Sicyos angulatus ameliorates acute liver injury by inhibiting oxidative stress via upregulation of anti-oxidant enzymes.

OBJECTIVE: We aimed to investigate the effect of Sicyos angulatus (SA) ethanolic extracts as antioxidants and potential treatments for liver disease. METHODS: To establish a mouse model of liver injury, C57BL/6 male mice were injected via the caudal vein with a single dose of concanavalin A (Con A, 15 mg kg-1). SA extracts were administered once by oral gavage 30 min before Con A injection. RESULTS: In vitro studies showed that SA decreased tert-butyl hydroperoxide (t-BHP)-induced reactive oxygen species (ROS) production. SA administration reduced plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, as well as hepatic ROS levels, in a dose-dependent manner. Moreover, SA increased the activities of the hepatic antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase in a dose-dependent manner. Furthermore, SA treatment reduced pro-apoptotic protein levels. Con A-mediated cytosolic release of Smac/DIABLO and apoptosis-inducing factor (AIF), which are markers of necrosis, were dramatically decreased in HepG2 cells treated with SA. CONCLUSION: SA ameliorated liver injury and might be a good strategy for the treatment of liver injury.

Effect of low-dosage electron beam irradiation on antioxidant activities of navel oranges during storage at a low temperature of 3°C.

Effects of low-dosage electron beam irradiation on antioxidant activities of Navel oranges during storage at a low temperature of 3°C were studied. Oranges were irradiated at dosages of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy and changes in antioxidant compounds and antioxidant activities were investigated. No changes in total phenolic contents or flavonoid contents were observed with an increase in radiation dosage. Also, no differences between non-irradiated and irradiated oranges in DPPH radical scavenging and ABTS radical scavenging activities, FRAP values, and reducing powers were observed. Electron beam irradiation at dosages less than 1 kGy does not affect levels of antioxidant compounds and antioxidant activities of Navel oranges.

Anti-Inflammatory Effect of Mangostenone F in Lipopolysaccharide-Stimulated RAW264.7 Macrophages by Suppressing NF-κB and MAPK Activation.

Mangostenone F (MF) is a natural xanthone isolated from Garcinia mangostana. However, little is known about the biological activities of MF. This study was designed to investigate the anti-inflammatory effect and underlying molecular mechanisms of MF in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. MF dose-dependently inhibited the production of NO, iNOS, and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß) in LPS-stimulated RAW264.7 macrophages. Moreover, MF decreased the NF-κB luciferase activity and NF-κB DNA binding capacity in LPS-stimulated RAW264.7 macrophages. Furthermore, MF suppressed the NF-κB activation by inhibiting the degradation of IκBα and nuclear translocation of p65 subunit of NF-κB. In addition, MF attenuated the AP-1 luciferase activity and phosphorylation of ERK, JNK, and p38 MAP kinases. Taken together, these results suggest that the anti-inflammatory effect of MF is associated with the suppression of NO production and iNOS expression through the down-regulation of NF-κB activation and MAPK signaling pathway in LPS-stimulated RAW264.7 macrophages.

Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

The phenolic compounds of many fruits have been known to be efficient cellular protective antioxidants. In this study, antioxidative and antiviral properties of flowering cherry cultivars (Prunus yedoensis, Prunus sargentii, Prunus lannesiana, and Prunus cerasus) in Korea were investigated. The antioxidant property was assayed for specific activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) hydroxy radical scavenging activity, reducing power capacity, and superoxide dismutase (SOD) like activity. In addition, antiviral activity was determined by inhibition studies on the infection cycle of porcine epidemic diarrhea virus (PEDV), measured as minimum concentration of cherry extracts that inhibited 50% of cytopathic effect (CPE) on PEDV. Our results show that the four varieties of cherries contain substantially high antioxidants and antiviral activities. In particular, P. cerasus contains higher antioxidants and antiviral activities as well as polyphenolic content than other varieties. Our data indicate that Korean native cherry cultivars could be beneficial supplements of dietary antioxidants and natural antiviral agents.

Leafy vegetable mix supplementation improves lipid profiles and antioxidant status in C57BL/6J mice fed a high fat and high cholesterol diet.

Daily consumption of an antioxidant-rich leafy vegetable mix (LVM) was assessed for beneficial effects on plasma lipid profiles, tissue lipid peroxidation, and oxidative DNA damage in C57BL/6J mice fed a high fat and high cholesterol diet (20% fat and 1% cholesterol, wt/wt) for 4 weeks. The LVM contained beet leaf, angelica, red leaf lettuce, dandelion, green cos lettuce, lollo rosso, romaine lettuce (12.5%, respectively), scotch kale, and red kale (6.25%, respectively). The mice (n = 16) were randomly divided into either the control (high fat and cholesterol diet without LVM) or the LVM (high fat and cholesterol diet with 8% LVM supplement) groups after a 1-week acclimation. Lipid peroxidation as measured by thiobarbituric acid-reactive substances in the plasma, liver, heart, and kidney was significantly lower. Antioxidants (glutathione and beta-carotene) and antioxidant enzyme activities (glutathione peroxidase, glutathione reductase, and superoxide dismutase) were improved in mice fed LVM diet. In the comet assay, tail extent moment, olive tail moment, and tail length were significantly less in the hepatocyte and lymphocyte DNA of the LVM group, indicating the beneficial effect of LVM on the resistance of hepatocytes and lymphocytes DNA to oxidative damage. Findings from the present study suggest that dietary supplementation with LVM may be useful for protecting cells from lipid peroxidation and oxidative DNA damage.

