Effect of five fungicides on growth and ochratoxin A production by two Aspergillus carbonarius and Aspergillus niger isolated from Moroccan grapes

2014 ◽  
Vol 4 (3) ◽  
pp. 118-126
Author(s):  
Souad Zouhair ◽  
Souad Qjidaa Qjidaa ◽  
Atar Selouane ◽  
Driss Bouya ◽  
Cony Decock ◽  
...  
Keyword(s):  
Growth Rate ◽  
Ochratoxin A ◽  
Fungal Growth ◽  
Inhibitory Effect ◽  
Aspergillus Carbonarius ◽  
Total Inhibition ◽  
Germination And Growth ◽  
Dose Dependent Increase ◽  
Dose Dependent

Five fungicides azoxystrobin (ortiva), benomyl (benlate), hexaconazole (hexa), pyrimethanil (scala) and thiabendazole (tectocal) were tested sepa-rately in vitro for their ability to inhibit the growth of two ochratoxigenic strains of A. niger and A. carbonarius previously isolated from grapes. All fungicides effectively reduced the growth rate of A. carbonarius and A. niger from 34 to 100% at the recommended dose (RD). Thiabendazole caused total inhibition of spore germination and growth of the two strains, regardless of the doses assayed. Benomyl completely inhibited growth of A. niger whereas for A. carbonarius, concentrations above 0.02xRD were required to prevent the growth. The inhibitory effect of hexaconazole, azoxystrobin and pyrime-thanil was dose-dependent. At sub-lethal concentrations of three fungicides, a dose-dependent increase in in ochratoxin A biosynthesis by two strains was observed. The use of fungicide should be checked for its ability to inhibit fungal growth as well as for their effect in terms of mycotoxins biosynthesis.

Chemical control of fungal growth and ochratoxin A production by Aspergillus isolated from Moroccan grapes

2018 ◽  
Vol 7 (2) ◽  
pp. 84-91
Author(s):  
Adil Laaziz ◽  
Souad Qjidaa ◽  
Yousra El Hammoudi ◽  
Abdelouahed Hajjaji ◽  
Amina Bouseta
Keyword(s):  
Ochratoxin A ◽  
Radial Growth ◽  
Culture Medium ◽  
Fungal Growth ◽  
Sublethal Concentration ◽  
Agar Culture ◽  
Total Inhibition ◽  
Yeast Autolysate ◽  
Germination And Growth ◽  
Czapek Yeast Autolysate Agar

The aim of this study was to evaluate the effect of three fungicides azoxystrobin (Ortiva), hexaconazole (Hexa) and pyrimethanil (Pyrus) for their ability to inhibit the radial growth and ochratoxin A (OTA) production by five ochratoxigenic strains of Aspergillus carbonarius and A. niger previously iso-lated from Moroccan grapes. Our results showed that, the addition of the fungicides to the Czapek Yeast Autolysate agar culture medium reduced the growth of the ochratoxigenic strains. Pyrimethanil caused total inhibition of spore germination and growth of the five strains, for all dose tested. Where-as hexaconazole totally inhibited the growth of 4 strains and gave growth for the MUCL 49227 strain (2.67 mm/day) at sublethal concentration. The reduction in radial growth was less marked for azoxystrobin, with growth rate varying between 0 and 6.37 mm/day depending on the strain and the azoxystrobin concentration. Analysis of variance showed that the effect of single factors (fungicides, concentration and strain) and their interactions on growth and OTA production were highly significant (P=0.000).These findings suggest that the use of tested fungicides have to potential for reduction in production of OTA.

Effect of Fungicides on Growth and Ochratoxin A Production by Aspergillus carbonarius from Brazilian Wine Grapes

2016 ◽  
Vol 79 (9) ◽  
pp. 1508-1516 ◽  
Author(s):  
MICHELLE F. TERRA ◽  
NATHASHA de A. LIRA ◽  
FABIANA R. F. PASSAMANI ◽  
WILDER DOUGLAS SANTIAGO ◽  
MARIA das GRAÇAS CARDOSO ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Fungal Growth ◽  
Aspergillus Carbonarius ◽  
Low Doses ◽  
Effective Strategy ◽  
Wine Grapes ◽  
Chemical Fungicides ◽  
Better Than ◽  
Main Factor

