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1.
Int J Nanomedicine ; 14: 8361-8378, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749615

RESUMO

Purpose: This study aimed to evaluate the anti-colitis potential of platinum nanoparticles (PtNPs). Materials and methods: 5-, 30- and 70-nm PtNPs were administered to C57BL/6 mice once daily by intragastric gavage for 8 d during and after 5-d dextran sodium sulfate treatment. Results: According to body weight change, stool blood and consistency, and colon length and histopathology, PtNPs size-dependently alleviated DSS-induced murine colitis. PtNPs enhanced gut-barrier function by upregulating the colonic expressions of heat-shock protein 25 and tight junction proteins. Based on colonic myeloperoxidase activity, colonic and peripheral levels of interleukin-6 and tumor necrosis factor-α, and peripheral counts of white blood cells, PtNPs attenuated colonic and systemic inflammation. By suppressing lipopolysaccharide-triggered production of proinflammatory mediators, including nitric oxide, tumor necrosis factor-α and interleukin-6, PtNPs exerted direct anti-inflammatory activities in RAW264.7 macrophages through a mechanism involving intracellular reactive oxygen species scavenging and Toll-like receptor 4/NF-κB signaling suppression. High-throughput 16S rRNA sequencing of fecal samples unveiled that PtNPs induced gut dysbiosis by unfavorably altering α-diversity, Firmicutes/Bacteroidetes ratio, and richness of certain specific bacteria. Conclusion: PtNPs are a promising anti-colitis agent, but may negatively impact gut-microbiota.

2.
J Food Sci ; 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730276

RESUMO

Sturgeon meat has been found to be suitable as surimi raw materials. The present study determined the modori phenomenon in sturgeon surimi gels and identified its relationship with cathepsins. In all heat-treated gels (25 to 90 °C, at 5 °C intervals), the 40 °C-incubated sturgeon surimi gel showed the weakest gel properties and water-holding capacity (P < 0.05), a rough protein gel network under SEM, and the highest protein solubility and trichloroacetic acid-soluble peptides content (P < 0.05). SDS-PAGE indicated that the myosin heavy chain band of sturgeon surimi gels was almost completely degraded at 40 °C. Moreover, the highest cathepsin L activity was observed in 40 °C-treated sturgeon surimi gels (P < 0.05). Our results suggested that the modori phenomenon in sturgeon surimi gels occurred at 40 °C, which was partially attributed to cathepsin L, thereby allowing for the better exploitation and utilization of sturgeon surimi.

3.
Mater Sci Eng C Mater Biol Appl ; 105: 110102, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546340

RESUMO

The Hydroxyapatite (HA, Ca10(PO4)6(OH)2) has attracted widely research interests in many aspects, especially in repairing and replacing human hard tissues due to its brilliant biocompatibility, biological activity and so on. In the present article, HA nano-rods were rapidly developed via hydrothermal reaction synthesized with two representative surfactants (hexadecyltrimethylammonium bromide and sodium dodecyl sulfate) taken oyster shells as raw materials. The scanning electron microscopy (SEM) observations demonstrated that the micromorphology of synthesized HA was constructed of relatively regular nano-rods. From the zeta potential (ZP) analysis, the zeta potential of the developed HA was affected by different surfactants, which demonstrated the opposite potential value. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results showed the HA phase was successfully and rapidly developed on the surface of oyster shell with the help of surfactants. The bio-safety of HA nano-rods was confirmed by MTT cytotoxicity assay using pre-osteoblasts cells. A possible hard-template transformation mechanism from the calcite and aragonite phases into the HA phase was proposed.

4.
Molecules ; 24(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505731

RESUMO

To expand the utilization of oyster protein (OP), the effects of high pressure (100 to 500 MPa) on chemical forces, structure, microstructure, and digestibility properties were investigated. High pressure (HP) treatment enhanced the electrostatic repulsion (from -13.3Control to -27.8HP200 mV) between protein molecules and avoided or retarded the formation of protein aggregates. In addition, the HP treated samples showed uniform distribution and small particle size. The changes in electrostatic interaction and particle size contributed to the improvement of solubility (from 10.53%Control to 19.92%HP500 at pH 7). The stretching and unfolding of protein were modified by HP treatment, and some internal hydrophobic groups and -SH groups were exposed. HP treatment modified the secondary structure of OP. The treated samples contained less α-helix and ß-sheet structures, whereas the proportions of ß-sheet and random coil structures were increased. The treated samples have high digestibility in the stomach (from 26.3%Control to 39.5%HP500) and in the total digestive process (from 62.1%Control to 83.7%HP500). In addition, the total digestive production showed higher percentages of small peptides (<1 kDa) after HP treatment. The protein solubility and digestibility were increased after HP treatment, and high solubility and high digestibility might increase the chance that OP become a kind of protein supplement.