Structural importance of the acyl group in substrate specificity of purified bovine lysophospholipase D.

The structural importance of the acyl group in lysophosphatidylcholine (LPC) as substrate of purified bovine lysophospholipase D (lysoPLD) was investigated. Among LPCs with saturated acyl chains, the K(m) value decreased according to the length of the acyl chain (C12-C16) up to the palmitoyl group, while the V(m) value showed no remarkable change. But, the extension of the acyl size to C18, as observed with 1-stearoyl LPC (K(m), 8.5 mM), rather resulted in a remarkable increase in the K(m) value. Meanwhile, the introduction of one double bond in the C18 saturated acyl chain led to a remarkable reduction in the K(m) value, as observed with 1-oleoyl LPC (K(m), 0.48 mM). Furthermore, 1-linoleoyl LPC (K(m), 56 microM) with two double bonds exhibited a smaller K(m) value than 1-oleoyl LPC, suggesting that the unsaturation degree might be important in augmenting the binding affinity of LPCs. A similar phenomenon was also observed with 1-arachidonoly LPC (K(m), 79 microM) or 1-docosahexaenoyl LPC (K(m), 36 microM). Overall, the order of catalytic efficiency (V(m)/K(m) value) of those LPCs seemed to be affected by the K(m) value rather than the V(m) value, which differed by at most threefold among LPC derivatives. Next, the introduction of a hydroperoxide group into 1-linoleoyl-LPC or 1-arachidonoyl LPC led to a further reduction in K(m) values (1-hydroperoxylinoleoyl LPC, 26 microM; 1-hydroperoxyarachidonoyl LPC, 33 microM), accompanied by a further increase in the V(m)/K(m) values. Additionally, phosphatidylcholines (PCs) with an oxidized acyl chain at sn-2 position were found to be efficient as 1-palmitoyl LPC as substrates of lysoPLD. Taken together, the catalytic efficiency of LPCs or oxidized PCs as substrates of lysoPLD seems to be determined by the property of the acyl chain, length of the acyl chain, unsaturation degree and oxidation status.

Inhibition of lysophospholipase D activity by unsaturated lysophosphatidic acids or seed extracts containing 1-linoleoyl and 1-oleoyl lysophosphatidic acid.

Lysophospholipase D (lysoPLD), generating lipid mediator lysophosphatidic acid (LPA) from lysophosphatidyclcholine (LPC), is known to be inhibited by lysophosphatidic acids. Meanwhile, some plant lipids are known to contain lysophospholipids as minor components. Therefore, it is interesting to test whether edible seed samples, rich in phospholipids, may contain lysophospholipids, which express a strong inhibition of lysoPLD activity. First, the structural importance of fatty acyl group in LPAs was examined by determining the inhibitory effect of various LPAs on bovine lysoPLD activity. The most potent in the inhibition of lysoPLD activity was linoleoyl-LPA ( K i, 0.21 microM), followed by arachidonoyl-LPA ( K i, 0.55 microM), oleoyl-LPA ( K i, 1.2 microM), and palmitoyl-LPA ( K i, 1.4 microM), based on the fluoresecent assay. The same order of inhibitory potency among LPA analogs with different acyl chains was also found in the spectrophotometric assay. Subsequently, the extracts of 12 edible seeds were screened for the inhibition of lysoPLD activity using both spectrophotometric and fluorescent assays. Among seed extracts tested, the extract from soybean seed, sesame seed, or sunflower seed (30 mg seed weight/mL) was found to exhibit a potent inhibition (>80%) of lysoPLD activity. In further study employing ESI-MS/MS analysis, major LPA components in seed extracts were identified to be 1-linoleoyl LPA, 1-oleoyl LPA, and 1-palmitoyl LPA with 1-linoleoyl LPA being more predominant. Thus, the potent inhibition of lysoPLD activity by seed extracts might be ascribed to the presence of LPA with linoleoyl group rather than other acyl chains.

Determination of volatile N-nitrosamines in irradiated fermented sausage by gas chromatography coupled to a thermal energy analyzer.

