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Li T.,China Agricultural University | Chen B.,China Astronaut Training Center | Du M.,Washington State University | Song J.,China Agricultural University | And 3 more authors.
Nutrients | Year: 2017

Oxidative stress is considered as an important mediator in the progression of metabolic disorders. The objective of this study was to investigate the potential hepatoprotective effects and mechanisms of bovine casein glycomacropeptide hydrolysates (GHP) on hydrogen peroxide (H2O2)-induced oxidative damage in HepG2 cells. Results showed that GHP significantly blocked H2O2-induced intracellular reactive oxygen species (ROS) generation and cell viability reduction in a dose-dependent manner. Further, GHP concentration-dependently induced heme oxygenase-1 (HO-1) expression and increased nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation. Moreover, pretreatment of GHP increased the activation of p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated protein kinase 1/2 (ERK1/2), which were shown to contribute to Nrf2-mediated HO-1 expression. Taken together, GHP protected HepG2 cells from oxidative stress by activation of Nrf2 and HO-1 via p38 MAPK and ERK1/2 signaling pathways. Our findings indicate that bovine casein glycomacropeptide hydrolysates might be a potential ingredient in the treatment of oxidative stress-related disorders and further studies are needed to investigate the protective effects in vivo. © 2017 by the authors; licensee MDPI, Basel, Switzerland.


Wang S.-C.,Shanghai JiaoTong University | Wang D.-M.,Shanghai JiaoTong University | Wang F.,Shanghai JiaoTong University | Wang Q.-G.,Shanghai JiaoTong University | And 2 more authors.
Chinese Journal of Tissue Engineering Research | Year: 2013

Background: The mechanical parameters of human bone tissue materials are not only the fundamental data for the stress calculation, fracture damage analysis and stress-related bone remodeling, but also one of the main indispensable factors for the further investigation of the characteristics of biomechanical behavior of human bone. However, no international standards for the bone mechanical property tests have been reported. Objective: To summarize the research progress on the topics of specimen preparation, specimen constraints and fixation, test data processing and experiment error of tension-compression testing. Methods: Under the environment of no specific standard for the tensile and compression testing of bone tissue to follow, the verified test methods and ways were introduced. The error and its decrease during the tension-compression testing were concluded and emphasized; the standardized bone tissue macro tension and compression test method was also introduced with the purpose of reducing the systematic errors. Results and Conclusion: By performing the tension-compression testing, key parameters such as elastic modulus, Poisson's ratio, tensile strength and compress strength of the bone tissue could be acquired. Important testing procedures involving designing and machining of standard specimen, specimen gripping, data processing and mechanical parameter calculation were tested. During each procedure, the systematic errors need to be reduced according to the latest researches.


Xu S.-P.,China Agricultural University | Mao X.-Y.,China Agricultural University | Cheng X.,China Agricultural University | Chen B.,China Astronaut Training Center
Food and Chemical Toxicology | Year: 2013

The effect of casein glycomacropeptide (GMP) as a specific regulating mediator in obese rats induced by high-fat (HF) diet was investigated. Male obese Sprague-Dawley (SD) rats induced by high-fat diet for 8. weeks period were fed high-fat, high-fat with GMP of 100. mg/kg BW (HFLG), 200. mg/kg BW (HFMG) and 400. mg/kg BW (HFHG) for 6. weeks. Compared with the high-fat control (HFC) group GMP supplementation significantly decreased adipose tissue weight, activity of fatty acid synthase (FAS) and glycerol-3-phosphate dehydrogenase (GPDH). Hepatic lipid droplet size, plasma and hepatic lipid levels markedly reduced. Moreover, GMP reduces plasma total cholesterol and low-density lipoprotein (LDL) cholesterol as well as hepatic-cholesterol and triglycerides. The liver steatosis observed in obese rats was also prevented by GMP supplement. In addition, GMP significantly diminished mitochondrial and liver malondialdehyde (MDA) production, and obviously elevated the activities of mitochondrial and hepatic superoxidase dismutase (SOD) and glutathione peroxidase (GSH-Px). Leptin production and proinflammatory cytokines such as TNF-α and IL-6 secretion decreased. Taken together, GMP can reduce lipid accumulation and enhance antioxidant capability of obese rats. It suggests that GMP can counteract high-fat diet-induced obesity, which might make it a potential ingredient with anti-obesity activity. © 2013 Elsevier Ltd.


