Preparation, Physicochemical and Hypoglycemic Properties of Natural Selenium-Enriched Coarse Tea Glycoproteins.

Various functional components in tea have been well developed, but less research has been explored on glycoproteins in tea. In this paper, three types of glycoprotein fractions, namely tea selenium-binding glycoprotein1-1 (TSBGP1-1), TSBGP2-1, and TSBGP3-1, respectively, were extracted and purified from selenium-enriched coarse green tea. Chemical analysis revealed that three fractions were glycoproteins, but their selenium content, molecular weight, and monosaccharide composition were significantly different. Fourier transforms infrared (FT-IR) analysis indicated that three fractions contained characteristic absorption peaks of glycoproteins but differed in secondary structural composition. Thermogravimetric (TG) analysis showed that the thermal stability of the three fractions was dramatically distinct. The in vitro hypoglycemic activity showed that TSBGPs significantly activated the insulin receptor substrate 2 (IRS2)/protein kinase B (Akt) pathway in LO2 cells, then enhanced glucose metabolism and inhibited gluconeogenesis, and finally ameliorated insulin resistance (IR) and glucose metabolism disorders. Furthermore, Pearson correlation analysis reveals that the hypoglycemic activity was significantly correlated with Se, protein, monosaccharide composition (especially glucose), molecular weight, and secondary structure. Our results show that Se-enriched tea glycoprotein is a desirable candidate for developing anti-diabetic food, and TSBGP-2 and TSBGP-3 had a better regulation effect. Our results can provide a research reference for the extraction, physicochemical property, and function of selenium-enriched plant glycoproteins.

Effect of Xanthan Gum/Soybean Fiber Ratio in the Batter on Oil Absorption and Quality Attributes of Fried Breaded Fish Nuggets.

Xanthan gum (XG) and soybean fiber (SF) at varying ratios were incorporated into the batter to inhibit oil absorption in fried battered and breaded fish nuggets (BBFNs). BBFNs were prepared with 1.2% XG and SF blends (at ratios 1:3, 1:2, 1:1, 2:1, and 3:1 w/w), fried at 170 °C (40 s) followed by 190 °C (30 s), then evaluated for pickup, oil absorption, textural characteristics, and other quality attributes. Compared with the control (without the addition of XG and SF), fried BBFNs prepared with XD and SF had a significantly reduced fat content (P < 0.05). Among all the treatments, fried BBFNs with a 1:2 w/w ratio of XG and SF had the lowest fat content in the crust and the core (16.2% and 0.6%, respectively) and the highest moisture content. When compared with other treatments, the 1:2 w/w treatment group displayed a more intense golden yellow color, higher crispness, lower hardness, and a more compact structure in the crust, a greater elasticity and chewiness of the core, and the least oil penetration. The results proved that the combined addition of XG and SF in the batter can effectively inhibit oil absorption, which may be used to guide the production of low-fat fried BBFNs. PRACTICAL APPLICATION: This study clearly showed that the combined addition of XG and SF at different ratios in the batter significantly affected fat content and quality attributes of fried BBFNs. The inhibition of oil absorption and improvement of color and textural characteristics in fried BBFNs depended on the XG/SF ratio added to the batter, and a 1:2 w/w ratio was found to produce the maximum enhancement.

High sodium causes hypertension: evidence from clinical trials and animal experiments.

Hypertension is a cardiovascular disease affecting approximately one out of every seven people worldwide. High-sodium consumption has been generally accepted as a risk factor for developing hypertension. Today, global sodium consumption greatly exceeds guidelines recommended by all medical institutions. This review synthesizes the data of landmark mammalian and human studies which investigated the role of sodium in the pathogenesis of hypertension, along with modern studies questioning this relationship. Recent studies concerning the potential pathways by which high-sodium concentration induces hypertension were reviewed. Human trials and population studies revealed a strong correlation between high blood pressure and average dietary sodium; and animal studies found a dramatic reduction in vascular function in a variety of mammals treated with high-sodium diets. In spite of a few contrarian studies, we found overwhelming evidence that elevated sodium consumption could cause hypertension.

