The Antifungal Activity of Loquat (Eriobotrya japonica Lindl.) Leaves Extract Against Penicillium digitatum

This study was performed to determine the antifungal activity of loquat (Eriobotrya japonica Lindl) leaf extract (LLE) against the citrus postharvest pathogen Penicillium digitatum (P. digitatum). The LLE exhibited an antifungal activity against P. digitatum, with a minimum inhibitory concentration (MIC) of 0.625 mg/ml and a minimum fungicidal concentration (MFC) of 1.25 mg/ml. Significant inhibitory effects of LLE on mycelial growth and spore germination of P. digitatum were seen in a dose-dependent manner. Simultaneously, to investigate possible antifungal mechanisms by LLE, we analyzed their influence on morphological changes, cell membrane permeability, cell wall and cell membrane integrity, and adenosine phosphates (ATP, ADP, and AMP) levels. Alterations, such as sunken surface and malformation, occurred in the LLE-treated P. digitatum spores. Furthermore, intracellular inclusion content decreased after LLE treatment, indicating an increase in cell membrane permeability. Besides, the LLE treatment induced a significant decline in the level of adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) with a noticeable addition of extracellular ATP, ADP, and AMP during the entire treatment period. Overall, the results manifested that the antifungal activity of LLE against P. digitatum can be attributed to the derangement of cell membrane permeability and disordered energy metabolism. This is the first report on the mechanism of antifungal activity of LLE and could be useful in the development of targeted fungicides from natural origin.

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Fungicidal Actions and Resistance Mechanisms of Prochloraz to Penicillium digitatum

Plant Disease ◽

10.1094/pdis-05-20-1128-re ◽

2020 ◽

pp. PDIS-05-20-1128

Author(s):

Yuchao Zhang ◽

Bao Zhang ◽

Chaoxi Luo ◽

Yanping Fu ◽

Fuxing Zhu

Keyword(s):

Cell Membrane ◽

Target Genes ◽

Membrane Integrity ◽

Point Mutations ◽

Resistance Mechanisms ◽

Penicillium Digitatum ◽

Cell Membrane Permeability ◽

Baseline Sensitivity ◽

Cell Membrane Integrity ◽

Citrus Groves

The demethylation inhibitor (DMI) fungicide prochloraz has been widely used in China to control citrus green mold, which is caused by Penicillium digitatum. The 50% effective concentration (EC50) values of prochloraz for 129 isolates of P. digitatum collected in 2017 from citrus groves of four provinces of China ranged from 0.0032 to 0.4582 mg/liter. Analysis of the distribution of natural logarithms of EC50 values indicated that 111 isolates with EC50 values lower than 0.05 mg/liter could be considered sensitive to prochloraz. Relative baseline sensitivity was established based on the 111 sensitive isolates, and the mean EC50 value was 0.0090 ± 0.0054 mg/liter (SD). Prochloraz at 60, 100, and 140 mg/liter provided preventive efficacies of 67.8, 93.0, and 96.4%, respectively. Prochloraz at 0.005 and 0.01 mg/liter disrupted cell membrane integrity of conidia but reduced cell membrane permeability of mycelia. Prochloraz at 0.01 mg/liter reduced ergosterol content in mycelia by 41.8%. Two prochloraz-resistant isolates with EC50 values of 3.97 and 5.68 mg/liter were attained by consecutive subculturing on prochloraz-amended PDA. Studies on the expression levels of three potential target genes, CYP51A, CYP51B, and CYP51C, demonstrated that whether in the absence or presence of prochloraz, only CYP51B in the resistant isolates was overexpressed at least 10-fold higher than that of the sensitive ones. Sequencing of the three genes showed that only CYP51B in the resistant isolates had a 199-bp insertion in the promoter region. In addition, only CYP51B displayed point mutations of G405S, G389C, and Y390S in the coding regions in the resistant isolates. These results were important for understanding the resistance mechanisms of P. digitatum to prochloraz.

