Integrated Network Pharmacology and Experimental Approach to Investigate the Protective Effect of Jin Gu Lian Capsule on Rheumatoid Arthritis by Inhibiting Inflammation via IL-17/NF-κB Pathway.

Purpose: This study aimed to investigate the main pharmacological action and underlying mechanisms of Jin Gu Lian Capsule (JGL) against rheumatoid arthritis (RA) based on network pharmacology and experimental verification. Methods: Network pharmacology approaches were performed to explore the core active compounds of JGL, key therapeutic targets, and signaling pathways. Molecular docking was used to predict the binding affinity of compounds with targets. In vivo experiments were undertaken to validate the findings from network analysis. Results: A total of 52 targets were identified as candidate JGL targets for RA. Sixteen ingredients were identified as the core active compounds, including, quercetin, myricetin, salidroside, etc. Interleukin-1 beta (IL1B), transcription factor AP-1 (JUN), growth-regulated alpha protein (CXCL1), C-X-C motif chemokine (CXCL)3, CXCL2, signal transducer and activator of transcription 1 (STAT1), prostaglandin G/H synthase 2 (PTGS2), matrix metalloproteinase (MMP)1, inhibitor of nuclear factor kappa-B kinase subunit beta (IKBKB) and transcription factor p65 (RELA) were obtained as the key therapeutic targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the efficacy of JGL was functionally involved in regulating immune-mediated inflammation, in which IL-17/NF-κB signaling was recommended as one of the main pathways. Molecular docking suggested that the core active compounds bound strongly to their respective targets. Experimentally, JGL treatment mitigated inflammation, showed analgesic activity, and ameliorated collagen-induced arthritis. Enzyme-linked immunosorbent assay showed that JGL effectively reduced the serum levels of cytokines, chemokines, and MMPs. Immunohistochemistry staining showed that JGL markedly reduced the expression of the targets in IL-17/NF-κB pathway including IL-17A, IL-17RA, NF-κB p65, C-X-C motif ligand 2, MMP1 and MMP13. Conclusion: This investigation provided evidence that JGL may alleviate RA symptoms by partially inhibiting the immune-mediated inflammation via IL-17/NF-κB pathway.

Potential association factors for developing effective peptide-based cancer vaccines.

Peptide-based cancer vaccines have been shown to boost immune systems to kill tumor cells in cancer patients. However, designing an effective T cell epitope peptide-based cancer vaccine still remains a challenge and is a major hurdle for the application of cancer vaccines. In this study, we constructed for the first time a library of peptide-based cancer vaccines and their clinical attributes, named CancerVaccine (https://peptidecancervaccine.weebly.com/). To investigate the association factors that influence the effectiveness of cancer vaccines, these peptide-based cancer vaccines were classified into high (HCR) and low (LCR) clinical responses based on their clinical efficacy. Our study highlights that modified peptides derived from artificially modified proteins are suitable as cancer vaccines, especially for melanoma. It may be possible to advance cancer vaccines by screening for HLA class II affinity peptides may be an effective therapeutic strategy. In addition, the treatment regimen has the potential to influence the clinical response of a cancer vaccine, and Montanide ISA-51 might be an effective adjuvant. Finally, we constructed a high sensitivity and specificity machine learning model to assist in designing peptide-based cancer vaccines capable of providing high clinical responses. Together, our findings illustrate that a high clinical response following peptide-based cancer vaccination is correlated with the right type of peptide, the appropriate adjuvant, and a matched HLA allele, as well as an appropriate treatment regimen. This study would allow for enhanced development of cancer vaccines.

Genome-Wide Identification and Analysis of the Growth-Regulating Factor Family in Zanthoxylum armatum DC and Functional Analysis of ZaGRF6 in Leaf Size and Longevity Regulation.