5.
Genomics ; 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31095997

RESUMO

Shewanella baltica 128 is a specific spoilage organism (SSO) isolated from the refrigerated shrimp that results in shrimp spoilage. This study reported the complete genome sequencing of this strain, with the primary annotations associated with amino acid transport and metabolism (8.66%), indicating that S. baltica 128 has good potential for degrading proteins. In vitro experiments revealed Shewanella baltica 128 could adapt to the stress conditions by regulating its growth and biofilm formation. Genes that related to the spoilage-related metabolic pathways, including trimethylamine metabolism (torT), sulfur metabolism (cysM), putrescine metabolism (speC), biofilm formation (rpoS) and serine protease production (degS), were identified. Genes (LuxS, pfs, LuxR and qseC) that related to the specific QS system were also identified. Complete genome sequence of S. baltica 128 provide insights into the QS-related spoilage potential, which might provide novel information for the development of new approaches for spoilage detection and prevention based on QS target.

6.
Food Res Int ; 120: 679-687, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31000286

RESUMO

Litopenaeus vannamei is an extremely perishable food because of rapid microbial growth and chemical degradation after harvesting. Biopreservation is a food preservation technology based on the addition of "positive" bacteria to kill or prevent the growth of undesirable microorganisms. In this study, the cooperation between lactic acid bacteria (LAB) strains (Lactobacillus plantarum AB-1 and Lactobacillus casei) regulated by the AI-2/LuxS was investigated in vitro and on shrimp. The antimicrobial activity of L. plantarum AB-1 was significantly increased in the co-culture compared with the mono-culture in vitro, and the transcription of the quorum sensing luxS gene and bacteriocin regulatory operons (plnB and plnC) in L. plantarum AB-1 were also significantly increased in co-culture (P < .05), indicating cooperation and that the production of bacteriocin in L. plantarum AB-1 might be related to the LuxS/AI-2 quorum sensing (QS) system. The results were confirmed by adding the exogenous AI-2 molecule signal to L. plantarum AB-1 in vitro. In the on shrimp experiments, the spoilage organisms (mainly Shewanella baltica) in shrimp samples were significantly inhibited after co-inoculation with L. plantarum AB-1 and L. casei, and the values of total volatile basic nitrogen (TVB-N) and pH in co-inoculated shrimp were also significantly decreased (P < .05). In addition, the AI-2 activities in co-inoculated shrimp were significantly higher during refrigerated storage. The results suggest that the cooperation and bacteriocin production of lactic acid bacteria might by regulated by the AI-2/LuxS system, and the co-inoculation of L. plantarum AB-1 and L. casei in shrimp is an effective strategy for biopreservation of shrimp.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31017521

RESUMO

Gold nanoparticles (AuNPs) have been previously shown to induce gut dysbiosis during colitis in mice, but the underlying mechanism is not clear yet. Here, we evaluated the effects of AuNPs (5 nm diameter, coated with tannic acid, polyvinylpyrrolidone or citrate) on H2O2 accumulation and pathogen antagonization by an intestinal strain of Lactobacillus gasseri under aerobic cultural conditions. AuNPs (0.65 µg/mL) reduced over 50% of H2O2 accumulation by L. gasseri, and significantly inhibited the antagonistic action of L. gasseri on growth of four foodborne enteric pathogens, i.e. Salmonella enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus in associative cultures.

