The isoflavones genistein and daidzein increase hepatic concentration of thyroid hormones and affect cholesterol metabolism in middle-aged male rats

Abstract

 We examined whether isoflavones increase hepatic thyroid hormone concentrations and affect cholesterol metabolism in middle-aged rats  Serum T3 was not affected while hepatic T3 was almost doubled, which supports increased local T3 availability.  Obtained results are compatible with displacement of TH from TTR, major transport protein in rodent blood and human CSF.  Hepatic increase of T3 correlated with up-regulated expression of the Cyp7a1 gene and elevated 7α-hydroxycholesterol  IF also lowered 24-hydroxycholesterol and desmosterol in liver and serum, while the total cholesterol levels remained unchanged.

Anti-Inflammatory Effects of Dietary Plant Stanol Supplementation Are Largely Dependent on the Intake of Cholesterol in a Mouse Model of Metabolic Inflammation

“…The collection of blood and tissue specimens, biochemical determination of lipids in plasma, RNA isolation, cDNA synthesis, and qPCR were determined as described previously [ 11 , 12 , 13 ]. Hepatic sterol content was determined by gas-liquid chromatography–mass spectroscopy, as described elsewhere [ 14 ].…”

Serum 4β-hydroxycholesterol increases during fluconazole treatment

“…Serum concentrations of cholesterol were quantified using gas chromatography (GC)-flame ionization detection with 5αcholestane as an internal standard [24,25]. Quantification of the cholesterol precursors lanosterol, 24,25-dihydrolanosterol, desmosterol, and lathosterol (surrogate markers of the endogenous cholesterol synthesis rate) and the plant sterols campesterol and sitosterol (surrogate markers of cholesterol absorption) was performed by highly specific and sensitive GC-mass spectrometry-selected ion monitoring (GC-MS-SIM) with epicoprostanol as an internal standard [24,25]. The oxysterols 4β-, 7α-, 24S-, and 27-hydroxycholesterol were quantified by an isotope dilution GC-MS-SIM methodology using the corresponding deuterium-labeled oxysterols as internal standards [25].…”

“…Quantification of the cholesterol precursors lanosterol, 24,25-dihydrolanosterol, desmosterol, and lathosterol (surrogate markers of the endogenous cholesterol synthesis rate) and the plant sterols campesterol and sitosterol (surrogate markers of cholesterol absorption) was performed by highly specific and sensitive GC-mass spectrometry-selected ion monitoring (GC-MS-SIM) with epicoprostanol as an internal standard [24,25]. The oxysterols 4β-, 7α-, 24S-, and 27-hydroxycholesterol were quantified by an isotope dilution GC-MS-SIM methodology using the corresponding deuterium-labeled oxysterols as internal standards [25]. The serum bile acids cholic acid, deoxycholic acid, chenodeoxycholic acid, lithocholic acid, and ursodeoxycholic acid were quantified by an isotope dilution GC-MS-SIM method according to [26].…”

Effect of DL-Methionine Supplementation on Tissue and Plasma Antioxidant Status and Concentrations of Oxidation Products of Cholesterol and Phytosterols in Heat-Processed Thigh Muscle of Broilers

“…The concentrations of phytosterols, COPs (7α-hydroxycholesterol (7α-OH cholesterol), 7β-hydroxycholesterol (7β-OH cholesterol), 7-ketocholesterol) and POPs (7α-hydroxychampesterol (7α-OH champesterol), and 7β-hydroxycampesterol (7β-OH champesterol), 7-ketocampesterol, 7α-hydroxysitosterol (7α-OH sitosterol), 7β-hydroxysitosterol (7β-OH sitosterol), and 7-ketositosterol) in heat-processed thigh muscle were determined by gas chromatography-mass spectrometry [24,25]. Cholesterol was determined by gas chromatography-flame ionization detection [26]. For technical reasons, analyses of cholesterol, phytosterols, COPs, and POPs could be performed only in 8 samples per group which were randomly selected.…”