Antifungal activity of Juniperus essential oils against dermatophyte, Aspergillus and Candida strains

AIMS: The increasing resistance to antifungal compounds and the reduced number of available drugs led us to search therapeutic alternatives among aromatic plants and their essential oils, empirically used by antifungal proprieties. In this work the authors report on the antifungal activity of Juniperus essential oils (Juniperus communis ssp. alpina, J. oxycedrus ssp. oxycedrus and J. turbinata). METHODS AND RESULTS: Antifungal activity was evaluated by determination of MIC and MLC values, using a macrodilution method (NCCLS protocols), on clinical and type strains of Candida, Aspergillus and dermatophytes. The composition of the oils was ascertained by GC and GC/MS analysis. All essential oils inhibited test dermatophyte strains. The oil from leaves of J. oxycedrus ssp. oxycedrus is the most active, with MIC and MLC values ranging from 0.08-0.16 microl ml(-1) to 0.08-0.32 microl ml(-1), respectively. This oil is mainly composed of alpha-pinene (65.5%) and delta-3-carene (5.7%). CONCLUSIONS: J. oxycedrus ssp. oxycedrus leaf oil proved to be an emergent alternative as antifungal agent against dermatophyte strains. delta-3-Carene, was shown to be a fundamental compound for this activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Results support that essential oils or some of their constituents may be useful in the clinical management of fungal infections, justifying future clinical trials to validate their use as therapeutic alternatives for dermatophytosis.     

Thymbra capitata essential oil has a significant antimicrobial activity against methicillin-resistant Staphylococcus aureus pre-formed biofilms

Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant opportunistic pathogen with a great ability to form biofilms. Herein, the antimicrobial potential of Thymbra capitata essential oil (EO) against MRSA biofilms was investigated. The determination of the minimum inhibitory concentration (MIC) and the minimum lethal concentration (MLC) of the T. capitata EO was first investigated on a group of clinical isolates from septicaemias, diabetic foot ulcers and osteomyelitis. Biofilms were incubated with the EO at the MLC and its anti-biofilm potential was investigated. A strong antimicrobial activity was observed, with MIC and MLC values between 0·32 and 0·64 mg l⁻¹. However, the concentration of EO necessary for the eradication of planktonic cells was insufficient to significantly reduce the biofilm biomass of some isolates. Nevertheless, cell culturability and overall cellular metabolism was strongly reduced in all biofilms tested, only when the EO was tested. Contrary to the tested antibiotics, T. capitata EO showed a significant antimicrobial activity against MRSA biofilms, by reducing cellular metabolism and cellular culturability.     

Membrane damage as first and DNA as the secondary target for anti‐candidal activity of antimicrobial peptide P7 derived from cell‐penetrating peptide ppTG20 against Candida albicans

P7, a peptide analogue derived from cell‐penetrating peptide ppTG20, possesses antibacterial and antitumor activities without significant hemolytic activity. In this study, we investigated the antifungal effect of P7 and its anti‐Candida acting mode in Candida albicans. P7 displayed antifungal activity against the reference C. albicans (MIC = 4 μM), Aspergilla niger (MIC = 32 μM), Aspergillus flavus (MIC = 8 μM), and Trichopyton rubrum (MIC = 16 μM). The effect of P7 on the C. albicans cell membrane was examined by investigating the calcein leakage from fungal membrane models made of egg yolk l ‐phosphatidylcholine/ergosterol (10 : 1, w/w) liposomes. P7 showed potent leakage effects against fungal liposomes similar to Melittin‐treated cells. C. albicans protoplast regeneration assay demonstrated that P7 interacted with the C. albicans plasma membrane. Flow cytometry of the plasma membrane potential and integrity of C. albicans showed that P7 caused 60.9 ± 1.8% depolarization of the membrane potential of intact C. albicans cells and caused 58.1 ± 3.2% C. albicans cell membrane damage. Confocal laser scanning microscopy demonstrated that part of FITC‐P7 accumulated in the cytoplasm. DNA retardation analysis was also performed, which showed that P7 interacted with C. albicans genomic DNA after penetrating the cell membrane, completely inhibiting the migration of genomic DNA above the weight ratio (peptide : DNA) of 6. Our results indicated that the plasma membrane was the primary target, and DNA was the secondary intracellular target of the mode of action of P7 against C. albicans. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.     

