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A novel peptide, named BF2-X, was designed based on the structure-activity analysis of an analogue of Buforin II, named BF2-A. The BF2-X was a hybrid peptide containing the N-terminal residues 5 to 13 of BF2-A and three repeats of the C-terminal regular alpha-helical motif RLLR, and the residues 8 valine were replaced by leucine. The results of bioinformatics analysis had showed that compared with BF2-A, the helicity, positive charge, hydrophobicity rate and C-terminal amphipathy of BF2-X had remarkably enhanced. Both peptides showed a random coil structure in an aqueous solution, while displaying a typical alpha-helical structure in 50% trifluoroethanol solution (a membrane mimic condition). BF2-X exhibited higher alpha-helical contents than BF2-A in hydrophobic environment. BF2-X displayed potent antimicrobial activities against a broad spectrum of microorganisms. And BF2-X showed stronger antimicrobial activities against bacteria tested than parent peptide BF2-A. These results suggest that the alpha-helical content was directly correlated with the enhanced antibacterial activity. Both peptides had no hemolytic action on mouse erythrocyte.
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We studied immune modulation and antioxidant effects of wheat peptides on immunosuppressed mice. Mice were administrated with wheat peptides orally for 10 days and treated with cyclophosphamide at the 8th day. The indexes including serum hemolysin, plaque forming cells, spleen cells proliferation, liver antioxidant enzymes activties, malondialdehyde (MDA), scavenging serum 2,2-Diphenyl-1-picrylhydrazyl and *OH and macrophage phagocytic ability in vitro were measured to assess the immune functions and antioxidation abilities. In vivo study shows that cyclophosphamide significantly decreases serum hemolysin (HC50) and phagocytic function of macrophages. Simultaneously, liver superoxide dismutase, catalase activity and total oxidation capacity were decreased and malondialdehyde was increased. Wheat peptides could recover HC50 and spleen cell proliferation when orally administrated. Furthermore, they could also enhance serum 2,2-Diphenyl-1-picrylhydrazyl and *OH scavenging. In conclusion, wheat peptides can help body resist the stress related disorders in immune and antioxidant system.
Subject(s)
Animals , Male , Mice , Adjuvants, Immunologic , Pharmacology , Antioxidants , Pharmacology , Immunocompromised Host , Allergy and Immunology , Oxidative Stress , Peptides , Allergy and Immunology , Pharmacology , Random Allocation , Triticum , Chemistry , Allergy and ImmunologyABSTRACT
Objective To investigate the adhesion mechanism of Lactobacillus acidophilus FN001外to Peyer's patches. Methods Adhesion of L. acidophilus FN001 to mice Peyer's patches was studied in vitro using a fluorescent quantization method. The nature of adhesion mediator was studied by the effects of physical, chemical and enzymatic pre-treatments of the bacteria on their adhesion and effect of sugars on in- hibition of adhesion. The presence of lectin-like proteins in the cell surface was determined by hemagglutina- tion. Effect of L. acidophilus FN001 on inhibition of adhesion of pathogens to Peyer's patches was also stud- ied. Results The adhesion of L. acidophilus FN001 was strongly inhibited in the presence of D-mannose and methyl-ct-D-mannoside. Pretreatment of L. acidophilus FN001 with pepsin and trypsin decreased the ad- hesive capacity indicating that cell surface proteins are involved in adhesion to Peyer's patches. L. acidophi- lus FN001 could agglutinate rabbit red cell in mannose specific manner and protease pretreatment could de-crease hemagglutinin, suggesting that L. acidophilus FN001 has mannose specific lectin (s). In adherence inhibition assay, L. acidophilus NF001 could significantly inhibit adhesion of E. coli ATCC25922 to Peyer's patches when L. acidophilus NF001 were applied to Peyer's patches first or at the same time with pathogen. Conclusion It was concluded that a mannose-specific protein mediated adhesion of L. acidophilus FN001 to the Peyer's patches, and L. acidophilus FN001 could inhibit adhesion of pathogen with similar lectins speci- ficity to Peyer's patches.
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Objective:To investigate the effects of the β-casomorphin-7 on in vitro and in vivo mice splenic lymphocyte and macrophage nitric oxide production.Methods:Splenocytes proliferation assay and nitrite determination were employed for the studies of effects of β-casomorphin-7 on mice splenic lymphocyte and macrophage following in vitro stimulation of β-casomorphin-7 and in vivo intrapetitoneal administration and drinking β-casomorphin-7 solution administration.Results:In vitro study, β-casomorphin-7 showed a stimulation as well as a suppression of lymphocyte proliferation and significantly(P＜0.01) suppressed the production of nitric oxide. In vivo study, β-casomorphin-7 actions on lymphocytes and macrophages were accordant in intraperitoneal administration and drinking β-casomorphin-7 solution administration. β-casomorphin-7 significantly(P＜0.01) increased in splenic lymphocyte proliferative response and suppressed nitric oxide production in peritoneal macrophages.Conclusion:The present study indicates that the β-casomorphin-7 has the immunomodulatory effects and β-casomorphin-7 may be permeable into peripheral blood intact in mice of 2-3 weeks of age.
