scholarly journals Citronellal Exerts Its Antifungal Activity by Targeting Ergosterol Biosynthesis in Penicillium digitatum

2021 ◽  
Vol 7 (6) ◽  
pp. 432
Author(s):  
Qiuli OuYang ◽  
Yangmei Liu ◽  
Okwong Reymick Oketch ◽  
Miaoling Zhang ◽  
Xingfeng Shao ◽  
...  

Ergosterol (ERG) is a potential target for the development of antifungal agents against Penicillium digitatum, the pathogen of green mold in citrus fruits. This study examined the mechanism by which citronellal, a typical terpenoid of Cymbopogon nardus essential oil, acts on ergosterol to exhibit its antifungal activity against P. digitatum. We previously reported that citronellal inhibited the growth of P. digitatum with minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 1.36 and 2.72 mg/mL, respectively. In citronellal-treated cells, the membrane integrity and ergosterol contents significantly decreased, whereas lanosterol, which serves as a precursor for ergosterol biosynthesis, massively accumulated. Addition of 150 mg/L of exogenous ergosterol decreased the inhibitory rate of citronellal, restoring the ergosterol content and hence the membrane structure to normal levels, and triggered expression of nearly all ERG genes. Based on our findings, we deduce that citronellal damages the cell membrane integrity of P. digitatum by down-regulating the ERG genes responsible for conversion of lanosterol to ergosterol, the key downregulated gene being ERG3, due to the observed accumulation of ergosta-7,22-dienol.

2011 ◽  
Vol 11 ◽  
pp. 1489-1495 ◽  
Author(s):  
Auri R. Duval ◽  
Pedro H. Carvalho ◽  
Maieli C. Soares ◽  
Daniela P. Gouvêa ◽  
Geonir M. Siqueira ◽  
...  

Fifteen 7-chloro-4-arylhydrazonequinolines have been evaluated for their in vitro antifungal activity against eight oral fungi:Candida albicans, C. parapsilosis, C. lipolytica, C. tropicalis, C. famata, C. glabrata, Rhodutorula mucilaginosa, andR. glutinis. Several compounds exhibited minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) activities comparable with the first-line drug fluconazole. These results could be considered as an important starting point for the rational design of new antifungal agents.


2021 ◽  
Vol 14 (11) ◽  
pp. 1130
Author(s):  
Cornelia Babii ◽  
Mihaela Savu ◽  
Iuliana Motrescu ◽  
Lucian Mihail Birsa ◽  
Laura Gabriela Sarbu ◽  
...  

Infections caused by Candida are very difficult to treat due to increasing antifungal resistance. Recent studies showed that patients with Candida infections resistant to fluconazole have very few treatment options. Therefore, finding new efficient antifungal agents is a matter of medical high priority. The aim of this study was to explore the antifungal potential of BrCl-flav-a representative of a new class of synthetic flavonoids with bromine as halogen substituent at the benzopyran core against four Candida clinical strains. Determination of minimum inhibitory concentration and minimum fungicidal concentration along with the time kill assay indicated a strong antifungal effect of BrCl-flav against C. albicans, C. parapsilosis, C. krusei and C. glabrata. The investigation of anti-Candida mechanism of action using fluorescence microscopy and scanning electron microscopy revealed that Br-Cl flav could inhibit fungal growth by impairing the membrane integrity, the resulting structural damages leading to cell lysis. BrCl-flav also showed important anti-virulence properties against Candida spp., inhibiting biofilm formation and yeast to hyphal transition. A strong synergistic antifungal effect against C. albicans strain was observed when BrCl-flav was used in combination with fluconazole. BrCl-flav has a good potential to develop new effective antifungal agents in the context of Candida spp. multidrug resistance phenomenon.


INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (12) ◽  
pp. 39-44
Author(s):  
A. P. Pandit ◽  
◽  
K. S. Khandagale ◽  
V. C Nakhate ◽  
N. N Dharmadhikari

The objective of the study was to prepare antifungal gel using leaves of Amaranthus viridis for the treatment of cutaneous candidiasis. The leaves were studied for pharmacognostic evaluation. The powder of leaves was tested for phytoconstituents. The plant extract was evaluated for the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and antifungal activity. Gel was prepared and evaluated for pH, viscosity, homogeneity and grittiness. MIC and MFC of extract were both found to be 600 mg. The zone of inhibition of extract was obtained at 21.2±0.2mm, which confirmed antifungal activity, due to presence of phenolic compound. Gel exhibited good antifungal activity, good spreadability, extrudability and high viscosity. Thus, gel loaded with leaves extract of A. viridis is a good choice for the treatment of cutaneous candidiasis.


