Investigation of the presence of prednisolone in bovine urine

E. de Rijke, P.W. Zoontjes, D. Samson, S. Oostra, S.S. Sterk, L.A. van Ginkel

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Abstract

Over the past 2 years low levels of prednisolone have been reported in bovine urine by a number of laboratories in EU member states. Concentrations vary, but are reported to be below approximately 3 g/l. In 40% of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.112.04 g/l. In this study the mechanism of formation of prednisolone was investigated. In-vitro conversion of cortisol by bacteria from faeces and soil, bovine liver enzymes and stability at elevated temperatures were studied. In-vitro bovine liver S9 incubation experiments showed a significant 20% decrease of cortisol within 6 hours, and formation of prednisolone was observed from 0.2 g/l at t = 0 to 0.5 g/l at t = 6. Under the influence of faeces, the stability of cortisol in urine is reduced and cortisol breaks down within 50 h. Prednisolone is formed up to 4 g/l at 70C after 15 h. However, this decreases again to 0 after 50 h. With soil bacteria, a slower decrease of cortisol was observed, but slightly higher overall formation of prednisolone, up to 7 g/l at 20C. As opposed to incurred urine, in fortified urine incubated with faeces or soil bacteria no prednisolone was detected. This difference may be explained by the presence of natural corticosteroids in the incurred sample. With UPLC-QToF-MS experiments, in urine and water samples incubated with faeces, metabolites known from the literature could be (tentatively) identified as 20ß-hydroxy-prednisolone, cortisol-21-sulfate, oxydianiline, tetrahydrocortisone-3-glucuronide and cortexolone, but for all compounds except 20ß-hydroxy-prednisolone no standards were available for confirmation. Based on the results of this study and literature data, for regulatory purposes a threshold of 5 g/l for prednisolone in bovine urine is proposed. Findings of prednisolone in concentrations up to 5 g/l in bovine urine can, most likely, originate from other sources than illegal treatment with growth promoters.
Original languageEnglish
Pages (from-to)605-613
JournalFood Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Volume31
Issue number4
DOIs
Publication statusPublished - 2014

Fingerprint

prednisolone
Prednisolone
urine
Urine
cattle
cortisol
Hydrocortisone
Feces
feces
Bacteria
Soil
soil bacteria
Soils
Liver
Tetrahydrocortisone
Cortodoxone
Enzyme Stability
liver
Glucuronides
adrenal cortex hormones

Keywords

  • performance liquid-chromatography
  • synthetic corticosteroids
  • domestic livestock
  • mass-spectrometry
  • feces
  • metabolites
  • liver

Cite this

@article{fdab71a5e2394b9bb42a47c2a0887ef0,
title = "Investigation of the presence of prednisolone in bovine urine",
abstract = "Over the past 2 years low levels of prednisolone have been reported in bovine urine by a number of laboratories in EU member states. Concentrations vary, but are reported to be below approximately 3 g/l. In 40{\%} of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.112.04 g/l. In this study the mechanism of formation of prednisolone was investigated. In-vitro conversion of cortisol by bacteria from faeces and soil, bovine liver enzymes and stability at elevated temperatures were studied. In-vitro bovine liver S9 incubation experiments showed a significant 20{\%} decrease of cortisol within 6 hours, and formation of prednisolone was observed from 0.2 g/l at t = 0 to 0.5 g/l at t = 6. Under the influence of faeces, the stability of cortisol in urine is reduced and cortisol breaks down within 50 h. Prednisolone is formed up to 4 g/l at 70C after 15 h. However, this decreases again to 0 after 50 h. With soil bacteria, a slower decrease of cortisol was observed, but slightly higher overall formation of prednisolone, up to 7 g/l at 20C. As opposed to incurred urine, in fortified urine incubated with faeces or soil bacteria no prednisolone was detected. This difference may be explained by the presence of natural corticosteroids in the incurred sample. With UPLC-QToF-MS experiments, in urine and water samples incubated with faeces, metabolites known from the literature could be (tentatively) identified as 20{\ss}-hydroxy-prednisolone, cortisol-21-sulfate, oxydianiline, tetrahydrocortisone-3-glucuronide and cortexolone, but for all compounds except 20{\ss}-hydroxy-prednisolone no standards were available for confirmation. Based on the results of this study and literature data, for regulatory purposes a threshold of 5 g/l for prednisolone in bovine urine is proposed. Findings of prednisolone in concentrations up to 5 g/l in bovine urine can, most likely, originate from other sources than illegal treatment with growth promoters.",
keywords = "performance liquid-chromatography, synthetic corticosteroids, domestic livestock, mass-spectrometry, feces, metabolites, liver",
author = "{de Rijke}, E. and P.W. Zoontjes and D. Samson and S. Oostra and S.S. Sterk and {van Ginkel}, L.A.",
year = "2014",
doi = "10.1080/19440049.2013.878479",
language = "English",
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pages = "605--613",
journal = "Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment",
issn = "1944-0049",
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}

Investigation of the presence of prednisolone in bovine urine. / de Rijke, E.; Zoontjes, P.W.; Samson, D.; Oostra, S.; Sterk, S.S.; van Ginkel, L.A.