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Changes of Cell Membrane Permeability Induced by DMSO and Ethanol in Suspension Cultures of Taxus Cuspidata

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.942 ◽

2011 ◽

Vol 236-238 ◽

pp. 942-948 ◽

Cited By ~ 1

Author(s):

Xue Qing Wang ◽

Yin Jin Yuan ◽

Jin Chuan Li ◽

Chen Chen

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Membrane Integrity ◽

Suspension Cultures ◽

Cell Membrane Permeability ◽

Taxus Cuspidata ◽

Extracellular Medium ◽

Cell Membrane Integrity ◽

Long Time ◽

Malonyl Dialdehyde

The changes of cell membrane permeability caused by dimethyl sulphoxide (DMSO) and ethanol, two commonly used solvents in study of water-insoluble elicitors, were investigated in suspension cultures of Taxus cuspidata. The extracellular medium became alkalinized in the case of DMSO while the medium pH fluctuated upon the addition of ethanol. When the content of DMSO or ethanol was larger than 2% (v/v), the concentration of intracellular malonyl dialdehyde (MDA) increased remarkably at day 5 compared to that of the control, while that of the extracellular MDA less changed at a DMSO content of below 2% (v/v) and increased rapidly within 15 min at a DMSO content of 4% (v/v). The electrical conductivity (EC) decreased slightly when DMSO content was below 2% (v/v) but increased markedly at day 5 when DMSO content reached 4% (v/v). EC less varied when the content of ethanol was below 0.4% (v/v) but changed obviously when the ethanol content was larger than 1% (v/v). The cell membrane integrity hardly broke in the case of small concentration of DMSO (below 1%, v/v), but the presence of even small amount of ethanol (0.4%, v/v) caused cell membrane integrity lost partly, especially long time contact. It is thus concluded that DMSO is a more suitable solvent for water-insoluble elicitors compared to ethanol especially at low concentration levels.

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Antimicrobial Effects of 7,8-Dihydroxy-6-Methoxycoumarin and 7-Hydroxy-6-Methoxycoumarin Analogues against Foodborne Pathogens and the Antimicrobial Mechanisms Associated with Membrane Permeability

Journal of Food Protection ◽

10.4315/0362-028x.jfp-17-050 ◽

2017 ◽

Vol 80 (11) ◽

pp. 1784-1790 ◽

Cited By ~ 1

Author(s):

Ji-Yeon Yang ◽

Jun-Hwan Park ◽

Myung-Ji Lee ◽

Ji-Hoon Lee ◽

Hoi-Seon Lee

Keyword(s):

Antimicrobial Activity ◽

Cell Membrane ◽

Membrane Permeability ◽

Foodborne Pathogens ◽

Antimicrobial Agents ◽

Functional Group ◽

Membrane Integrity ◽

Cell Membrane Permeability ◽

Antimicrobial Effects ◽

Structural Analogues

ABSTRACT The antimicrobial effects of 7,8-dihydroxy-6-methoxycoumarin and 7-hydroxy-6-methoxycoumarin isolated from Fraxinus rhynchophylla bark and of their structural analogues were determined in an attempt to develop natural antimicrobial agents against the foodborne pathogens Escherichia coli, Bacillus cereus, Staphylococcus intermedius, and Listeria monocytogenes. To elucidate the relationship between structure and antimicrobial activity for the coumarin analogues, isolated constituents and their structural analogues were evaluated against foodborne pathogens. Based on the culture plate inhibition zones and MICs, 6,7-dimethoxycoumarin, 7,8-dihydroxy-6-methoxycoumarin, 7-hydroxy-6-methoxycoumarin, and 7-methoxycoumarin, containing a methoxy functional group on the coumarin skeleton, had the notable antimicrobial activity against foodborne pathogens. However, 7-hydroxycoumarin and 6,7-dihydroxycoumarin, which contained a hydroxyl functional group on the coumarin skeleton, had no antimicrobial activity against these pathogens. An increase in cell membrane permeability was confirmed by electron microscopy observations, and release of extracellular ATP and cell constituents followed treatment with the ethyl acetate fraction of F. rhynchophylla extract. These findings indicate that F. rhynchophylla extract and coumarin analogues have potential for use as antimicrobial agents against foodborne pathogens and that the antimicrobial mechanisms are associated with the loss of cell membrane integrity.

