scholarly journals Synergistic antimicrobial effect of chitosan polymers and oligomers

2021 ◽  
Author(s):  
Maha Attjioui ◽  
Dominique Gillet ◽  
Nour Eddine El Gueddari ◽  
Bruno Maria Moerschbacher
Keyword(s):  
Plant Protection ◽  
Synergistic Effects ◽  
Fungal Growth ◽  
Antimicrobial Effect ◽  
Time Lapse ◽  
Inhibitory Effect ◽  
Degree Of Polymerization ◽  
Head Blight ◽  
Conidia Germination ◽  
Combined Application

This study evaluated the efficacy of the combined application of well-characterized chitosan polymer (degree of acetylation DA = 10%, degree of polymerization DPn = 90, dispersity ÐDP = 2.8) and oligomers (paCOS) (DP = 2-17) on conidia germination and mycelial growth of Fusarium graminearum, the major causal agent of Fusarium Head Blight in wheat. The polymer alone showed a higher inhibitory effect than the paCOS mixture alone, with half-maximal inhibitory concentrations (IC50) of less than 50 µg mL⁻¹ and more than 100 µg mL⁻¹, respectively. Using time-lapse microscopy, we also showed that paCOS did not affect conidia germination at 50 μg mL⁻¹, while chitosan polymer at the same concentration led to a delay in germination and in elongation of germ tubes. Scanning electron microscopy was used to observe the chitosan-induced changes in hyphal morphology. Surprisingly, the combination of chitosan polymer and paCOS led to strong synergistic effects in inhibiting conidia germination and fungal growth, as quantified by both the Abbot and Wadley equation. To our knowledge, this is the first report on a synergistic effect of a combination of chitosan polymers and oligomers, also highlighting for the first time the importance of ÐDP when studying structure-function relationships of functional biopolymers such as chitosan. The consequences of this finding for the improvement of chitosan-based antimicrobial or plant protective products are discussed. Given the economic importance of F. graminearum, this study suggests that the combination of chitosan polymer and oligomers can be used to support an efficient, sustainable plant protection strategy.

scholarly journals Exogenous Abscisic Acid and Gibberellic Acid Elicit Opposing Effects on Fusarium graminearum Infection in Wheat

2016 ◽  
Vol 106 (9) ◽  
pp. 986-996 ◽  
Author(s):  
Leann M. Buhrow ◽  
Dustin Cram ◽  
Dan Tulpan ◽  
Nora A. Foroud ◽  
Michele C. Loewen
Keyword(s):  
Gene Expression ◽  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Fusarium Graminearum ◽  
Fungal Growth ◽  
Head Blight ◽  
Combined Application ◽  
Subsequent Investigation ◽  
Metabolic Gene Expression ◽  
Axenic Conditions

Although the roles of salicylate (SA) and jasmonic acid (JA) have been well-characterized in Fusarium head blight (FHB)-infected cereals, the roles of other phytohormones remain more ambiguous. Here, the association between an array of phytohormones and FHB pathogenesis in wheat is investigated. Comprehensive profiling of endogenous hormones demonstrated altered cytokinin, gibberellic acid (GA), and JA metabolism in a FHB-resistant cultivar, whereas challenge by Fusarium graminearum increased abscisic acid (ABA), JA, and SA in both FHB-susceptible and -resistant cultivars. Subsequent investigation of ABA or GA coapplication with fungal challenge increased and decreased FHB spread, respectively. These phytohormones-induced effects may be attributed to alteration of the F. graminearum transcriptome because ABA promoted expression of early-infection genes, including hydrolases and cytoskeletal reorganization genes, while GA suppressed nitrogen metabolic gene expression. Neither ABA nor GA elicited significant effects on F. graminearum fungal growth or sporulation in axenic conditions, nor do these phytohormones affect trichothecene gene expression, deoxynivalenol mycotoxin accumulation, or SA/JA biosynthesis in F. graminearum-challenged wheat spikes. Finally, the combined application of GA and paclobutrazol, a Fusarium fungicide, provided additive effects on reducing FHB severity, highlighting the potential for combining fungicidal agents with select phytohormone-related treatments for management of FHB infection in wheat.

