Physicochemical properties and cell permeation efficiency of l-ascorbic acid loaded nanoparticles prepared with N-trimethyl chitosan and N-triethyl chitosan

The physicochemical properties and permeation efficiency of l-ascorbic acid (AA)-loaded nanoparticles (NPs) prepared using N-trimethyl chitosan (TMC) and Ntriethyl chitosan (TEC) were investigated. The sizes of AA-TMC-NPs and AA-TEC-NPs were 568±50 and 150±15 nm, respectively and both zeta potential values were slightly positively charged. The encapsulation efficiency (EE) of AA-TMC-NPs was consistently between 40 and 45%, but the EE of AA-TEC-NPs varied between 18 and 56%. The release rate increased with increased temperatures for both NPs. AA-TMC-NPs exhibited an initial burst release, while AA-TEC-NPs exhibited a controlled release, increasing rapidly after 2 h. The pH-related release pattern was similar to the temperature-related release pattern. The permeation efficiency into Caco-2 cells, in order from lowest to highest, was AA, an AA mixture with TMC, an AA mixture with TEC, AA-TMC-NPs, and AA-TEC-NPs. Both NPs showed potential to enhance the permeability of AA.     

Hypnotic effect of GABA from rice germ and/or tryptophan in a mouse model of pentothal-induced sleep

γ-Aminobutyric acid (GABA), a primary inhibitory neurotransmitter, and tryptophan (Trp), a substrate for melatonin, are found in functional foods and exert hypnotic effects. The hypnotic effects of 3 doses of GABA and a combined-preparation of GABA and Trp (GABA+Trp) were investigated in mice. Hypnotic activity was evaluated using pentothal-induced sleep time testing. Treatments included low, middle, and high doses of GABA and GABA+Trp. Low doses of GABA (low-GABA) and low-GABA+Trp reduced sleep latency and significantly (p<0.05) prolonged the sleep time induced by pentothal, compared with controls, although the melatonin concentration in the serum was not affected. On the other hand, the adenosine A1 receptor (AA1R) immunoreactivity in the suprachiasmatic nucleus of the hypothalamus was significantly (p<0.05) increased after administration of low-GABA and/or low-GABA+Trp, compared to controls. Low doses of GABA and/or Trp cause hypnotic effects that may be related to AA1R activation.     

Effect of gamma-aminobutyric acid produced by Lactobacillus sakei B2-16 on diet and exercise in high fat diet-induced Obese rats

Effect of gamma-aminobutyric acid (GABA) produced by Lactobacillus sakei B2-16 on diet and acute swimming exercise was investigated in rats with high fat diet (HFD)-induced obesity. The body weight gain in the GABA+Exercise group was significantly (p<0.05) lower than in the HFD group. Combined treatment with GABA and exercise decreased the body weight gain by 25.6%, compared to the HFD group. On the other hand, neither GABA supplementation nor exercise alone significantly (p>0.05) influenced reduction in body weight gain, compared to the HFD group. The weights of abdominal and epididymal fat tissues and the liver in the GABA+Exercise group were significantly (p<0.05) lower than in the HFD group. The activity of citrate synthase was significantly (p<0.05) elevated in the soleus muscle by GABA supplementation. GABA contributes to reduction in body weight gain and fat tissue weight by increasing physical activity during exercise.     

Punicalagin exhibits negative regulatory effects on LPS-induced acute lung injury