Antifungal activity of essential oils and their combinations in in vitro and in vivo conditions

Natural additives are in demand for the control of microbial growth in foods. Several natural compounds including essential oils (EOs) are being explored for food uses. In the present investigation, the antifungal activity of cinnamaldehyde, eugenol, peppermint and clove EOs and their combinations was evaluated against 12 species of Aspergillus, Fusarium, Penicillium and Rhizopus in in vitro and tomato fruit system (in-vivo). The EOs were able to inhibit complete growth of tested fungi at or below 0.6% level and 80?μL of EOs (except peppermint oil) in in vitro condition and tomato system, respectively. The fractional inhibitory studies showed either additive or indifferent effect by combining eugenol and peppermint, and indifferent or antagonist effect by combining the cinnamaldehyde and clove in both in vitro and in vivo studies. The findings may be useful for application of these EOs in foods, but their effects on organoleptic quality of foods need to be investigated.     

LAAE-14, a new anti-inflammatory drug, increases the survival of Candida albicans-inoculated mice

LAAE-14, a lipidic acid-amido ether derivative, has been recently described as a new anti-inflammatory drug. We have studied the effect of treatment with this compound on the susceptibility of mice to in vivo experimental Candida albicans infection. ICR mice orally treated with LAAE-14 (25 mg kg(-1)) and experimentally intravenously infected showed a significantly increased survival as compared to control mice. In vitro, the compound did not inhibit the growth of C. albicans yeast cells or the yeast-to-hyphal transition. The in vitro production of prostaglandin E2 by peritoneal macrophages in response to the yeasts and hyphae of C. albicans was significantly decreased upon treatment with LAAE-14, in a dose-dependent manner. Thus, reduced prostaglandin production during fungal infection could be an important factor in controlling fungal colonisation and infection.     

纳米银的抗菌特性及对多重耐药菌株的抗菌作用

【目的】利用革兰氏阴性细菌、革兰氏阳性细菌和真菌的模式菌株分析纳米银的抗菌特性,并评价纳米银对多重耐药菌株的抗菌作用。【方法】利用生物法合成的纳米银,以微量肉汤法测定3种标准菌株的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),并计算MBC/MIC比值。用系列浓度的纳米银处理3株标准菌株后经平板计数法绘制时间-杀菌曲线。采用菌落平板计数法测定了纳米银对3种标准菌株的"抗生素后效应"(post-antibiotic effect,PAE),最后在生物安全II级实验室测定纳米银对临床分离的多重耐药菌株的抗菌作用。【结果】用生物法合成了粒径5–30 nm的纳米银,zeta电位为–19.5 m V。该纳米银制剂对3种标准菌株的时间-杀菌曲线均表现为时间依赖型抗菌作用。纳米银对大肠杆菌和白色念珠菌"抗生素后效应"随着浓度增加而增加,对金黄色葡萄球菌无明显"抗生素后效应"。纳米银对3种标准菌株的MIC值和MBC值均在1.00–4.00μg/m L之间;对3株人源性多重耐药菌MIC值在6.00–26.00μg/m L之间,MBC值在1.00–32.00μg/m L之间;对14株动物源性多重耐药菌MIC值在4.00–10.00μg/m L之间,MBC值在8.00–16.00μg/m L之间。纳米银对所有测试菌株的MBC/MIC值均小于2。【结论】纳米银是一种时间依赖型的抗菌剂,有不同程度的"抗生素后效应",对人源和动物源性多重耐药菌有杀菌作用。     

Erythrina poeppigiana-derived phytochemical exhibiting antimicrobial activity against Candida albicans and methicillin-resistant Staphylococcus aureus

AIMS: To screen five phytochemicals isolated from Erythrina poeppigiana (Leguminosae) for antimicrobial activity against both Candida albicans and methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: Roots of E. poeppigiana were macerated with acetone and the chloroform-soluble fraction of the residue was subjected to repeated silica gel column chromatography using various eluting solvents. Structures of the isolated compounds were determined by extensive spectroscopic studies. Each compound was dissolved in dimethyl sulphoxide and added to agar plates (final concentration: 1.56-100 microg ml(-1)) and minimum inhibitory concentrations (MICs) against C. albicans and MRSA were determined. Spectral data indicated the presence of three different types of phytochemicals; isoflavonoids (erypoegin A, demethylmedicarpin and sandwicensin), alpha-methyldeoxybenzoin (angolensin) and cinnamylphenol (erypostyrene). While all compounds showed anti-MRSA activity in this concentration range, isoflavonoids and alpha-methyldeoxybenzoin failed to inhibit the growth of C. albicans. Erypostyrene (E-1-[2-hydroxy-4-methoxy-5-(gamma,gamma-dimethylallyl)benzyl]-2-(4-hydroxyphenyl)ethylene) exhibited not only the highest anti-MRSA activity (MIC value of 6.25 microg ml(-1)) but also anti-candidal potency (MIC value of 50 microg ml(-1)). The compound reduced viable cell numbers of C. albicans and MRSA by approximately 1 of 2000 and 1 of 1000 after 1 h incubation at each MIC, respectively. CONCLUSIONS: A new cinnamylphenol, erypostyrene, possessed anti-candidal and anti-MRSA activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Erypostyrene could be a leading candidate for development of antimicrobial agents with anti-candidal and anti-MRSA activity.     

