scholarly journals Analysis of the Carry-Over of Ochratoxin A from Feed to Milk, Blood, Urine, and Different Tissues of Dairy Cows Based on the Establishment of a Reliable LC-MS/MS Method

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2823 ◽  
Author(s):  
Zhiqi Zhang ◽  
Zhichen Fan ◽  
Dongxia Nie ◽  
Zhihui Zhao ◽  
Zheng Han
Keyword(s):  
Dairy Cows ◽  
Ochratoxin A ◽  
Limit Of Quantification ◽  
Fresh Milk ◽  
Liquid Chromatography Tandem Mass ◽  
Ochratoxin Α ◽  
Carry Over ◽  
First Time ◽  
Different Tissues

A rapid and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of ochratoxin A (OTA) and its metabolite ochratoxin α (OTα), for the first time, in dairy cow plasma, milk, urine, heart, liver, spleen, lung, and kidney. The established method was extensively validated by determining the linearity (R2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1–0.2 ng mL−1), recovery (75.3–114.1%), precision (RSD ≤ 13.6%), and stability (≥83.0%). Based on the methodological advances, the carry-over of OTA was subsequently studied after oral administration of 30 μg/kg body weight OTA to dairy cows. As revealed, OTA and OTα were detected in urine, with maximal concentrations of 1.8 ng mL−1 and 324.6 ng mL−1, respectively, but not in milk, plasma, or different tissues, verifying the protection effects of rumen flora against OTA exposure for dairy cows. Moreover, 100 fresh milk samples randomly collected from different supermarkets in Shanghai were also analyzed, and no positive samples were found, further proving the correctness of the in vivo biotransformation results. Thus, from the currently available data, regarding OTA contamination issues on dairy cows, no significant health risks were related to OTA exposure due to the consumption of these products.

scholarly journals In Vivo Kinetics and Biotransformation of Aflatoxin B1 in Dairy Cows Based on the Establishment of a Reliable UHPLC-MS/MS Method

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenbo Guo ◽  
Zhichen Fan ◽  
Kai Fan ◽  
Jiajia Meng ◽  
Dongxia Nie ◽  
...  
Keyword(s):  
Dairy Cows ◽  
High Performance ◽  
Life Time ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass ◽  
Carry Over ◽  
Dose Trial ◽  
Aflatoxin B

The in vivo kinetics of aflatoxin B1 (AFB1) and its carry-over as aflatoxin M1 (AFM1) in milk as well as the toxin loads in the tissue of dairy cows were assessed through a repetitive feeding trial of an AFB1-contaminated diet of 4 μg kg−1 body weight (b.w.) for 13 days. This was followed by a clearance period that ended with a single dose trial of an AFB1-contaminated diet of 40 μg kg−1 b.w. An ultra-high performance liquid chromatography tandem mass spectrometry method was developed and successfully validated by the determination of linearity (R2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1–0.2 ng ml−1), recovery (79.5–111.2%), and precision relative standard deviation (RSD) ≤14.7%) in plasma, milk, and various tissues. The repetitive ingestion of AFB1 indicated that the biotransformation of AFB1 to AFM1 occurred within 48 h, and the clearance period of AFM1 in milk was not more than 2 days. The carry-over rate of AFM1 in milk during the continuous ingestion experiment was in the range of 1.15–2.30% at a steady state. The in vivo kinetic results indicated that AFB1 reached a maximum concentration of 3.8 ± 0.9 ng ml−1 within 35.0 ± 10.2 min and was slowly eliminated from the plasma, with a half-life time (T1/2) of 931.1 ± 30.8 min. Meanwhile, AFM1 reached a plateau in plasma (0.5 ± 0.1 ng ml−1) at 4 h after the ingestion. AFB1 was found in the heart, spleen, lungs, and kidneys at concentrations of 1.6 ± 0.3, 4.1 ± 1.2, 3.3 ± 0.9 and 5.6 ± 1.4 μg kg−1, respectively. AFM1 was observed in the spleen and kidneys at concentrations of only 0.7 ± 0.2 and 0.8 ± 0.1 μg kg−1, respectively. In conclusion, the in vivo kinetics and biotransformation of AFB1 in dairy cows were determined using the developed UHPLC-MS/MS method, and the present findings could be helpful in assessing the health risks to consumers.