Punicalagin, mainly isolated from the fruit of Pomegranate (Punica granatum L.), is a natural polyphenolic compound. In the present study, we investigated the negative regulatory effect of punicalagin on acute lung injury (ALI) induced by Lipopolysaccharide (LPS). In the murine model of ALI, the data showed that punicalagin inhibited the production of TNF-α, IL-1β, and IL-6 and decreased protein concentration and myeloperoxidase activity with a single 4 mg/kg dose of punicalagin prior to the administration of intratracheal LPS in the bronchoalveolar lavage fluid. Furthermore, we investigated the effects of punicalagin how to modulate signal transduction. MAPK and NF-κB activation were measured by Western blot and immunocytochemical analysis. The data showed that punicalagin significantly inhibited phosphorylated p38 MAPK protein expression and shocked p65-NF-κB translocation into the nucleus. These results indicated punicalagin may exert negative regulatory effects on ALI partly through suppressing p38 MAPKs or/and NF-κB pathways. This study offered a novel therapeutic strategy for improving clinical effects of acute lung injury (ALI)/acute respiratory distress syndrome and provided more evidence for the health benefits of pomegranate fruits.     

Trans-caryophyllene suppresses tumor necrosis factor (TNFα)-induced inflammation in human chondrocytes

Proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) have been shown to be associated with the pathogenesis of cartilage damage in arthritis. Trans-caryophyllene (TC) is an important constituent of the essential oils of several species of plants. In this study, we found that TC treatment could inhibit TNF-α-induced matrix metallopeptidase 13, cyclooxygenase-2, and prostaglandin E2 (PGE2) production in human chondrocytes. Moreover, the increase in inducible nitric oxide synthase expression and NO production induced by TNF-α was able to be suppressed by TC treatment. Importantly, treatment with TC was also found to inhibit activation of the main proinflammatory regulator, interferon regulatory factor-1, which is increased in the presence of TNF-α. Interestingly, we also proved that TC’s effects on these mechanisms are dependent on the type 2 cannabinoid receptor. Taken together, the results of this study show that TC exerts anti-inflammatory effects in TNF-α-stimulated chondrocyte models.     

Alleviating effects of Opuntia ficus indica extracts on psychomotor alterations induced by ethanol in rats

Effects of Opuntia ficus indica (OFI) extracts on ethanol-induced psychomotor alterations were studied using Sprague-Dawley rats orally administered 4 g/kg of ethanol (EtOH group) or distilled water (control group). An OFI-group received OFI extracts (50, 100, and 200 mg/kg) 30 min prior to EtOH administration. Behavioral and hematological tests were evaluated 1, 2, 4, and 8 h after EtOH administration. Electroencephalogram (EEG) assessment was also performed. EtOH significantly (p<0.001) induced psychomotor alterations (reduced locomotion, balance, coordination, muscle strength, and tolerance to cold), compared with control group rats. Pre-treatment with OFI extracts alleviated alterations and also inhibited elevation of blood ethanol levels. EEG (percent of total power for delta, theta, alpha, and beta) results for OFI group rats were similar to control rats, indicating a countering of EtOHinduced EEG changes. Extracts of OFI can be effective for alleviation of psychomotor alterations induced by EtOH administration.     

Antimicrobial Properties of Ethylene Vinyl Alcohol/Epsilon-Polylysine Films and Their Application in Surimi Preservation

Polymer films based on ethylene vinyl copolymers (EVOH) containing a 29 % (EVOH 29) and a 44 % molar percentage of ethylene (EVOH 44), and incorporating ε-polylysine (EPL) at 0 %, 1 %, 5 % and 10 % were successfully made by casting. The optical properties and the amount of EPL released from the films to phosphate buffer at pH 7.5 were evaluated, films showing great transparency and those of EVOH 29 copolymer releasing a greater amount of EPL. The antimicrobial properties of the resulting films were tested in vitro against different foodborne microorganisms and in vivo in surimi sticks. With regard to the antimicrobial capacity tested in vitro in liquid medium at 37 °C and 4 °C against Listeria monocytogenes and Escherichia coli over a period of 72 h, films showed a considerable growth inhibitory effect against both pathogens, more notably against L. monocytogenes, and being EVOH 29 more effective than EVOH 44 films. At 37 °C, total growth inhibition was observed for EVOH 29 films incorporating 10 % EPL against both microorganisms whereas the copolymer EVOH 44 did show total inhibition against L. monocytogenes and the growth of E. coli was reduced by 6.64 log units. At 4 °C, no film was able to inhibit completely bacterial growth. Scanning electron microscopy micrographs showed corrugated cell surfaces with blisters and bubbles, and collapse of the cells appearing shorter and more compact after treatment with EPL. Finally, the films were successfully used to increase the shelf life of surimi sticks. The results show the films developed have a great potential for active food packaging applications.     

