• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.967-973
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• 2020

The fungal cell wall is a major target of antifungals. In this study, we report the antifungal activity of an ethanol extract from Aucklandia lappa against Candida albicans. We found that the extract caused cell wall injury by decreasing chitin synthesis or assembly and (1,3)-β-D-glucan synthesis. A sorbitol protection assay demonstrated that the minimum inhibitory concentration (MIC) of the A. lappa extract against C. albicans cells increased eight-fold from 0.78 to 6.24 mg/ml in 72 h. Cell aggregates, which indicate damage to the cell wall or membrane, were commonly observed in the A. lappatreated C. albicans cells through microscopic analysis. In addition, the relative fluorescence intensities of the C. albicans cells incubated with the A. lappa extract for 3, 5, and 6 h were 92.1, 84.6, and 79.8%, respectively, compared to the controls, estimated by Calcofluor White binding assay. This result indicates that chitin content was reduced by the A. lappa treatment. Furthermore, synthesis of (1,3)-β-D-glucan polymers was inhibited to 84.3, 79.7, and 70.2% of that of the control treatment following incubation of C. albicans microsomes with the A. lappa extract at a final concentration equal to its MIC, 2× MIC, and 4× MIC, respectively. These findings suggest that the A. lappa ethanol extract may aid the development of a new antifungal to successfully control Candidaassociated disease.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.216-220
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• 2005

Periconicin A and B, two new fusicoccane diterpenes originally isolated from the cultures of endophytic fungus Periconia sp. OBW-15, were tested by several biological assays. Periconicin A was consistently more active than periconicin B. In an antifungal activity assay, periconicin A showed potent inhibitory activity against the agents of human mycoses, including Candida albicans, Trichophyton mentagrophytes, and T. rubrum, with minimum inhibitory concentration (MIC) in the range of 3.12- 6.25 $\mug$ /ml. In a plant growth regulatory activity assay, periconicins inhibited hypocotyl elongation and root growth of Brassica campestris L. and Raphanus sativus L. At concentrations below 1 μg/ml, however, both compounds accelerated root growth by 110- 135%. From these results, it is apparent that a methyl group positioned in a cyclopentane ring may play an important role in plant and fungal growth inhibitory activity.

• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1216-1225
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• 2014

Biofilm-related infections of Candida albicans are a frequent cause of morbidity and mortality in hospitalized patients, especially those with immunocompromised status. Options of the antifungal drugs available for successful treatment of drug-resistant biofilms are very few, and as such, new strategies need to be explored against them. The aim of this study was to evaluate the efficacy of phenylpropanoids of plant origin against planktonic cells, important virulence factors, and biofilm forms of C. albicans. Standard susceptibility testing protocol was used to evaluate the activities of 13 phenylpropanoids against planktonic growth. Their effects on adhesion and yeast-to-hyphae morphogenesis were studied in microplate-based methodologies. An in vitro biofilm model analyzed the phenylpropanoid-mediated prevention of biofilm development and mature biofilms using XTT-metabolic assay, crystal violet assay, and light microscopy. Six molecules exhibited fungistatic activity at ${\leq}0.5mg/ml$, of which four were fungicidal at low concentrations. Seven phenylpropanoids inhibited yeast-to-hyphae transition at low concentrations (0.031-0.5 mg/ml), whereas adhesion to the solid substrate was prevented in the range of 0.5-2 mg/ml. Treatment with ${\leq}0.5mg/ml$ concentrations of at least six small molecules resulted in significant (p < 0.05) inhibition of biofilm formation by C. albicans. Mature biofilms that are highly resistant to antifungal drugs were susceptible to low concentrations of 4 of the 13 molecules. This study revealed phenylpropanoids of plant origin as promising candidates to devise preventive strategies against drug-resistant biofilms of C. albicans.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.527-533
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• 1998