scholarly journals High-Performance Liquid Chromatography-Tandem Mass Spectrometry for Buprenorphine Evaluation in Plasma—Application to Pharmacokinetic Studies in Rabbits

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 437
Author(s):  
Marta Tikhomirov ◽  
Błażej Poźniak ◽  
Tomasz Śniegocki
Keyword(s):  
High Performance ◽  
Pharmacokinetic Profile ◽  
Pharmacokinetic Studies ◽  
Limit Of Quantification ◽  
Reliable Determination ◽  
Main Challenge ◽  
Analytical Protocol ◽  
Liquid Chromatography Tandem Mass ◽  
Cost Efficient

The precise and reliable determination of buprenorphine concentration is fundamental in certain medical or research applications, particularly in pharmacokinetic studies of this opioid. The main challenge is, however, the development of an analytical method that is sensitive enough, as the detected in vivo concentrations often fall in very low ranges. Thus, in this study we aimed at developing a sensitive, repeatable, cost-efficient, and easy HPLC analytical protocol for buprenorphine in rabbit plasma. In order to obtain this, the HPLC-MS2 system was used to elaborate and validate the method for samples purified with liquid-liquid extraction. Fragment ions 468.6→396.2 and 468.6→414.2 were monitored, and the method resulted in a high repeatability and reproducibility and a limit of quantification of 0.25 µg/L with a recovery of 98.7–109.0%. The method was linear in a range of 0.25–2000 µg/L. The suitability of the analytical procedure was tested in rabbits in a pilot pharmacokinetic study, and it was revealed that the method was suitable for comprehensively describing the pharmacokinetic profile after buprenorphine intravenous administration at a dose of 300 µg/kg. Thus, the method suitability for pharmacokinetic application was confirmed by both the good validation results of the method and successful in vivo tests in rabbits.

The rumen simulation technique (Rusitec) as a method to determine the in vitro carry-over period following monensin treatment by measuring volatile fatty acid molar proportions

1998 ◽  
Vol 22 ◽  
pp. 145-146
Author(s):  
E. D. Mackintosh ◽  
R. H. Phipps ◽  
H. J. Grubb
Keyword(s):  
Fatty Acid ◽  
Dairy Cows ◽  
Volatile Fatty Acid ◽  
Simulation Technique ◽  
The Past ◽  
Lactating Dairy Cows ◽  
Carry Over ◽  
Ionophore Monensin

Ruminant and ruminal responses to feeding the gram-positive ionophore, monensin, have been researched extensively over the past 20 years. A proportion of many such in vivo experiments have used a change-over design. In doing so, the researcher either paid no attention to or was reasonably confident that any possible carry-over effects would have dissipated. Evidence does exist which leads to an estimation of duration to maximum treatment effects but such comparable evidence surrounding the duration of carry-over to monensin treatment is not available.An in vivo trial was proposed at the Centre for Dairy Research (CEDAR), to investigate the ruminal effects of feeding monensin to lactating dairy cows with 4-week periods of which 3 weeks was for change-over and adaptation. Therefore, before conducting such an expensive experiment, in terms of both time and money, an in vitro study using the rumen simulation technique (Rusitec) was carried out to determine if 3 weeks was considered adequate to eliminate carry-over effects when measuring volatile fatty acid (VFA) molar proportions.

scholarly journals An LC-MS/MS Method for Simultaneous Determination of the Toxic and Active Components of Cortex Periplocae in Rat Plasma and Application to a Pharmacokinetic Study

