Plasma homocysteine level and hepatic sulfur amino acid metabolism in mice fed a high-fat diet

Methionine metabolism forms homocysteine via transmethylation. Homocysteine is either 1) condensed to form cystathionine, which is cleaved to form cysteine, or 2) remethylated back to methionine. Measuring this cycle with the use of isotopically labeled methionine tracers is problematic, because the tracer is infused into and measured from blood, whereas methionine metabolism occurs inside cells. Because plasma homocysteine and cystathionine arise from intracellular metabolism of methionine, plasma homocysteine and cystathionine enrichments can be used to define intracellular methionine enrichment during an infusion of labeled methionine. Eight healthy, postabsorptive volunteers were given a primed continuous infusion of [1-13C]methionine and [ methyl-2H3]methionine for 8 h. Enrichments in plasma methionine, [13C]homocysteine and [13C]cystathionine were measured. In contrast to plasma methionine enrichments, the plasma [13C]homocysteine and [13C]cystathionine enrichments rose to plateau slowly (rate constant: 0.40 ± 0.03 and 0.49 ± 0.09 h−1, respectively). The enrichment ratios of plasma [13C]homocysteine to [13C]methionine and [13C]cystathionine to [13C]methionine were 58 ± 3 and 54 ± 3%, respectively, demonstrating a large intracellular/extracellular partitioning of methionine. These values were used to correct methionine kinetics. The corrections increase previously reported rates of methionine kinetics by ∼40%.

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Metabolomic Analysis of Biochemical Changes in the Plasma of High-Fat Diet and Streptozotocin-Induced Diabetic Rats after Treatment with Isoflavones Extract of Radix Puerariae

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2016/4701890 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Yan Zhang ◽

Ping Wang ◽

Youdong Xu ◽

Xianli Meng ◽

Yi Zhang

Keyword(s):

Liquid Chromatography ◽

Amino Acid ◽

Discriminant Analysis ◽

Least Squares ◽

High Fat Diet ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Diabetic Rats ◽

High Fat ◽

Radix Puerariae

The main purpose of this study was to investigate the protective effects of total isoflavones from Radix Puerariae (PTIF) in diabetic rats. Diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 40 mg/kg). At 26 weeks onwards, PTIF 421 mg/kg was administrated to the rats once daily consecutively for 10 weeks. Metabolic profiling changes were analyzed by Ultraperformance Liquid Chromatography-Quadrupole-Exactive Orbitrap-Mass Spectrometry (UPLC-Q-Exactive Orbitrap-MS). The principal component discriminant analysis (PCA-DA), partial least-squares discriminant analysis (PLS-DA), and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used for multivariate analysis. Moreover, free amino acids in serum were determined by high-performance liquid chromatography with fluorescence detector (HPLC-FLD). Additionally, oxidative stress and inflammatory cytokines were evaluated. Eleven potential metabolite biomarkers, which are mainly related to the coagulation, lipid metabolism, and amino acid metabolism, have been identified. PCA-DA scores plots indicated that biochemical changes in diabetic rats were gradually restored to normal after administration of PTIF. Furthermore, the levels of BCAAs, glutamate, arginine, and tyrosine were significantly increased in diabetic rats. Treatment with PTIF could regulate the disturbed amino acid metabolism. Consequently, PTIF has great therapeutic potential in the treatment of DM by improving metabolism disorders and inhibiting oxidative damage.

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Ginsenoside Rb1 ameliorates Glycemic Disorder in Mice With High Fat Diet-Induced Obesity via Regulating Gut Microbiota and Amino Acid Metabolism

Frontiers in Pharmacology ◽

10.3389/fphar.2021.756491 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xueyuan Yang ◽

Bangjian Dong ◽

Lijun An ◽

Qi Zhang ◽

Yao Chen ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Gut Microbiota ◽

High Fat Diet ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Sequencing Analysis ◽

Ginsenoside Rb1 ◽

High Fat ◽

The Impact

Accumulating evidences suggested an association between gut microbiome dysbiosis and impaired glycemic control. Ginsenoside Rb1 (Rb1) is a biologically active substance of ginseng, which serves anti-diabetic effects. However, its working mechanism especially interaction with gut microbes remains elusive in detail. In this study, we investigated the impact of Rb1 oral supplementation on high fat diet (HFD) induced obesity mice, and explored its mechanism in regulating blood glucose. The results showed that higher liver weight and lower cecum weight were observed in HFD fed mice, which was maintained by Rb1 administration. In addition, Rb1 ameliorated HFD induced blood lipid abnormality and improved insulin sensitivity. Several mRNA expressions in the liver were measured by quantitative real-time PCR, of which UCP2, Nr1H4, and Fiaf were reversed by Rb1 treatment. 16S rRNA sequencing analysis indicated that Rb1 significantly altered gut microbiota composition and increased the abundance of mucin-degrading bacterium Akkermansia spp. compared to HFD mice. As suggested via functional prediction, amino acid metabolism was modulated by Rb1 supplementation. Subsequent serum amino acids investigation indicated that several diabetes associated amino acids, like branched-chain amino acids, tryptophan and alanine, were altered in company with Rb1 supplementation. Moreover, correlation analysis firstly implied that the circulation level of alanine was related to Akkermansia spp.. In summary, Rb1 supplementation improved HFD induced insulin resistance in mice, and was associated with profound changes in microbial composition and amino acid metabolism.

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