Growth-regulating factors (GRFs) are plant-specific transcription factors that play an important role in plant growth and development. In this study, fifteen GRF gene members containing QLQ and WRC domains were identified in Zanthoxylum armatum. Phylogenetic and collinearity analysis showed that ZaGRFs were closely related to CsGRFs and AtGRFs, and distantly related to OsGRFs. There are a large number of cis-acting elements related to hormone response and stress induction in the GRF gene promoter region of Z. armatum. Tissue-specific expression analysis showed that except for ZaGRF7, all the ZaGRFs were highly expressed in young parts with active growth and development, including terminal buds, seeds, and young flowers, suggesting their key roles in Z. armatum growth and development. Eight ZaGRFs were selected to investigate the transcriptional response to auxin, gibberellin and drought treatments. A total of six ZaGRFs in the NAA treatment, four ZaGRFs in the GA3 treatment, and six ZaGRFs in the PEG treatment were induced and significantly up-regulated. Overexpression of ZaGRF6 increased branching and chlorophyll content and delayed senescence of transgenic Nicotiana benthamiana. ZaGRF6 increased the expression of CRF2 and suppressed the expression of ARR4 and CKX1, indicating that ZaGRF6 is involved in cytokinin metabolism and signal transduction. These research results lay a foundation for further analysis of the GRF gene function of Z. armatum and provide candidate genes for growth, development, and stress resistance breeding of Z. armatum.

Integrative Analysis of Metabolomics and Transcriptomics Reveals Molecular Mechanisms of Anthocyanin Metabolism in the Zikui Tea Plant (Camellia sinensis cv. Zikui).

In this study, we performed an association analysis of metabolomics and transcriptomics to reveal the anthocyanin biosynthesis mechanism in a new purple-leaf tea cultivar Zikui (Camellia sinensis cv. Zikui) (ZK). Three glycosylated anthocyanins were identified, including petunidin 3-O-glucoside, cyanidin 3-O-galactoside, and cyanidin 3-O-glucoside, and their contents were the highest in ZK leaves at 15 days. This is the first report on petunidin 3-O-glucoside in purple-leaf tea. Integrated analysis of the transcriptome and metabolome identified eleven dependent transcription factors, among which CsMYB90 had strong correlations with petunidin 3-O-glucoside, cyanidin 3-O-galactoside, and cyanidin 3-O-glucoside (PCC > 0.8). Furthermore, we also identified key correlated structural genes, including two positively correlated F3'H (flavonoid-3'-hydroxylase) genes, two positively correlated ANS (anthocyanin synthase) genes, and three negatively correlated PPO (polyphenol oxidase) genes. Overexpression of CsMYB90 in tobacco resulted in dark-purple transgenic calluses. These results showed that the increased accumulation of three anthocyanins in ZK may promote purple-leaf coloration because of changes in the expression levels of genes, including CsMYB90, F3'Hs, ANSs, and PPOs. These findings reveal new insight into the molecular mechanism of anthocyanin biosynthesis in purple-leaf tea plants and provide a series of candidate genes for the breeding of anthocyanin-rich cultivars.

Effects of thermoultrasonic treatment on characteristics of micro-nano particles and flavor in Greenland halibut bone soup.

In order to investigate the effects of thermoultrasonic treatment (TUT) on the formation of colloidal micro-nano particles (MNPs) and the quality of halibut bone soup, nutrients, particle characteristics, and flavor characteristics were analyzed. The morphology of MNPs was studied using an optical microscope. Results showed that TUT could increase the nutrient content (total sugars, 22.15 mg/100 mL; water soluble proteins, 173.24 mg/mL; fatty acids, 1779.7 mg/100 mL; solids, 3.16 g/100 mL), reduce the particle size (605.92 nm) and interfacial tension. Meanwhile, TUT make the halibut bone soup has better emulsifying characteristics and stability. The contents of flavor substances, such as esters, 5'-nucleotides, organic acids in the halibut bone soup were more abundant, while the contents of hexanal and 1-octen-3-ol and fishy off-flavor were reduced in TUT group. The overall odor and taste outline were more harmonious. Therefore, TUT can be used in the production of high quality fish bone soup, and TUT could be considered as a good deep processing technology for halibut bone and improve economic efficiency.

