Jianteng Wei

Polysaccharides from Enteromorpha prolifera enhance the immunity of normal mice

The effects of polysaccharides from Enteromorpha prolifera (PEP) on cell-mediated immunity, humoral immunity and mononuclear phagocytic system function were evaluated to assess the immunomodulatory potential of these macromolecules. Relevant immunological mechanisms were verified by biochemical assays and western blot analysis. Results showed that PEP could induce splenocyte proliferation. In vivo experiments on Kunming mice confirmed that PEP could improve cell-mediated immunity, humoral immunity and mononuclear phagocytic system function. To illustrate the mechanism, we determined several immune-related enzymes in the thymus and spleen. The results indicated that PEP could enhance the activities of alkaline phosphatase, superoxide dismutase and lactate dehydrogenase. PEP could also increase the level of NF-κB. These results suggested that PEP exhibited potent immunomodulatory properties and could be used as a novel potential immunostimulant in food and pharmaceutical industries.

Discovery of biomarkers for oxidative stress based on cellular metabolomics

Abstract Oxidative stress has a close relationship with various pathologic physiology phenomena and the potential biomarkers of oxidative stress may provide evidence for clinical diagnosis or disease prevention. Metabolomics was employed to identify the potential biomarkers of oxidative stress. High-performance liquid chromatography–diode array detector, mass spectrometry and partial least squares discriminate analysis were used in this study. The 10, 15 and 13 metabolites were considered to discriminate the model group, vitamin E-treated group and l-glutathione-treated group, respectively. Some of them have been identified, namely, malic acid, vitamin C, reduced glutathione and tryptophan. Identification of other potential biomarkers should be conducted and their physiological significance also needs to be elaborated.

Polysaccharide from Enteromorpha prolifera enhances non-specific immune responses and protection against Vibrio splendidus infection of sea cucumber

This study aimed to evaluate the effects of polysaccharide from Enteromorpha prolifera (PEP2) on the non-specific immune responses of sea cucumber. The non-specific humoral and cellular responses were determined, and sea cucumbers were challenged by Vibrio splendidus. The results indicate that PEP2 had no significant effect on the total coelomocyte counts. Both phagocytic capacity and respiratory burst activity were significantly increased by PEP2. Among the humoral responses, the activities of acid phosphatase, catalase and superoxide dismutase of sea cucumber were significantly enhanced by PEP2. However, no difference in alkaline phosphatase activity was observed between the experimental and control groups. In the challenge test, we found that PEP2 decreased the mortality rate of sea cucumbers and enhanced their resistance to V. splendidus. Thus, PEP2 could enhance the non-specific immune activity of sea cucumbers. PEP2 exhibited potent immunomodulatory properties and can be explored as a novel potential immunostimulant of sea cucumber.

Discovery and identification of potential biomarkers for alcohol-induced oxidative stress based on cellular metabolomics.

Biomarkers involved in alcohol-induced oxidative stress play an important role in alcoholic liver disease prevention and diagnosis. Alcohol-induced oxidative stress in human liver L-02 cells was used to discover the potential biomarkers. Metabolites from L-02 cells induced by alcohol were measured by high-performance liquid chromatography and mass spectrometry. Fourteen metabolites that allowed discrimination between control and model groups were discovered by multivariate statistical data analysis (i.e. principal components analysis, orthogonal partial least-squares discriminate analysis). Based on the retention time, UV spectrum and LC-MS findings of the samples and compared with the authentic standards, eight biomarkers involved in alcohol-induced oxidative stress, namely, malic acid, oxidized glutathione, γ-glutamyl-cysteinyl-glycine, adenosine triphosphate, phenylalanine, adenosine monophosphate, nitrotyrosine and tryptophan, were identified. These biomarkers offered important targets for disease diagnosis and other researches.