8.
Food Funct ; 10(2): 1007-1016, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30706920

RESUMO

Biogenic polyphosphate nanoparticles (BPNPs) from Synechococcus sp. PCC 7002 have been found to exhibit intestinal protective potential in vitro and ex vivo. The aim of this study was to evaluate the in vivo intestinal protective effect of BPNPs in experimental colitis. BPNPs were intragastrically administered to C57BL/6 mice daily for 9 d during and after 5 d dextran sodium sulfate (DSS) exposure. Based on the body weight, disease activity index, colon length and colon histology, BPNPs effectively ameliorated DSS-induced colitis in mice. According to colonic myeloperoxidase activity, colonic and peripheral proinflammatory cytokines, and hematological parameters, BPNPs alleviated the DSS-induced colonic and systemic inflammation. BPNPs enhanced the intestinal barrier function by upregulating the colonic expressions of heat shock protein 25 and tight junction proteins. By high-throughput sequencing of fecal 16S rRNA, BPNPs were found to maintain gut microbial homeostasis in colitis mice. Overall, BPNPs have a considerable in vivo efficacy to maintain gut health.


Assuntos
Colite/induzido quimicamente , Colite/tratamento farmacológico , Nanopartículas/administração & dosagem , Polifosfatos/farmacologia , Synechococcus/classificação , Animais , Sulfato de Dextrana/toxicidade , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Polifosfatos/química
9.
Molecules ; 24(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781435

RESUMO

This study investigated the effects of α-tocopherol (α-TOH) on the physicochemical properties of sturgeon surimi during 16-week storage at -18 °C. An aliquot of 0.1% (w/w) of α-TOH was added into the surimi and subjected to frozen storage, and 8% of a conventional cryoprotectant (4% sorbitol and 4% sucrose, w/w) was used as a positive control. Based on total viable count, pH and whiteness, α-TOH exhibited a better protection for frozen sturgeon surimi than cryoprotectant during frozen storage. According to soluble protein content, carbonyl content, total sulfhydryl content, and surface hydrophobicity, α-TOH and cryoprotectant showed the same effects on retarding changes of proteins. The results of breaking force, deformation, gel strength, water-holding capacity and microstructure of sturgeon surimi indicated that the gel properties of frozen sturgeon surimi were retained by α-TOH. Our results suggest that α-TOH is an attractive candidate to maintain the quality of sturgeon surimi during frozen storage.


Assuntos
Crioprotetores/farmacologia , Peixes/metabolismo , Congelamento , alfa-Tocoferol/farmacologia , Animais , Produtos Pesqueiros/análise , Produtos Pesqueiros/microbiologia , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Compostos de Sulfidrila/metabolismo
10.
Int J Biol Macromol ; 127: 349-356, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30615968

RESUMO

ε-Poly-l-lysine (PL) has high antimicrobial activity and a wide antimicrobial spectrum and is applied broadly in the food industry. However, PL may lose part of its activity in phosphate systems, which are typically used in seafood processing. To enhance antimicrobial activity under high phosphate conditions, DNA/PL nanoparticles were fabricated via the nanoprecipitation method. The DNA/PL nanoparticle size was smallest when the ethanol to water ratio was 7:1, and the mean diameter was 101 nm. UV-vis showed hypochromism and a redshift of the DNA in the presence of PL, indicating an intercalative interaction between DNA and PL. FTIR spectroscopy revealed that strong hydrogen bonds and hydrophobic interactions were involved in DNA/PL nanoparticle formation. Compared with that of PL, the antimicrobial activity of the nanoparticles against S. aureus, B. subtilis, and E. coli was enhanced. Additionally, the DNA/PL nanoparticles still retained higher antimicrobial activity in the phosphate system than free PL. The antimicrobial mechanistic analysis provided evidence that the DNA/PL nanoparticles showed high bioactivity due to cell membrane damage. This work provides a potential method to enhance the antimicrobial activity of PL under adverse conditions, which can promote the application of PL in seafood containing phosphate compounds.


Assuntos
Antibacterianos , Bactérias/crescimento & desenvolvimento , Adutos de DNA , Lisina/análogos & derivados , Nanopartículas/química , Fosfatos/química , Polilisina , Antibacterianos/química , Antibacterianos/farmacologia , Adutos de DNA/química , Adutos de DNA/farmacologia , Lisina/química , Lisina/farmacologia , Polilisina/química , Polilisina/farmacologia
11.
Food Funct ; 10(2): 723-732, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30664135