Synergistic Antitumor Effect of 5-Fluorouracil Combined with Constituents from Pleurospermum lindleyanum in Hepatocellular carcinoma SMMC-7721 Cells

2020 ◽  
Vol 20 ◽  
Author(s):  
Xiao-Feng Zhu ◽  
Xiao-Jin Li ◽  
Zhong-Lian Cao ◽  
Xiu-Jie Liu ◽  
Ping Yang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Treatment Effectiveness ◽  
Synergistic Effects ◽  
Folk Medicine ◽  
Inhibitory Effect ◽  
Caspase 9 ◽  
Whole Plant ◽  
Anti Cancer ◽  
Induced Apoptosis

Background: A Chinese folk medicine plant Pleurospermum lindleyanum possesses pharmacological activities of heat-clearing, detoxifying and preventing from hepatopathy, coronary heart disease, hypertension, and high altitude sickness. We isolated and characterized its constituents to investigate its synergistic effects against human hepatoma SMMC-7721 cells. Objective: The aim of this study was to explore the synergistic anti-cancer activities of isolates from P. lindleyanum with 5-FU on hepatoma SMMC-7721 cells in vitro and their primary mechanisms. Methods: Sequential chromatographic techniques were conducted for the isolation studies. The isolates structures were established by spectroscopic analysis as well as X-ray crystallographic diffraction. Growth inhibition was detected by MTT assay. The isobologram method was used to assess the effect of drug combinations. Flow cytometry and western blot were used to examine apoptosis and protein expression. Results: A new coumarin (16), along with sixteen known compounds, were isolated from the whole plant of P. lindleyanum and their structures were elucidated by spectroscopic methods. Four coumarins (2, 3, 5, and 16), two flavonoids (8 and 9) and three phytosterols and triterpenes (12-14) were found to synergistically enhance the inhibitory effect of 5-FU against SMMC-7721 cells. Among them, compounds 3 and 16 exhibited the best synergistic effects with IC50 of 5-FU reduced by 16-fold and 22-fold possessing the minimum Combination Index (CI) 0.34 and 0.27. The mechanism of action of combinations might be through synergistic arresting for the cell cycle at G1 phases and the induction of apoptosis. Moreover, western blotting and molecular docking revealed that compounds 3 or 5 might promote 5-FU-induced apoptosis by regulating the expression of Caspase 9 and PARP. Conclusion: Constituents from P. lindleyanum may improve the treatment effectiveness of 5-FU against hepatocellular carcinoma cells.

scholarly journals Combined Application of Pan-AKT Inhibitor MK-2206 and BCL-2 Antagonist Venetoclax in B-Cell Precursor Acute Lymphoblastic Leukemia

2021 ◽  
Vol 22 (5) ◽  
pp. 2771
Author(s):  
Anna Richter ◽  
Elisabeth Fischer ◽  
Clemens Holz ◽  
Julia Schulze ◽  
Sandra Lange ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Cell ◽  
Cell Lines ◽  
Morphological Changes ◽  
Synergistic Effects ◽  
Lymphoblastic Leukemia ◽  
Tumor Cell Proliferation ◽  
Akt Inhibitor ◽  
Akt Phosphorylation ◽  
Combined Application

Aberrant PI3K/AKT signaling is a hallmark of acute B-lymphoblastic leukemia (B-ALL) resulting in increased tumor cell proliferation and apoptosis deficiency. While previous AKT inhibitors struggled with selectivity, MK-2206 promises meticulous pan-AKT targeting with proven anti-tumor activity. We herein, characterize the effect of MK-2206 on B-ALL cell lines and primary samples and investigate potential synergistic effects with BCL-2 inhibitor venetoclax to overcome limitations in apoptosis induction. MK-2206 incubation reduced AKT phosphorylation and influenced downstream signaling activity. Interestingly, after MK-2206 mono application tumor cell proliferation and metabolic activity were diminished significantly independently of basal AKT phosphorylation. Morphological changes but no induction of apoptosis was detected in the observed cell lines. In contrast, primary samples cultivated in a protective microenvironment showed a decrease in vital cells. Combined MK-2206 and venetoclax incubation resulted in partially synergistic anti-proliferative effects independently of application sequence in SEM and RS4;11 cell lines. Venetoclax-mediated apoptosis was not intensified by addition of MK-2206. Functional assessment of BCL-2 inhibition via Bax translocation assay revealed slightly increased pro-apoptotic signaling after combined MK-2206 and venetoclax incubation. In summary, we demonstrate that the pan-AKT inhibitor MK-2206 potently blocks B-ALL cell proliferation and for the first time characterize the synergistic effect of combined MK-2206 and venetoclax treatment in B-ALL.

scholarly journals Double Gamers—Can Modified Natural Regulators of Higher Plants Act as Antagonists against Phytopathogens? The Case of Jasmonic Acid Derivatives

2020 ◽  
Vol 21 (22) ◽  
pp. 8681
Author(s):  
Nicolò Orsoni ◽  
Francesca Degola ◽  
Luca Nerva ◽  
Franco Bisceglie ◽  
Giorgio Spadola ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Fungal Species ◽  
Phytopathogenic Fungi ◽  
Phaeomoniella Chlamydospora ◽  
Horticultural Crops

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae,F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani,Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.

scholarly journals In vitro activity of allicin combined with two antibiotics on intestinal Shigella