Evaluation and Application of a Novel Quantitative Antioxidant Activity Assay Based on Cellular Metabolomics

A novel quantitative antioxidant activity assay based on cellular metabolomics, named cellular metabolomics antioxidant activity (CMAA) assay, was established and applied in this paper. CMAA assay evaluates antioxidant activity by considering the change rules of the cellular metabolites of different treatment groups of human liver carcinoma cell line HepG2 cells subjected to oxidative stress. This assay considers cellular metabolites as the main analytical index, principal components analysis (PCA), and orthogonal projections to latent structures discriminant analysis (OPLS-DA) as the main multi- and megavariate data analysis method and vitamin E (VE) as a standard substance to quantify antioxidant activities. The antioxidant activities of flavonoids extracted from Cynomorium songaricum Rupr. (CS) were measured by the CMAA assay. The results showed that the antioxidant activity of flavonoids extracted from CS was successfully evaluated using the CMAA assay, and the antioxidant activity of flavonoids extracted from CS was about 1/5 of the same concentration of VE. It indicated that the proposed approach, as an effective tool for evaluating the antioxidant capacity, was feasible.

Effect of the ionic liquid group in novel interpenetrating polymer networks on the adsorption properties for oleuropein from aqueous solutions

By combining the advantages of ionic liquids with those of interpenetrating polymer networks, a novel ionic liquid modified adsorbent with a structure of an interpenetrating polymer network (PS/PVIm) was prepared and then used to enrich oleuropein to investigate the interactive forces between the adsorbent and oleuropein. The effects of contact time, initial concentration and temperature on the adsorption behaviour were systematically studied. The results of a static adsorption experiment showed that the adsorption process of the original resin (PS–CH2Cl) for oleuropein obeyed a pseudo-second-order kinetic model, whereas that of the PS/PVIm towards oleuropein could be well depicted by pseudo-first-order and pseudo-second-order kinetic models, indicating the different adsorption behaviours of both the adsorbents. The Freundlich isotherm model could reasonably depict the adsorption process. Adsorption thermodynamics analysis indicated that the adsorption process was spontaneous and feasible. A dynamic adsorption and desorption experiment further validated the high affinity of PS/PVIm for oleuropein and the introduction of an ionic liquid imidazolium group and interpenetration polymer network can improve the adsorption efficiency. However, the adsorption rate decreased. The results of the present study have a significant importance in designing and preparing appropriate resins with ionic liquids and high adsorption efficiency to enrich oleuropein from olive leaves extract.

Antibacterial Activity of Hydroxytyrosol Acetate from Olive Leaves (Olea Europaea L.)

Abstract Vibrio spp. are pathogens of many bacterial diseases which have caused great economic losses in marine aquaculture. The strategy of alternative medical treatment that is utilised by herbalists has expanded in the past decade. The aim of our study is to discover the antibacterial molecules against Vibrio spp. Bacterial growth inhibition, membrane permeabilisation assessment and DNA interaction assays, as well as agarose gel electrophoresis, were employed to elucidate the antibacterial activity of hydroxytyrosol acetate. Results showed that hydroxytyrosol acetate had antibacterial activity against Vibrio spp. and it played the role via increasing bacterial membrane permeabilisation. The DNA interaction assay and agarose gel electrophoresis revealed that hydroxytyrosol acetate interacted with DNA. Hydroxytyrosol acetate enhanced the fluorescent intensity of DNA binding molecules and mediated supercoiled DNA relaxation. The present study provides more evidence that hydroxytyrosol acetate is a novel antibacterial candidate against Vibrio spp.

Establishment and application of a method for screening the therapeutic drugs of ethanol-induced liver injury based on cellular metabonomics

A drug-screening method to test the capacity of drugs to protect against ethanol-induced liver injury based on cellular metabonomics was established and applied in this study. It screens for the ability to protect against ethanol-induced liver injury by considering changes in the cellular metabolites of human normal liver L-02 cells subjected to ethanol treatment. This method considers cellular metabolites as the main analytical index, principal component analysis and orthogonal partial least squares discriminant analysis as the main multi- and megavariate data analysis methods, and vitamin C as the standard substance to determine the ability to protect against ethanol-induced liver injury. Ability to protect against ethanol-induced liver injury unit = [190 - 50× (14.318 - 10 × Y predictive value)1/2 ] × ability 1 μg/mL vitamin C. Olive leaf extract, Lycium barbarum L extract and fish roe peptide were screened using the established methods. Olive leaf OP phase had the strongest ability to protect against ethanol-induced liver injury, at 81.88. The value for L. barbarum L was 37.56. The fish roe peptide water phase was 63.07. All three have the ability to protect against ethanol-induced liver injury. The drug-screening method for ability to protect against ethanol-induced liver injury based on cell metabonomics is a fast, accurate and effective method for quantitative detection of ability to protect against ethanol-induced liver injury.