RESUMO

Microalgae are potential iron supplements for improving iron deficiency through an unknown mechanism. To analyze the increase in non-heme iron absorption caused by microalgae, six different microalgal feeds were prepared from Spirulina, Chlorella and Synechococcus sp. PCC 7002 as the main source of dietary iron (25 mg kg-1; denoted as H-Sp, H-Ch, and H-Sy, respectively) or as a partial source of dietary iron (5 mg kg-1; denoted as L-Sp, L-Ch, and L-Sy, respectively) to suppress iron-deficiency anemia in rats. The hemoglobin regeneration efficiencies in anemic rats were in the order ferric citrate (34.7 ± 1.8%) < H-Ch (49.9 ± 4.1%) ≈ H-Sy (50.6 ± 5.3%) ≈ L-Sp (46.9 ± 6.2%) ≈ L-Ch (43.1 ± 6.9%) ≈ L-Sy (43.5 ± 2.4%) ≈ FeSO4 (47.2 ± 4.9%) < H-Sp (54.8 ± 5.5%). The percentage content of intestinal nanosized iron in the H-Sp, H-Ch, and H-Sy treatment groups was significantly higher than that in the L-Sp, L-Ch, and L-Sy groups, and was significantly higher in the microalgal diet groups than in the ferric citrate group, providing strong evidence for nanosized iron supplementation from microalgae. Overall, microalgae, especially Spirulina, are functional iron nutritive fortifiers that can supply intestinal nanosized iron.


Assuntos
Anemia Ferropriva/dietoterapia , Ferro na Dieta/administração & dosagem , Ferro na Dieta/uso terapêutico , Microalgas , Ração Animal/análise , Animais , Chlorella , Dieta/veterinária , Suplementos Nutricionais , Hemoglobinas/metabolismo , Hepcidinas/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Spirulina , Baço/metabolismo
12.
J Nanobiotechnology ; 16(1): 86, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30384844

RESUMO

BACKGROUND: Gold nanoparticles (AuNPs) are attracting interest as potential therapeutic agents to treat inflammatory diseases, but their anti-inflammatory mechanism of action is not clear yet. In addition, the effect of orally administered AuNPs on gut microbiota has been overlooked so far. Here, we evaluated the therapeutic and gut microbiota-modulating effects, as well as the anti-inflammatory paradigm, of AuNPs with three different coatings and five difference sizes in experimental mouse colitis and RAW264.7 macrophages. RESULTS: Citrate- and polyvinylpyrrolidone (PVP)-stabilized 5-nm AuNPs (Au-5 nm/Citrate and Au-5 nm/PVP) and tannic acid (TA)-stabilized 5-, 10-, 15-, 30- and 60-nm AuNPs were intragastrically administered to C57BL/6 mice daily for 8 days during and after 5-day dextran sodium sulfate exposure. Clinical signs and colon histopathology revealed more marked anti-colitis effects by oral administration of Au-5 nm/Citrate and Au-5 nm/PVP, when compared to TA-stabilized AuNPs. Based on colonic myeloperoxidase activity, colonic and peripheral levels of interleukin-6 and tumor necrosis factor-α, and peripheral counts of leukocyte and lymphocyte, Au-5 nm/Citrate and Au-5 nm/PVP attenuated colonic and systemic inflammation more effectively than TA-stabilized AuNPs. High-throughput sequencing of fecal 16S rRNA indicated that AuNPs could induce gut dysbiosis in mice by decreasing the α-diversity, the Firmicutes/Bacteroidetes ratio, certain short-chain fatty acid-producing bacteria and Lactobacillus. Based on in vitro studies using RAW264.7 cells and electron spin resonance oximetry, AuNPs inhibited lipopolysaccharide (LPS)-triggered inducible nitric oxide (NO) synthase expression and NO production via reduction of Toll-like receptor 4 (TLR4), and attenuated LPS-induced nuclear factor kappa beta activation and proinflammatory cytokine production via both TLR4 reduction and catalytic detoxification of peroxynitrite and hydrogen peroxide. CONCLUSIONS: AuNPs have promising potential as anti-inflammatory agents; however, their therapeutic applications via the oral route may have a negative impact on the gut microbiota.

