48 research outputs found

    Effects of grape pomace on the antioxidant defense system in diet-induced hypercholesterolemic rabbits

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    The effects of grape seeds extract and grape peels extract prepared from grape pomace on the activity of antioxidant enzymes, degree of lipid peroxidation in serum and liver tissue were investigated in rabbits fed on high cholesterol diet. New Zealand white rabbits were divided as follows ; 1) NOR (normal group); 2) CHOL (cholesterol group); 3) GSH (cholesterol + grape seed extract group); 4) GPE (cholesterol + grape peel extract); 5) GSP (cholesterol + grape seed powder); 6) GPP (cholesterol + grape peel powder); 7) GE (cholesterol + grape seed and peel extract); 8) GP (cholesterol + grape seed and peel powder). Eight groups of rabbits were studied for 8 weeks. At the end of the experimental period, rabbits were sacrificed and the liver tissue were removed. Then, GSH, GPx, GST, CAT and MDA in the liver were measured. In liver tissues, total glutathione contents (GSH), glutathione peroxidase (GPx) and catalase (CAT) activity, which was significantly higher by grape seed extract supplementation. The level of malondialdehyde (MDA) was lower in the serum of rabbits fed grape seed extract or grape peel powder plus cholesterol than in the serum of rabbits fed cholesterol alone. It is therefore likely that grape seed extract prepared from grape pomace functioned as antioxidants in vivo, negating the effects of the oxidative stress induced by 1% cholesterol diet. The grape seed extract was found effective in converting the oxidized glutathione into reduced glutathione, and in removing H2O2 that is created by oxidative stress. The grape peel powder was found to have small influence on reduced glutathione content, CAT and GPX activity, but it increased GST activity in liver tissues, resulting in promoting the combination of lipid peroxide and glutathione (GSH), and further, lowering the formation of lipid peroxide in the serum. Therefore, grape pomace (grape seed extract and grape peel powder) supplementation is considered to activate the antioxidant enzyme system and prevent damage with hypercholesterolemia

    Growth Inhibition and Apoptosis with H31 Metabolites from Marine Bacillus SW31 in Head and Neck Cancer Cells

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    ObjectivesTo determine whether a novel marine micro-organism with anticancer properties, H31, the metabolic product of Bacillus SW31, has anti-tumor effects on head and neck cancer, and potential for apoptotic-enhancing anti-cancer treatment of affected patients.MethodsThe cell viability and apoptosis assays were performed. Changes in the signal pathway related to apoptosis were investigated. Then, the therapeutic effects of H31 were explored in mouse xenograft model and drug toxicity of H31 was examined in zebrafish model.ResultsWe identified the anticancer activity of H31, a novel metabolic product of Bacillus SW31. Bacillus SW31, a new marine micro-organism, has 70% homology with Bacillus firmus and contains potent cytotoxic bioactivity in head and neck cancer cells using MTT assay. Combined with c-JUN, p53, cytochrome C, and caspase-3, H31 induced apoptosis of KB cells, a head and neck cancer cell line. In a separate in vivo model, tumor growth in C3H/HeJ syngeneic mice was suppressed by H31. In addition, in a zebrafish model used for toxicity testing, a considerable dose of H31 did not result in embryo or neurotoxicity.ConclusionGrowth inhibition and apoptosis were achieved both in vitro and in vivo in head and neck cancer cells after exposure to H31, a metabolite from the marine Bacillus species, without any significant toxicity effects even at considerable H31 dose concentrations

    The Antimicrobial Peptide Histatin-5 Causes a Spatially Restricted Disruption on the Candida albicans Surface, Allowing Rapid Entry of the Peptide into the Cytoplasm