Zhou J.,China Agricultural University | Mao X.-Y.,China Agricultural University | Wang X.,China Agricultural University | Ai T.,China Agricultural University | And 2 more authors.
European Journal of Nutrition | Year: 2014

Purpose: The effects of orally administered β-lactoglobulin hydrolysate-iron complex (β-LGH-Fe) on haematological and biochemical parameters in anaemic rats were evaluated. Female weaning Sprague-Dawley rats were fed with iron-deficient diet to induce iron deficiency anaemia. After 6 weeks, the obtained anaemic rats were divided into five groups: iron deficiency control group (iron-deficient diet without β-LGH-Fe complex supplementation, IDC); three groups supplemented with different dosages of β-LGH-Fe complex (0.5 mg Fe/kg BW, iron-deficient diet with low β-LGH-Fe, IDLFe; 2.0 mg Fe/kg BW, iron-deficient diet with medium β-LGH-Fe, IDMF; 4.0 mg Fe/kg BW, iron-deficient diet with high β-LGH-Fe, IDHFe); and ferrous sulphate-supplemented group at a dosage of 2.0 mg Fe/kg BW. Results: β-LGH-Fe complex could significantly improve hematocrit and haemoglobin decrease, and normalise the serum iron level, total iron-binding capacity and transferrin saturation of anaemic rats in a dose-dependent manner. Serum ferritin content and hepatic nonheme iron level were also increased. In addition, the antioxidant enzyme activities of superoxidase dismutase, catalase and glutathione peroxidase in both plasma and liver homogenate were improved. The production of malondialdehyde and pro-inflammatory cytokines (TNF-α and IL-6) decreased. Conclusions: It suggests that β-LGH-Fe complex can ameliorate iron deficiency anaemia, which might make it a potential ingredient with anti-anaemia activity. © 2013 Springer-Verlag Berlin Heidelberg.


Cheng X.,China Agricultural University | Cheng X.,China Astronaut Training Center | Gao D.,China Agricultural University | Chen B.,Northeast Agricultural University | Mao X.,China Agricultural University
Nutrients | Year: 2015

Systemic low-grade inflammation and increased circulating lipopolysaccharide (LPS) contribute to metabolic dysfunction. The inhibitory effects and underlying molecular mechanisms of casein glycomacropeptide (GMP) hydrolysate on the inflammatory response of LPS-stimulated macrophages were investigated. Results showed that the inhibitory effect of GMP hydrolysates obtained with papain on nitric oxide (NO) production were obviously higher than that of GMP hydrolysates obtained with pepsin, alcalase and trypsin (p < 0.05), and the hydrolysate obtained with papain for 1 h hydrolysis (GHP) exhibited the highest inhibitory effect. Compared with native GMP, GHP markedly inhibited LPS-induced NO production in a dose-dependent manner with decreased mRNA level of inducible nitric oxide synthase (iNOS). GHP blocked toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway activation, accompanied by downregulation of LPS-triggered significant upregulation of tumor necrosis factor (TNF)-α and interleukin (IL)-1β gene expression. Furthermore, GHP could neutralize LPS not only by direct binding to LPS, but also by inhibiting the engagement of LPS with the TLR4/MD2 complex, making it a potential LPS inhibitor. In conclusion, these findings suggest that GHP negatively regulates TLR4-mediated inflammatory response in LPS-stimulated RAW264.7 cells, and therefore may hold potential to ameliorate inflammation-related issues. © 2015 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | China Astronaut Training Center, Washington State University and China Agricultural University
Type: Journal Article | Journal: Nutrients | Year: 2017

Oxidative stress is considered as an important mediator in the progression of metabolic disorders. The objective of this study was to investigate the potential hepatoprotective effects and mechanisms of bovine casein glycomacropeptide hydrolysates (GHP) on hydrogen peroxide (HO)-induced oxidative damage in HepG2 cells. Results showed that GHP significantly blocked HO-induced intracellular reactive oxygen species (ROS) generation and cell viability reduction in a dose-dependent manner. Further, GHP concentration-dependently induced heme oxygenase-1 (HO-1) expression and increased nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation. Moreover, pretreatment of GHP increased the activation of p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated protein kinase 1/2 (ERK1/2), which were shown to contribute to Nrf2-mediated HO-1 expression. Taken together, GHP protected HepG2 cells from oxidative stress by activation of Nrf2 and HO-1 via p38 MAPK and ERK1/2 signaling pathways. Our findings indicate that bovine casein glycomacropeptide hydrolysates might be a potential ingredient in the treatment of oxidative stress-related disorders and further studies are needed to investigate the protective effects in vivo.

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