13.
Mar Drugs ; 16(10)2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30308963

RESUMO

In this paper, a novel natural influenza A H1N1 virus neuraminidase (NA) inhibitory peptide derived from cod skin hydrolysates was purified and its antiviral mechanism was explored. From the hydrolysates, novel efficient NA-inhibitory peptides were purified by a sequential approach utilizing an ultrafiltration membrane (5000 Da), sephadex G-15 gel column and reverse-phase high-performance liquid chromatography (RP-HPLC). The amino acid sequence of the pure peptide was determined by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) was PGEKGPSGEAGTAGPPGTPGPQGL, with a molecular weight of 2163 Da. The analysis of the Lineweacer⁻Burk model indicated that the peptide was a competitive NA inhibitor with Ki of 0.29 mM and could directly bind free enzymes. In addition, docking studies suggested that hydrogen binding might be the driving force for the binding affinity of PGEKGPSGEAGTAGPPGTPGPQGL to NA. The cytopathic effect reduction assay showed that the peptide PGEKGPSGEAGTAGPPGTPGPQGL protected Madin⁻Darby canine kidney (MDCK) cells from viral infection and reduced the viral production in a dose-dependent manner. The EC50 value was 471 ± 12 µg/mL against H1N1. Time-course analysis showed that PGEKGPSGEAGTAGPPGTPGPQGL inhibited influenza virus in the early stage of the infectious cycle. The virus titers assay indicated that the NA-inhibitory peptide PGEKGPSGEAGTAGPPGTPGPQGL could directly affect the virus toxicity and adsorption by host cells, further proving that the peptide had an anti-viral effect with multiple target sites. The activity of NA-inhibitory peptide was almost inactivated during the simulated in vitro gastrointestinal digestion, suggesting that oral administration is not recommended. The peptide PGEKGPSGEAGTAGPPGTPGPQGL acts as a neuraminidase blocker to inhibit influenza A virus in MDCK cells. Thus, the peptide PGEKGPSGEAGTAGPPGTPGPQGL has potential utility in the treatment of the influenza virus infection.

14.
Mar Drugs ; 16(9)2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30201855

RESUMO

Probiotic-derived polyphosphates have attracted interest as potential therapeutic agents to improve intestinal health. The current study discovered the intracellular accumulation of polyphosphates in a marine cyanobacterium Synechococcus sp. PCC 7002 as nano-sized granules. The maximum accumulation of polyphosphates in Synechococcus sp. PCC 7002 was found at the late logarithmic growth phase when the medium contained 0.74 mM of KH2PO4, 11.76 mM of NaNO3, and 30.42 mM of Na2SO4. Biogenic polyphosphate nanoparticles (BPNPs) were obtained intact from the algae cells by hot water extraction, and were purified to remove the organic impurities by Sephadex G-100 gel filtration. By using 100 kDa ultrafiltration, BPNPs were fractionated into the larger and smaller populations with diameters ranging between 30⁻70 nm and 10⁻30 nm, respectively. 4',6-diamidino-2-phenylindole fluorescence and orthophosphate production revealed that a minor portion of BPNPs (about 14⁻18%) were degraded during simulated gastrointestinal digestion. In vitro studies using lipopolysaccharide-activated RAW264.7 cells showed that BPNPs inhibited cyclooxygenase-2, inducible nitric oxide (NO) synthase expression, and the production of proinflammatory mediators, including NO, tumor necrosis factor-α, interleukin-6, and interleukin-1ß through suppressing the Toll-like receptor 4/NF-κB signaling pathway. Overall, there is promise in the use of the marine cyanobacterium Synechococcus sp. PCC 7002 to produce BPNPs, an anti-inflammatory postbiotic.

15.
Food Res Int ; 113: 189-196, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30195513

RESUMO

The aim of this study was to investigate the fermentation properties of fish protein (FP) glycated with glucose at two different heating time (24 h and 48 h, 50 °C, GFP24 and GFP48), using an in vitro batch fermentation model of human distal colon. The heated fish protein in absent of glucose was also as controls. The lower glycation extent of fish protein, with a lower browning intensity and bound sugar, enhanced the production of acetate and propionate. The formation of indole and ammonia was inhibited by the glycation of fish protein, but less affected by its glycation extent. Compared to FP, the glycation of fish protein significantly increased (p < .05) the relative abundance of genera Lactococcus for GFP24 (47%) and GFP48 (71%), whereas decreased dominant genera Bacteroides for GFP24 (32%) and GFP48 (23%). Compared to GFP24, GFP48 indicated significantly higher relative abundance of Holdemania, Streptococcus, Enterococcus and Lactobacillus, and lower amounts of Parabacteroides (p < .05). In the meantime, the heated treatments in the absent of glucose resulted in the increase of some genera Dialister, Arobacter, Clostridium_sensu_stricto_1, Phascolarctobacterium and Veillonella, and also ammonia production. Furthermore, the correlation analysis confirmed that the glycation of fish protein for the decrease of ammonia and indole production was associated with the changes of some proteolytic bacteria genera, including Bacteroides, Dialister and Parabacteroides. Thus, the glycated fish protein rich in Amadori products greatly change the profiles of fermentation metabolite and gut microbiota, and these changes can have a potential impact on host health.