ABSTRACT Prevention in the field of mycotoxin-producing fungi is the most effective strategy for controlling the presence of mycotoxins in foods. Chemical fungicides are widely used to protect crops, so their implications on mycotoxin production need to be considered. Therefore, the aim of this study was to evaluate the effect in vitro and on grapes of five fungicides commonly used on grape cultures in Brazil on Aspergillus carbonarius growth and ochratoxin A (OTA) production. At the doses recommended by manufacturers, most fungicides significantly reduced A. carbonarius growth and OTA production in vitro, whereas this effect was influenced by the type of fungicide, dose, and temperature. Temperature was the main factor that influenced the effectiveness of fungicides. In general, at 15°C, fungicides showed the greatest reduction on fungal growth and OTA production. Fungicide effect on grapes was different to that on a semisynthetic grape medium. All fungicide doses were not effective at controlling A. carbonarius in grapes. Thus, the direct effect of fungicides on grapes must be studied to obtain a better approximation of field conditions. The results indicate that the use of fungicides at the doses recommended by manufacturers is better than the application at low doses. This study showed that at the lowest doses, where fungal growth is not inhibited, fungicides positively stimulate OTA production.

scholarly journals In-Vitro Antidiabetic Effect of Ziziphus mucronata Leave Extracts

2021 ◽  
Vol 11 (6-S) ◽  
pp. 9-13
Author(s):  
Olaitan Kabir Abolaji ◽  
A.N. Ukwuani-Kwaja ◽  
I Sani ◽  
M.N. Sylvester
Keyword(s):  
Glucose Production ◽  
Inhibitory Effect ◽  
Alpha Amylase ◽  
Antidiabetic Activity ◽  
Anthraquinone Glycosides ◽  
Enzymes Inhibition ◽  
Ziziphus Mucronata ◽  
Dose Dependent Increase ◽  
Dose Dependent

Background: Diabetes is a metabolic disorder characterized by hyperglycemia due to the body’s inability to produce insulin or inaction of the produced insulin or a combination of both. One antidiabetic therapeutic approach is to reduce gastrointestinal glucose production and absorption through the inhibition of carbohydrate digesting enzymes such as alpha-amylase as well as through the inhibition of hemoglobin glycosylation. Objective: This study sets out to evaluate the in vitro antidiabetic activity of Ziziphus mucronata extracts for their effect on alpha-amylase and glycosylation of hemoglobin. Methods: Successive gradient maceration of Z. mucronata leaves were carried out using Hexane, Acetone, Methanol and separately with water to obtain four (4) extracts labelled HE, AE, ME, and WE respectively. These were subjected to in vitro studies for their inhibitory effect on alpha-amylase and hemoglobin glycosylation, Standard laboratory methods were used to screen for phytochemicals of the most potent extract. Results: The result showed that AE, ME and WE extract exhibited a dose-dependent increase in percentage inhibition of both alpha-amylase and hemoglobin glycosylation. However, on a stricking note, the AE showed a more potent data result with percentage (%) potency of 71.02 at 1mg/ml, the lowest glucose concentration (of 25mg/ml) at 0.242nm as well as the highest hemoglobin glycosylation inhibitory mean concentration of 3.663nm after 72 hours. The AE of Z. mucronata (the most potent) revealed the presence of alkaloids, anthraquinone, glycosides, flavonoids, phenols, saponin, tanins and terpenoids. Conclusion: Thus, the Acetone extract is more likely to give a lead antidiabetic drug molecule of drug when further explored; which somewhat justify the folkloric claims of Z. mucronata leave as an antidiabetic. Keywords: Heamoglabin glycosylation, Alpha-amylase enzymes, Inhibition, Glucose.

scholarly journals PF-06869206 is a selective inhibitor of renal Pi transport: evidence from in vitro and in vivo studies

2020 ◽  
Vol 319 (3) ◽  
pp. F541-F551
Author(s):  
Linto Thomas ◽  
Jianxiang Xue ◽  
Viktor N. Tomilin ◽  
Oleh M. Pochynyuk ◽  
Jessica A. Dominguez Rieg ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Open Probability ◽  
Ok Cells ◽  
Increased Risk ◽  
Dose Dependent Increase ◽  
Dose Dependent