In: Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment, Vol. 31, No. 4, 2014, p. 605-613.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Investigation of the presence of prednisolone in bovine urine

AU - de Rijke, E.

AU - Zoontjes, P.W.

AU - Samson, D.

AU - Oostra, S.

AU - Sterk, S.S.

AU - van Ginkel, L.A.

PY - 2014

Y1 - 2014

N2 - Over the past 2 years low levels of prednisolone have been reported in bovine urine by a number of laboratories in EU member states. Concentrations vary, but are reported to be below approximately 3 g/l. In 40% of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.112.04 g/l. In this study the mechanism of formation of prednisolone was investigated. In-vitro conversion of cortisol by bacteria from faeces and soil, bovine liver enzymes and stability at elevated temperatures were studied. In-vitro bovine liver S9 incubation experiments showed a significant 20% decrease of cortisol within 6 hours, and formation of prednisolone was observed from 0.2 g/l at t = 0 to 0.5 g/l at t = 6. Under the influence of faeces, the stability of cortisol in urine is reduced and cortisol breaks down within 50 h. Prednisolone is formed up to 4 g/l at 70C after 15 h. However, this decreases again to 0 after 50 h. With soil bacteria, a slower decrease of cortisol was observed, but slightly higher overall formation of prednisolone, up to 7 g/l at 20C. As opposed to incurred urine, in fortified urine incubated with faeces or soil bacteria no prednisolone was detected. This difference may be explained by the presence of natural corticosteroids in the incurred sample. With UPLC-QToF-MS experiments, in urine and water samples incubated with faeces, metabolites known from the literature could be (tentatively) identified as 20ß-hydroxy-prednisolone, cortisol-21-sulfate, oxydianiline, tetrahydrocortisone-3-glucuronide and cortexolone, but for all compounds except 20ß-hydroxy-prednisolone no standards were available for confirmation. Based on the results of this study and literature data, for regulatory purposes a threshold of 5 g/l for prednisolone in bovine urine is proposed. Findings of prednisolone in concentrations up to 5 g/l in bovine urine can, most likely, originate from other sources than illegal treatment with growth promoters.

AB - Over the past 2 years low levels of prednisolone have been reported in bovine urine by a number of laboratories in EU member states. Concentrations vary, but are reported to be below approximately 3 g/l. In 40% of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.112.04 g/l. In this study the mechanism of formation of prednisolone was investigated. In-vitro conversion of cortisol by bacteria from faeces and soil, bovine liver enzymes and stability at elevated temperatures were studied. In-vitro bovine liver S9 incubation experiments showed a significant 20% decrease of cortisol within 6 hours, and formation of prednisolone was observed from 0.2 g/l at t = 0 to 0.5 g/l at t = 6. Under the influence of faeces, the stability of cortisol in urine is reduced and cortisol breaks down within 50 h. Prednisolone is formed up to 4 g/l at 70C after 15 h. However, this decreases again to 0 after 50 h. With soil bacteria, a slower decrease of cortisol was observed, but slightly higher overall formation of prednisolone, up to 7 g/l at 20C. As opposed to incurred urine, in fortified urine incubated with faeces or soil bacteria no prednisolone was detected. This difference may be explained by the presence of natural corticosteroids in the incurred sample. With UPLC-QToF-MS experiments, in urine and water samples incubated with faeces, metabolites known from the literature could be (tentatively) identified as 20ß-hydroxy-prednisolone, cortisol-21-sulfate, oxydianiline, tetrahydrocortisone-3-glucuronide and cortexolone, but for all compounds except 20ß-hydroxy-prednisolone no standards were available for confirmation. Based on the results of this study and literature data, for regulatory purposes a threshold of 5 g/l for prednisolone in bovine urine is proposed. Findings of prednisolone in concentrations up to 5 g/l in bovine urine can, most likely, originate from other sources than illegal treatment with growth promoters.

KW - performance liquid-chromatography

KW - synthetic corticosteroids

KW - domestic livestock

KW - mass-spectrometry

KW - feces

KW - metabolites

KW - liver

U2 - 10.1080/19440049.2013.878479

DO - 10.1080/19440049.2013.878479

M3 - Article

VL - 31

SP - 605

EP - 613

JO - Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment

JF - Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment

SN - 1944-0049

IS - 4

ER -