Linezolid Exerts Greater Bacterial Clearance but No Modification of Host Lung Gene Expression Profiling: A Mouse MRSA Pneumonia Model.

BACKGROUND: Linezolid (LZD) is beneficial to patients with MRSA pneumonia, but whether and how LZD influences global host lung immune responses at the mRNA level during MRSA-mediated pneumonia is still unknown. METHODS: A lethal mouse model of MRSA pneumonia mediated by USA300 was employed to study the influence of LZD on survival, while the sublethal mouse model was used to examine the effect of LZD on bacterial clearance and lung gene expression during MRSA pneumonia. LZD (100mg/kg/day, IP) was given to C57Bl6 mice for three days. On Day 1 and Day 3 post infection, bronchoalveolar lavage fluid (BALF) protein concentration and levels of cytokines including IL6, TNFα, IL1ß, Interferon-γ and IL17 were measured. In the sublethal model, left lungs were used to determine bacterial clearance and right lungs for whole-genome transcriptional profiling of lung immune responses. RESULTS: LZD therapy significantly improved survival and bacterial clearance. It also significantly decreased BALF protein concentration and levels of cytokines including IL6, IL1ß, Interferon-γ and IL17. No significant gene expression changes in the mouse lungs were associated with LZD therapy. CONCLUSION: LZD is beneficial to MRSA pneumonia, but it does not modulate host lung immune responses at the transcriptional level.

Composition, secondary structure, and self-assembly of oat protein isolate.

The amino acid compositions, secondary structure, and self-assembly of oat protein isolate (OPI), which was purified from the high-protein Chinese oat, have been investigated by using a combination of amino acid analysis, Fourier transform infrared spectroscopy (FTIR), and tapping mode atomic force microscopy (TP-AFM). OPI, with molecular weights ranging from 14.0 kDa to 66.0 kDa, was rich in essential amino acids and contained 24.7% glutamic acid and 8.1% leucine. The amino acid contents of OPI are 4.5-8.7 times higher than those of oat flour. The secondary structures of OPI have been quantified by the deconvolution of the amide I band of the FTIR spectrum of OPI, which were found to contain approximately 7% beta-turn, 19% alpha-helix, and 74% beta-sheet. Tapping mode AFM results further suggest that the oat protein isolate has two major types of shapes, ellipsoidal and disk-like. At protein concentrations below 0.5 mg/mL, most of the OPI molecules are in the isolated form. However, when the concentration of OPI reaches 1.0 mg/mL, some of the OPI molecules self-assembled into large and heterogeneous protein aggregates.

Identification of rat lung--prominent genes by a parallel DNA microarray hybridization.

BACKGROUND: The comparison of organ transcriptomes is an important strategy for understanding gene functions. In the present study, we attempted to identify lung-prominent genes by comparing the normal transcriptomes of rat lung, heart, kidney, liver, spleen, and brain. To increase the efficiency and reproducibility, we first developed a novel parallel hybridization system, in which 6 samples could be hybridized onto a single slide at the same time. RESULTS: We identified the genes prominently expressed in the lung (147) or co-expressed in lung-heart (23), lung-liver (37), lung-spleen (203), and lung-kidney (98). The known functions of the lung-prominent genes mainly fell into 5 categories: ligand binding, signal transducer, cell communication, development, and metabolism. Real-time PCR confirmed 13 lung-prominent genes, including 5 genes that have not been investigated in the lung, vitamin D-dependent calcium binding protein (Calb3), mitogen activated protein kinase 13 (Mapk13), solute carrier family 29 transporters, member 1 (Slc29a1), corticotropin releasing hormone receptor (Crhr1), and lipocalin 2 (Lcn2). CONCLUSION: The lung-prominent genes identified in this study may provide an important clue for further investigation of pulmonary functions.