Plasma phosphate (Pi) levels are tightly controlled, and elevated plasma Pi levels are associated with an increased risk of cardiovascular complications and death. Two renal transport proteins mediate the majority of Pi reabsorption: Na+-phosphate cotransporters Npt2a and Npt2c, with Npt2a accounting for 70–80% of Pi reabsorption. The aim of the present study was to determine the in vitro effects of a novel Npt2a inhibitor (PF-06869206) in opossum kidney (OK) cells as well as determine its selectivity in vivo in Npt2a knockout (Npt2a−/−) mice. In OK cells, Npt2a inhibitor caused dose-dependent reductions of Na+-dependent Pi uptake (IC50: ~1.4 μmol/L), whereas the unselective Npt2 inhibitor phosphonoformic acid (PFA) resulted in an ~20% stronger inhibition of Pi uptake. The dose-dependent inhibitory effects were present after 24 h of incubation with both low- and high-Pi media. Michaelis-Menten kinetics in OK cells identified an ~2.4-fold higher Km for Pi in response to Npt2a inhibition with no significant change in apparent Vmax. Higher parathyroid hormone concentrations decreased Pi uptake equivalent to the maximal inhibitory effect of Npt2a inhibitor. In vivo, the Npt2a inhibitor induced a dose-dependent increase in urinary Pi excretion in wild-type mice (ED50: ~23 mg/kg), which was completely absent in Npt2a−/− mice, alongside a lack of decrease in plasma Pi. Of note, the Npt2a inhibitor-induced dose-dependent increase in urinary Na+ excretion was still present in Npt2a−/− mice, a response possibly mediated by an off-target acute inhibitory effect of the Npt2a inhibitor on open probability of the epithelial Na+ channel in the cortical collecting duct.

Impact of Water Activity and Temperature on Growth and Ochratoxin A Production of Two Aspergillus carbonarius Isolates from Wine Grapes in Greece

2007 ◽  
Vol 70 (12) ◽  
pp. 2884-2888 ◽  
Author(s):  
CHRYSOULA C. TASSOU ◽  
PANTELIS I. NATSKOULIS ◽  
EFSTATHIOS Z. PANAGOU ◽  
APOSTOLOS E. SPIROPOULOS ◽  
NARESH MAGAN
Keyword(s):  
Ochratoxin A ◽  
Water Activity ◽  
Color Change ◽  
Fungal Growth ◽  
Grape Juice ◽  
Lag Phase ◽  
Aspergillus Carbonarius ◽  
Wine Grapes ◽  
Wine Production

The aim of this study was to determine the effects of water activity (aw; 0.85 to 0.98) and temperature (10 to 40°C) on the radial growth rate and ochratoxin A (OA) production of two Aspergillus carbonarius isolates in vitro. The isolates were obtained from wine grapes cultivated in Greece, and the trial was conducted with a synthetic grape juice medium similar in composition to grapes between veraison (beginning of color change) and ripeness. Fungal growth and OA production data were collected for 55 days. Response surface curves and cardinal values for aw and temperature were obtained using multiple regression analysis. The lag phase lasted from less than 1 to 10 days. Both isolates grew optimally at 30 to 35°C and 0.96 aw, but maximum OA production occurred under suboptimal growth conditions (15 to 20°C and 0.93 to 0.96 aw). Growth also was observed at 0.85 aw and 25°C, however at this same aw the fungus failed to produce mycelium at any other temperatures tested. The isolates produced OA at 15 to 30°C and 0.90 to 0.98 aw. Maximum OA production was detected after 25 days of incubation at 20°C and 0.96 aw and was 3.14 and 2.67 μgg−1, respectively, for the two strains. The isolated strains used in this study were more xerotolerant than others from the Mediterranean basin. These data will allow producers to identify and thus monitor critical environmental conditions effectively in wine grapes. These data also increase the knowledge base concerning the ability of A. carbonarius to grow and produce toxin under different ecological conditions and can contribute to the development of secondary models for the prediction and risk assessment of OA in wine production.

scholarly journals In Vitro Effects of Doxycycline on Replication of Feline Coronavirus