猴头菌子实体小分子提取物的分离与体外抑制幽门螺旋杆菌的分析

本研究以甲硝唑为阳性对照,利用HPD-100大孔树脂和95%乙醇将猴头菌子实体中小分子活性物质进行富集,得到乙醇制备液（MREEs）;然后对乙醇制备液分别使用石油醚（60-90℃）和氯仿进行多次萃取,得到石油醚萃取物（A1、A2）和氯仿萃取物（B）,并进行GC-MS测定;对MREEs和A1、A2、B分别进行药敏试验,同时对5种幽门螺旋杆菌进行最低抑菌浓度测定。结果表明,使用大孔树脂得到的MREEs有较好的抑菌活性,得到的A1、A2和B对幽门螺旋杆菌的抑菌率均高于40.0%,其中石油醚萃取物A1在Helicobacter pylori SSI中的抑菌率甚至高达62.9%;A1、A2和B使用GC-MS测定出的主要成分分别是邻苯二甲酸二丁酯（A1,4.53%和A2,6.93%）和棕榈酸2.87%,但仍有大量成分没有被测出。另外,在最低抑菌浓度试验中,A1相应组分对Helicobacter pylori W₂504、Helicobacter pylori 9和Helicobacter pylori ATCC 43504的最低抑菌浓度都为0.25mg/mL,A2对Helicobacter pylori 78的最低抑菌浓度仅为0.25mg/mL,而B对Helicobacter pylori W₂504、Helicobacter pylori 9的最低抑菌浓度均仅为0.125mg/mL,说明通过石油醚和氯仿萃取得到的猴头菌子实体提取物对幽门螺旋杆菌具有潜在的抑菌作用。     

Convenient lipase-assisted preparation of both enantiomers of suprofen,a non-steroidal anti-inflammatory drug

The resolution of rac-suprofen (1) catalysed by lipase in organic solvents was investigated. Direct esterification of rac-1 with methanol in dichorometane catalysed by Novozym® 435 furnished the pharmacologically active (+)-(S)-suprofen as unreacted product with excellent enantiomeric excess. The same procedure in toluene using Mucor miehei lipase adsorbed in Celite as catalyst afforded (−)-(R)-suprofen with good optical purity. © 1996 Wiley-Liss, Inc.     

Antifungal activity of lichen compounds against dermatophytes: a review

The growth rate inhibition of dermatophytes by compounds extracted by acetone, ethanol, methanol and water derived from representatives of several lichen genera (e.g. Caloplaca, Everniastrum, Heterodermia, Hypotrachyna, Platismatia and Ramalina) were compared on the basis of a worldwide review of published research. The examined dermatophytes included Epidermophyton floccosum, Microsporum audouinii, M. canis, M. gypseum, M. nanum, Trichophyton longifusus, T. mentagrophytes, T. rubrum, T. tonsurans and T. violaceum. The influence of selected secondary lichen compounds, for example, usnic acid, on the growth rates of these dermatophytes was also reviewed. The measurement of inhibition by lichen compounds was performed by several methods, but mostly those employing disc diffusion, broth dilution and agar dilution. The fungicidal activity of water-extracted compounds from Heterodermia leucomela and Hypotrachyna cirrhata and of methanol-extracted compounds from Evernia divaricata and Ramalina pollinaria, as well as protolichesterinic and 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acids, are distinguished.     

Ibuprofen, a unique anti-inflammatory compound with antifungal activity against dermatophytes

Ibuprofen showed significant antifungal activity in vitro against dermatophytes at pH 5 (MIC: 5–40 μg ml^-1). In this respect it is comparatively more efficient than two well known and medically used antifungal compounds, benzoic and salicylic acids. This compound with anti-inflammatory activity which is not found in any other conventional antifungal organic acids, may have clinical prospects.     

Synthesis,antimicrobial and antiviral activity of substituted benzimidazoles

In the present study we have synthesized (4-nitrophenyl)-[2-(substituted phenyl)-benzoimidazol-1-yl]-methanones, (2-bromophenyl)-[2-(substituted phenyl)-benzoimidazol-1-yl]-methanone analogues (1–14) and evaluated them for their antimicrobial and antiviral potential. The results of antimicrobial screening indicated that none of the synthesized compounds were effective against the tested bacterial strains. Compounds 3, 11, 13 and compounds 5, 11, 12 were found to be active against Aspergillus niger and Candida albicans respectively, and may be further developed as antifungal agents. Furthermore, evaluation against a panel of different viruses pointed out the selective activity of compounds 5 and 6 against vaccinia virus and Coxsackie virus B4.     