2017 ◽  
Vol 6 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Yuchi Jia ◽  
Xiaomei Wu
Keyword(s):  
Intestinal Tract ◽  
Inhibitory Concentration ◽  
Synergistic Effects ◽  
Antagonistic Effect ◽  
Additive Effects ◽  
In Vitro Activity ◽  
Antibacterial Effects ◽  
Combined Application ◽  
Combined Use

Abstract Objective We aimed to evaluate the combined antibacterial effects of allicin in combination with levofloxacin and ceftriaxone on Shigella isolated from the intestinal tract in vitro. Materials and Methods Using a checkerboard design, broth microdilution assay was used to test the effects of the compounds on the organism. We also determined the MIC of the two groups of antibacterial drugs against 30 strains of Shigella and calculated the fractional inhibitory concentration (FIC) index, to judge the combination effect. Result After the combined application of allicin and ceftriaxone the MIC decreased significantly. Distribution of the FIC index was as follows: FIC ≤0.5, accounting for 10%; 0.5< FIC ≤1.0, accounting for 60%; 1 < FIC ≤2, accounting for 30%; FIC >2, percentage is zero. After combined application of allicin and levofloxacin, distribution of FIC index was as follows: FIC≤0.5, ratio is zero; 0.5< FIC ≤1, accounting for 56.7%; 1 < FIC ≤2, accounting for 43.3%; FIC >2, ratio is zero. Conclusion After the combined use of ceftriaxone, levofloxacin, and allicin, most of the tests showed synergistic effects and additive effects on Shigella, while some of them showed no correlation and no antagonistic effect.

Abstract 341: Synergistic Effects of Renal Dopamine and Gastrin Receptors in Hypertension

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Yue Chen ◽  
Shuo Zhen ◽  
Laureano Asico ◽  
Pedro Jose ◽  
Chunyu Zeng
Keyword(s):  
Atpase Activity ◽  
Sodium Excretion ◽  
Synergistic Effects ◽  
Inhibitory Effect ◽  
Receptor Interaction ◽  
Gastrin Receptor ◽  
Wky Rats ◽  
Link Type ◽  
Renal Dopamine ◽  
Stimulation Of

Oral NaCl produces stronger natriuresis and diuresis as compared with venous infusion of same amount of NaCl, indicating the existence of renal-gastric axis. Although numerous hormones are secreted in gastrointestinal tract, gastrin is evident one due to its natriuretic effects and taken-up by the renal proximal tubule (RPT) cells. We hypothesize that there is an interaction between gastrin and dopamine receptor in kidney, which synergistically increases sodium excretion, the impaired interaction would be involved in the pathogenesis of hypertension. In WKY rats, infusion of gastrin, via renal artery, induced natriuresis and diuresis, which was blocked in the presence of CI988, a gastrin receptor blocker. Similarly, the natriuretic and diuretic effect of fenoldopam, a D1-like receptor agonist, was blocked by the D1-like receptor antagonist, SCH23390 , indicating that gastrin and fenoldopam, via individual receptor, play natriuretic and diuretic effects. Our further study found that lower dosages of gastrin or fenoldopam could not induce natriuresis and diuresis alone, while putting together induced natriuretic and diuretic effects. The above-mentioned effects were lost in SHRs. We also found, in the presence of SCH23390 , gastrin-mediated natriuresis and diuresis was partially blocked. Similarly, in the presence of CI988, the natriuretic and diuretic effects of fenoldopam were partially blocked, indicating the interaction between gastrin and D1-like receptor. The gastrin/D1-like receptor interaction was also confirmed in the RPT cells. Stimulation of one receptor increased the expression of the other. Stimulation of either D1-like receptor or gastrin receptor inhibited the Na + -K + -ATPase activity in RPT cells, while in the presence of SCH23390 , the inhibitory effect of gastrin on Na + -K + -ATPase activity was partially blocked. In the presence of CI988, D1-like receptor-mediated inhibitory effect of Na + -K + -ATPase activity in RPT cells was partially inhibited. It indicated the synergistic effect between gastrin and D1-like receptor would increase the sodium excretion in WKY rats; the impaired interaction might be involved in the pathogenesis of hypertension.

Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Spore Germination ◽  
Field Experiments ◽  
Synergistic Effects ◽  
Field Trials ◽  
Head Blight ◽  
Mycelium Growth ◽  
Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

scholarly journals Antiproliferative Activity of Combined Biochanin A and Ginsenoside Rh2 on MDA-MB-231 and MCF-7 Human Breast Cancer Cells

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2908 ◽  
Author(s):  
Guixing Ren ◽  
Zhenxing Shi ◽  
Cong Teng ◽  
Yang Yao
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Human Breast Cancer ◽  
Synergistic Effects ◽  
Inhibitory Effect ◽  
Biochanin A ◽  
Migration And Invasion ◽  
Ginsenoside Rh2 ◽  
Human Breast ◽  
Mcf 7

Breast cancer is the most frequently diagnosed cancer in women worldwide. The antiproliferative activities of biochanin A (BA) and ginsenoside Rh2 were determined by evaluating their inhibitory effect on MDA-MB-231 human breast cancer cell proliferation. The combination of BA with Rh2 was also assessed. In MDA cells, combination treatment led to a decrease in the EC50 values of BA and Rh2 to 25.20 μM and 22.75 μM, respectively. In MCF-7 cells, the EC50 values of combined BA and Rh2 decreased to 27.68 μM and 25.41 μM, respectively. BA combined with Rh2 also improved the inhibition of MDA-MB-231 and MCF-7 cell migration and invasion compared to the individual compounds. Western blot analysis demonstrated upregulation in p-p53, p-p38, and p-ASK1 proteins while levels of TRAF2 were downregulated. These results suggest that BA combined with Rh2 exhibits synergistic effects against MDA-MB-231 and MCF-7 cell proliferation.

scholarly journals Fungicidal effect of silver nanoparticles on toxigenic fungi in cocoa

2016 ◽  
Vol 51 (12) ◽  
pp. 1929-1936 ◽  
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Faccelo Osma Cruz ◽  
Oscar Orlando Ortíz-Rodriguez
Keyword(s):  
Silver Nanoparticles ◽  
Fusarium Solani ◽  
Theobroma Cacao ◽  
Mycelial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Inhibitory Effect ◽  
Plant Tissues ◽  
Inhibition Effect ◽  
Toxigenic Fungi

Abstract: The objective of this work was to evaluate the microbicidal effect of silver nanoparticles (AgNPs) on potentially toxigenic fungi affecting cocoa (Theobroma cacao) crops. These fungi, isolated from diseased cocoa pods, were characterized phenotypically and genotypically. The microbicidal effect was assessed by measuring radial mycelial growth, in synthetic culture media, and at different AgNP concentrations in plant tissues. The inhibition effect was monitored in Petri dishes, and changes in fungal structures were observed through scanning electron microscopy. Two potentially toxigenic fungi were highly prevalent: Aspergillus flavus and Fusarium solani. The inhibition assays, performed in liquid and solid synthetic culture media, showed that AgNPs did not significantly affect the growth of these fungi, even at the highest concentration (100 ppm). By contrast, they showed a positive inhibitory effect in plant tissues, especially in the cortex, when infected with A. flavus, in which an 80 ppm dose completely inhibited fungal growth. However, once fungi have managed to penetrate inside the pods, their growth is unavoidable, and AgNP effect is reduced. On F. solani, the studied nanomaterial only induced some texture and pigmentation changes. The microbicidal effect of chemically synthesized silver nanoparticles is greater in plant tissues than in culture media.

scholarly journals The effects of a synthetic insecticide and a mineral oil on alfalfa insect pests

2018 ◽  
Vol 33 (3-4) ◽  
pp. 221-231 ◽  
Author(s):  
Ivelina Nikolova ◽  
Natalia Georgieva
Keyword(s):  
Acyrthosiphon Pisum ◽  
Insect Pests ◽  
Plant Protection ◽  
Good Control ◽  
Plant Protection Products ◽  
Mineral Oil ◽  
Synthetic Insecticide ◽  
Combined Application ◽  
Negative Environmental Impact ◽  
Integrated Pest Control

The effects of the synthetic insecticide Eforia 043 ZK (thiamethoxam+lambdacyhalothrin), applied alone and at 1/5 and 2/5 reduced doses in a mix with the mineral oil Akarzin, on Tychius flavus Beck. (Coleoptera: Curculionidae), Adelphocoris lineolatus Goeze (Hemiptera: Miridae), Acyrthosiphon pisum Harr. (Hemiptera: Aphididae), harmful thrips (Thysanoptera) and cicadas (Hemiptera: suborder Auchenorrhyncha) were studied. The efficacy of Eforia (applied alone and in reduced doses) was significantly higher against A. pisum, followed by A. lineolatus and harmful thrips, compared to cicadas. The insecticidal action of Akarzin had a better protective effect against A. pisum, followed by A. lineolatus, in comparison with thrips and cicadas. Combined application of the broad-spectrum insecticide Eforia provided good control against insect pests. The mix of Eforia?s reduced 1/5 dose with the mineral oil showed the highest toxicity throughout the reporting period. Eforia applied at the reduced dose of 2/5 with Akarzin followed in efficacy. A synergistic effect was observed in combinations and was defined as subadditive synergism. Reduced dosage of Eforia and decrease in negative environmental impact of the plant protection products is a friendly approach to integrated pest control. It is important to apply innovative formulations of plant protection products that are safer both for plants and the environment.

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