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Ran X.-G.,Guangdong Academy of Agricultural Sciences | Ran X.-G.,State Key Laboratory of Livestock and Poultry Breeding | Ran X.-G.,The Key Laboratory of Animal Nutrition and Feed Science South China of Ministry of Agriculture | Ran X.-G.,Guangdong Public Laboratory of Animal Breeding and Nutrition | Wang L.-Y.,South China University of Technology
Journal of the Science of Food and Agriculture | Year: 2014

BACKGROUND: Relatively little attention is paid to collagen-rich cattle short tendons (musculus extensor communis, musculus flexor digitorum, musculus digitorum profundis) as a source of high content and relatively pure collagen, a meat-processing by-product that is used to a minimal extent. Thus, suitable extraction processes from a meat production by-product to gain intact collagen is promising, which thus become interesting from an economic and environmental point of view. RESULTS: Two extraction methods were compared: a 48 h pepsin treatment using 0.5 mol L-1 acetic acid and an extraction using pepsin treatment after ultrasonic treatment in a 0.5 mol L-1 acetic acid solution (the total ultrasonic and pepsin treatment time was 48 h). The results indicated that the optimal conditions for the extraction of collagen from cattle tendon with the ultrasonic-pepsin tandem method is: 4°C, tendon pre-swollen for 12 h in 0.5 mol L-1 acetic acid, pepsin amount: 50 U mg-1 of sample, ultrasonic-pepsin tandem treatment time for 18 h and 30 h, respectively. Extracted cattle tendon collagen using ultrasonic and pepsin treatment in tandem was characterised by amino acid analysis, SDS-PAGE, FT-IR, solubility and thermal denaturation temperature. The results show that the ultrasonic-pepsin tandem method can effectively improve the efficiency of pepsin extraction of natural collagen without any compromise of the resultant collagen quality. CONCLUSION: This study provides a favourable process to deal with poorly extractable residue by use of ultrasonic and pepsin treatment in tandem. Extracted collagen possesses an intact molecular structure, which is useful and particularly important for its biomedical applications, such as drug delivery systems, wound dressings, and scaffolds. © 2013 Society of Chemical Industry. Source

Chen W.,Guangdong Academy of Agricultural Sciences | Chen W.,The Key Laboratory of Animal Nutrition and Feed Science South China of Ministry of Agriculture | Chen W.,State Key Laboratory of Livestock and Poultry Breeding | Chen W.,Guangdong Public Laboratory of Animal Breeding and Nutrition | And 21 more authors.
Food and Chemical Toxicology | Year: 2014

In order to explore the latter, the dose-response relationship of various concentrations of genistein on both cellular proliferation and the redox system were examined. The proliferation of primary muscle cells was promoted by a low concentration of genistein but was inhibited by high concentrations, which also enhanced lipid oxidation and suppressed membrane fluidity. By selecting a high concentration (200. μM) as a pro-oxidant treatment, the mechanism underlying the pro-oxidant function of genistein was then explored. The generation of intracellular reactive oxygen species (ROS) was stimulated by 200. μM genistein, with inhibited expression of NADPH oxidase 4 and cyclooxygenase 1 and 2 as well as increased activity of the glutathione redox system. The cellular expression of 5-lipoxygenase, however, was up-regulated by 200. μM genistein and the addition of 5-lipoxygenase inhibitor (Zileuton) decreased genistein-induced intracellular ROS level, close to that from the addition of the ROS scavenger, N-acetylcysteine. It is concluded that higher concentrations of genistein exert pro-oxidant potential in the primary muscle cells through enhancing ROS production in a 5-lipoxygenase-dependent manner. © 2014 Elsevier Ltd. Source

Chen W.,Guangdong Academy of Agricultural Sciences | Chen W.,State Key Laboratory of Livestock and Poultry Breeding | Chen W.,The Key Laboratory of Animal Nutrition and Feed Science South China of Ministry of Agriculture | Lv Y.T.,South China Agricultural University | And 12 more authors.
Poultry Science | Year: 2013

Unlike the mammalian fetus, development of the avian embryo is independent of the maternal uterus and is potentially vulnerable to physiological and environmental stresses close to hatch. In contrast to the fetus of late gestation in mammals, skeletal muscle in avian embryos during final incubation shows differential developmental characteristics: 1) muscle mobilization (also called atrophy) is selectively enhanced in the type II fibers (pectoral muscle) but not in the type I fibers (biceps femoris and semimembranosus muscle), involving activation of ubiquitin-mediated protein degradation and suppression of S6K1-mediated protein translation; 2) the proliferative activity of satellite cells is decreased in the atrophied muscle of late-term embryos but enhanced at the day of hatch, probably preparing for the postnatal growth. The mobilization of muscle may represent an adaptive response of avian embryos to external (environmental) or internal (physiological) changes, considering there are developmental transitions both in hormones and requirements for glycolytic substrates from middle-term to late-term incubation. Although the exact mechanism triggering muscle fiber atrophy is still unknown, nutritional and endocrine changes may be of importance. The atrophied muscle fiber recovers as soon as feed and water are available to the hatchling. In ovo feeding of late-term embryos has been applied to improve the nutritional status and therein enhances muscle development. Similarly, in ovo exposure to higher temperature or green light during the critical period of muscle development are also demonstrated to be potential strategies to promote pre- and posthatch muscle growth. © 2013 Poultry Science Association Inc. Source

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