p < 0.05), which was confirmed by the LIVE/DEAD assay. These results indicate the promising potential of the C. officinale extract-containing denture-lining material as an antifungal dental material.

Evaluation of toxicological and antimicrobial activity of lavender and immortelle essential oils.

Lavender and immortelle essential oils (EOs) are widely used to treat a spectrum of human conditions. The aim of this study was to investigate cyto/genotoxic effects of lavender and immortelle EOs using plant cells (Allium cepa) and human lymphocytes, as well as their antimicrobial potential using nine strains of bacteria and fungi. Our results for lavender and immortelle EOs showed that the frequency of chromosome aberrations (CAs) was increased in comparison with controls. For both oils, increased frequency of apoptosis for all concentrations, as well as the frequency of necrosis (0.10/0.30 µl/ml for lavender/immortelle, respectively) was demonstrated. In human lymphocytes, differences for minute fragments between immortelle oil (0.10 µl/ml) and controls were observed. Increased frequency of apoptosis was detected for immortelle oil (0.20 µl/ml), while both oils (0.20; 0.30 µl/ml lavender, and immortelle at all concentrations) induced higher frequency of necrosis in comparison with controls. Lavender EO was effective against all tested Gram-positive and Gram-negative bacteria, while immortelle EO inhibited only Gram-positive bacteria. Both oils exhibited antifungal effect. Our results demonstrated that lavender and immortelle EOs showed cyto/genotoxic effects in both, plant and human cells, as well as antimicrobial properties. Further studies are needed to strengthen these findings.

Lecithins-Zein nanoparticles for antifungal treatment: Enhancement and prolongation of drug retention in skin with reduced toxicity.

Fungal infections are one of the major skin healthcare issues and cause significant morbidity. Ketoconazole (KC) as a broad-spectrum antifungal drug is widely used to treat skin fungal diseases. However, its therapeutic effects are limited by low concentration, short duration of drug efficacy in the skin and severe systemic toxicity. Here, the ketoconazole loaded Lecithins-Zein nanoparticles (KLZ-NPs) with core-shell structure were designed to resolve above problems. In vitro penetration test confirmed that the ketoconazole concentration of the KLZ-NPs group in the stratum corneum and deeper layers increased significantly (2.98-fold, 1.51-fold higher to free ketoconazole, respectively). Meanwhile, follicular closing technique showed the formed nanoparticles via follicle pathway into the skin had been significantly enhanced, and the results of the visual fluorescent images also confirmed it. Additionally, in the in vivo imaging experiment, the fluorescence intensity of the single applying of the DiR-LZ-NPs was higher than that of the thrice usage of the free DiR. More importantly, the results also indicated that the accumulation of nanoparticles in the liver and spleen was significantly reduced. Hence, Lecithins-Zein nanoparticles are a promising strategy to enhance the drug concentration, prolong efficacy and reduce systemic toxicity in the topical administration for antifungal treatment.

Improvement of the pharmacokinetic/pharmacodynamic relationship in the treatment of invasive aspergillosis with voriconazole. Reduced drug toxicity through novel rapid release formulations.

Voriconazole (VCZ) is currently the first-line treatment for invasive aspergillosis, although the doses are limited by its poor solubility and high hepatic toxicity. The aim of this study was to develop a solid self-dispersing micellar system of VCZ to improve the pharmacokinetic/pharmacodynamic (PK/PD) relationship and reduce hepatotoxicity. In this work, solid micellar systems of VCZ are formulated with different polysorbate 80 ratios using mannitol as a hydrophilic carrier. The novel micellar systems were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dissolution studies. Self-dispersing micellar systems reduced VCZ crystallinity, leading to an improvement in its dissolution rate. The in vitro susceptibility test also revealed that the most common microorganisms in invasive aspergillosis exhibited low minimum inhibitory concentration (MIC) values for micellar systems. Pharmacokinetic studies indicated an improvement in bioavailability for MS-1:3:0.05, and changes in its biodistribution to different organs. MS-1:3:0.05 showed an increased concentration in lungs and a significant decrease in VCZ accumulated in the liver.

N-acetylcysteine reduces amphotericin B deoxycholate nephrotoxicity and improves the outcome of murine cryptococcosis.

Cryptococcosis is a life-threatening fungal infection, and its current treatment is toxic and subject to resistance. Drug repurposing represents an interesting approach to find drugs to reduce the toxicity of antifungals. In this study, we evaluated the combination of N-acetylcysteine (NAC) with amphotericin B (AMB) for the treatment of cryptococcosis. We examined the effects of NAC on fungal morphophysiology and on the macrophage fungicidal activity 3 and 24 hours post inoculation. The therapeutic effects of NAC combination with AMB were investigated in a murine model with daily treatments regimens. NAC alone reduced the oxidative burst generated by AMB in yeast cells, but did not inhibit fungal growth. The combination NAC + AMB decreased capsule size, zeta potential, superoxide dismutase activity and lipid peroxidation. In macrophage assays, NAC + AMB did not influence the phagocytosis, but induced fungal killing with different levels of oxidative bursts when compared to AMB alone: there was an increased reactive oxygen species (ROS) after 3 hours and reduced levels after 24 hours. By contrast, ROS remained elevated when AMB was tested alone, demonstrating that NAC reduced AMB oxidative effects without influencing its antifungal activity. Uninfected mice treated with NAC + AMB had lower concentrations of serum creatinine and glutamate-pyruvate transaminase in comparison to AMB. The combination of NAC + AMB was far better than AMB alone in increasing survival and reducing morbidity in murine-induced cryptococcosis, leading to reduced fungal burden in lungs and brain and also lower concentrations of pro-inflammatory cytokines in the lungs. In conclusion, NAC + AMB may represent an alternative adjuvant for the treatment of cryptococcosis.

