scholarly journals Antifungal and antiaflatoxigenic activities of coumarinyl thiosemicarbazides against Aspergillus flavus NRRL 3251

2017 ◽  
Vol 68 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Tihomir Kovač ◽  
Marija Kovač ◽  
Ivica Strelec ◽  
Ante Nevistić ◽  
Maja Molnar
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Antifungal Activity ◽  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Oxidative Stress Response ◽  
Oxidative Status ◽  
Biochemical Assays ◽  
Effect Estimation ◽  
Activity Estimation

Abstract The antifungal and antiaflatoxigenic effects of two series of coumarinyl thiosemicarbazides on Aspergillus flavus NRRL 3251 were studied. Fungi were grown in YES medium for 72 h at 29 °C in the presence of 0, 0.1, 1, and 10 μg mL-1 of coumarinyl thiosemicarbazides: one series with substitution in position 7 and another with substitution in position 4 of the coumarin core. Dry mycelia weight determination was used for antifungal activity estimation, while the aflatoxin B1 content in YES media, determined by the dilute and shoot LC-MS/MS technique, was used for the antiaflatoxigenic effect estimation. Standard biochemical assays were used for oxidative status marker (TBARS, SOD, CAT, and GPX) determination in A. flavus NRRL 3251 mycelia. Results show that 7-substituted-coumarinyl thiosemicarbazides possess a better antifungal and antiaflatoxigenic activity than 4-substituted ones. The most prominent substituted compound was the compound 3, N-(4-chlorophenyl)-2-(2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)acetyl)hydrazine-1-carbothioamide, which completely inhibited aflatoxin production at the concentration of 10 μg mL-1. Oxidative stress response of A. flavus exposed to the selected compounds points to the modulation of oxidative stress as a possible reason of aflatoxin production inhibition.

scholarly journals Piperine inhibits aflatoxin B1 production in Aspergillus flavus by modulating fungal oxidative stress response

2017 ◽  
Vol 107 ◽  
pp. 77-85 ◽  
Author(s):  
Isaura Caceres ◽  
Rhoda El Khoury ◽  
Sylviane Bailly ◽  
Isabelle P. Oswald ◽  
Olivier Puel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Oxidative Stress Response

scholarly journals The bZIP Transcription Factor AflRsmA Regulates Aflatoxin B1 Biosynthesis, Oxidative Stress Response and Sclerotium Formation in Aspergillus flavus

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 271
Author(s):  
Xiuna Wang ◽  
Wenjie Zha ◽  
Linlin Liang ◽  
Opemipo Esther Fasoyin ◽  
Lihan Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Stress Response ◽  
Secondary Metabolites ◽  
Secondary Metabolism ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Opportunistic Pathogen ◽  
Oxidative Stress Response ◽  
Bzip Transcription Factor

Fungal secondary metabolites play important roles not only in fungal ecology but also in humans living as beneficial medicine or harmful toxins. In filamentous fungi, bZIP-type transcription factors (TFs) are associated with the proteins involved in oxidative stress response and secondary metabolism. In this study, a connection between a bZIP TF and oxidative stress induction of secondary metabolism is uncovered in an opportunistic pathogen Aspergillus flavus, which produces carcinogenic and mutagenic aflatoxins. The bZIP transcription factor AflRsmA was identified by a homology research of A. flavus genome with the bZIP protein RsmA, involved in secondary metabolites production in Aspergillus nidulans. The AflrsmA deletion strain (ΔAflrsmA) displayed less sensitivity to the oxidative reagents tert-Butyl hydroperoxide (tBOOH) in comparison with wild type (WT) and AflrsmA overexpression strain (AflrsmAOE), while AflrsmAOE strain increased sensitivity to the oxidative reagents menadione sodium bisulfite (MSB) compared to WT and ΔAflrsmA strains. Without oxidative treatment, aflatoxin B1 (AFB1) production of ΔAflrsmA strains was consistent with that of WT, but AflrsmAOE strain produced more AFB1 than WT; tBOOH and MSB treatment decreased AFB1 production of ΔAflrsmA compared to WT. Besides, relative to WT, ΔAflrsmA strain decreased sclerotia, while AflrsmAOE strain increased sclerotia. The decrease of AFB1 by ΔAflrsmA but increase of AFB1 by AflrsmAOE was on corn. Our results suggest that AFB1 biosynthesis is regulated by AflRsmA by oxidative stress pathways and provide insights into a possible function of AflRsmA in mediating AFB1 biosynthesis response host defense in pathogen A. flavus.

scholarly journals Exposure of Aspergillus fumigatus to Atorvastatin Leads to Altered Membrane Permeability and Induction of an Oxidative Stress Response

2020 ◽  
Vol 6 (2) ◽  
pp. 42
Author(s):  
Ahmad Ajdidi ◽  
Gerard Sheehan ◽  
Kevin Kavanagh
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Membrane Permeability ◽  
High Serum ◽  
Oxidative Stress Response ◽  
High Serum Cholesterol ◽  
Statin Drug ◽  
Coa Reductase