Effects of 1-MCP treatment on sprouting and preservation of ginger rhizomes during storage at room temperature.

The purpose of this study was to explore the effects of 1-MCP on the sprouting and preservation of ginger rhizomes during storage at room temperature. Ginger rhizomes were treated with 1 µL L-1 1-methylcyclopropene (1-MCP) and stored at 23 ± 0.2 °C. Our data showed that application of 1-MCP reduced the rate of sprouting during storage compared with the control rhizome. Respiration rate and the reducing sugar content were also reduced following 1-MCP treatment, while the starch content increased. 1-MCP treatment increased the total phenol content and inhibited polyphenol oxidase (PPO) activity. 1-MCP treatment was also associated with a higher ascorbic acid content but a reduced crude fiber content. The generation of superoxide anion free radicals (O2-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) was lower following 1-MCP treatment, while the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were higher compared with the controls. These results suggested that application of 1-MCP could reduce sprouting rates, decrease the accumulation of ROS, and maintain the quality of ginger rhizomes during storage at room temperature. It would be useful to further explore the role and mechanisms of action of ethylene in regulating the sprouting of ginger rhizomes.

Ginsenoside 20(S)-protopanaxadiol inhibits triple-negative breast cancer metastasis in vivo by targeting EGFR-mediated MAPK pathway.

Metastasis is the primary cause of cancer recurrence and cancer related mortality in triple-negative breast cancer (TNBC). EGFR overexpression is in 50-75% TNBC and EGFR-mediated signaling has potential as an attractive therapeutic target in some specific subtypes of breast cancer due to its significant association with tumor metastasis and poor prognosis. Therefore, identification of promising therapeutic strategies targeting EGFR with higher specificity toward cancer metastasis is urgently needed. 20(S)-protopanaxadiol (PPD), one of the major active metabolites from Panax ginseng, has been widely reported to possess pleiotropic anticancer activities in various cancers. In this study, we investigated the effect of PPD against cancer metastasis and the related molecular mechanisms in TNBC in vitro and in vivo. PPD (>30 µM) suppressed cell proliferation by arresting cell cycle in G0/1 phase and triggering cells apoptosis as shown by cell viability assay, flow cytometry analysis and colony formation assay, whereas lower dose of PPD (<20 µM) decreased metastatic potential of MDA-MB-231 and SUM159 cells through direct inhibition of cell adhesion, motility and invasiveness. In TNBC xenograft and syngeneic models, PPD treatment markedly decreased tumor growth and lung metastasis. PPD reversed epithelial-mesenchymal transition (EMT), decreased the expression and activity of matrix metalloproteinases (MMPs) while increased the expression of tissue inhibitors of metalloproteinases (TIMPs) as shown by Western blot and gelatin zymography. Cell signaling pathways that control the expression or activation of these processes were investigated by Western blot and ELISA assay. PPD treatment reduced the phosphorylation of EGFR and down-regulated the activation ERK1/2, p38 and JNK signaling, which was further validated by using the agonists or inhibitors of EGFR and MAP kinases family. Collectively, these findings suggest that PPD holds therapeutic potential against the tumor metastasis of TNBC via targeting EGFR-mediated MAPK pathway.

Identification of natural product compounds as quorum sensing inhibitors in Pseudomonas fluorescens P07 through virtual screening.