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Objective To explore the influence of high fat diet on the intestinal gene expression profile in C57BL/6 mice. Method C57BL/6 mice were randomly assigned to two groups (n=8). The control group consumed an ordinary diet. The experimental group was fed with a high fat diet. All mice were sacrificed at the end of 6 w and the intestinal gene expressions were detected by oligonucleotide microarray analysis with Affymetrix GeneChip Mouse U430A consisting of 13 097 genes. Results Among the 13 097 genes obtained from gene expression profile analysis, there were 88 and 179 genes up -and down-regulated respectively, in mice fed with high fat diet compared with the control. The differentially expressed genes were mainly related to free radical oxidative stress, DNA repair, induction of apoptosis, transport, signal transduction and inflammation immune response. Conclusion High fat diet may widely modulate the expression of many genes in the intestine in mice.
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Objective:To investigate the antihypertensive effects of mung bean protein,peanut protein and rice protein alcalase hydrolysates with in vitro angiotensin I-converting enzyme(ACE) inhibitory activity in spontaneously hypertensive rats(SHR) . Method:The impact of digestive proteases on ACE inhibitory activity of hydrolysates of peanut,mung bean and rice protein isolates were evaluated under simulated gastrointestinal digestion and their antihypertensive effects were investigated in SHR after single oral administration. Results:All of three kinds of protein hydrolysates showed antihypertensive activities after single oral administration at a dose of 600 mg/kg bw,most potent in mung bean protein while least in peanut protein. There were no significant changes in the heart rate of SHR after oral administration of protein hydrolysates. Conclusion:Mung bean protein,peanut protein and rice protein hydrolysates all showed antihypertensive activity,but their potent inhibitory activities on ACE did not correlate with their antihypertensive activities found in SHR.
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Objective:To study the protective effects of exogenous nucleotides on lipopolysaccharide(LPS)immunnostimulation and its mechanism.Method:Forty healthy Kunming mice were randomly divided into five groups:control group,nucleotides(NT)groups(4h,18h),nucleotides free(NF)groups(4h,18h).Control group and NF groups were fed with nucleotide-free diet.NT groups were fed with nucleotide-supplemented diet(0.25% nucleotides).On D 15,mice were lavaged with physiological saline(control)or LPS,and were killed 4 or 18 h later.Serum,liver,small intestine,and peritoneal macrophage were sampled in germfree state.Results:Hepatic Na+K+-ATPase,intestinal superoxide dismutase(SOD),serum total anti-oxidation ability,peritoneal macrophage-produced interleukin 10(IL-10)were increased,and intestinal malonaldehyde(MDA),serum alanine aminotransferase(ALT),intestinal myeloperoxidase(MPO),peritoneal macrophage-produced interleukin 1(IL-1)were decreased with nucleotides supplement.Conclusion:Exogenous nucleotides can help to maintain oxidation-antioxidation and inflammation-antiinflammation balance,and protect mice from injury under LPS immunostimulation.
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Objective: To investigate the effect of zinc sulfate and zinc methionine on growth and their possible regulating mechanism in mice. Method: Ninety male KM mice were randomly divided into three groups. The control group was fed on basal diet containing zinc of 11. 67 mg/kg 10d. The ZnSO4 group and Zn-Met group were fed on the diets supplemented with ZnSO4 or Zn-Met at 30 mg/kg(on the basis of Zn) for 10 d. Initial and final body weight,serum zinc concentration, growth hormone (GH),the levels of growth hormone receptor (GHR) and insulin like growth factor 1 (IGF-1) mRNA were determined. Results: Both ZnSO4 and Zn-Met enhanced body weight and serum zinc concentration of mice,Zn-Met more effectively than ZnSO4 for body weight . Both forms of zinc had no effect on GH and the expression of GHR mRNA , but both up-regulated the expression of IGF-1 mRNA. As compared to ZnSO4, Zn-Met enhanced the level of IGF-1 mRNA significantly. Conclusion: Both ZnSO4 and Zn-Met had no effect on GH and the expression of GHR Mrna,but enhanced the expression of IGF-1 mRNA. Zn-Met enhanced the body weight gain and up-regulated IGF-1 mRNA expression more effectively than ZnSO4.
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Objective:To explore the effect of lipoic acid (LA) on chronic oxidative stress,cytokines and inflammatory gene expression with mice fed with high fat diet (HFD) and whether LA supplementation could prevent development of chronic inflammation.Methods:C57BL/6 mice were randomly assigned to three groups.The control group were administrated with an ordinary diet.The two experimental groups were fed with a high fat diet or high fat plus 0.1% LA.Antioxidants defense index such as SOD,CAT,GSH-Px and MDA were examined after 10 week.Cytokines such as IFN-?,IL-4,IL-6,TNF-? and IL-10 were examined after 10 week,respectively.Gene expression related to oxidative stress and inflammation were confirmed by QRT-PCR.Results:HFD led to potently weaken antioxidant defenses in mice.HFD significantly increased levels of IFN-?,IL-6 and TNF-?,and decreased levels of IL-4 and IL-10 in mice plasma.QRT-PCR results showed an up-regulation of inflammation related genes and a down-regulation antioxidant-related genes.Conclusion:LA is a possibly effective supplementation with HFD,both to prevent from the development of long-term oxidative stress and to attenuate chronic inflammation.