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Zhen Li ◽  
Yang Li ◽  
Jin Li ◽  
Rui Liu ◽  
Jia Hao ◽  
...  
Keyword(s):  
Oral Administration ◽  
Multiple Reaction Monitoring ◽  
Gradient Elution ◽  
Rat Plasma ◽  
Pharmacokinetic Studies ◽  
Simple Liquid ◽  
Active Components ◽  
Limit Of Quantification ◽  
Liquid Chromatography Tandem Mass

A sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine the toxic and other active components including isovanillin, scopoletin, periplocin, periplogenin, and periplocymarin after oral administration of cortex periplocae extract to rats. Plasma samples were prepared by protein precipitation with methanol. All compounds were separated on a C18 column with gradient elution using acetonitrile and formic acid aqueous solution (0.1%, v/v) as the mobile phase at a flow rate of 0.3 mL/min. The detection of all compounds was accomplished by multiple-reaction monitoring (MRM) in the positive electrospray ionization mode. The LC-MS/MS method exhibited good linearity for five analytes. The lower limit of quantification (LLOQ) was 0.48 ng/mL for scopoletin, periplogenin, and periplocymarin; 2.4 ng/mL for isovanillin and periplocin. The extraction recoveries of all compounds were more than 90% and the RSDs were below 10%. It was found that the absorption of scopoletin and periplocin was rapid in vivo after oral administration of cortex periplocae extract. Furthermore, periplocymarin possessed abundant plasma exposure. The results demonstrated that the validated method was efficiently applied for the pharmacokinetic studies of isovanillin, scopoletin, periplocin, periplogenin, and periplocymarin after oral administration of cortex periplocae extract.

Lipid peroxidation as one mode of action in ochratoxin A toxicity in rats and chicks

1997 ◽  
Vol 77 (2) ◽  
pp. 287-292 ◽  
Author(s):  
Dirk Hoehler ◽  
Ronald R. Marquardt ◽  
Andrew A.F. Rohlich
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acids ◽  
Ochratoxin A ◽  
Sunflower Oil ◽  
Mode Of Action ◽  
Unsaturated Fatty Acids ◽  
Corn Oil ◽  
Iron Catalyst ◽  
Different Tissues

The objective of this study was to determine whether lipid peroxidation is one mode of action in ochratoxin A (OA) toxicity in vivo. Lipid peroxidation was monitored by analyzing malondialdehyde (MDA) in different tissues by HPLC. A refinement study on the MDA assay was carried out, which showed the importance of the addition of an iron catalyst for the decomposition of hydroperoxides to yield a maximum amount of MDA from a given sample. The rat experiment was designed in a 2 × 2 factorial arrangement using 4 × 6 animals. The four different diets were fed for 21 d and contained either 1% corn oil and 9% tallow (Diets I and III) or 10% corn oil (Diets II and IV); in groups III and IV, 5 mg OA were added per kilogram of diet. For the chick experiment 4 × 8 Leghorn cockerels received diets for 14 d with no added sunflower oil (Diets I and III), whereas the diets of groups II and IV were supplemented with 2.5% sunflower oil. In groups III and IV, 2.5 mg OA were added per kilogram of diet. In both experiments OA decreased the performance of the animals significantly. In the rat experiment an increased lipid peroxidation due to a higher dietary level of unsaturated fatty acids could be obtained, when muscle samples were oxidatively stressed with Fe3+ and ascorbic acid. In the chick experiment there were very clear effects of the dietary treatment on the MDA concentrations of different tissues, as both a higher supply with unsaturated fatty acids and OA increased most of the MDA values significantly. These data suggest that lipid peroxides are formed in vivo by OA, but the effects may vary considerably from species to species, and may also be influenced by other factors. Key words: Ochratoxin A, lipid peroxidation, malondialdehyde, rat, chick

scholarly journals Determination of myrislignan levels in BALB/c mouse plasma by LC-MS/MS and a comparison of its pharmacokinetics after oral and intraperitoneal administration