Pseudomonas fluorescens, a Gram-negative psychrotrophic bacteria, is the main microorganism causing spoilage of chilled raw milk and aquatic products. Quorum sensing (QS) widely exists in bacteria to monitor their population densities and regulate numerous physiological activities, such as the secretion of siderophores, swarming motility and biofilm formation. Thus, searching for quorum sensing inhibitors (QSIs) may be another promising way to control the deterioration of food caused by P. fluorescens. Here, we screened a traditional Chinese medicine (TCM) database to discover potential QSIs with lesser toxicity. The gene sequences of LuxI- and LuxR-type proteins of P. fluorescens P07 were obtained through whole-genome sequencing. In addition, the protein structures built by homology modelling were used as targets to screen for QSIs. Twenty-one compounds with a dock score greater than 6 were purchased and tested by biosensor strains (Chromobacterium violaceum CV026 and Agrobacterium tumefaciens A136). The results showed that 10 of the compounds were determined as hits (hit rate: 66.67%). Benzyl alcohol, rhodinyl formate and houttuynine were effective QSIs. The impact of the most active compound (benzyl alcohol) on the phenotypes of P. fluorescens P07, including swimming and swarming motility, production of extracellular enzymes and siderophores, N-acylhomoserine lactone (AHLs) content and biofilm formation were determined. The inhibitory mechanism of benzyl alcohol on the QS system of P. fluorescens P07 is further discussed. This study reveals the feasibility of searching for novel QSIs through virtual screening.

Effects of xylitol and stevioside on the physical and rheological properties of gelatin from cod skin.

Jelly and confectionery products are high in sugar and calories. Xylitol and stevioside are natural low-calorie sweeteners and they can be used as an alternative; however, their effects on fish gelatin are unknown. The gelatin was extracted from cod skins and added to xylitol or stevioside (0, 2, 6, 10, 14, and 20% (w/v)) to form gel products. This paper investigated how xylitol and stevioside affected the physical and rheological behaviors of fish gelatin, such as color, gel strength, texture profile analysis, storage modulus (G'), loss modulus (G″), and viscosity. Results showed that the change of color and viscosity in gel products were similar when various concentrations of xylitol or stevioside were added to the fish gelatin. But the effects of xylitol/stevioside on texture profile analysis and G', G″ were different, which might due to the structure variation in xylitol and stevioside. The linear structure of xylitol resulted in ionic interaction, hydrogen bonding, van der Waals forces, and hydrophobic association between xylitol and fish gelatin. Therefore, xylitol is a promising sweetener substitute, which was probably related to its greater solubility and number of -OH groups.

Effects of freezing conditions on quality changes in blueberries.

BACKGROUND: Freezing preservation is one of the most effective methods used to maintain the flavour and nutritional value of fruit. This research studied the effects of different freezing conditions, -20 °C, -40 °C, -80 °C, and immersion in liquid nitrogen, on quality changes of freeze-thawed blueberries. The water distribution estimates of blueberries were measured based on low-field nuclear magnetic resonance (LF-NMR) analysis. The pectin content, drip loss, and fruit texture were also detected to evaluate quality changes in samples. RESULTS: The freezing curves of blueberry showed super-cooling points at -20 °C and - 40 °C, whereas super-cooling points were not observed at -80 °C or in liquid nitrogen. After freeze-thaw treatment, the relaxation time of the cell wall water (T21 ), cytoplasm water and extracellular space (T22 ), and vacuole water (T23 ) were significantly shortened compared to fresh samples, which suggested a lower liquidity. Although the freezing speed for samples immersed in liquid nitrogen was faster than other treatments, samples treated at -80 °C showed better quality regarding vacuole water holding, drip loss, and original pectin content retention. CONCLUSION: This study contributed to understanding how freezing temperature affects the qualities of blueberries. The super-fast freezing rate might injure fruit, and an appropriate freezing rate could better preserve blueberries. © 2018 Society of Chemical Industry.

Internalization and dissemination of human norovirus and Tulane virus in fresh produce is plant dependent.