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 312
Author(s):  
Magdalena Dunowska ◽  
Sayani Ghosh
Keyword(s):  
Inhibitory Concentration ◽  
Infectious Virus ◽  
Treatment Options ◽  
Inhibitory Effect ◽  
Virus Titration ◽  
Reverse Transcription Quantitative Pcr ◽  
In Vitro Effects ◽  
Dose Dependent ◽  
Feline Coronavirus

Feline infectious peritonitis (FIP) is a sporadic fatal disease of cats caused by a virulent variant of feline coronavirus (FCoV), referred to as FIP virus (FIPV). Treatment options are limited, and most of the affected cats die or are euthanized. Anecdotally, doxycycline has been used to treat FIP-affected cats, but there are currently no data to support or discourage such treatment. The aim of this study was to establish whether doxycycline inhibits replication of FIPV in vitro. The virus was cultured in Crandell-Rees feline kidney cells with various concentrations of doxycycline (0 to 50 µg/mL). The level of FIPV in cultures was determined by virus titration and FCoV-specific reverse-transcription quantitative PCR. Cell viability was also monitored. There was no difference in the level of infectious virus or viral RNA between doxycycline-treated and untreated cultures at 3, 12- and 18-hours post-infection. However, at 24 h, the growth of FIPV was inhibited by approximately two logs in cultures with >10 µg/mL doxycycline. This inhibition was dose-dependent, with inhibitory concentration 50% (IC50) 4.1 µg/mL and IC90 5.4 µg/mL. Our data suggest that doxycycline has some inhibitory effect on FIPV replication in vitro, which supports future clinical trials of its use for the treatment of FIP-affected cats.

scholarly journals In vitro study on the effect of cornin on the activity of cytochrome P450 enzymes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qun Zhang ◽  
Zengqiang Qu ◽  
Yanqing Zhou ◽  
Jin Zhou ◽  
Junwei Yang ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drug Interaction ◽  
Liver Microsomes ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cytochrome P450 Enzymes ◽  
Drug Drug Interaction ◽  
Dose Dependent

Abstract Background Cornin is a commonly used herb in cardiology for its cardioprotective effect. The effect of herbs on the activity of cytochrome P450 enzymes (CYP450s) can induce adverse drug-drug interaction even treatment failure. Therefore, it is necessary to investigate the effect of cornin on the activity of CYP450s, which can provide more guidance for the clinical application of cornin. Methods Cornin (100 μM) was incubated with eight isoforms of CYP450s, including CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6, and 2E1, in pooled human liver microsomes. The inhibition model and corresponding parameters were also investigated. Results Cornin exerted significant inhibitory effect on the activity of CYP3A4, 2C9, and 2E1 in a dose-dependent manner with the IC50 values of 9.20, 22.91, and 14.28 μM, respectively (p < 0.05). Cornin inhibited the activity of CYP3A4 non-competitively with the Ki value of 4.69 μM, while the inhibition of CYP2C9 and 2E1 by cornin was competitive with the Ki value of 11.31 and 6.54 μM, respectively. Additionally, the inhibition of CYP3A4 by cornin was found to be time-dependent with the KI/Kinact value of 6.40/0.055 min− 1·μM− 1. Conclusions The inhibitory effect of cornin on the activity of CYP3A4, 2C9, and 2E1 indicated the potential drug-drug interaction between cornin and drugs metabolized by these CYP450s, which needs further investigation and validation.

Immunomodulatory activities of whey fractions in efferent prefemoral lymph of sheep

1996 ◽  
Vol 63 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Chun W. Wong ◽  
Geoffrey O. Regester ◽  
Geoffrey L. Francis ◽  
Dennis L. Watson
Keyword(s):  
Immune Responses ◽  
Bovine Milk ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Milk Whey ◽  
Significant Difference ◽  
Lymphocyte Phenotypes ◽  
Dose Dependent