6-(3,4-Dichlorophenyl)amino-7-chloro-5,8-quinolinedione (RCK50) was tested for antifungal activities in mice systemically infected with Candida albicans. The therapeutic potential of RCK50 was also assessed in comparison with ketoconazole. CK50 had $ED_{50}$ 0.22${\pm}$0.01mg/kg. Ketoconazole as a positive control had $ED_{50}$ 6.00${\pm}$1.70mg/kg. Intraperitoneally administered RCK50 at the $ED_{50}$ for 7 days and 14 days reduced Candida albicans colony count in the kidneys and liver. And administered RCK50 at the $ED_{50}$ for 14 days improved survival rates. The genotoxicities of RCK50 had been evaluated. RCK50 was negative in Ames test with Salmonella typhimurium and chromosomal aberration test in CHL cells. RCK50 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK50 has no genotoxic potential under these experimental conditions. Acute oral toxicity studies of RCK50 were carried out in ICR mice of both sexes. RCK50 did not show acute oral toxicities and $LD_{50}$ values were over 2,850mg/kg in ICR mice.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.276-284
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• 2008

A lactic acid bacterium having antifungal activity was isolated from kimchi. It was identified as Lactobacillus plantarum based on its morphological and biochemical properties, and 16S rRNA sequence, and designated as Lb. plantarum AF1. This isolate inhibited the growth of Aspergillus flavus ATCC 22546, A. fumigatus ATCC 96918, A. petrakii PF-1, A. ochraceus PF-2, A. nidulans PF-3, Epicoccum nigrum KF-1, and Cladosporium gossypiicola KF-2 under a dual culture overlay assay. Also, the antimicrobial activity was found to be active against various species of Gram-positive and Gram-negative bacteria. The antifungal activity was found to be stable after heat ($121^{\circ}C$, 15 min) and proteolytic enzyme treatment, but it was unstable over pH 5.0. The antifungal compound(s) was estimated to have a low molecular mass (below 3,000 Da).

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.72-78
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• 2005

The present study was conducted to evaluate the application of Chamaecyparis obtusa and to investigate potential utilization of essential oil from C. obtusa as plant-based medicine. The antifungal activity of essential oil from leaves and twigs of C. obtusa (Sieb. Et Zucc) was determined and the major components of active fractions against Microsporum canis (KCTC6591) and Trichophyton mentagrophytes (KCTC6077) were identified by GC/MS analysis. In treatment of essential oil from C. obtusa, the strain M. canis was more resistant than the other, T. mentagrophytes. In the agar diffusion assay, essential oil from C. obtusa inhibited hyphal growth of M. canis and T. mentagrophytes at the concentration of more than 5,000 ppm. The zones named B and C in the TLC assay of essential oil from C. obtusa showed antifungal activities. Among four sub-fractions of n-hexane extract from B and C zones, named as B-1, B-2, C-1 and C-2, the C-2 showed the highest antifungal activity. Instrumental GC/MS analysis for sub-fractions showed that a major component of C-1 was ${\alpha}$-terpineol as terpene alcohol, while C-2 contained sesquiterpenes such as elemol, cedrol and eudesmol.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.52-59
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• 2000

A rapid assay to determine respiration inhibition of Saccharomyces cerevisiae by chemicals was developed. S. cerevisiae was harvested with two different liquid media, yeast extract-peptone-dextrose (YPD) medium capable of occurring both glucose fermentation and mitochondrial respiration, and non-fermentable carbon-yeast extract (NFY) medium capable of occurring respiration only Wells in 96-well plate were loaded with each cell suspension and various concentrations of 46 fungicides with various modes of action. n NFY medium, the non-fermentable carbon source, ethanol (NFY-E medium), glycerol (NFY-G medium) or lactate (NFY-L medium), was used. After incubation for $1{\sim}3$ days, minimum inhibitory concentrations (MICs) of the chemicals were recorded in the media. Of the 46 inhibitors employed in this study, four inhibitors of fungal respiration by blockage of electron flux in the mitochondrial respiratory chain, azoxystrobin, kresoxim-methyl, metominostrobin, and trifloxystrobin, exhibited strong antifungal activity in all of NFY media, but no activity in YPD medium. In contrast to this, five N-trihalomethylthio fungicides showed much stronger antifungal activities in YPD medium than three NFY media. Eleven fungicides inhibited growth of S. cerevisiae in all media and the other 26 fungicides showed no antifungal activity in all media. Thus, our rapid and efficient in vitro method can be considered as an alternative assay system for respiration inhibitor.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.201-209
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• 2006

