The hyperglycemic regulatory effect of sprouted quinoa yoghurt in high-fat-diet and streptozotocin-induced type 2 diabetic mice via glucose and lipid homeostasis.

Recently, we have proposed that quinoa yoghurt (QY) has the anti-diabetic properties based on an in vitro study. Here, its antidiabetic activity was further validated by investigating its hypoglycemic and hypolipidemic influence in high fat diet/streptozotocin-induced type 2 diabetes mellitus (T2DM) mice. The results showed that QY increased the body weights of and reduced the fasting blood glucose levels in T2DM mice. QY significantly (p < 0.05) reduced the serum levels of total cholesterol, triglyceride and LDL-C, while it increased the HDL-C level. In addition, the hepatic glycogen content, and superoxide dismutase, catalase, and glutathione peroxidase activities were significantly (p < 0.05) increased, while lipid peroxidation was remarkably reduced. Sprouted QY had the highest influence on serum oxidation when compared with non-germinated QY. The level of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) were significantly (p < 0.05) decreased, while the level of anti-inflammatory cytokine IL-10 was increased. Histopathological studies showed that QY protected the tissue structure of the liver of T2DM mice. Immunohistochemistry showed that QY increased AKT-2 and AMPK-α2 expressions, while it suppressed p85. The qRT-PCR analysis indicated that QY exerted its hypoglycemic and anti-hyperlipidemic effects through the AKT/AMPK/PI3K signaling pathway. Germination significantly (p < 0.05) influenced the glucose and lipid homeostasis in T2DM mice in such a way that sprouted QY showed the highest hypoglycemic and cholesterol-lowering effects when compared with non-germinated QY.

In vitro modulation of glucagon-like peptide release by DPP-IV inhibitory polyphenol-polysaccharide conjugates of sprouted quinoa yoghurt.

Glucagon-like peptide-1 (GLP-1) is an important signal in the peripheral and neural systems, which contributes to the maintenance of glucose and energy homeostasis. In this study, 1H NMR validated polyphenols and polysaccharides extracted from sprouted quinoa yoghurt were used as isolates and conjugates to upregulate the stimulation of GLP-1 release in NCI-H716 cells. In addition, we explored their effect on proglucagon and prohormone convertase 3 mRNA expressions, HNF-3γ and CCK-2R gene protein expression, as well as cytosolic calcium release. Variations in concentration showed a dose-dependent GLP-1 stimulation, and were significantly optimized by germination. Proglucagon mRNA expression in NCI-H716 cells was upregulated, and was relatively highest with QYPSP1 treatments in a 2.68 fold. The results suggested that the conjugates had greater potential to stimulate GLP-1 release than their isolates. Sprouted quinoa yoghurt could therefore be a potential functional food useful to regulate glucose and energy homeostasis.

Identification of a novel type I pullulanase from Fervidobacterium nodosum Rt17-B1, with high thermostability and suitable optimal pH.

Pullulanase could be used in many industrial processes due to its ability to hydrolyze α-1,6-glucosidic linkage. During the use of high temperature conditions in industrial production, pullulanase requires high resistance of heat. In this study, a novel type I pullulanase from Fervidobacterium nodosum Rt17-B1 (FN-pullulanase) with a suitable optimal pH and thermostability was discovered. Sequence analysis of FN-pullulanase showed that the enzyme had the typical motif of type I pullulanase (YNWGYDP). The recombinant FN-pullulanase, expressed in Escherichia coli, was purified as a single band on SDS-PAGE with a molecular mass of about 95 kDa. The enzyme showed optimum activity at pH 5.0 and 80 °C, and its specific activity was 25.93 U/mg. FN-pullulanase also exhibited good pH stability and thermostability. More than 80% of its initial activity was retained after incubated on ice at pH 3.5-9.0 for 24 h. Its half-life at 65 °C was 115.5 h. The enzyme could completely convert pullulan to maltotriose, as well as hydrolyze soluble starch or amylopectin to maltose, maltotriose, maltotetraose, maltopentaose and maltohexaose (G2-G6). Generally, this study identified a novel FN-pullulanase with both high thermostability and suitable optimum pH, which had the potential to be used in starch conversion process.

α-Glucosidase and ACE dual inhibitory protein hydrolysates and peptide fractions of sprouted quinoa yoghurt beverages inoculated with Lactobacillus casei.

Dietary protein peptides from quinoa yoghurt beverage (QYB) fermented with probiotic lactic acid bacteria strains play a protective role against diabetes and hypertension. In this study, the α-glucosidase and ACE inhibitory activities of germination-based protein hydrolysates of QYB were investigated. All protein hydrolysates exhibited a dose and strain-dependent inhibition on the enzymes. The inhibition of α-glucosidase was the highest in QLCSY13 (IC50 = 8.86 mg/mL), while ACE inhibition was the highest in QLCZ (IC50 = 0.03 mg/mL). Overall, QLCSY13 had the highest inhibitory activities, which was ascribed to its relatively higher amino acid contents and hydrophobicity. In addition, the ACE and α-glucosidase inhibitory activities of peptide fractions identified by RP-HPLC were 127 ±â€¯4.29 mg/mL and 10.39 ±â€¯4.73 mg/mL respectively. Among the potent inhibitory peptide sequences identified, both LAHMIVAGA and VAHPVF significantly had α-glucosidase and ACE inhibitory activities. Consequently, dietary protein peptides present in QYB had anti-hypertensive and anti-diabetic potentials.

Absolute quantification of twelve oligosaccharides in human milk using a targeted mass spectrometry-based approach.

Human milk oligosaccharides (HMOs) are beneficial to infants' growth. Currently, the challenges were the complex operation and weak separation which limited the accurate quantification of HMOs. Liquid chromatography-mass spectrometry (LC-MS/MS) under multi-reaction monitoring (MRM) mode was developed here to separate and quantitatively determine 12 oligosaccharides in human milk. The degree of polymerization of 12 oligosaccharides ranged from 3 to 6. Among 12 HMOS, four pairs of isomeric oligosaccharides (LNFPⅠand LNFPⅢ; LSTa、LSTb and LSTc; 2FL and 3FL; 3SL and 6SL) were successfully separated. Variations of HMOs among 61 individuals from Beijing, China were observed using the present method. Pairwise correlations analysis showed high correlation in abundance between LNDFH Ⅱand 6SL, LSTc and 6SL, LNDFH Ⅱ and LSTa, LSTa and LSTc, LSTa and 6SL. This method allows accurate and reliable quantitative determination of 12 oligosaccharides in human milk, and could be adopted in determining variations in HMOs among samples.