16.
Food Sci Nutr ; 6(4): 1023-1031, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29983966

RESUMO

Gelatin is an anti-inflammatory dietary component, and its predominant metabolites entering circulation are prolyl-hydroxyproline (Pro-Hyp) and glycine. We evaluated the protective effects of orally administered gelatin, glycine, and Pro-Hyp 10:3:0.8 (w/w/w) against dextran sodium sulfate (DSS)-induced colitis in mice. According to clinical, histological, and biochemical parameters, they exhibited significant activities in the order of gelatin < glycine < Pro-Hyp. Gelatin prevented the DSS-induced increase in interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the colon, rather than in peripheral blood. Glycine and Pro-Hyp attenuated the DSS-induced rise in colonic IL-6 and TNF-α, as well as peripheral IL-1ß, IL-6, and TNF-α. Hematologic results show the attenuation of DSS-induced leukocytosis and lymphocytosis by glycine and Pro-Hyp, rather than gelatin. These findings suggest that glycine and Pro-Hyp constitute the material basis for gelatin's anticolitis efficacy, and they have better anticolitis activities and distinct mechanisms of action when ingested as free compounds than as part of gelatin.

17.
J Agric Food Chem ; 66(30): 8026-8035, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29975063

RESUMO

Polyphosphates are one of the active compounds from probiotics to maintain gut health. The current research extracted and purified intact biogenic polyphosphate nanoparticles (BPNPs) from Synechococcus sp. PCC 7002 cells. BPNPs were near-spherical anionic particles (56.9 ± 15.1 nm) mainly composed of calcium and magnesium salt of polyphosphate and were colloidally stable at near-neutral and alkaline pH. BPNPs survived gastrointestinal digestion in mice and could be absorbed and transported by polarized Caco-2 cell monolayers. They dose-dependently increased the tightness of intercellular tight junction and the expression of claudin-4, occludin, zonula occludens-1, and heat shock protein 27 in Caco-2 cell monolayers. BPNPs also effectively attenuated H2O2-induced cell death, plasma membrane impairment, and intracellular superoxide production in NCM460 cells. In addition, they conferred resistance to H2O2-induced barrier disruption in freshly excised mouse small intestine. Our results suggest that BPNPs are a promising postbiotic nanomaterial with potential applications in gut health maintenance.


Assuntos
Células Epiteliais/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Nanopartículas/metabolismo , Polifosfatos/farmacologia , Synechococcus/metabolismo , Animais , Células CACO-2 , Células Epiteliais/metabolismo , Humanos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Ocludina/genética , Ocludina/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Polifosfatos/metabolismo , Synechococcus/química , Junções Íntimas/genética , Junções Íntimas/metabolismo
18.
J Food Sci Technol ; 55(7): 2795-2800, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30042596

RESUMO

Numerous bacterial species utilize quorum sensing molecules acyl-homoserine-lactones (AHLs) to communicate, however, crosstalk often complicates the dynamics and behaviors of mixed populations. In this study, we developed a luxR mutant of wild type Shewanella baltica SA03 (WT SA03), and aimed to investigate the role of S. baltica LuxR (AHLs receptor) involved in the spoilage of refrigerated shrimp (Litopenaeus vannamei) by inoculating WT SA03 and luxR mutant of S. baltica SA03 (ΔluxR SA03), respectively. The results indicated the maximum growth rate of total viable bacteria in shrimp inoculated with ΔluxR SA03 was 73.34% lower than that of WT SA03. The lag time of total bacteria in shrimp treated with ΔluxR SA03 were 87.6 h, significantly longer than that of WT SA03. Meanwhile, the total volatile basic nitrogen concentrations of shrimp treated with WT SA03 were significantly higher than that of ΔluxR SA03 after 2 days of storage, which were in agreement with the decrease of the content of AHLs of the shrimp. The results indicated S. baltica might utilize AHLs produced by other bacteria and accelerate the shrimp spoilage process through LuxR receptor system.