Human norovirus (NoV) is a leading cause of fresh produce associated outbreaks. Previous research indicates that the roots of growing leafy greens and berries internalize human NoV. However the effect of plant type and inoculum level on internalization rates has not been directly compared. In this study we compared the internalization and dissemination rates of human NoV and its surrogate, Tulane virus (TV) in green onion, radishes, and Romaine lettuce. We also evaluated the effect inoculum level and plant growth matrix on the rate of viral internalization. In the hydroponic growth system, we detected internalization and dissemination of human NoV RNA in green onions. In hydroponically growing green onions inoculated with high titer TV, we found higher rates of internalization and dissemination compared to green onions inoculated with low titer TV. In soil growth systems, no infectious TV was detected in either green onion or radishes. However, in Romaine lettuce plants grown in soil approximately 4 log10 PFU/g was recovered from all tissues on day 14 p.i. Overall, we found that the type of plant, growth matrix, and the inoculum level influences the internalization and dissemination of human NoV and TV.

[Relationship between pre-clinical toxicity and efficacy of traditional Chinese medicine].

Based on the different category of syndromes between traditional Chinese medicine(TCM) and Western medicine, the relationship between the efficacy and non-clinical toxicity of the TCM was analyzed. If TCM preparations have the same pharmacological targets to treat disease with modern medicine or the Chinese herbal preparations treat the diseases with its toxicity, their toxicity often exhibits the amplification and extension of activity; on the other hand, if TCM preparations have overlapped pharmacological targets but not completely the same with modern medicine, or if they have totally different pharmacological targets, the toxicity of TCM could not be inferred by pharmacological activity. With the great progress in extraction and separation technique for active parts of TCM as well as the application of some novel technique and excipients, some toxicity may be from the reactions unrelated with the pharmacological activity. In conclusion, better design and quality control could be obtained by understanding the relationship between pharmacological and toxicological study for the investigation of new traditional medicine.

Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency.

Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. Saccharomyces cerevisiae, Candida albicans, and Komagataella pastoris) and prokaryotes (Pseudomonas fluorescens). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate-an iron chelating agent-to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.

Transcriptomic analysis of the response of Pseudomonas fluorescens to epigallocatechin gallate by RNA-seq.

Epigallocatechin gallate (EGCG) is a main constituent of green tea polyphenols that are widely used as food preservatives and are considered to be safe for consumption. However, the underlying antimicrobial mechanism of EGCG and the bacterial response to EGCG are not clearly understood. In the present study, a genome-wide transcriptional analysis of a typical spoilage bacterium, Pseudomonas fluorescens that responded to EGCG was performed using RNA-seq technology. A total of 26,365,414 and 23,287,092 clean reads were generated from P. fluorescens treated with or without 1 mM EGCG and the clean reads were aligned to the reference genome. Differential expression analysis revealed 291 upregulated genes and 134 downregulated genes and the differentially expressed genes (DEGs) were verified using RT-qPCR. Most of the DGEs involved in iron uptake, antioxidation, DNA repair, efflux system, cell envelope and cell-surface component synthesis were significantly upregulated by EGCG treatment, while most genes associated with energy production were downregulated. These transcriptomic changes are likely to be adaptive responses of P. fluorescens to iron limitation and oxidative stress, as well as DNA and envelope damage caused by EGCG. The expression of specific genes encoding the extra-cytoplasmic function sigma factor (PvdS, RpoE and AlgU) and the two-component sensor histidine kinase (BaeS and RpfG) were markedly changed by EGCG treatment, which may play important roles in regulating the stress responses of P. fluorescens to EGCG. The present data provides important insights into the molecular action of EGCG and the possible cross-resistance mediated by EGCG on P. fluorescens, which may ultimately contribute to the optimal application of green tea polyphenols in food preservation.

Effect of 6-gingerol on physicochemical properties of grass carp (Ctenopharyngodon idellus) surimi fortified with perilla oil during refrigerated storage.

