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Zhou Q.,Agricultural University of Hebei | Zhou Q.,Engineering Technology Research Center for Agricultural Product Processing of Hebei | Yin Z.-P.,Agricultural University of Hebei | Ma L.,Agricultural University of Hebei | And 4 more authors.
Natural Product Research | Year: 2014

This study aimed to determine the antioxidant activity of oligomeric proanthocyanidin from Rhodiola rosea L. (OPCRR). The free radical-scavenging activities exhibited by OPCRR, as determined by using 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical and superoxide anion (O2) scavenging assays, were greater than that of vitamin C. The effects of OPCRR on the antioxidant enzymes activity and lipid peroxide content in vivo were evaluated through three observation biomarkers, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in serum, heart, liver and brain tissues in mice. The OPCRR significantly enhanced the SOD and GSH-Px activities, and reduced the MDA content in mice. These results indicated that the OPCRR has a great potential to be a natural antioxidant due to its considerable antioxidant activities in vitro and in vivo. © 2014 Taylor & Francis. Source

Dong H.,Agricultural University of Hebei | Dong H.,Engineering Technology Research Center for Agricultural Product Processing of Hebei | Li C.,Agricultural University of Hebei | Li C.,Engineering Technology Research Center for Agricultural Product Processing of Hebei | And 9 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2014

In order to obtain a thymidylate synthetase deficient E. coli strain which was caused by endogenous insertion sequence IS1, we used extreme glucose levels (4%) and streptomycin below minimum inhibitory concentration (1.25 μg/mL) to enhance the transposition frequency of IS1, then obtained the thyA-null mutant by the method of trimethoprim (TMP) directional selection. The structure of the mutant gene was analysed by PCR amplification and DNA sequencing, the growth characteristics of thyA-null mutant was revealed by monitored the growth curve in minimal medium with or without thymine. A plasmid pMG36e-thyA, containing the wild type thyA gene and antibiotics resistance gene, was transformed into the thyA-null strain. We screened the transformants according to antibiotics resistance gene on the plates with thymine, but according to thyA on the plates without thymine. So we tested whether the thyA-null mutant could use the exogenous thyA to recover the growing ability on minimal medium plates. After enhanced the transposition frequency of IS1, we screened a thyA-null mutant by use of GSCTt medium containing 3 μg·mL-1 of TMP and the mutant was named D8. The molecular weight of PCR products of D8 was bigger then the wild type obviously and DNA sequenceing indicated that a whole IS1 was insert in the thyA gene. D8 was unable to grow in the minimum medium without addition of thymidine but its growing ability was restored by using exogenous thyA located on plasmid. The endogenous insertion sequence IS1 of Escherichia, coli was able to insert into thyA and silence the gene, our research lay the foundation for constrcting nutritional deficient strain make ues of endogenous insertion sequence. Source

Zhou Q.,Agricultural University of Hebei | Zhou Q.,Engineering Technology Research Center for Agricultural Product Processing of Hebei | Wang S.-S.,Agricultural University of Hebei | Yang G.,Agricultural University of Hebei | And 3 more authors.
Journal of Integrative Agriculture | Year: 2016

Searching alternative feed antibiotics is always a study hotspot in the field of animal production. In this study, the anti-pathogenic activities and probiotics stimulatory effects of 30 kinds of herbs were screened through Oxford cup method and Hungate roll method. 15 herbs showed significantly antibacterial activities (P<0.05) against Escherichia coli, Salmonella enteritidis, Salmonella typhimurium and Staphylococcus aureus. Seven herbs showed greatly stimulatory promoting effects on Lactobacillus acidophilus and Bifidobacterium longum. Finally, five herbs were combined for the developed formulation with selective antibacterial properties and they were Mume Fructus (35%), Isatidis Folium (25%), Moslae Herba (20%), Chrysanthemi Indici Flos (13%) and Bupleuri Radix (7%). The herbal formulation showed significantly antibacterial abilities against four pathogens and stimulatory promoting abilities on two probiotics in vitro and the equivalent activities in broiler chickens in vivo against E. coli and L. acidophilus. The toxicity study showed it had no toxicity, which indicated that it would be a kind of preferred candidate for an alternative antibiotic in future animal production. © 2016 Chinese Academy of Agricultural Sciences. Source

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