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Effect of CuO Nanoparticles on the Cell Membrane Permeability of A549 and its Exclusion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.343-344.77 ◽

2011 ◽

Vol 343-344 ◽

pp. 77-80

Author(s):

Xiao Yan Xie ◽

Li Li Xu ◽

Dong Mei Gao

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Membrane Integrity ◽

Cuo Nanoparticles ◽

Cell Membrane Permeability ◽

Lung Cells ◽

Cuo Nps ◽

Dose Dependent ◽

Human A549 ◽

A549 Lung

This study was conducted to explore the effect of CuO nanoparticles (NPs) on the cell membrane permeability and its exclusion from cells. Human A549 lung cells were exposed to 5mg/L and 15mg/L CuO NPs. Cell membrane permeability was evaluated in 2h and 4h. After 4 hours exposure, the membrane was damaged. Exclusion of copper from cells after 24h exposure with 5mg/L and 15 mg/L CuO NPs are time and dose dependent. And the cell viability was resumed gradually. It is concluded that CuO NPs could induce cytotoxicity, and destroy the membrane integrity. One detoxify mechanism was the exclusion of excessive copper from cells themselves.

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Antifungal Activity of Essential Oil Compounds (Geraniol and Citral) and Inhibitory Mechanisms on Grain Pathogens (Aspergillus flavus and Aspergillus ochraceus)

Molecules ◽

10.3390/molecules23092108 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2108 ◽

Cited By ~ 20

Author(s):

Xi Tang ◽

Ye-Lin Shao ◽

Ya-Jie Tang ◽

Wen-Wen Zhou

Keyword(s):

Antifungal Activity ◽

Essential Oil ◽

Cell Membrane ◽

Membrane Permeability ◽

Cell Membrane Permeability ◽

Aspergillus Ochraceus ◽

Ros Generation ◽

Inhibitory Mechanisms ◽

Preservation Method ◽

Essential Oil Compounds

The grain contamination by Aspergillus spp. has been a serious issue. This study exhibited the excellent antifungal effects of the essential oil compounds (EOCs) geraniol and citral against common grain pathogens (A. flavus and A. ochraceus) in vitro and in situ. The inhibitory mechanisms were also evaluated from the perspective of cell membrane permeability, reactive oxygen species (ROS) generation, and Aspergillus spp. growth-related gene expression. Meanwhile, the combined effects of EOCs in the vapor phase and modified atmosphere packaging (MAP) were examined to find an alternative preservation method for controlling Aspergillus spp. The results indicated that citral exhibited the antifungal activity mainly by downregulating the sporulation- and growth-related genes for both pathogens. Geraniol displayed inhibitory effectiveness against A. flavus predominantly by inducing the intracellular ROS accumulation and showed toxicity against A. ochraceus principally by changing cell membrane permeability. Furthermore, the synthetic effects of EOCs and MAP (75% CO2 and 25% N2) induced better grain quality than the current commercial fumigant AlP. These findings reveal that EOCs have potential to be a novel grain preservative for further application.

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Sarcolemmal permeability changes during early myocardial anoxia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084089 ◽

1978 ◽

Vol 36 (2) ◽

pp. 642-643

Author(s):

M. Ashraf ◽

L. Landa ◽

L. Nimmo ◽

C. M. Bloor

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Cell Membrane Permeability ◽

Enzyme Release ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Sarcolemmal Permeability ◽

Membrane Changes

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.

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