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Jili Zhang ◽  
Hongfei Si ◽  
Jichao Sun ◽  
Kun Lv ◽  
Biqing Yan ◽  
...  
Keyword(s):  
Formic Acid ◽  
Intraperitoneal Administration ◽  
Internal Standard ◽  
Pharmacokinetic Parameters ◽  
Clinical Effects ◽  
Limit Of Quantification ◽  
Mouse Plasma ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass

Abstract Background Myrislignan is a natural product from Myristica sp. with diverse pharmacological activities. Recently, the anti-Toxoplasma gondii (T. gondii) activity of myrislignan has been proposed, and in vivo studies of its pharmacokinetics in BALB/c mice are necessary to further evaluate the clinical effects of myrislignan. Results In this study, a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to quantify myrislignan levels in mouse plasma using dehydrodiisoeugenol as an internal standard (IS) in positive ion mode. Chromatographic separation of the analytes was achieved using an ACE Ultracore Super C18 analytical column (2.5 μm, 2.1 × 50 mm) at 30 °C. A gradient mobile phase consisting of water (0.1 % formic acid) and acetonitrile (0.1 % formic acid) was delivered at a flow rate of 0.4 mL/min. Myrislignan and the IS eluted at 1.42 and 1.71 min, respectively. A good excellent linear response across the concentration range of 1-1000 ng/mL was achieved (r2 = 0.9973). The lower limit of quantification (LLOQ) was 1 ng/mL, and the inter- and intra-day accuracy and precision of the method showed relative standard deviations (RSDs) less than 10 %. The method was applied to examine the pharmacokinetics of myrislignan in mouse plasma following a single oral administration of 200 mg/kg or intraperitoneal administration of 50 mg/kg myrislignan, and the bioavailability (F) of orally administered myrislignan was only 1.97 % of the bioavailability of intraperitoneally administered myrislignan. Conclusions A rapid and sensitive LC-MS/MS method has been was developed, validated and successfully used to determine myrislignan levels in mice after oral or intraperitoneal administration. This study is the first to report the pharmacokinetic parameters of myrislignan in mice and to compare its pharmacokinetics after oral and intraperitoneal administration, which will be useful for further research on the administration of myrislignan in animals and humans.

Pigments of Fungi. LXIX. Total Synthesis of (R)-Ochratoxin α and the Formal Total Synthesis of Ochratoxin

2002 ◽  
Vol 55 (3) ◽  
pp. 213 ◽  
Author(s):  
C. Donner ◽  
M. Gill
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Ochratoxin A ◽  
Propylene Oxide ◽  
Biologically Active ◽  
Acid Component ◽  
Ochratoxin Α ◽  
First Time

(R)-Ochratoxin α, the monochiral carboxylic acid component of the biologically active dipeptide ochratoxin A, is synthesized for the first time over nine steps from (R)-propylene oxide. The method constitutes a versatile and general route to functionalized dihydroisocoumarins.

scholarly journals L-Type Amino Acid Transporter 1-Utilizing Prodrugs of Ketoprofen Can Efficiently Reduce Brain Prostaglandin Levels

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 344
Author(s):  
Ahmed Montaser ◽  
Marko Lehtonen ◽  
Mikko Gynther ◽  
Kristiina M. Huttunen
Keyword(s):  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Transporter ◽  
Aliphatic Amino Acid ◽  
Liquid Chromatography Tandem Mass ◽  
Acid Transporter ◽  
Parenchymal Cells ◽  
First Time

In order to efficiently combat neuroinflammation, it is essential to deliver the anti-inflammatory drugs to their target sites in the brain. Pro-drugs utilizing the L-type amino acid transporter 1 (LAT1) can be transported across the blood-brain barrier (BBB) and the cellular barriers of the brain’s parenchymal cells. In this study, we evaluated, for the first time, the efficacy of LAT1-utilizing prodrugs of ketoprofen (KPF) on cyclooxygenase (COX) enzymes in vitro and prostaglandin E2 production in vivo by using an enzymatic assay and liquid chromatography- tandem mass spectrometry method, respectively. Aliphatic amino acid-conjugated pro-drugs inhibited the peroxidase activity of COX in vitro in their intact form (85% inhibition, IC50 ≈ 1.1 µM and 79%, IC50 ≈ 2.3 µM), which was comparable to KPF (90%, IC50 ≈ 0.9). Thus, these compounds acted more as KPF derivatives rather than pro-drugs. In turn, aromatic amino acid-conjugated pro-drugs behaved differently. The ester pro-drug inhibited the COX peroxidase activity in vitro (90%, IC50 ≈ 0.6 µM) due to its bioconversion to KPF, whereas the amide pro-drug was inactive toward COX enzymes in vitro. However, the amide pro-drug released KPF in the mouse brain in sufficient and effective amounts measured as reduced PGE2 levels.