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AIM:To elucidate the molecular mechanisms of lipoic acid (LA) on redox regulation and digestive function in intestine of C57BL/6 mice fed high fat diet (HFD).METHODS:C57BL/6 mice were randomly assigned to one of three groups (n=8). The control group consumed an ordinary diet. The other two experimental groups were fed with a high fat diet,high fat plus 0.1% LA. After 6 weeks,the activities of digestive enzymes were examined. In order to evaluate the antioxidant status of the mice,superoxide dismutase (SOD),malondialdehyde (MDA),total antioxidant capacity (TAC) and reactive oxygen species (ROS) in intestinal homogenate were measured. To investigate the molecular mechanisms underlying the effects of LA,the gene expression profiles in intestine were examined using the GeneChip microarray system.RESULTS:A depressed antioxidant defense system,accompanied by digestive and absorptive function impairment,was observed in HFD-fed mice. These changes were partially restored in the LA-treated group. DNA microarray analysis of intestine showed that LA ingestion up-regulated the expression of genes related to free-radical scavenger enzymes,digestive enzymes and transporters.CONCLUSION:Treatment with LA improves redox homeostasis and the function of intestine in mice fed HFD. The mechanism may involve preventing oxidative stress by scavenging ROS directly and increasing those of free-radical scavenger enzymes gene expression indirectly.
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Objective: To study the effects of exogenous nucleotides on immune function in mice.Methods: Sixty Kunming mice, (20?2) g, 5-6 weeks old were divided into three treatments groups (fed 0,0.05%,0.25% nucleotide-supplemented diet respectively). Each treatment was divided into two groups: normal group and immunodepression group. Mice in immunodepression groups were injected with cyclophosphamide (150 mg/kg bw) on the 2nd day in order to suppress the immune function and the mice in normal group were treated with normal saline at the same time. All mice were injected with SRBC on the 6th day. 0,0.05%,0.25% nucleotides were added into basic diet respectively and fed for 10 days. Body weight gain, organ index (thymus and spleen), SI, antibody anti SRBC and antibody secreting cell number in spleen were measured. Results: The body weight gain(P
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Objective To investigate the changes in femoral gene expression profiles in C57BL/6 mice fed high-fat diet (HFD) via clustering analysis of DNA microarray.Method Sixteen male C57BL/6 mice (4w old) were randomly assigned to two groups,8 in each,after 4-d ordinary diet for adaptation.The control group was fed with an ordinary diet,and the HFD group with HFD(19.5% lard).All mice were sacrificed at the end of 12w and the femoral gene expression was detected by oligonucleotide microarray analysis with Affymetrix Gene Chip Mouse U430A.DAVID,an online tool,was used for clustering analysis on femoral gene expression.Results Longtime administration of HFD caused femoral gene expressed differences related to cation ion channel,transcription regulation and signal transduction,bone mineralization,phosphate metabolic process regulation,and collagen synthesis.Conclusion Longtime intake of HFD will change the expression of numerous bone metabolism-related genes in bone of mice,and then inhibit bone formation.
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Objective To explore the effect of high-fat diet(HFD) on redox states of duodenum and calcium absorption in mice,and to analyze the relation between them.Method Fifty C57BL/6 male mice were randomly assigned to five groups.The control group consumed an ordinary diet(0.6% Ca,w/w),and other four groups were fed with HFD(19.64%lard,0.6% Ca),HFD plus 0.1% lipoid acid(LA),HFD with calcium supplement(1.6%Ca) and HFD with 1.6% Ca and 0.1% LA supplement.Calcium apparent absorption was measured by mineral balance study after feeding for 8 w.Plasma and duodenum levels of ROS,SOD,CAT,MDA,GSH/GSSG,and T-AOC were measured to evaluate the antioxidant status.Results HFD induced oxidative stress of duodenum and decrease of intestinal calcium absorption in mice.There were positive correlations between calcium apparent absorption with GSH/GSSG(r=0.801,P
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Objective: To study the effect of dietary nucleotides on DNA damage of thymocytes in mice. Methods: KM mice (n=30) , 5-6 weeks, were randomized into 3 groups,negative group (group 1), positive group (group 2) and nucleotides group (group 3). Mice in group 1 and 2 were fed nucleotide-free diet and group 3 nucleotide-supplemented diet (0.25% nucleotides). Mice in group 2, 3 were given single cyclophosphamide intraperitoneal injection of 150 mg/kg bw at day 21. DNA damage in thymus lymphocytes was evaluated 18 h after injection by single-cell gel electrophoresis (SCGE) assay. Thymus and spleen were weighed. Results: Dietary nucleotides had no effect on weights of thymus and spleen, but significantly decreased the number of damaged lymphocytes and the degree of damage. Conclusion: Dietary nucleotides may protect thymocytes DNA in mice from damage.