Dai Cheng

Isolation, purification, structural analysis and immunostimulatory activity of water-soluble polysaccharides from Grifola Frondosa fruiting body

A new polysaccharide had been successfully isolated from maitake mushroom (Grifola Frondosa)-GFP. HPLC and Monosaccharide analysis showed that the average molecular weight of GFP was 155kDa and it was mainly composed of rhamnose, xylose, mannose, glucose, molar ratio of 1.00: 1.04: 1.11: 6.21. FTIR, methylation analysis and NMR were used to analyze the structural characterization of GFP. Structural analysis results revealed that its backbone consisted of (1→4)-linked methylation, Glcp residues were major structural polysaccharide GFP units, accounting of the polysaccharide backbone speculate GFP every→3)-Glcp-(1→and one→3,4)-Glcp-(1→connected interval with a small amount of 1→, 1→4, 1→6 glycosidic linkage. MTT assay showed that GFP could significantly improve the proliferation activity of RAW264.7 cells in a certain range of concentrations and time. Scanningelectro microscopy (SEM) results indicated that GFP could induce RAW264.7 cells activation. GFP could obviously increase the proliferation index and enhance the immunostimulatory activity such as the cytokine and chemokine production.

Antioxidant capacity and chemical constituents of Chinese jujube (Ziziphus jujuba Mill.) at different ripening stages

Chinese jujube (Ziziphus jujuba Mill.) is admired for its high nutritional value and has been commonly used in traditional Chinese medicine for its remarkable health functions. The antioxidant capacity (AOC) and the other qualitative parameters of jujube were measured at ripening stages of green maturity (GM), white maturity (WM), halfred maturity (HM), and red maturity (RM). AOC was screened with DPPH radical scavenging activity, Trolox equivalent antioxidant capacity, and reducing power. Jujube showed a significant (p<0.05) increase in the total soluble solids and titratable acidity, and firmness have no change of all maturity stages, while ascorbic acid showed a significant (p<0.05) declining trend. At stage of GM, the total phenolic content (TPC), total flavonoid content (TFC), and AOC in peel were the highest, and then rapidly decreased after WM. Meanwhile TPC and AOC in pulp reached a peak value in WM then declined, but TFC declined slowly during maturity.

Protective effect of apple (Ralls) polyphenol extract against aluminum-induced cognitive impairment and oxidative damage in rat.

Aluminum (Al) has long been implicated in the pathogenesis of Alzheimers disease (AD). Dietary polyphenols have been strongly associated with reduced risk of AD and the other nervous diseases. We aimed to evaluate the preventive effect of the apple polyphenol extract (APE) on Al-induced biotoxicity, in order to provide a new focus on the design of strategies to prevent AD and the other human diseases related to Al overload. Control, Al-treated (171.8 mg Al kg(-1)day(-1) 10 weeks), APE+Al (Al-treatment as previously plus 200 mg kg(-1)day(-1) 10 weeks), and group of APE per se were used. Al intake caused memory impairment, significant decrease of acetylcholinesterase, CK, SOD, CAT activity and the rate of ATP synthesis, increase the Al content, the level of malondialdehyde and β-amyloid 42. Administration of APE significantly improved memory retention, attenuated oxidative damage, acetylcholinesterase activity and Al level in Al treated rats. Furthermore, chlorogenic acid (ChA) was used for analyzing stability of polyphenols-Al(3+) complex. Log K1 was 10.51, and the mole ratio of Al(3+) to ligand was 1:1. We further found that the amounts of Al increased significantly in feces of the rats gavaged with AlCl3 plus ChA compared with AlCl3. Our finding has shown APE has neuroprotective effects against Al-induced biotoxicity. Chelating with Al and disturbing its absorption could account for the neuroprotective roles of dietary polyphenols against Al toxicity.