Plant Disease ◽  
2020 ◽  
pp. PDIS-05-20-1128
Author(s):  
Yuchao Zhang ◽  
Bao Zhang ◽  
Chaoxi Luo ◽  
Yanping Fu ◽  
Fuxing Zhu

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Martin Muthee Gakuubi ◽  
Angeline W. Maina ◽  
John M. Wagacha

The objective of this study was to evaluate the antifungal activity of essential oil (EO) ofEucalyptus camaldulensisDehnh. against fiveFusariumspp. commonly associated with maize.The essential oil had been extracted by steam distillation in a modified Clevenger-type apparatus from leaves ofE. camaldulensisand their chemical composition characterized by gas chromatography mass spectrometry. Poisoned food technique was used to determine the percentage inhibition of mycelial growth, minimum inhibitory concentration, and minimum fungicidal concentration of the EO on the test pathogens. Antifungal activity of different concentrations of the EO was evaluated using disc diffusion method. The most abundant compounds identified in the EO were 1,8-cineole (16.2%),α-pinene (15.6%),α-phellandrene (10.0%), and p-cymene (8.1%). The EO produced complete mycelial growth inhibition in all the test pathogens at a concentration of 7-8 μL/mL after five days of incubation. The minimum inhibitory concentration and minimum fungicidal concentration of the EO on the test fungi were in the range of 7-8 μL/mL and 8–10 μL/mL, respectively. These findings confirm the fungicidal properties ofE. camaldulensisessential oils and their potential use in the management of economically importantFusariumspp. and as possible alternatives to synthetic fungicides.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9767
Author(s):  
Rong Cheng ◽  
Wei Li ◽  
Klarke M. Sample ◽  
Qiang Xu ◽  
Lin Liu ◽  
...  

Candida parapsilosis is a major fungal pathogen that leads to sepsis. New and more effective antifungal agents are required due to the emergence of resistant fungal strains. MAF-1A is a cationic antifungal peptide isolated from Musca domestica that is effective against a variety of Candida species. However, the mechanism(s) of its antifungal activity remains undefined. Here, we used RNA-seq to identify differentially expressed genes (DEGs) in Candida parapsilosis following MAF-1A exposure. The early (6 h) response included 1,122 upregulated and 1,065 downregulated genes. Late (18 h) responses were associated with the increased expression of 101 genes and the decreased expression of 151 genes. Upon MAF-1A treatment for 18 h, 42 genes were upregulated and 25 genes were downregulated. KEGG enrichment showed that the DEGs in response to MAF-1A were mainly involved in amino acid synthesis and metabolism, oxidative phosphorylation, sterol synthesis, and apoptosis. These results indicate that MAF-1A exerts antifungal activity through interference with Candida parapsilosis cell membrane integrity and organelle function. This provides new insight into the interaction between Candida parapsilosis and this antimicrobial peptide and serves as a reference for future Candida parapsilosis therapies.


2019 ◽  
Vol 5 (1) ◽  
pp. 23
Author(s):  
Rahayu Kusdarwati, Ayu Ratnaningtyas, Dewa Ketut Meles

Abstract Saprolegnia sp. is a fungus that causes the Saprolegniasis disease can infection eggs and fresh water fish. Treatment Saprolegniasis done using chemical drugs, however the use of drugs is bad for the environment and biota. The purpose of the research was to determined the antifungal activity include a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) from Kaempferia galanga L. to Saprolegnia sp. by in vitro. This research used 9 different concentrations of Kaempferia galanga L extract were 50%, 12.5%, 6.25%, 3.12%, 1.56%, 0.78%, 0, 39%, 0.2%, positive control used H2O2 3% and negative control used DMSO 10%. The results showed that the extract of Kaempferia galanga L had an antifungal activity were inhibits and kill with minimum inhibitory concentration (MIC) was 0.39% equivalen with 3,9 mg/ml and minimu fungicidal concentration (MBC) was 1.56% equivalen with 15,6 mg/ml. The existence of antifungal activity against Saprolegnia sp. by in vitro caused by some active compounds from the extracts of the Kaempferia galanga L. are polyphenolic compounds, flavonoin, saponins and essential oils.


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