Quality Changes and Establishment of Predictive Models for Bighead Carp (Aristichthys nobilis) Fillets During Frozen Storage

The objectives of this study were to investigate quality changes of bighead carp fillets during frozen storage by measuring free fatty acids (FFA), salt extractable protein (SEP) content, Ca²⁺-ATPase activity, and total sulfhydryl (SH) content and to develop predictive models based on them. FFA increased with the extension of storage time. Meanwhile, SEP content, SH content, and Ca²⁺-ATPase activity all decreased during storage. A marked inhibition (p?2+-ATPase activity and SH content decrease was observed during storage of bighead carp fillets at ?30 °C, compared to those stored at ?10 and ?20 °C. Additionally, the relative errors of models based on Ca²⁺-ATPase and SH were all below 10 %. Thus, the lower frozen temperature can inhibit quality damage effectively, and a reliable estimation of quality changes could be performed by models based on Ca²⁺-ATPase and SH.     

Highly Broad-Specific and Sensitive Enzyme-Linked Immunosorbent Assay for Screening Sulfonamides: Assay Optimization and Application to Milk Samples

The optimum conditions of an enzyme-linked immunosorbent assay (ELISA) in regard to different monoclonal antibodies (MAbs), assay format, immunoreagents, and several physicochemical factors (pH, salt, detergent, and solvent) were investigated to develop a broad-specific and sensitive immunoassay for detection of sulfonamides in milk samples. Two previously produced broad-specific MAbs, 4D11 and 4C7, and eight structurally different haptens conjugated with bovine serum albumin (BSA) were used as coating antigens in a competitive indirect ELISA (ciELISA). In addition, six hapten-HRP conjugates and the two MAbs were evaluated in a competitive direct ELISA. After optimization, a highly broad-specific and sensitive ciELISA for screening for sulfonamides was obtained based on MAb 4D11 and the BS-BSA heterologous-coating antigen, demonstrating a 50 % specific binding (IC₅₀) for 22 sulfonamides at concentrations below 100 ng mL^?1. This is the first report of an immunoassay that is capable of detecting more than 20 sulfonamides based on MAbs. The optimized ciELISA was used to quantify the five sulfonamides, SMZ, SDM, SQX, SMM, and SMX in spiked milk samples. Recoveries of 89–104.6 % and coefficients of variation of 11.9–19.1 % demonstrated the potential of the ciELISA to simultaneously monitor multiple sulfonamides in diluted milk samples without further purification steps.     

The probiotic characteristics and GABA production of Lactobacillus plantarum K154 isolated from kimchi

In order to identify strains with a high GABA production ability and glutamate decarboxylase activity, 273 bacteria were isolated from kimchi. K154 produced 154.86 μg/mL of GABA in an MRS broth containing 1% MSG, 170.42 μg/mL of GABA in an MRS broth containing 2% MSG, and 201.78 μg/mL of GABA in an MRS broth containing 3% MSG. K154 was identified as Lactobacillus plantarum based on API carbohydrate fermentation pattern testing. The 16s rDNA sequence was investigated in order to determine physiological characteristics. The optimum growth temperature of K154 was 37°C. K154 was more sensitive to novobiocin and bacitracin than to other antibiotics, and exhibited greater resistance to polymyxin B and vancomycin. K154 was comparatively tolerant to bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus at rates of 19.0, 18.9, and 13.6% respectively.     