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    Antimicrobial peptides play an important role in host defense against microbial pathogens. Their high cationic charge and strong amphipathic structure allow them to bind to the anionic microbial cell membrane and disrupt the membrane bilayer by forming pores or channels. In contrast to the classical pore-forming peptides, studies on histatin-5 (Hst-5) have suggested that the peptide is transported into the cytoplasm of Candida albicans in a non-lytic manner, and cytoplasmic Hst-5 exerts its candicidal activities on various intracellular targets, consistent with its weak amphipathic structure. To understand how Hst-5 is internalized, we investigated the localization of FITC-conjugated Hst-5. We find that Hst-5 is internalized into the vacuole through receptor-mediated endocytosis at low extracellular Hst-5 concentrations, whereas under higher physiological concentrations, Hst-5 is translocated into the cytoplasm through a mechanism that requires a high cationic charge on Hst-5. At intermediate concentrations, two cell populations with distinct Hst-5 localizations were observed. By cell sorting, we show that cells with vacuolar localization of Hst-5 survived, while none of the cells with cytoplasmic Hst-5 formed colonies. Surprisingly, extracellular Hst-5, upon cell surface binding, induces a perturbation on the cell surface, as visualized by an immediate and rapid internalization of Hst-5 and propidium iodide or rhodamine B into the cytoplasm from the site using time-lapse microscopy, and a concurrent rapid expansion of the vacuole. Thus, the formation of a spatially restricted site in the plasma membrane causes the initial injury to C. albicans and offers a mechanism for its internalization into the cytoplasm. Our study suggests that, unlike classical channel-forming antimicrobial peptides, action of Hst-5 requires an energized membrane and causes localized disruptions on the plasma membrane of the yeast. This mechanism of cell membrane disruption may provide species-specific killing with minimal damage to microflora and the host and may be used by many other antimicrobial peptides

    Individual Shrink Wrapping of Zucchini Fruit Improves Postharvest Chilling Tolerance Associated with a Reduction in Ethylene Production and Oxidative Stress Metabolites

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    We have studied the effect of individual shrink wrapping (ISW) on the postharvest performance of refrigerated fruit from two zucchini cultivars that differ in their sensitivity to cold storage: Sinatra (more sensitive) and Natura (more tolerant). The fruit was individually shrink wrapped before storing at 4°C for 0, 7 and 14 days. Quality parameters, ethylene and CO2 productions, ethylene gene expression, and oxidative stress metabolites were assessed in shrink wrapped and non-wrapped fruit after conditioning the fruit for 6 hours at 20°C. ISW decreased significantly the postharvest deterioration of chilled zucchini in both cultivars. Weight loss was reduced to less than 1%, pitting symptoms were completely absent in ISW fruit at 7 days, and were less than 25% those of control fruits at 14 days of cold storage, and firmness loss was significantly reduced in the cultivar Sinatra. These enhancements in quality of ISW fruit were associated with a significant reduction in cold-induced ethylene production, in the respiration rate, and in the level of oxidative stress metabolites such as hydrogen peroxide and malonyldialdehyde (MDA). A detailed expression analysis of ethylene biosynthesis, perception and signaling genes demonstrated a downregulation of CpACS1 and CpACO1 genes in response to ISW, two genes that are upregulated by cold storage. However, the expression patterns of six other ethylene biosynthesis genes (CpACS2 to CpACS7) and five ethylene signal transduction pathway genes (CpCTR1, CpETR1, CpERS1, CpEIN3.1 and CpEN3.2), suggest that they do not play a major role in response to cold storage and ISW packaging. In conclusion, ISW zucchini packaging resulted in improved tolerance to chilling concomitantly with a reduction in oxidative stress, respiration rate and ethylene production, as well as in the expression of ethylene biosynthesis genes, but not of those involved in ethylene perception and sensitivity.This work was supported by grants AGL2011-30568-C02/ALI from the Spanish Ministry of Science and Innovation, and AGR1423 from the Consejería de Economía, Innovación y Ciencia, Junta de Andalucía, Spain. Z.M. acknowledges FPU program scholarships from MEC, Spain. S.M. is funded by grant PTA2011-479-I from the Spanish Ministry of Science and Innovation

    PTPRR, cerebellum, and motor coordination.

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    Tyrosine phosphorylation is a powerful mechanism of modulation for proliferation, differentiation, and functioning of neurons. The protein products of the neuronal mouse gene PTPRR are physiological regulators of mitogen-activated protein kinase (MAPK) activities. PTPRR(-/-) mice display deficits of motor coordination and balance skills. PTPRR gene orthologues are found in many vertebrates. Recent observations suggest that the human episodic ataxia 2 (EA2) and spinocerebellar ataxia types 6 (SCA6), 12 (SCA12), and 14 (SCA14) might be associated with impaired phosphorylation levels of cerebellum calcium channels and receptors. The concept that MAPK signaling is a key process in tuning synaptic plasticity in cerebellar circuits is now emerging, with numerous implications for understanding cerebellar functions and cerebellar disorders.Journal ArticleReviewSCOPUS: ar.jinfo:eu-repo/semantics/publishe
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