Validation of an isotope dilution gas chromatography–mass spectrometry method for combined analysis of oxysterols and oxyphytosterols in serum samples

Schött, Hans-Frieder; Lütjohann, Dieter

doi:10.1016/j.steroids.2015.02.006

Cited by 36 publications

(28 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition other researches on the quantification of serum and/or CSF has been published. In comparison to the published GC-MS [16–18,21,22], LC-APCI-MS [23, 24] and LC-ESI-MS [27, 28] methods, to the best of our knowledge, the present methods using Ag + CIS-MS and PE derivatization provided lower a LOD level, allowing for the quantification of low concentrations of OHCs in serum and CSF. The present Ag + CIS and PE analytical methods seem to be the best candidates for the simultaneous quantitation of 24S-, 25-, and 27-OHC in serum and CSF.…”

Section: Resultsmentioning

confidence: 77%

See 1 more Smart Citation

Hydroxycholesterol Levels in the Serum and Cerebrospinal Fluid of Patients with Neuromyelitis Optica Revealed by LC-Ag+CIS/MS/MS and LC-ESI/MS/MS with Picolinic Derivatization: Increased Levels and Association with Disability during Acute Attack

et al. 2016

View full text Add to dashboard Cite

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS). Hydroxycholesterols (OHCs), metabolites of CNS cholesterol, are involved in diverse cellular responses to inflammation and demyelination, and may also be involved in the pathogenesis of NMO. We aimed to develop a sensitive and reliable method for the quantitative analysis of three major OHCs (24S-, 25-, and 27-OHCs), and to evaluate their concentration in the cerebrospinal fluid (CSF) and serum of patients with NMO. The levels of the three OHCs in the serum and CSF were measured using liquid chromatography-silver ion coordination ionspray tandem mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry with picolinyl ester derivatization, respectively. The linear range was 5–250 ng/mL for 24S- and 27-OHC, and 0.5–25 ng/mL for 25-OHC in serum, and was 0.1–5 ng/mL for 24S- and 27-OHC, and 0.03–1 ng/mL for 25-OHC in CSF. Precision and accuracy were 0.5%–14.7% and 92.5%–109.7%, respectively, in serum, and were 0.8%–7.7% and 94.5%–119.2%, respectively, in CSF. Extraction recovery was 82.7%–90.7% in serum and 68.4%–105.0% in CSF. When analyzed in 26 NMO patients and 23 control patients, the 25-OHC (0.54 ± 0.96 ng/mL vs. 0.09 ± 0.04 ng/mL, p = 0.032) and 27-OHC (2.68 ± 3.18 ng/mL vs. 0.68 ± 0.25 ng/mL, p = 0.005) were increased in the CSF from NMO patients. When we measured the OHCCSF index that controls the effects of blood–brain barrier disruption on the level of OHC in the CSF, the 27-OHCCSF index was associated with disability (0.723; 95% confidence interval (CI)– 0.181, 0.620; p = 0.002), while the 24-OHCCSF index (0.518; 95% CI– 1.070, 38.121; p = 0.040) and 25-OHCCSF index (0.677; 95% CI– 4.313, 18.532; p = 0.004) were associated with the number of white blood cells in the CSF of NMO patients. Our results imply that OHCs in the CNS could play a role in the pathogenesis of NMO.

show abstract

Section: Resultsmentioning

confidence: 77%

“…Over several years a variety of methods for the quantitative analysis of OHCs in biological fluids have been reported [16–22]. The most established methods are based on gas or liquid chromatography coupled with mass spectrometry.…”

Section: Introductionmentioning

confidence: 99%

Hydroxycholesterol Levels in the Serum and Cerebrospinal Fluid of Patients with Neuromyelitis Optica Revealed by LC-Ag+CIS/MS/MS and LC-ESI/MS/MS with Picolinic Derivatization: Increased Levels and Association with Disability during Acute Attack

et al. 2016

View full text Add to dashboard Cite

show abstract

“…This is particularly relevant for oxysterols, which are found in very low concentrations. To overcome these problems, these compounds are derivatized [35,[47][48][49][50], this approach gives low LOD and high sensitivity and also less background for quantitative measurement. However, the latter requires another step in sample processing, which further increases the time and cost of analysis.…”

Section: Discussionmentioning

confidence: 99%

Determination of total plasma oxysterols by enzymatic hydrolysis, solid phase extraction and liquid chromatography coupled to mass-spectrometry