BACKGROUND: Surimi is produced from deboned fish muscle through washing to remove blood, lipids, sarcoplasmic proteins and other impurities. There is an increasing interest in the fortification of surimi with ω-3 polyunsaturated fatty acids because of their health benefits. However, lipid oxidation should be considered as an important factor during storage. Hence, in this study, the quality properties and oxidative stability of surimi fortified with 30 g kg-1 perilla oil (PO), or 5 g kg-1 6-gingerol (GI) or their combination (PO+GI) was investigated. RESULTS: Perilla oil significantly improved whiteness of surimi gel, but negatively influenced its gel strength, water holding capacity (WHC) and texture. However, there was no significant difference in texture properties among GI, PO+GI and control groups. During the whole storage period, GI and PO+GI groups had higher gel strength and WHC than control and PO groups. Moreover, lower thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), carbonyl content and total plate count (TPC) were observed in GI group compared with other groups. CONCLUSION: Perilla oil and 6-gingerol could be applied together to effectively fortify surimi qualities. Additionally, 6-gingerol could prevent lipid and protein oxidation and microbial growth of surimi during refrigerated storage. © 2017 Society of Chemical Industry.

The prevalence and risk factors of stroke in patients with chronic schizophrenia.

OBJECTIVE: To investigate the stroke risk and risk factors in patients with chronic schizophrenia. PATIENTS AND METHODS: This study was a large-sample, cross-sectional survey. A total of 363 patients with chronic schizophrenia were selected from the Changping Traditional Chinese Medicine Hospital, Beijing, in August 2014. The patients were divided into either stroke group or control group based on the presence of stroke. Clinical evaluation included positive and negative syndrome scale assessment and a detailed questionnaire to collect the general information and disease-related conditions. RESULTS: The prevalence of stroke was 16.5% (60 cases). Stroke and control groups showed a significant difference in age, sex, smoking, combined medication, doses, negative factor score in positive and negative syndrome scale, body mass index, waist circumference, and systolic blood pressure. Multivariate analysis showed that a number of factors are significantly related to stroke, including age, sex, smoking, combined medication, doses, body mass index, and systolic blood pressure. CONCLUSION: The prevalence of stroke is relatively higher in Chinese patients with chronic schizophrenia. Chronic schizophrenia patients are more likely to suffer from stroke; meanwhile, a number of risk factors were identified, including old age, female sex, smoking history, combined medication with a variety of drugs, high doses, obesity, and high blood pressure.

[Study on characteristic spectrum of ingredients from different species Cordyceps and its anti-fibrotic activity on human embryonic fibroblasts].

In this study, 10 samples of parasites, cursive, and the whole from six different species of Cordyceps were determined and compared by HPLC and LC-MS methods. Uridine, adenosine, and cordycepin were selected as the main evaluation index. The anti-fibrotic activity of different species Cordyceps extracts was observed using in vitro TGF-ß1-induced ECM accumulation in human embryonic fibroblasts CCC-ESF-1. The results demonstrated that the number of atoms and hyphae ingredients of different species showed little difference, however, the content distribution of each component has obvious significance. The in vitro anti-fibrotic activities of different species were as follow： Cordyceps flower > Cicada Cordyceps (Cicada flower)> Silkworm Cordyceps> Tussah Cordyceps>natural Cordyceps. Our preliminary data could serve as reference for the discovery of artificial alternatives of natural Cordyceps.

[Study on main pharmacodynamics and underlying mechanisms of 999 Ganmaoling].

