Antifungal Properties of Urtica dioca against Six Phytopathogenic Fungi

2021 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Cláudia Ferreira ◽  
Rui Oliveira

Several phytopathogenic fungi greatly affect the production of important crops across the globe, as they lead to huge losses. To control diseases caused by fungal phytopathogens, a wide range of synthetic fungicides are applied in the fields. However, these agrochemicals are harmful for ecosystems (aerial, aquatic and terrestrial), non-target organisms and humans. In addition, since these antifungals have one specific cellular target, fungi can acquire resistance to them via the accumulation of mutations. Plant extracts provide natural alternatives to the use of synthetic fungicides in agriculture. Several plants are rich in secondary metabolites, including alkaloids, coumarins, flavonoids, terpenoids and saponins, which confer antifungal activity. This sustainable option is biodegradable, environmentally friendly and proves to be safer, and it is less prone to development resistance since they often have several cellular targets. This study was conducted to investigate the antifungal activity of Urtica dioica extract against Colletotrichum acutatum, Colletotrichum gloeosporioides, Colletotrichum godetiae, Colletotrichum nymphaeae, Diplodia corticola and Phytophthora cinnamomi. Urtica dioica extract was prepared with 50% (v/v) ethanol, the solvent was evaporated at a low pressure, and the residue was dissolved in water. The extract was incorporated into PDA medium at different concentrations (100, 500, 1000 and 2000 µg/mL) and mycelial discs were placed in the center of each Petri dish. Growth was measured in terms of radial mycelial growth in the third, sixth and ninth days of incubation, at 25 °C and in the dark. Urtica dioica extract was able to inhibit the growth of all strains except C. nymphaeae. Growth inhibition was around 20% at 2000 µg/mL for the remaining Colletotrichum species. An inhibition of growth was also observed with D. corticola in a concentration-dependent manner, from 100 µg/mL to 2000 µg/mL and revealed statistically significant differences (p < 0.05) between these concentrations. Regarding the growth of P. cinnamomi, significant differences were observed between the 100 µg/mL and 2000 µg/mL extract (p < 0.0001 and p < 0.05 on day 3 and 6, respectively). The most pronounced mycelial growth reduction (39.9%) was observed on day 3, an effect that is significantly different from (24.9%; p < 0.05) the result observed on the sixth day of incubation. Overall, the results of this work suggest U. dioca as a potential, ecologically sustainable alternative to conventional fungicides to protect crops from damage caused by phytopathogenic fungi.

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 94
Author(s):  
Cláudia Ferreira ◽  
Rui Oliveira

Synthetic fungicides for crops protection raise environmental and human concerns due to accumulation in edible vegetables, showing significant toxicity to humans, and in soil, groundwater and rivers, affecting ecological balance. In addition, they are prone to the development of resistant strains because of the single target-based mechanism of action. Plant extracts provide attractive alternatives, as they constitute a rich source of biodegradable secondary metabolites, such as phenols, flavonoids and saponins, which have multiple modes of antifungal action and a lower probability of the development of resistant fungi. This work has the objective of identifying plant extracts with antifungal activity, aiming to contribute to food safety and sustainable agricultural practices. We selected a saponin-containing plant, Plantago major, and extracted secondary metabolites with 50% (v/v) ethanol, dried by evaporation, and dissolved in water. For antifungal activity, the phytopathogenic fungi Colletotrichum acutatum, Colletotrichum gloeosporioides, Colletotrichum godetiae, Colletotrichum nymphaeae, Diplodia corticola and Phytophthora cinnamomi were selected because they affect fruits and vegetables, such as strawberry, almond, apple, avocado, blueberry and chestnut trees. The aqueous extract was incorporated into PDA medium at different concentrations and mycelial discs were placed in the center of each Petri dish. Growth was measured as the radial mycelial growth at 3, 6, and 9 days incubation at 25 °C in the dark. The maximum growth inhibition (32.2%) was obtained against P. cinnamomi with 2000 µg/mL extract followed by C. gloeosporioides (25.7%) on the sixth day and by C. godetiae and C. nymphaeae (21.1%) on the ninth day. Results show that P. major presents antifungal activity in all phytopathogenic fungi tested and the extract can be used to protect important crops, by inhibiting the development of fungal infections and promoting food security and a sustainable agriculture.


2021 ◽  
Vol 9 (4) ◽  
pp. 839
Author(s):  
Muhammad Rafiullah Khan ◽  
Vanee Chonhenchob ◽  
Chongxing Huang ◽  
Panitee Suwanamornlert

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.