Discrimination of the origin of commercial red ginseng concentrates using LC-MS/MS and electronic nose analysis based on a mass spectrometer

The geographical origin of commercial red ginseng concentrates was studied using LC-MS/MS and electronic nose analysis based on mass spectrometry. For LC-MS/MS, the Ra1, Rb1, Rg2 ginsenosides showed large differences between Korean and Chinese varieties. Rh2 and F2 were found only in Chinese red ginseng concentrate. Ion fragments were obtained using an electronic nose. Discriminant function analysis of fragment patterns allowed grouping into Korean, Chinese, and suspect origin concentrates. The mixing ratios of suspect origin specimens were predicted based on analysis of different mixing ratios of known specimens of Korean and Chinese origin. LC-MS/MS and electronic nose analysis together allowed method advantages and disadvantages to complement and compensate.     

Ethylacetate extracts of the muscles of Anguilla japonica suppress glucose levels in db/db mice via activation of AMP-activated protein kinase

Hypoglycemic effects of ethylacetate extracts of Anguilla japonica (EMA) muscles in db/db mice were investigated. To understand the mechanism responsible for the hypoglycemic effects of EMA, the effects of EMA on AMP-activated protein kinase (AMPK) activation in L6 myotubes and in vivo using type II diabetic db/db mice were analyzed. In L6 myotubes, the phosphorylation degrees of AMPK and acetyl-CoA carboxylase (ACC) were markedly increased and glucose uptake was significantly (p<0.001) increased by EMA, compared with untretaed L6 myotubes. However, in L6 myotubes, these effects were abolished by compound C, an AMPK inhibitor. Moreover, EMA significantly reduced non-fasting blood glucose and serum insulin levels, and strongly induced AMPK phosphorylation in skeletal muscle tissues of db/db mice. EMA regulates glucose levels in L6 myotubes and in diabetic mice by activation of AMPK. Beneficial effects for diabetes treatment are indicated.     

Identification of oxidative modification of shrimp (Metapenaeus ensis) tropomyosin induced by malonaldehyde

In this study, shrimp tropomyosin was subjected to malonaldehyde (MDA)-induced oxidative stress in aqueous situation. The in vivo cross-linking of tropomyosin was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the structural changes were investigated by differential scanning calorimetry, circular dichroism, and Fourier transform infrared spectroscopy (FTIR). The location of the resulting protein carbonyls was determined by mass spectrometry. The SDS-PAGE of the cross-linked tropomyosin showed four new bands corresponding to two, three, four, and five-time molecular weights of tropomyosin. The conformational structures were partly destroyed because of the thermal denaturation at higher temperatures. The α-helix content increased, and new chemical bonds were formed by the MDA modification. These physiochemical properties were confirmed by the identification of amino acid side-chain modifications by using liquid chromatography–tandem mass spectrometry. Lysine (Lys), glutamine (Gln), and asparagine (Asn) residues in tropomyosin were modified at four lysine (Lys-76, 168, 189, and 233), five glutamine (Gln-61, 70, 118, 147, and 247), and four asparagine (Asn-17, 107, 203, and 215) sites. Apart from these MDA modification sites, oxidized methionine was observed by data search. These results indicate that some active food ingredients, such as MDA, can react with the side chains of amino acids resulting in structural changes in the protein.     

Antioxidant and antiinflammatory activities of cyanidin-3-glucoside and cyanidin-3-rutinoside in hydrogen peroxide and lipopolysaccharide-treated RAW264.7 cells

Cyanidin-3-glucoside (C3G) and cyanidin-3-rutinoside (C3R) are 2 major anthocyanins found in Korean Rubus fruits (blackberries, raspberries, and black raspberries). The antioxidant and antiinflammatory effects of C3G and C3R in RAW264.7 murine macrophage cells were determined. Anthocyanins (5, 10, and 20 μg/mL) significantly (p<0.05) reduced H₂O₂-induced cytotoxicity in H₂O₂-stimulated RAW264.7 cells, compared with control cells. Incubation with C3G or C3R significantly (p<0.05) decreased intracellular reactive oxygen species and DNA damage (Hoechst and comet assay), and the cellular ferric reducing antioxidant power also increased, compared with control cells. Nitric oxide production in LPS-stimulated RAW264.7 cells treated with C3G and C3R was reduced by 41.9 and 34.4%, respectively. In addition, LPS-induced prostaglandin E₂ production was significantly (p<0.05) inhibited by C3G (51.7%) and C3R (58.6%), compared with LPS-stimulated control cells. Protein expressions of iNOS and COX-2 decreased in cells treated with anthocyanins. Anthocyanins down-regulated NF-κB expression and up-regulated I-κB expression in LPS-treated macrophages.     