Hepatoprotective effects of apple polyphenol extract on aluminum-induced liver oxidative stress in the rat

This study was undertaken to determine the effectiveness of apple (Ralls) polyphenol extract (APE) in modulating aluminum chloride (AlCl3) induced hepatotoxicity in rats. The rats were distributed among 4 groups and fed different diets with or without AlCl3 (171.8 mg Al·kg(-1)·day(-1)) and APE (200 mg·kg(-1)·day(-1)) for 10 weeks. The activities of superoxide dismutase and catalase as well as the levels of glutathione and ATP synthesis were decreased by comparison with the control, while the activities of transaminases in serum, the levels of Al, and ATP hydrolysis were increased significantly in the liver of the Al-treated group. Furthermore, abnormal changes in the histological structure of the liver were observed in the Al-treated group. However, these toxic effects of Al were significantly reduced when the rats were fed diets supplemented with APE. This suggests that APE plays a role in the reduction of the toxic effects from Al in rats.

Immunomodulatory Activity of Docosahexenoic Acid on RAW264.7 Cells Activation through GPR120-Mediated Signaling Pathway

In this study, we elucidated the immunomodulatory activity of docosahexaenoic acid (DHA) on protein expression in RAW264.7 cells and its molecular mechanism. The results showed that the proliferation index of RAW264.7 cells at 48 h was about 173.03 ± 7.82% after the treatment of 2.4 μM DHA. DHA could activate RAW264.7 cells by the G-protein coupled cell membrane receptor GPR120-C-Raf- mitogen-activated protein kinases (MAPKs)-nuclear factor κB (NF-κB) p65 pathway. In addition, 2.4 μM of DHA could significantly increase (P < 0.01) the mRNA and protein expression of inducible nitric oxide synthase (iNOS), which is consistent with the result of the NO release. ELISA results revealed that DHA could enhance the protein expression of cytokines IL-1β, IL-6, IL-10, IL-12, TNF-α, IFN-γ, and TGF-β. These results indicated that the immunomodulatory mechanism of RAW264.7 cells by DHA was associated with the release of NO and cytokines by stimulating the GPR120, C-Raf, and MAPKs to the NF-κB p65 pathway.

Dietary Chlorella vulgaris Ameliorates Altered Immunomodulatory Functions in Cyclophosphamide-Induced Immunosuppressive Mice

Based on the well-known toxicity of cyclophosphamide (CYP) on the immune system, this research investigated the modulating effects of the long-term dietary Chlorella vulgaris (CV) supplementation on the immunosuppression induced by CYP in mice, in order to provide a novel dietary design to mitigate the side effects of CYP therapy. Control, CYP-treated, CYP + CV (6%), CYP + CV (12%) and CYP + CV (24%) were used for 6 weeks, CV supplement in diet recovered the significantly reduced immunological function in CYP treated mice. As CV may have a modulating function through the inducible expression of cytokines, we assayed the expressions of interleukin-2 (IL-2), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Our results suggested that CYP significantly reduced the lymphocytes proliferation and phagocytic activities of macrophages, and stimulated the production of IL-2, IL-12, TNF-α and IFN-γ and that this impairment has been successfully adjusted by CV supplementation. Treatment with the algae also enhanced the natural killer (NK) cells cytotoxicity, and ameliorate histological changes of the spleen in CYP-treated mice. Therefore, as we found in this study, a diet supplemented with whole CV has beneficial effects on CVP-induced immunosuppression, through its immunomodulatory potential.

Inhibitory effect on HT-29 colon cancer cells of a water-soluble polysaccharide obtained from highland barley

A water-soluble polysaccharide (BP-1) was obtained from highland barley (Hordeum vulgare L.) by hot water extraction and purification of sepharose column chromatography. BP-1 had an average molecular weight of about 6.7×104Da and was composed of glucose (Glc), xylose (Xyl), arabinose (Ara) and rhamnose (Rha) with a relative molar ratio of 8.82:1.92:1.50:1.00. It was found that BP-1 inhibited proliferation of human colon cancer cells (HT-29) in a time- and dose-dependent manner with half maximal inhibitory concentration at 48h of 48.18μg/mL. Western blotting results showed that BP-1 enhanced the phosphorylation of c-Jun N-terminal kinase (JNK), processes associated with the reactive oxygen species (ROS) formation and inhibited nuclear factor-κB (NF-κB) translocation from cytoplasm into nucleus. Meanwhile, the BP-1-induced apoptosis was related to the regulation of apoptosis-associated proteins, such as B-cell lymphoma-2 (Bcl-2), release of cytochrome C from mitochondria to cytoplasm and activation of caspase-8 and caspase-9. These results suggest that BP-1-induced HT-29 apoptosis through ROS-JNK and NF-κB-mediated caspase pathways.