Antifungal activities of 43 different plant oils were evaluated against different phytopathogenic fungi. Thyme oil showed highest antifungal activity among the tested oils. The major of thyme oil were found to be thymol, carvacrol, bomeol, p-cymene and linalool. Thymol and carvacrol were found to be responsible for thyme's antifungal activity. The spore germination assay was conducted on Alternaria mail and Botrytis cinerea. Thymol and carvacrol strongly inhibited spore germination in the fungi test. In addition, thymol and carvacrol showed a curative effectiveness to gray mold disease on cucumber crop. The antifungal activities of alkylphenol and alkylaniline compounds, which has similar molecular structure to that of thymol or cavacrol, were also tested. It was found that alkylphenol compounds also show higher inhibition to spore germination. Thus, thymol, carvacrol and alkylphenol compounds can be used an potent antifungal agents.

• Journal of Korea Foresty Energy
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• v.19 no.1
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• pp.49-60
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• 2000

The traditional Korea medical book already recorded various biological activities of the Korean mistletoes. The objective of this study was examine antifungal activities of MeOH extract from the Korean mistletoe through column chromatography on three fungi, such as Tyromyces palustris Endothia nitschkei and Trichophyton rubrum. No mistletoes had anti-fungal activity against T. palusties. Extracts of V. album var. coloratum showed the highest hyphal growth-inhibitory activity against E. nitschkei and leaf extract of this species had higher activity than twig extract. Further fractionation of most active fraction and following antifungal assay showed that its anti-fungal activity might be caused by synergism if its components. It was suggested that Viscum album var. coloratum shows significantly antifungal activities against E. nitschkei and T. rubrum. Further examination is needed to find out more exact active compounds.

• Genomics & Informatics
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• v.19 no.4
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• pp.39.1-39.8
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• 2021

Tamoxifen (TAM) is an anticancer drug used to treat estrogen receptor (ER)-positive breast cancer. However, its ER-independent cytotoxic and antifungal activities have prompted debates on its mechanism of action. To achieve a better understanding of the ER-independent antifungal action mechanisms of TAM, we systematically identified TAM-sensitive genes through microarray screening of the heterozygous gene deletion library in fission yeast (Schizosaccharomyces pombe). Secondary confirmation was followed by a spotting assay, finally yielding 13 TAM-sensitive genes under the drug-induced haploinsufficient condition. For these 13 TAM-sensitive genes, we conducted a comparative analysis of their Gene Ontology (GO) 'biological process' terms identified from other genome-wide screenings of the budding yeast deletion library and the MCF7 breast cancer cell line. Several TAM-sensitive genes overlapped between the yeast strains and MCF7 in GO terms including 'cell cycle' (cdc2, rik1, pas1, and leo1), 'signaling' (sck2, oga1, and cki3), and 'vesicle-mediated transport' (SPCC126.08c, vps54, sec72, and tvp15), suggesting their roles in the ER-independent cytotoxic effects of TAM. We recently reported that the cki3 gene with the 'signaling' GO term was related to the ER-independent antifungal action mechanisms of TAM in yeast. In this study, we report that haploinsufficiency of the essential vps54 gene, which encodes the GARP complex subunit, significantly aggravated TAM sensitivity and led to an enlarged vesicle structure in comparison with the SP286 control strain. These results strongly suggest that the vesicle-mediated transport process might be another action mechanism of the ER-independent antifungal or cytotoxic effects of TAM.