2010 ◽  
Vol 25 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Natasa Duduk ◽  
Aleksa Obradovic ◽  
Mirko Ivanovic

Effects of the volatile phase of thyme, cinnamon and clove essential oils on Colletotrichum acutatum were investigated. Mycelial disc was placed in the center of the Petri dish (V=66 ml) containing PDA. Different volumes of either non- or ethanol-diluted essential oils were placed on the inner side of the dish cover to obtain final concentrations of 153, 107, 76, 46, 15, 14, 12, 11, 7.6, 3.82, 1.53, 0.153 and 0.0153 ?l/L of air. The dishes were sealed with Parafilm and incubated in up-side-down position. After 7 days of incubation, mycelial growth was recorded by measuring the colony diameter. If no mycelial growth was recorded, the disc was transferred to a new PDA plate in order to evaluate whether the activity was either fungistatic or fungicidal. Mean growth values were obtained and then converted to inhibition percentage of mycelial growth compared with the control treatment. All the tested essential oils inhibited mycelial growth of C. acutatum in the dose dependent manner. Mycelial growth was totally inhibited by thyme oil in the concentration of 76 ?l/L of air. The same results were obtained by cinnamon and clove oil in the concentration of 107 ?l/L of air. Thyme and cinnamon oil had fungicidal effect in concentrations of 107 and 153 ?l/L respectively. The results obtained provide evidence on the antifungal in vitro effect of the tested essential oils as potential means for the control of C. acutatum.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


2012 ◽  
Vol 7 (9) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Paraj Shukla ◽  
Suresh Walia ◽  
Vivek Ahluwalia ◽  
Balraj S. Parmar ◽  
Muraleedharan G. Nair

Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 μg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 – 60 μg/mL.


2016 ◽  
Vol 311 (3) ◽  
pp. H725-H734 ◽  
Author(s):  
Hélène Vancraeyneste ◽  
Rogatien Charlet ◽  
Yann Guerardel ◽  
Laura Choteau ◽  
Anne Bauters ◽  
...  

Platelets are capable of binding, aggregating, and internalizing microorganisms, which enhances the elimination of pathogens from the blood. The yeast Candida albicans is a pathobiont causing life-threatening invasive infections. Its cell wall contains β-1,3 glucans that are known to trigger a wide range of host cell activities and to circulate during infection. We studied the effect of β-1,3 glucan fractions (BGFs) consisting of diglucosides (Glc2), tetraglucosides (Glc4), and pentaglucosides (Glc5) on human platelets, their mechanisms of action, and their possible impact on host defenses. The effect of BGFs on the coagulation process was determined by measuring thrombin generation. Platelets pretreated with BGFs were analyzed in terms of activation, receptor expression, aggregation, and adhesion to neutrophils and to C. albicans. The results show that BGFs affected the endogenous thrombin potential in a concentration-dependent manner. For platelet activation, BGFs at a low concentration (2 μmol/l) reduced ATP release and prevented the phosphorylation of protein kinase C. BGFs diminished the expression of P-selectin and the activation of αIIbβ3. BGFs decreased platelet aggregation and the interaction between thrombin-stimulated platelets and neutrophils, fibrinogen, and C. albicans. GLc5 decreased ATP release and TGF-β1 production in response to TLR4 upregulation in thrombin-stimulated platelets, but TLR4 blockage abolished the effect of BGFs on platelets. This study provides evidence that fungal pentaglucosides modulate platelet activity mediated via TLR4 stimulation and reduce platelet-neutrophil interaction.


1990 ◽  
Vol 272 (3) ◽  
pp. 683-690 ◽  
Author(s):  
G G Chang ◽  
M S Shiao ◽  
K R Lee ◽  
J J Wu

Oxidation of 1,N6-ethenoadenosine monophosphate (epsilon AMP) with periodate cleaved the cis-diol of the ribose ring and resulted in the formation of a dialdehyde derivative (epsilon AMP-dial). At room temperature epsilon AMP-dial was unstable and underwent beta-elimination to give 4′,5′-anhydro-1,N6-ethenoadenosine dialdehyde acetal (A epsilon Ado-dial). These nucleotide analogues were found to inactivate human placental alkaline phosphatase in a time- and concentration-dependent manner. epsilon AMP-dial was shown to be an affinity label for the enzyme on the basis of the following criteria. (a) Kinetics of the enzyme activity loss over a wide range of epsilon AMP-dial concentration showed a saturating phenomenon. Removal of the phosphate group made the reagent (A epsilon Ado-dial) become a general chemical modifying reagent. (b) The artificial substrate p-nitrophenyl phosphate gave substantial protection of the enzyme against inactivation. (c) epsilon AMP-dial was a substrate and a partial mixed-type inhibitor for the enzyme. Results of the inhibition and protection studies indicated that the reagent and substrate could combine with the enzyme simultaneously. Besides the phosphate-binding domain, an induced hydrophobic region is proposed for the substrate-binding site for human placental alkaline phosphatase.


