Time filter

Source Type

Liu L.,Key Laboratory of Agro Food Processing and Quality Control | Liu L.,Chinese Academy of Agricultural Sciences | Lv J.-P.,Key Laboratory of Agro Food Processing and Quality Control | Lv J.-P.,Chinese Academy of Agricultural Sciences | Uluko H.,Chinese Academy of Agricultural Sciences
Journal of Agricultural and Food Chemistry | Year: 2013

As a highly efficient and easily absorbable source of chromium, the identities of the chromium-binding substances in yeast remain unclear. In this study, a mild extraction procedure involving extraction with ammonia, three-gel filtration, and high-performance liquid chromatography was adopted to obtain two chromium-binding substances from high-chromium yeast. A low-molecular-weight chromium-binding substance was identified, with mass-to-charge ratios (m/z) of 769 and 712, which included glutamic acid, glycine, and cysteine in an approximate ratio of 1:1:1, as well as nicotinic acid and chromium(III). Furthermore, it significantly potentiated (by 51%) the action of insulin to stimulate the conversion of 14C-glucose into lipid in adipocytes. A novel high-molecular-weight chromium-binding substance was also isolated: electrospray ionization tandem mass spectrometry tentatively identified it as HUB1 target protein-1, glyceraldehyde-3-phosphate dehydrogenase, or ribosomal protein L2A(L5A)(rp8)(YL6). This is the first report of a high-molecular-weight chromium-binding substance in yeast and merits further studies. © 2013 American Chemical Society.

Liu L.,Chinese Academy of Agricultural Sciences | Liu L.,Key Laboratory of Agro Food Processing and Quality Control | Cui W.M.,Chinese Academy of Agricultural Sciences | Cui W.M.,Key Laboratory of Agro Food Processing and Quality Control | And 8 more authors.
RSC Advances | Year: 2015

The purpose of this paper was to assess and compare the impact of GTF, CrCl3 and Cr(pic)3 on glucose metabolism and explore the underlying mechanism of GTF in insulin-resistant 3T3-L1 adipocytes. The insulin-resistant 3T3-L1 adipocytes were induced by incubation with insulin for 48 h. Purified GTF from high chromium yeast was used in this study, with a m/z of 769 to 712, and glutamic acid, glycine, and cysteine in an approximate ratio of 1:1:1. In addition nicotinic acid and Cr(iii). GTF, CrCl3, Cr(pic)3 and rosiglitazone (positive control) were applied to the cells. The effective dose of GTF ranged from 0.5 μg mL-1 to 1.5 μg mL-1. GTF decreased cell viability significantly (P < 0.01) at doses of 3 μg mL-1 or higher. Glucose consumption in insulin-resistant 3T3-L1 adipocytes induced by GTF increased significantly (P < 0.05) when incubated with GTF after 12 h. Among GTF, Cr(pic)3 and CrCl3, GTF stimulated glucose consumption is the greatest. In the presence of insulin, the relative expression level of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), insulin receptor substrate-2 (IRS-2) and glucose transporter 4 (GLUT4) mRNA were increased by GTF by 2.4, 4.1, 0.9 and 1.1-fold, respectively, however, only IRS-1 was increased by 2.3-fold in the absence of insulin. GTF affected mRNA levels of IR and IRS-1 significantly (P < 0.01) as compared to the other two. This study not only further demonstrates that chromium containing complexes show promise in reducing insulin resistance in instances of type 2 diabetes, but also that among the chromium complexes, GTF performs the best. Additionally, new mechanistic details of how GTF affects mRNA levels of insulin signalling proteins were revealed. © The Royal Society of Chemistry 2015.

Discover hidden collaborations