scholarly journals Herb-Drug Interaction: Application of a UPLC-MS/MS Method to Determine the Effect of Polygonum capitatum Extract on the Tissue Distribution and Excretion of Levofloxacin in Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Li Yuan ◽  
Hao Chen ◽  
Xue Ma ◽  
Jie Pan ◽  
Zi-Peng Gong ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Tissue Distribution ◽  
Urinary System ◽  
Limit Of Quantification ◽  
Chinese Herbal ◽  
Combined Application ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectroscopy ◽  
Cumulative Excretion

Polygonum capitatum has unique curative effects on the urinary system. In fact, many Polygonum capitatum-based preparations are currently used in the clinic. In China, the combination of levofloxacin (LVFX) with a Chinese herbal preparation derived from Polygonum capitatum has been used for the clinical treatment of urinary system diseases, which can improve the curative effects and reduce the side effects of LVFX. However, the herb-drug interaction (HDI) between these drugs has not been reported and the effect of Polygonum capitatum on the in vivo process of LVFX is unclear. In this article, a sensitive ultraperformance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) method was developed to evaluate the effects of the combined application of LVFX and the Polygonum capitatum extract on tissue distribution and excretion. Thereafter, the method was validated for selectivity, accuracy, precision, linearity, lower limit of quantification (LLOQ), dilution integrity, recovery, and matrix effect. Based on tissue distribution, LVFX could diffuse into all of the tested tissues, with significant differences in the content of each tissue between the coadministration group and single administration group. At 48 h after the combination was orally administered, the urinary cumulative excretion of LVFX decreased from 20.69% to 11.84% while its fecal cumulative excretion decreased from 26.08% to 13.28%. Our results suggest that a drug interaction exists between the two drugs in the process of distribution and excretion. This study provides important experimental evidence for further studies on the clinical efficacy and mechanism of the Polygonum capitatum extract and LVFX.

A Physiologic Regulator of Collagen-Induced Platelet Aggregation: Inhibition by Clq

1981 ◽  
Vol 45 (02) ◽  
pp. 110-115 ◽  
Author(s):  
György Csákó ◽  
Eva A Suba
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
High Specificity ◽  
Turbidimetric Method ◽  
Specific Manner ◽  
Aggregation Inhibition ◽  
Different Tissues

SummaryPlatelet aggregations were studied by a turbidimetric method in citrated human platelet-rich plasmas (PRP) in vitro. Human Clq inhibited the aggregations caused by collagens derived from different tissues and species. Clq was needed by weight in comparable quantities to collagen for neutralizing the aggregating effect. The dependence of the inhibitory reaction on the preincubation of platelets with Clq and the differences in the occurrence of aggregating substances in supernatants of PRP triggered with collagen in the presence or absence of Clq, confirmed that Clq exerts its effect by preventing fixation of collagen to platelets. In addition, the high specificity of the inhibitory action of Clq for collagen-induced platelet aggregation was demonstrated by results obtained for testing a variety of aggregating agents in combination with Clq and/or collagen.Since normal concentrations of Clq in the blood are in the range of inhibitory doses of Clq for collagen-induced platelet aggregations in vitro and upon activation of complement Clq is known to dissociate from Cl, it is proposed that Clq may participate in a highly specific manner in regulating platelet reactivity to collagen in vivo.

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