19种常见中药材醇提物的体外抗菌活性筛选

为考察19种中药材乙醇提取物的体外抗临床常见致病菌的活性,该文将中药粗粉用80%乙醇浸泡提取,提取液减压浓缩制备成浸膏,采用琼脂打孔法测定提取物抑菌圈,通过微量倍比稀释法测定最低抑菌浓度(MIC)和最低杀菌浓度(MBC/MFC)。结果表明:所筛选的19种中药材乙醇提取物对不同的菌株具有不同程度的抑制作用,14种中药材乙醇提取物抗SA、EC、PA和CA的抑菌圈范围在8～27 mm之间,其中地锦草、四块瓦、三颗针、马尾黄连和土大黄的提取物抗SA、EC的抑菌圈范围在10.3～26.6 mm之间。马尾黄连、孜然、地锦草、广西莪术、穿心莲、益母草、吴茱萸、土大黄、叶上花、土连翘、凤尾草和三颗针的醇提物对MRSA和铜绿假单胞菌耐药菌均具有显著的抗微生物活性,其MIC/MBC值在391～6 250μg·m L^-1之间;地锦草、三颗针抗MRSA的最低MIC值分别为391、781μg·m L^-1,抗PA耐药菌的最低MIC值均为1 562.5μg·m L^-1;马尾黄连、孜然和三颗针的醇提物对白色念珠菌耐药菌有中等抑制作用,杀菌效果不明显。该...     

In vitro efficacy of nisin Z against Candida albicans adhesion and transition following contact with normal human gingival cells

Aim:  To investigate the nisin Z innocuity using normal human gingival fibroblast and epithelial cell cultures, and its synergistic effect with these gingival cells against Candida albicans adhesion and transition from blastospore to hyphal form.
Methods and Results:  Cells were cultured to 80% confluence and infected with C. albicans in the absence or presence of various concentrations of nisin Z. Our results indicate that only high concentrations of nisin Z promoted gingival cell detachment and differentiation. Determination of the LD₅₀ showed that the fibroblasts were able to tolerate up to 80  μ g ml⁻¹ for 24 h, dropping thereafter to 62  μ g ml⁻¹ after 72 h of contact, compared to 160  μ g ml⁻¹ after 24 h, and 80  μ g ml⁻¹ after 72 h recorded by the gingival epithelial cells which displayed a greater resistance to nisin Z. The use of nisin Z even at low concentration (25  μ g ml⁻¹) at appropriate concentrations with gingival cells significantly reduced C. albicans adhesion to gingival monolayer cultures and inhibited the yeast's transition.
Conclusion:  These findings show that when used at non-toxic levels for human cells, nisin Z can be effective against C. albicans adhesion and transition and may synergistically interact with gingival cells for an efficient resistance against C. albicans .
Significance and Impact of the Study:  This study suggests the potential usefulness of nisin Z as an antifungal agent, when used in an appropriate range.     

In-vitro evaluation of the antimicrobial activity of Bauhinia variegata,locally known as koiralo

Bauhinia variegata, commonly known as Koiralo is considered as medicinal plant in Nepal and India. The alcoholic extract of this plant was found to have antimicrobial activity against Bacillus subtilis (ATCC 6635) Pseudomonas aeruginosa (ATCC 27853), Salmonella typhi, Shigella dysenteriae, Staphylococcus aureus (ATCC 29213) and Vibrio cholerae. The largest zone of inhibition (18 mm) was found to be exhibited against B. subtilis. For this organism the minimum bactericidal concentration (MBC) of the crude extract was 0.39 mg/ml. The extract was found to be more effective against gram-positive than gram-negative bacteria. The antimicrobial activity of the extract was found to be decreased during purification.     

Multiple effects of a novel compound from Burkholderia cepacia against Candida albicans

A novel compound (named CF66I) produced by Burkholeria cepacia CF-66 strain was investigated for its antifungal activity against Candida albicans. This compound exhibited excellent antifungal activity in a dose- and time-dependent manner. Uptake analysis revealed that the compound preferentially acted against the fungal cell wall, and was also able to enter the cells. Transmission electron microscopy indicated that this compound caused loosening of the cell wall and a significant increase in the cell wall thickness was noted; however, no alterations were observed in the contents of the cell wall components. CF66I probably affected the normal assembly and integration of fungal cell wall components by interrupting the weak interactions between them, such as hydrogen and hydrophobic bonds. Propidium iodide (PI) staining indicated that on exposure to CF66I C. albicans cells became permeable to PI. Marked alterations in lipid and sterol contents were observed, and the major changes were a depletion of total lipids and ergosterol, concomitant with an increase in lanosterol content. These observations suggested that the novel compound CF66I may have considerable potential for development of a new class of antifungal agents.