Eicosapentaenoic acid induced SKOV-3 cell apoptosis through ERK1/2-mTOR-NF-κB pathways.

Eicosapentaenoic acid (EPA), a typical kind of n-3 polyunsaturated fatty acids, has been considered to be a potent antitumor adjuvant. However, the mechanism related to EPA-induced SKOV-3 cell apoptosis has not been investigated. In this study, we elucidated the anticancer effect of EPA on SKOV-3 cells and its molecular mechanisms. The results of fluorescence microscopy showed that EPA induced typical apoptotic morphological features in SKOV-3 cells. Flow cytometric analysis indicated that EPA induced apoptosis of SKOV-3 cells through cells arrested at the S phase. Western blotting results showed that EPA could inhibit the phosphorylation of ERK1/2 and Akt, which restrained mammalian target of rapamycin (mTOR) phosphorylated. Simultaneously, EPA downregulated the phosphorylation status of mTOR, which may act as an upstream regulator of EPA-blocked nuclear factor &kgr;B (NF-&kgr;B) p65 translocation from the cytoplasm into the nucleus; the apoptotic mechanism of SKOV-3 cells induced by EPA was associated with the release of cytochrome c, Bax-to-Bcl-2 expression ratio, and activation of caspase-3 and caspase-9. The results suggested that EPA induced SKOV-3 cell apoptosis through ERK1/2, Akt–mTOR–NF-&kgr;B pathways.

Determination of Aluminum in Edible Jellyfish Using Chrome Azurol S with Spot Test on Filter Paper

Aluminum (Al) has been well known as an environmental factor that may affect several enzymes and other biomolecules related to Alzheimers disease. The increasing use of Al in the preparation and storage of food currently represents the main form of Al exposure for the general public. The present study was aimed to develop a household procedure for the rapid test determination of Al in edible jellyfish. The method was developed based on the reaction of Chrome Azurol S with Al in acidic medium, forming a colored compound on the surface of filter paper. Experimental design methodologies were used to optimize the measurement conditions. The proposed method was applied successfully to the analysis of Al in edible jellyfish products in clinical laboratory and household settings.

Evidences for Chlorogenic Acid — A Major Endogenous Polyphenol Involved in Regulation of Ripening and Senescence of Apple Fruit

To learn how the endogenous polyphenols may play a role in fruit ripening and senescence, apple pulp discs were used as a model to study the influences of chlorogenic acid (CHA, a major polyphenol in apple pulp) on fruit ripening and senescence. Apple (‘Golden Delicious’) pulp discs prepared from pre-climacteric fruit were treated with 50 mg L-1 CHA and incubated in flasks with 10 mM MES buffer (pH 6.0, 11% sorbitol). Compared to the control samples, treatment with CHA significantly reduced ethylene production and respiration rate, and enhanced levels of firmness and soluble solids content of the pulp discs during incubation at 25°C. These results suggested that CHA could retard senescence of the apple pulp discs. Proteomics analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry (MALDI-TOF/TOF) revealed that the expressions of several key proteins correlated to fruit ripening and senescence were affected by the treatment with CHA. Further study showed that treating the pulp discs with CHA remarkably reduced levels of lipoxygenase, β-galactosidase, NADP-malic enzyme, and enzymatic activities of lipoxygenase and UDP-glucose pyrophosphorylase, all of which are known as promoters of fruit ripening and senescence. These results could provide new insights into the functions of endogenous phenolic compounds in fruit ripening and senescence.