Volatile N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) in irradiated pepperoni and salami sausages were determined using a gas chromatography coupled to a thermal energy analyzer (GC-TEA). These fermented sausages with aerobic or vacuum packaging were irradiated at 0, 5, 10, and 20 kGy, and then stored for 4 weeks at 4 degrees C. Both NDMA and NPYR in the fermented sausage were significantly reduced by irradiation. The vacuum packaging showed significantly lower (P < 0.05) N-nitrosamine levels than that of the aerobic ones. After storage, the contents of NDMA and NPYR in the irradiated sausage were lower than those of the non-irradiated control. Results indicated that a high dose of irradiation (>10 kGy) was needed to reduce the carcinogenic N-nitrosamines in the fermented sausage during storage and the GC-TEA analysis was effective in determining the N-nitrosamines in irradiated meats even at low trace levels.

Change of an egg allergen in a white layer cake containing gamma-irradiated egg white.

This study was conducted to evaluate the reduction of an egg allergen in a cake containing gamma-irradiated egg white. A white layer cake was manufactured by a commercial formula with 10- or 20-kGy-irradiated egg white. Enzyme-linked immunosorbent assays (ELISAs) with immunoglobulin (Ig) E from egg-allergic patients and with rabbit anti-ovalbumin IgG were used to identify and quantify ovalbumin (OVA) in the samples. Concentrations of native OVA detected by IgE and IgG in the control were 432.88 and 375.46 microg/g sample, respectively. However, native OVA in samples with 10- and 20-kGy-irradiated egg white was detected at low concentrations (14.27 and 8.78 microg/g, respectively) by IgE (P < 0.05); IgG recognized OVA more often in 10- and 20-kGy samples than in controls. Conformational cleavage of OVA by irradiation could explain the IgG result. The results appear to suggest that irradiating egg white might reduce its allergenicity, which could be used in the production of baked goods of reduced allergenicity.

Effects of irradiated phytic acid on antioxidation and color stability in meat models.

Lipid oxidation and color stability of meats treated with irradiated phytic acid were investigated during storage for 2 weeks at 4 degrees C. The phytic acid in deionized distilled water (DDW) was degraded by irradiation at 10 and 20 kGy, and the irradiated phytic acid showed a strong antiradical activity. For measuring the antioxidant effects of irradiated phytic acid in food models, beef and pork were prepared with DDW (control), irradiated (10 and 20 kGy) or non-irradiated phytic acid, and ascorbic acid as a model system. Irradiated phytic acid significantly inhibited the lipid oxidation in meats compared to the control and ascorbic acid treated samples during storage (P < 0.05). The redness of the meats treated with phytic acid had a higher value than did the control and ascorbic acid treated samples, but a significant difference was not observed in the samples treated with phytic acid regardless of irradiation treatment. Irradiated phytic acid was also effective in inhibiting the loss of heme iron and metmyoglobin formation during storage. Results indicated that irradiation might be helpful for improving the antioxidant activity of phytic acid in meats.

Changes in the antigenic and immunoglobulin E-binding properties of hen's egg albumin with the combination of heat and gamma irradiation treatment.

This study was carried out to evaluate the changes in the allergenic and antigenic properties of hen's egg albumin (ovalbumin [OVA]) with the combination of heat and gamma irradiation treatment. OVA solution samples were treated by (i) heating (sample 1), (ii) irradiation after heating (sample 2), and (iii) heating after irradiation (sample 3). Samples were isothermally heated and irradiated at the absorption dose of 10 kGy. Competitive indirect enzyme-linked immunosorbent assays (ELISAs) were performed with blood serum to test the ability of treated OVA to bind to immunoglobulin E (IgE) and mouse murine monoclonal antibody (IgG). OVA's ability to bind to mouse IgG changed upon heating at 75 degrees C, and its ability to bind to egg-allergic IgE changed upon heating at 80 degrees C. The ELISAs showed that egg-allergic IgE did not recognize OVA very well when heated at > or = 80 degrees C, while mouse IgG retained better activity under these conditions. Egg-allergic IgE binding was low both for OVA samples treated by heating and for samples treated by irradiation followed by heating. These results show that allergies induced by OVA could be effectively reduced by the combination of heat and gamma irradiation treatment.

Allergenicity of hen's egg ovomucoid gamma irradiated and heated under different pH conditions.

This study was conducted to evaluate the effect of a treatment combining gamma radiation and heating on the allergenic properties of hen's egg ovomucoid (OM) under basic pH conditions. OM solutions of 2.0 mg/ml with pHs of 7.0, 9.0, and 10.0 were gamma irradiated at 10 kGy, heated at 100 degrees C for 15 min, or both. Half of the treated pH 10.0 sample solution was restored to pH 7.4 by dialysis. OM solutions were tested by a competitive direct enzyme-linked immunosorbent assay formatted with immunoglobulin E from egg-hypersensitive patients. An equation was obtained for quantifying intact OM from the standard curve, and the detected concentration of intact OM was calculated. The concentration of intact OM decreased with irradiation or heating, and the rate of the decrease was higher for a basic pH condition than for the physiological condition. The combination of irradiation and heating was very effective in reducing the amount of intact OM regardless of the pH condition. After treatment, the restoration of the pH to 7.4 did not affect the concentration of OM. The results of this study indicate that a combination of irradiation and heating might be an effective method for reducing egg hypersensitivity resulting from OM.