19.
Food Funct ; 9(5): 2853-2864, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29700505

RESUMO

The aim of this research was to investigate the impact of a diet containing galactooligosaccharide (GOS)-fish peptide (FP) conjugates prepared via Maillard reaction on the colonic fermentation properties and the composition of gut microbiota in Sprague-Dawley rats. The rats were fed the GOS diet, FP diet, GOS and FP mixture (GOS/FP) diet, GOS glycated with FP (80 °C for 120 min, G-GOS/FP) diet, or control (CK) diet for three weeks. Compared to the GOS/FP diet, the G-GOS/FP diet greatly changed the pattern of SCFA production in the hindgut of rats, by increasing the total SCFA (44%), butyrate (55%) and propionate (1.23-fold) levels in the proximal colon, and the butyrate levels (74%) in the distal colon, and decreased the production of ammonia in feces (P < 0.05). The G-GOS/FP altered the colonic microbiota by increasing (P < 0.05) the relative abundance of Anaerovibrio (7.43-fold) and Prevotella-9 (2.47-fold), and by decreasing (P < 0.05) the relative abundance of Alloprevotella (0.57-fold) and Holdemanella (0.64-fold), and showed a similar relative abundance of Bifidobacterium, when compared with GOS/FP. The GOS/FP diet increased the number of Lactobacillus and the intensity of fermentation in the cecum, but the G-GOS/FP diet and GOS diet did not have these effects, showing that the glycation clearly altered the fermentability of the fish peptide. It is concluded that the glycation-induced modification of GOS by mild thermal treatments showed its fermentation persistence in the colon of the host, and improved some prebiotic activities of GOS. These results may provide new strategies for oligosaccharides in combination with peptides to modulate the intestinal environment to promote human health.


Assuntos
Bactérias/metabolismo , Microbioma Gastrointestinal , Oligossacarídeos/metabolismo , Peptídeos/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ácido Butírico/metabolismo , Carpas , Colo/metabolismo , Colo/microbiologia , Fermentação , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Masculino , Prebióticos/análise , Ratos , Ratos Sprague-Dawley
20.
J Food Sci Technol ; 55(5): 1903-1912, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29666543

RESUMO

Shewanella baltica and Acinetobacter are among the predominant spoilage bacteria in refrigerated shrimp (Litopenaeus vannamei). S. baltica are incapable of producing acyl-homoserine lactone (AHL) quorum sensing signals, but can respond to environmental AHLs. In this paper, Acinetobacter was found to produce three AHLs, i.e. N-butanoyl-l-homoserine lactone (C4-HSL), N-(3-oxohexanoyl)-l-homoserine lactone (O-C6-HSL) and N-(3-oxooctanoyl)-l-homoserine lactone (O-C8-HSL), according to thin-layer chromatography using the bioreporter Agrobacterium tumefaciens A136. The agar diffusion and ß-galactosidase assays revealed that S. baltica could eavesdrop on these three AHLs from Acinetobacter. Eavesdropping on Acinetobacter AHLs especially C4-HSL was found to boost the growth of S. baltica particularly under nutrient limiting conditions (up to 40-fold increase) in the co-culture experiments. The azocasein assay revealed that S. baltica produced fourfold more extracellular proteases in response to Acinetobacter AHLs. As demonstrated by the biofilm crystal violet staining assay and confocal laser scanning microscopy, eavesdropping also decreased the biofilm-forming capacity of Acinetobacter. By inoculation of S. baltica and Acinetobacter onto surface-sterilized shrimp, eavesdropping was found to endow a growth advantage to S. baltica in vivo, resulting in a 0.5 day shortened shelf life of shrimp according to total volatile basic nitrogen levels and sensory analysis. Overall, the AHL-dependent eavesdropping increased the spoilage potential of S. baltica, providing a fresh perspective on the spoilage process of refrigerated L. vannamei, and this may inspire the development of novel preservation techniques in the future to further reduce post-harvest loss of shrimp.

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