2013 ◽  
Vol 59 (3) ◽  
pp. 295-304
Author(s):  
I.S. Severina ◽  
A.Yu. Schegolev ◽  
A.E. Medvedev

Isatin (indole-dione) is an endogenous indole that exibits a wide range of biological and physiological activity. The influence of isatin derivatives 5-nitroisatin and arbidol (an antiviral preparatation) on spermine NONO-induced activation of human platelet soluble guanylyl cyclase was investigated. 5-nitroistnin and arbidol had no effect on basal activity, but synergistically increased in a concentration-dependent manner the spermine NONO-induced activation of this enzyme. 5-Nitroisatin and arbidol, like YC-1, sensitized guanylyl cyclase towards nitric oxide (NO) and produced a leftward shift of the spermine NONO concentration response curve. At the same time both compounds used did not influence the activation of guanylyl cyclase by YC-1 and did not change the synergistic increase of spermine NONO-induced activation of soluble guanylyl cyclase in the presence of YC-1. This suggests that 5-nitroisanin and arbidol did not compete with YC-1. Addition of isatin did not change the synergistic increase in the spermine NONO-induced guanylyl cyclase activation by 5-nitroisatin and arbidol and did not influence a leftward shift of spermine NONO concentration response curve produced by these compounds. These data suggest lack of competitive interaction between isatin and both its derivatives used.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 839-839 ◽  
Author(s):  
Giannoula Klement ◽  
Lena Kikuchi ◽  
Mark Kieran ◽  
Nava Almog ◽  
Tai-Tung Yip ◽  
...  

Abstract We report a new function for platelets: selective sequestration of tumor-derived angiogenesis regulatory proteins above the concentration of these molecules in plasma. Iodinated VEGF in a Matrigel pellet (from 100 to 600 ng/100 microl), implanted subcutaneously in mice, accumulates almost exclusively in platelets in a dose-dependent manner over a period as long as 2–3 weeks, without raising plasma levels of VEGF. Similarly, platelet VEGF increases in the presence of a single microscopic VEGF-secreting human tumor of up to only 1 mm3 in SCID mice without any increase of VEGF in plasma. In addition to VEGF, other factors such as bFGF, PDGF, BDNF, endostatin and other regulators of angiogenesis are taken up by platelets in a selective and quantifiable manner which is dependent on tumor generation of these molecules. Our data show that these proteins are not simply associated with the platelet surface, but are internalized. Furthermore, they are protected from degradation within the platelet, and are not released by classical degranulating agents, such as thrombin, ADP or epinephrine. Incubation of human platelets with endostatin at above physiological levels results in decrease of the majority of platelet-associated VEGF and bFGF in a concentration-dependent manner. Using SELDI-ToF mass spectroscopy of platelet extracts, we have found that this novel property of platelets enables the detection of microscopic tumors that undetectable by any presently available diagnostic method. The platelet angiogenic profile is more inclusive than a single biomarker because it can detect a wide range of tumor types and tumor sizes. Relative changes in the platelet angiogenic profile permit the tracking of a tumor throughout its development, beginning from an early in situ cancer. Conclusions: (i) While the half-life of mouse platelets is approximately 3 days, the platelet angiogenic profile persists for as long as the tumor (or Matrigel pellet) is present. This indicates that platelets may continuously scavenge proteins which regulate angiogenesis. (ii) The fact that the presence of a human tumor can now be detected at microscopic size, suggests that it may not be necessary to know the type and location of a tumor before initiating treatment, especially since it is feasible to use anti-cancer therapies of little or no toxicity. Figure Figure


2007 ◽  
Vol 13 (5) ◽  
pp. 341-347 ◽  
Author(s):  
R. Pérez-Sánchez ◽  
F. Infante ◽  
C. Gálvez ◽  
J.L. Ubera

The yield, chemical composition, and antifungal properties of essential oils from six populations of Thymus zygis Loefl. ex L. were studied. Phytopathogenic fungi Pythium irregulare, Rhizoctonia solani, Colletotrichum acutatum, Fusarium oxysporum, and Sclerotinia sclerotiorum showed a clear inhibition in the poisoned food test. Inhibition is tested by EC50. This activity indicator ranges from 86 ppm in the most active oils to 577 ppm. Among the identified components of the oils, 3-octanol and α-terpinene had the highest correlation with the antifungal activity. Yield, antifungal activity, and plant morphology, led to the selection of the population T. zygis ssp. gracilis harvested at flowering stage as most suitable for potential agronomical use.


Sign in / Sign up

Export Citation Format

Share Document