Mendiara

Domeño

Nerı́n

et al. 2018

Journal of Pharmaceutical and Biomedical Analysis

View full text Add to dashboard Cite

The potential use of cholesterol esterases was tested to avoid alkaline hydrolysis for cleavage of plasma esterified oxysterols. The enzymatic hydrolysis was optimized by testing two sources of enzyme-Pseudomonas and bovine pancreas, presence of surfactants, incubation time and amount of enzyme. Free forms of 4β-, 7-, 24-, 25- and 27-hydroxycholesterol (HC) as well 7-ketocholesterol (7-KC) were analyzed by liquid chromatography and mass-spectrometry using the deuterated internal standard, 25-HC(d6). Enzymatic hydrolysis was more effective using the Pseudomonas enzyme and in presence of surfactants. Compared to alkaline hydrolysis, it generated a cleaner chromatographic baseline and better recovery of the internal standard. Oxysterols were assayed with detection limits between 7 and 31 pg/mL. Interassay coefficients of variation were lower than 10% and extraction recovery efficiencies, higher than 90%. The procedure was used to characterize plasma levels of Cyp7b1-deficient rat, where it showed increased plasma levels of 7, 24 and 25-HC. Due to the low volume of sample required, it may be used in other animal models, particularly rodents, as well as in pediatric samples where sample amount is always a problem. Thus, the proposed new method offers mild enzymatic processing that greatly facilitates oxysterol determinations to delineate their role in physiopathology.

show abstract

“…The serum concentrations of the surrogate markers of cholesterol absorption (campesterol, sitosterol, cholestanol), cholesterol synthesis (lathosterol, lanosterol, desmosterol) and bile acid synthesis (7α-hydroxy-cholesterol, 27-hydroxy-cholesterol) were measured with gas chromatography-mass spectrometry-selected ion monitoring [ 22 , 23 ]. The trimethylsilyethers of the sterols and oxysterols were separated on a DB-XLB (30 m length × 0.25 mm internal diameter, 0.25 μm film) column (Agilent Technologies, Waldbronn, Germany) using the 6890N Network GC system (Agilent Technologies, Waldbronn, Germany).…”

Section: Methodsmentioning

confidence: 99%

Influence of Chitosan Treatment on Surrogate Serum Markers of Cholesterol Metabolism in Obese Subjects

Lütjohann¹,

Marinova

Wolter

et al. 2018

Nutrients

Self Cite

View full text Add to dashboard Cite

Chitosan treatment results in significantly lower serum low density lipoprotein (LDL) cholesterol concentrations. To assess the working mechanisms of chitosan, we measured serum surrogate markers of cholesterol absorption (campesterol, sitosterol, cholestanol), synthesis (lathosterol, lanosterol, desmosterol), and degradation to bile acids (7α-hydroxy-cholesterol, 27-hydroxy-cholesterol), corrected for cholesterol concentration (R_sterols). Over 12 weeks, 116 obese subjects (Body Mass Index, BMI 31.7, range 28.1–38.9 kg/m2) were studied under chitosan (n = 61) and placebo treatments (n = 55). The participants were briefly educated regarding improvement of nutrition quality and energy expenditure. Daily chitosan intake was 3200 mg. Serum LDL cholesterol concentration decreased significantly more (p = 0.0252) under chitosan (−8.67 ± 18.18 mg/dL, 5.6%) than under placebo treatment (−1.00 ± 24.22 mg/dL, 0.9%). This reduction was not associated with the expected greater decreases in markers of cholesterol absorption under chitosan treatment. Also, increases in markers of cholesterol synthesis and bile acid synthesis under chitosan treatment were not any greater than under placebo treatment. In conclusion, a significant selective reduction of serum LDL cholesterol under chitosan treatment is neither associated with a reduction of serum surrogate markers of cholesterol absorption, nor with increases of markers for cholesterol and bile acid synthesis.

show abstract

Validation of an isotope dilution gas chromatography–mass spectrometry method for combined analysis of oxysterols and oxyphytosterols in serum samples

Cited by 36 publications

References 45 publications

Hydroxycholesterol Levels in the Serum and Cerebrospinal Fluid of Patients with Neuromyelitis Optica Revealed by LC-Ag+CIS/MS/MS and LC-ESI/MS/MS with Picolinic Derivatization: Increased Levels and Association with Disability during Acute Attack

Hydroxycholesterol Levels in the Serum and Cerebrospinal Fluid of Patients with Neuromyelitis Optica Revealed by LC-Ag+CIS/MS/MS and LC-ESI/MS/MS with Picolinic Derivatization: Increased Levels and Association with Disability during Acute Attack

Determination of total plasma oxysterols by enzymatic hydrolysis, solid phase extraction and liquid chromatography coupled to mass-spectrometry

Influence of Chitosan Treatment on Surrogate Serum Markers of Cholesterol Metabolism in Obese Subjects

Contact Info

Product

Resources

About