Aspergillus fumigatus is a serious cause of disease in immune-deficient patients and in those with pulmonary malfunction (e.g., cystic fibrosis (CF), asthma). Atorvastatin is a member of the statin drug family, which are the main therapeutic agents used to decrease high serum cholesterol levels by inhibiting (HMG-CoA) reductase enzyme. The aim of the work presented here was to analyse the antifungal activity of atorvastatin and assess its effect on the virulence of A. fumigatus. Atorvastatin demonstrated strong antifungal activity and reduced the growth and viability of A. fumigatus. Exposure of A. fumigatus to atorvastatin led to a reduction in ergosterol content and increased membrane permeability, as evidenced by the release of protein, amino acids and gliotoxin. Proteomic analysis revealed an increased abundance of proteins associated with an oxidative stress response, such as the glutathione s-transferase family protein (+8.43-fold), heat shock protein Hsp30/Hsp42 (+2.02-fold) and 5-demethoxyubiquinone hydroxylase, mitochondrial (+1.73-fold), as well as secondary metabolites such as isocyanide synthase A icsA (+8.52-fold) and non-ribosomal peptide synthetase fmpE (+3.06-fold). The results presented here indicate that atorvastatin has strong antifungal properties and may have potential application in the treatment of A. fumigatus infections alone or in combination with existing antifungal agents.

scholarly journals Comparison of transradial versus transfemoral diagnostic coronary angiography in terms of oxidative stress: Which option is more physiological?

2021 ◽  
Vol 19 ◽  
pp. 205873922110280
Author(s):  
Veysel Oktay ◽  
Bengisu Keskin ◽  
Ebru Serin ◽  
Dogac Oksen ◽  
Aysem Kaya ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Coronary Angiography ◽  
Oxidative Stress Response ◽  
Oxidative Status ◽  
Heart Catheterization ◽  
Laboratory Findings ◽  
Cell Counts ◽  
Total Oxidative Status ◽  
White Blood Cell Counts

In this randomized, single-center, clinical study we aimed to compare the oxidative stress response in patients undergoing diagnostic transradial or transfemoral elective coronary angiography. Sixty patients with stable angina pectoris undergoing elective coronary angiography to either transradial ( n = 30) or transfemoral ( n = 30) approach were included. The levels of plasma total oxidative status (TOS) were measured and compared just before and immediately after the procedure in both groups. The clinical and laboratory findings were compatible between the two groups. Although the levels of plasma total oxidative status after coronary angiography were increased in both groups (TF pTOS 20. ± :3; 34 ± 3 vs TR pTOS 18 ± 2; 23 ± 4), this was more pronounced in the transfemoral group as compared with the transradial group (ΔpTOS: 11 ± 4 vs 4 ± 3, p < 0.001) In correlation analysis, TOS levels and white blood cell counts ( r = 0.25, p = 0.042), total cholesterol levels ( r = 0.267, p = 0.041), triglyceride levels ( r = 0.253, p = 0.049), serum creatinine levels ( r = 0.260, p = 0.043) were found to be moderately positively correlated. This study showed that oxidative stress response associated with heart catheterization is more evident in patients undergoing transfemoral coronary angiography versus transradial coronary angiography.

scholarly journals Antifungal Activity of Fused Mannich Ketones Triggers an Oxidative Stress Response and Is Cap1-Dependent in Candida albicans

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e62142 ◽  
Author(s):  
Tristan Rossignol ◽  
Béla Kocsis ◽  
Orsolya Bouquet ◽  
Ildikó Kustos ◽  
Ferenc Kilár ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Candida Albicans ◽  
Stress Response ◽  
Antifungal Activity ◽  
Oxidative Stress Response

scholarly journals VeA Is Associated with the Response to Oxidative Stress in the Aflatoxin Producer Aspergillus flavus

2014 ◽  
Vol 13 (8) ◽  
pp. 1095-1103 ◽  
Author(s):  
Sachin Baidya ◽  
Rocio M. Duran ◽  
Jessica M. Lohmar ◽  
Pamela Y. Harris-Coward ◽  
Jeffrey W. Cary ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Complex Formation ◽  
Osmotic Stress ◽  
Signaling Pathway ◽  
Aspergillus Flavus ◽  
Fungal Species ◽  
Oxidative Stress Response ◽  
Content Type ◽  
Osmotic Stress Response

ABSTRACT Survival of fungal species depends on the ability of these organisms to respond to environmental stresses. Osmotic stress or high levels of reactive oxygen species (ROS) can cause stress in fungi resulting in growth inhibition. Both eukaryotic and prokaryotic cells have developed numerous mechanisms to counteract and survive the stress in the presence of ROS. In many fungi, the HOG signaling pathway is crucial for the oxidative stress response as well as for osmotic stress response. This study revealed that while the osmotic stress response is only slightly affected by the master regulator veA , this gene, also known to control morphological development and secondary metabolism in numerous fungal species, has a profound effect on the oxidative stress response in the aflatoxin-producing fungus Aspergillus flavus . We found that the expression of A. flavus homolog genes involved in the HOG signaling pathway is regulated by veA . Deletion of veA resulted in a reduction in transcription levels of oxidative stress response genes after exposure to hydrogen peroxide. Furthermore, analyses of the effect of VeA on the promoters of cat1 and trxB indicate that the presence of VeA alters DNA-protein complex formation. This is particularly notable in the cat1 promoter, where the absence of VeA results in abnormally stronger complex formation with reduced cat1 expression and more sensitivity to ROS in a veA deletion mutant, suggesting that VeA might prevent binding of negative transcription regulators to the cat1 promoter. Our study also revealed that veA positively influences the expression of the transcription factor gene atfB and that normal formation of DNA-protein complexes in the cat1 promoter is dependent on AtfB.

Sign in / Sign up

Export Citation Format

Share Document