To observe synergistic effects of 999 Ganmaoling (GML) and its Chinese/Western materia medica (CMM and WMM) on pharmacodynamic action and to study underlying mechanisms, their anti-inflammatory, antipyretic effects were compared by assaying the increased capillary permeability induced by glacial acetic acid in mice, ear swelling induced by Xylene in mice, non-specific pleurisy induced by carrageenan in rats, and yeast induced fever in rats. Crystal violet (CV) and microbial activity (XTT) assay were used to evaluate the inhibition of GML and its CMM and WMM on KPN biofilm formation, and scanning electron microscopy (SEM) was applied for observing KPN biofilm morphology changes. The results showed that compared with control group, GML could reduce exudation amount of Evans-Blue and the degree of Ear swelling significantly, and CMM and WMM have no significant effects. The concentration of TNF-α and IL-1ß of rat pleural effusion in GML, CMM and WMM group decreased significantly. The concentration of TNF-α, IL-1ß and IL-8 in GML group, TNF-α, IL-8 in WMM group and IL-8 in CMM in rats serum decreased significantly. The body temperature in rats decreased significantly in GML and WMM group after 4-8 h of administration. CMM group showed no significant difference in rat body temperature compare with control. Compared with control group, GML (55-13.75 g•L⁻¹) could inhibit KPN biofilm formation and reduce number of viable cells in the KPN biofilm. CMM (45-22.5 g•L⁻¹) and WMM (10 g•L⁻¹) could also inhibit KPN biofilm formation and reduce number of viable cells (P<0.01). Result of SEM also showed that GML (55 g•L⁻¹) and its CMM (45 g•L⁻¹) and WMM (10 g•L⁻¹) could interfere the bacterial arrangement of KPN biofilm and extracellular matrix. GML and its CMM & WMM could inhibit the formation of KPN biofilm, CMM & WMM in GML showed synergism and complementation in inhibit KPN biofilm. Results showed that GML had obvious anti-inflammatory and antipyretic effects and could destruct KPN mature biofilm. WMM and CMM showed obvious synergistic effect against inflammation and inhibition of KPN biofilm formation and reduction of number of viable cells but no same effects against fever.

Comparative study on acid-soluble and pepsin-soluble collagens from skin and swim bladder of grass carp (Ctenopharyngodon idella).

BACKGROUND: Collagen has a wide range of applications in food, biomedical and pharmaceutical products. RESULTS: The collagens in grass carp (Ctenopharyngodon idella) skin and swim bladder were extracted using acetic acid and pepsin. Higher yield of pepsin-soluble collagen (PSC) was obtained from skin (178 g kg(-1)) than from swim bladder (114 g kg(-1)). Not surprisingly, yields of PSC from skin and swim bladder were also higher than those of acid-soluble collagen (ASC) from the same organs (89 and 51 g kg(-1)). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles showed that ASC and PSC were type I collagens, with PSC containing a higher proportion of α components than ASC. Fourier transform infrared spectra revealed that ASC and PSC were very similar in their protein secondary structures. Scanning electron micrographs showed that the collagens had a spongy structure, with more pores being obtained in swim bladder than in skin collagens. The collagens showed high solubility in the acidic pH range. However, their solubility decreased in the presence of NaCl at concentrations above 20 g kg(-1). CONCLUSION: Collagens were successfully extracted from the skin and swim bladder of grass carp. These fish by-products could serve as an alternative source of collagens for a wide variety of applications in the food and nutraceutical industries.

Inhibition of quorum sensing, biofilm, and spoilage potential in Shewanella baltica by green tea polyphenols.

We investigated the quorum sensing (QS) system of Shewanella baltica and the anti-QS related activities of green tea polyphenols (TP) against spoilage bacteria in refrigerated large yellow croaker. Autoinducer-2 (AI-2) and the diketopiperazines (DKPs) cyclo-(L-Pro-L-Leu) and cyclo-(L-Pro-L-Phe) were detected in the culture extract of S. baltica XH2, however, no N-acylhomoserine lactones (AHLs) activity was observed. Green TP at sub-inhibitory concentrations interfered with AI-2 and DKPs activities of S. baltica without inhibiting cell growth and promoted degradation of AI-2. The green TP treatment inhibited biofilm development, exopolysaccharide production and swimming motility of S. baltica in a concentration- dependent manner. In addition, green TP decreased extracellular protease activities and trimethylamine production in S. baltica. A transcriptional analysis showed that green TP repressed the luxS and torA genes in S. baltica, which agreed with the observed reductions in QS activity and the spoilage phenotype. Epigallocatechin gallate (EGCG)-enriched in green TP significantly inhibited AI-2 activity of S. baltica. These findings strongly suggest that green TP could be developed as a new QS inhibitor for seafood preservation to enhance shelf life.