scholarly journals Phytotoxicity Assessment of Certain Phytochemical Products Containing Pyrrolizidine Alkaloids

2013 ◽  
Vol 59 (5) ◽  
pp. 250-253
Author(s):  
Șeremet Oana Cristina ◽  
Olaru Ot ◽  
Ilie Mihaela ◽  
Negreș Simona ◽  
Bălălău D
Keyword(s):  
Pyrrolizidine Alkaloids ◽  
Inhibitory Concentration ◽  
Regression Curve ◽  
Symphytum Officinale ◽  
Tussilago Farfara ◽  
Acidic Conditions ◽  
Stoichiometric Reaction ◽  
Therapeutic Compounds ◽  
Linear Regression Curve

AbstractIntroduction: Tussilago farfara (coltsfoot), Petasites hybridus (common butterbur), Senecio vernalis (eastern groundsel) and Symphytum officinale (comfrey) are species traditionally used in phytotherapy that besides the therapeutic compounds contain toxic pyrrolizidine alkaloids (PAs). The aim of the paper is to determine the total PAs content and the phytotoxicity of the above species. Material and methods: The quantitative determination of pyrrolizidine alkaloids is based on the stoichiometric reaction of protonated alkaloids with methyl orange. In acidic conditions the dye is released from the complex and its color is assessed spectrophotometrically using a linear regression curve of senecionine as a standard. The phytotoxicity was assessed by Triticum bioassay that studies the effect of the extracts (0.001-5.00%, w/v) upon root elongation (inhibitory concentration - IC50) and on the karyokinetic film. Results: The highest amount of total PAs was found in Senecio vernalis (654.8 ± 35.96 μg/g dry plant) and the lowest in Petasites hybridus. The lowest IC50 was found for Tussilago farfara followed by Petasites hybridus, Senecio vernalis, and Symphytum officinale. The results were supported by microscopic examination. Conclusions: The results of the spectrophotometric assay are consistent with the ones found in the literature. All extracts inhibited the elongation of the main root of wheat caryopses, however, no correlation between phytotoxicity and the PAs concentration could be emphasized

Alkaloidy pirolizydynowe – źródła i zagrożenie dla zdrowia ludzi

2018 ◽  
Vol 19 (3) ◽  
Author(s):  
Małgorzata Kania-Dobrowolska ◽  
Justyna Baraniak ◽  
Radosław Kujawski ◽  
Marcin Ożarowski
Keyword(s):  
Medicinal Plants ◽  
Pyrrolizidine Alkaloids ◽  
Food Products ◽  
Borago Officinalis ◽  
Human Food ◽  
Food Grains ◽  
Symphytum Officinale ◽  
Tussilago Farfara

The pyrrolizidine alkaloids are commonly found in many plants. They are present in well-known medicinal plants as: comfrey (Symphytum officinale L.), common butterbur (Petasites hybridus L.), coltsfoot (Tussilago farfara L.) or borage (Borago officinalis L.). Some of this plants are not used in phytotherapy or are used with big restrictions. We must pay attention that several human food products can be a source for pyrrolizidine alkaloids ingestion as a consequence of pollution of farmlands by plants originated from families: Senecio, Echium, Heliotropium, Crotalaria, Boraginaceae and Eupatorium. When harvesting, it may lead to contamination of food grains and feed for livestock. In consequence, pyrrolizidine alkaloids are detected in food products just like: baker’s goods, cakes, milk, cheese, yoghurts or meet.

scholarly journals Microscopic Analysis of Bacterial Inoculum Effect Using Micropatterned Biochip

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 300
Author(s):  
Jung Ho Hwang ◽  
Sang Young Lee ◽  
Jungil Choi
Keyword(s):  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Microscopic Analysis ◽  
Microfluidic System ◽  
Timely Manner ◽  
Testing Conditions ◽  
Bacterial Inoculum ◽  
Clinical Environments ◽  
Inoculum Effect

Antimicrobial resistance has become a major problem in public health and clinical environments. Against this background, antibiotic susceptibility testing (AST) has become necessary to cure diseases in an appropriate and timely manner as it indicates the necessary concentration of antibiotics. Recently, microfluidic based rapid AST methods using microscopic analysis have been shown to reduce the time needed for the determination of the proper antibiotics. However, owing to the inoculum effect, the accurate measurement of the minimal inhibitory concentration (MIC) is difficult. We tested four standard bacteria: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, against five different antibiotics: piperacillin, cefotaxime, amikacin, levofloxacin, and ampicillin. The results showed that overall, the microfluidic system has a similar inoculum effect compared to the conventional AST method. However, due to the different testing conditions and determination protocols of the growth of the microfluidic based rapid AST, a few results are not identical to the conventional methods using optical density. This result suggests that microfluidic based rapid AST methods require further research on the inoculum effect for practical use in hospitals and can then be used for effective antibiotic prescriptions.

scholarly journals Reduction in the in vitro sensitivity oF Drechslera tritici-repentis, isolated from wheat, to strobilurin and triazole fungicides

2017 ◽  
Vol 43 (1) ◽  
pp. 20-25
Author(s):  
Rosane Baldiga Tonin ◽  
Erlei Melo Reis ◽  
Aveline Avozani
Keyword(s):  
Inhibitory Concentration ◽  
In Vitro Sensitivity ◽  
Randomized Design ◽  
Inhibition Data ◽  
Ic50 Values ◽  
Control Failure ◽  
Quinone Outside Inhibitors ◽  
Completely Randomized Design

ABSTRACT Reports of failure in the chemical control of wheat yellow leaf spot led to determination of the sensitivity of Drechslera tritici-repentis (Dtr) to the fungicides quinone outside inhibitors (QoIs) and demethylation inhibitors (DMIs). The IC50 was obtained for strobilurins (azoxystrobin, kresoxim-methyl, picoxystrobin and pyraclostrobin) and for triazoles (cyproconazole, epoxiconazole, propiconazole, prothioconazole and tebuconazole), using five Dtr isolates. Seven concentrations of the fungicides were tested in the bioassay: 0.00; 0.01; 0.10; 1.00; 10:00 and 20.00 and 40.00 mg/L active ingredient (a.i.). Assays consisted of completely randomized design and four replicates. Each experiment was performed twice, using the average of the two tests for statistical analysis. The percentage inhibition data for conidial germination (QoIs) and for mycelial growth (DMIs) were subjected to logarithmic regression analysis, calculating the 50% inhibitory concentration (IC50) based on the generated equation. There was a reduction in the sensitivity of Dtr isolates to strobilurins. IC50 values ranged from 0.58 to > 40.00 mg/L. The lowest sensitivity of isolates was detected for azoxystrobin, kresoxim-methyl, picoxystrobin and trifloxystrobin. Pyraclostrobin was most efficient, showing IC50 between 0.58 and 1.03 mg/L. The IC50 ranged from 0.35 to 1.37 mg/L for epoxiconazole, from 0.49 to 1.28 mg/L for propiconazole and from 1.41 to 2.34 mg/L for tebuconazole. Prothioconazole was most potent, showing IC50 between 0.09 and 0.21 mg/L. The hypothesis that the control failure can be attributed to the reduced Dtr sensitivity to the fungicides QoIs and DMIs was confirmed.

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