SummaryStudies on the immunomodulatory activities of ruminant milk and colostral whey fractions were undertaken. By comparing with boiled colostral whey in a preliminary experiment, a putative heat-labile immunostimulatory factor for antibody responses was found to be present in ovine colostral whey. Studies were then undertaken in sheep in which the efferent prefemoral lymphatic ducts were cannulated bilaterally, and immune responses in the node were measured following subcutaneous injection in the flank fold of whey protein preparations of various purities. A significant sustained decline of efferent lymphocyte output was observed following injection with autologous crude milk whey or colostral whey preparations, but no changes were observed in interferon-gamma levels in lymph plasma. Two bovine milk whey fractions (lactoperoxidase and lactoferrin) of high purity were compared in bilaterally cannulated sheep. A transient decline over the first 6 h was seen in the efferent lymphocyte output and lymph flow rate after injection of both fractions. A significant difference was seen between the two fractions in interferongamma levels in lymph at 6 h after injection. However, no significant changes in the proportion of the various efferent lymphocyte phenotypes were seen following either treatment. Whereas both fractions showed a significant inhibitory effect in a dose-dependent manner on the proliferative response of T lymphocytes, but not B lymphocytes, to mitogenic stimulation in vitro, no similar changes were seen following in vivo stimulation with these two fractions.

scholarly journals Antidiabetic Activity and Phytochemical Constituents of Syzygium cumini Seeds in Puducherry Region, South India

2018 ◽  
Vol 9 (07) ◽  
Author(s):  
Kandan Prabakaran ◽  
Govindan Shanmugave
Keyword(s):  
Inhibitory Effect ◽  
Seed Extract ◽  
Antidiabetic Activity ◽  
Appreciable Amount ◽  
Syzygium Cumini ◽  
Characteristic Functional ◽  
Infrared Spectral ◽  
Phytochemical Constituents ◽  
Dose Dependent Increase ◽  
Dose Dependent

Syzygium cumini is widely used in traditional medicine to treat diabetes in India. The present study was carried out to evaluate the phytochemical bioactive compounds from Syzygium cumini seed extract and its invitro anti-diabetic activity. The phytochemical screening showed appreciable amount of flavonoid and steroid in the seed extract. The infrared spectral data obtained revealed the presence of characteristic functional groups of alcohol, hydroxyl, aldehydes, alkanes, alkenes, nitro compound and aliphatic amines etc. The extract exhibits the dose-dependent increase in the inhibitory effect on alphaamylase enzyme upto 95.4%. The result suggested that significant amount of flavonoid in Syzygium cumini seed is responsible for antidiabetic properties and it is further confirmed by higher intensity of alpha amylase inhibitory effect.

scholarly journals In vitro inhibitory effect of obtusofolin on the activity of CYP3A4, 2C9, and 2E1

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Liu ◽  
Ping Chen ◽  
Xiaojun Du ◽  
Junxia Sun ◽  
Shasha Han
Keyword(s):  
Human Liver ◽  
Competitive Inhibition ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cytochrome P450 Enzymes ◽  
Inhibition Model ◽  
Dose Dependent

Abstract Background Obtusofolin is the major active ingredient of Catsia tora L., which possesses the activity of improving eyesight and protecting the optic nerve. Investigation on the interaction of obtusofolin with cytochrome P450 enzymes (CYP450s) could provide a reference for the clinical application of obtusofolin. Methods The effect of obtusofolin on the activity of CYP450s was investigated in the presence of 100 μM obtusofolin in pooled human liver microsomes (HLMs) and fitted with the Lineweaver–Burk plots to characterize the specific inhibition model and kinetic parameters. Results Obtusofolin was found to significantly inhibited the activity of CYP3A4, 2C9, and 2E1. In the presence of 0, 2.5, 5, 10, 25, 50, and 100 μM obtusofolin, the inhibition of these CYP450s showed a dose-dependent manner with the IC50 values of 17.1 ± 0.25, 10.8 ± 0.13, and 15.5 ± 0.16 μM, respectively. The inhibition of CYP3A4 was best fitted with the non-competitive inhibition model with the Ki value of 8.82 μM. While the inhibition of CYP2C9 and 2E1 was competitive with the Ki values of 5.54 and 7.79 μM, respectively. After incubating for 0, 5, 10, 15, and 30 min, the inhibition of CYP3A4 was revealed to be time-dependent with the KI value of 4.87 μM− 1 and the Kinact value of 0.0515 min− 1. Conclusions The in vitro inhibitory effect of obtusofolin implying the potential drug-drug interaction between obtusofolin and corresponding substrates, which needs further in vivo validations.

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