Quaternized Chitosan-Coated Montmorillonite Interior Antimicrobial Metal-Antibiotic in Situ Coordination Complexation for Mixed Infections of Wounds.

Conventional drug delivery systems for natural clay materials still face critical challenges in their practical application, including multiple bacterial infections, combined infection of bacteria and fungi, and low sterilization efficiency. In this work, we address these challenges using the multifunctional montmorillonite nanosheet-based (MMT-based) drug nanoplatform, which involves the antibiotic 5-fluorocytosine (5-FC), antibacterial metal copper ions, and quaternized chitosan (QCS). Composite material QCS/MMT/5-FCCu can can strongly inhibit Staphylococcus aureus (a typical Gram-positive bacterium), Escherichia coli (a typical Gram-negative bacterium), and Candida albicans (a fungus) because 5-FC coordinates with copper ions in situ and due to the deposition of QCS. The subsequent drug release behavior of 5-FCCu was studied, and the results show an initial high concentration kills microorganisms and long-acting sustained release inhibition. Moreover, in vivo wound experiments and toxicity experiments show the promotion of wound healing and excellent biocompatibility. As a demonstration of the utility of the latter, we have shown that the MMT-based smart platform can be used for the treatment of mixed infections of wounds.

YO-001A, a new antifungal agent produced by Streptomyces sp. YO15-A001.

A new antifungal compound YO-001A was found from the culture broth of Streptomyces sp. YO15-A001, which was isolated from a soil sample collected in Toyama Prefecture. YO-001A was identified through morphological changes-based screening of the rice blast fungus, Pyricularia oryzae (P. oryzae). YO-001A is a new 26-membered macrolide of the oligomycin family, which exhibits potent antifungal activity against P. oryzae with an IC50 of 0.012 µM by disrupting mitochondrial respiration via inhibition of the FOF1-ATPase activity.

The classic azole antifungal drugs are highly potent endocrine disruptors in vitro inhibiting steroidogenic CYP enzymes at concentrations lower than therapeutic Cmax.

Azole antifungal drugs are used worldwide to treat a variety of fungal infections such as vulvovaginal candidiasis, particularly in pregnant women who are at increased risk. The aim of this study was to mechanistically investigate the endocrine disrupting potential of four commonly used azole antifungal drugs; clotrimazole, miconazole, ketoconazole and fluconazole in vitro using the H295R cell assay and two recombinant, CYP17A1 and CYP19A1 (aromatase), assays. Steroids were quantified using LC-MS/MS. In both recombinant assays, all four azoles inhibited the CYP enzymes investigated, at therapeutically relevant concentrations. However, responses were much more complex in the H295R cell line. Clotrimazole inhibited steroid production in a dose-dependent manner with IC50 values for CYP17A1 and CYP19A1 in the range 0.017-0.184 µM. Miconazole and ketoconazole increased all steroids on the hydroxylase axis (IC50 MIC: 0.042-0.082 µM, KET: 0.041-1.2 µM), leading to accumulation of progestagens and corticosteroids and suppression of androgens and estrogens, indicating inhibition of CYP17A1, in particular lyase activity. However, ketoconazole suppressed all steroids at higher concentrations, resulting in bell-shaped curves for all steroids on the hydroxylase axis. Fluconazole was found to inhibit CYP17A1-lyase activity, causing suppression of androgens (IC50 = 114-209 µM) and estrogens (IC50 = 28 µM). The results indicate that these four azole drugs are highly potent in vitro and, based on plasma Cmax values, may exert endocrine disrupting effects at therapeutically relevant concentrations. This raises concern for endocrine related effects in patients using azole antifungal drugs, particularly when taken during sensitive periods like pregnancy.

Antimicrobial and antibiofilm activities of prenylated flavanones from Macaranga tanarius.

BACKGROUND: The emergence of antibiotic resistant microorganisms presents a worldwide problem that requires novel antibiotic and non-antibiotic strategies, and biofilm formation is a mechanism of drug resistance utilized by diverse microorganisms. The majority of microorganisms live in biofilms that help their survival against starvation, antimicrobial agents, and immunological defense systems. Therefore, it is important novel compounds be identified that inhibit biofilm formation and cell survival without drug resistance. STUDY DESIGN: In this study, the antimicrobial and antibiofilm activities of five prenylated flavanones (Okinawan propolins) isolated from fruits of Macaranga tanarius (L.) were investigated against 14 microorganisms including 10 pathogens. RESULTS: Of these five propolins, propolin D at 5-10 µg/ml significantly inhibited biofilm formation by three Staphylococcus aureus strains, a Staphylococcus epidermidis strain, and a Candida albicans with MICs from 10 to 50 µg/ml, and in C. albicans, propolin D was found to inhibit biofilm formation by reducing cell aggregation and downregulated the expressions of hypha/biofilm-related genes including ECE1 and HWP1. Interestingly, at sub-MIC concentrations (10-50 µg/ml), propolin D significantly inhibited biofilm formation by enterohemorrhagic E. coli O157:H7, uropathogenic E. coli O6:H1, and Acinetobacter baumannii without affecting planktonic cell growth, but did not inhibit biofilm formation by a commensal E. coli K-12 strain, three probiotic Lactobacillus plantarum strains, or two Pseudomonas aeruginosa strains. And, propolin D reduced fimbriae production by E. coli O157:H7 and repressed gene expression of curli fimbriae genes (csgA and csgB). Also, propolin D was minimally toxic in a Caenorhabditis elegans nematode model. CONCLUSION: These findings show that prenylated flavanones, especially propolin D from Macaranga tanarius (Okinawan propolis), should be considered potential candidates for the development of non-toxic antibacterial and antifungal agents against persistent microorganisms.