Carpesium abrotanoides extract inhibits inducible nitric oxide synthase expression induced by toll-like receptor agonists

Inflammation is a pathological and physiological process which is known to be involved in numerous diseases, while it is notable that a considerable proportion of chronic inflammatory diseases overlap with the development of cancer. One of the most important proteins for inflammatory responses is inducible nitric oxide synthase (iNOS). The present study investigated the effect of the extract of Carpesium abrotanoides L. (ECA) on inflammation by modulating iNOS expression induced by toll-like receptors (TLRs) agonists in murine macrophages. ECA suppressed iNOS expression induced by lipopolysaccharide (TLR4 agonist), macrophage-activating lipopeptide 2-kDa (TLR2 and TLR6 agonist), and polyriboinosinic polyribocytidylic acid (TLR3 agonist). All the results suggest that ECA can modulate TLR signaling pathways and subsequent chronic inflammatory responses.     

Novel bioconversion of sodium glutamate to γ-poly-glutamic acid and γ-amino butyric acid in a mixed fermentation using Bacillus subtilis HA and Lactobacillus plantarum K154

Both γ-poly-glutamic acid (γ-PGA) and γ-amino butyric acid (GABA) were produced from sodium glutamate in a mixed fermentation. A culture broth was obtained using a defined medium including 3% glutamate and Bacillus subtilis HA for 3 days at 42°C, with 1.20×10⁸ CFU/mL viable cells, a 0.46 Pa·sⁿ consistency index, and a 1.94% mucilage content. In a second fermentation using Lactobacillus plantarum K154 at 37°C for 3 days, 1.29% of the remaining glutamic acid in the viscous culture broth was converted to 0.86% GABA. Glutamic acid in the first culture broth fortified with 5% skim milk was completely converted to GABA. The final co-cultured broth had 0.48% GABA, a 0.294% tyrosine content, and viable cells of 1.06×10⁹ CFU/mL (L. plantarum K154) and 5.42×10⁵ CFU/mL (B. subtilis HA). Serial co-culturing of these two bacteria can provide novel ingredients fortified with γ-PGA, GABA, peptides, and probiotics.     

Role of calcium content in antibacterial activity of donkeys’ milk toward E. coli

The objective of this study was to investigate the effect of calcium content in raw donkeys’ milk (DM) on its antibacterial activity against Escherichia coli. Antibacterial assay was performed in artificially contaminated milk samples (without and with added CaCl₂ and EDTA) incubated at 38 °C (donkeys’ body temperature). The EDTA was added to DM to bind its calcium ions, while CaCl₂ was used as the donor of calcium ions. The content of calcium, lysozyme (LYZ) and lactoferrin (LF) as well as pH value were determined in all of the tested milk samples. DM samples showed varying degrees of antibacterial activity against the tested E. coli strains. The milk samples with higher calcium content possessed stronger antibacterial potential toward the tested bacteria. The determinated calcium-dependant antibacterial activity of DM was proved thorough addition of CaCl₂ and EDTA to DM. Calcium content in tested samples was in the range from 377.1 to 1,231 mg/l. The LYZ and LF in tested DM were present at concentrations between 0.98–3.74 g/l and 2.2–54.3 mg/l, respectively. LF was not detected in five of the tested samples, and pH values of the samples were in range from 7.11 to 7.25.