Chinese olive (Canarium album L.) fruit regulates glucose utilization by activating AMP-activated protein kinase.

A growing body of evidence demonstrates obesity-induced insulin resistance is associated with the development of metabolic diseases. This study was designed to investigate ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc)-mediated attenuation of obesity and hyperglycemia in a mouse model. About 60% HFD-fed mice were treated intragastrically with CO-EtOAc for last 6 weeks, and body weight, blood biochemical parameters as well as hepatic inflammation response were investigated. Our results showed that CO-EtOAc treatment significantly reduced the formation of hepatic lipid droplets, body weight gain, blood glucose, and improved serum biochemical parameters in HFD-induced obese and insulin resistant mice. We further explored the molecular mechanism underlying the blood glucose modulating effect of CO-EtOAc using L6 myotubes model. We conclude that CO-EtOAc effectively increases the glycogen content and glucose uptake by stimulating the membrane translocation of glucose transporter 4. In addition, CO-EtOAc depolarizes the mitochondrial membrane and decreases the mitochondrial oxygen consumption, which may result in AMPK activation and the consequent mitochondrial fission. This study shows that CO-EtOAc prevents the development of obesity in mice fed with HFD and is also capable of stimulating glucose uptake. The possible mechanism might be due to the effects of CO-EtOAc on activation of AMPK and promotion of mitochondrial fission.

Investigation of the Characteristics and Antibacterial Activity of Polymer-Modified Copper Oxide Nanoparticles.

The proliferation of drug-resistant pathogens continues to increase, giving rise to serious public health concerns. Many researchers have formulated metal oxide nanoparticles for use as novel antibacterial agents. In the present study, copper oxide (CuO) was synthesized by simple hydrothermal synthesis, and doping was performed to introduce different polymers onto the NP surface for bacteriostasis optimization. The polymer-modified CuO NPs were analyzed further with XRD, FTIR, TEM, DLS and zeta potential to study their morphology, size, and the charge of the substrate. The results indicate that polymer-modified CuO NPs had a significantly higher bacteriostatic rate than unmodified CuO NPs. In particular, polydopamine (PDA)-modified CuO (CuO-PDA) NPs, which carry a weakly negative surface charge, exhibited excellent antibacterial effects, with a bacteriostatic rate of up to 85.8 ± 0.2% within 3 h. When compared to other polymer-modified CuO NPs, CuO-PDA NPs exhibited superior bacteriostatic activity due to their smaller size, surface charge, and favorable van der Waals interactions. This may be attributed to the fact that the CuO-PDA NPs had relatively lipophilic structures at pH 7.4, which increased their affinity for the lipopolysaccharide-containing outer membrane of the Gram-negative bacterium Escherichia coli.

CaO recovered from eggshell waste as a potential adsorbent for greenhouse gas CO2.

The growing number of industrial carbon emissions have resulted in a significant increase in the greenhouse gas carbon dioxide (CO2), which, in turn, will have a major impact on climate change. Therefore, the reduction, storage, and reuse of CO2 is an important concern in modern society. Calcium oxide (CaO) is known to be an excellent adsorbent of CO2 in a high-temperature environment. However, since deterioration of the adsorbent is likely to occur after repeated cycles of adsorption under high temperature conditions, it would be desirable to mitigate this phenomenon, in order to maintain the stability of CaO. In the present study, common eggshell waste was used as the starting material. The main component of eggshell waste is calcium carbonate (CaCO3), which was purified to produce CaO. Different surfactants and amino-containing polymers were added to synthesize CaO-based adsorbents with different configurations and pore sizes. The amount of CO2 adsorbed was determined using a thermogravimetric analyzer (TGA). The results showed that the CO2 adsorption capacity of the synthetic CaO recovered from purified eggshell waste could reach 0.6 g-CO2/g-sorbent, indicating a good adsorption capacity. CaO modified with a dopamine-containing polymer was shown to have an adsorption capacity of 0.62 g-CO2/g-sorbent. Moreover, it showed an excellent adsorption capacity of 0.40 g-CO2/g-sorbent, even after 10 cycles of CO2 adsorption. The present study suggests that using eggshell waste to synthesize CaO-based adsorbents for effective CO2 adsorption can not only reduce environmental waste, but also have the potential to capture greenhouse gas CO2 emissions, which conforms to the principles of green chemistry.

Evaluation of Chemical Compositions, Antioxidant Capacity and Intracellular Antioxidant Action in Fish Bone Fermented with Monascus purpureus.

Fish bones (FBs) are aquatic by-products that are sources of antioxidant-active peptides, calcium dietary supplements, and biomedical materials. Usually, fermentation of these by-products via microorganisms brings desirable changes, enhancing their value. This study investigates the value addition of FB when fermented with Monascus purpureus (MP) for different time intervals, such as 3 days (F3) and 6 days (F6). The results indicate that the soluble protein, peptide, amino acid and total phenol content, as well as the antioxidant capacity (DPPH, ABTS+ radical scavenging activity, and relative reducing power), of F3 and F6 were significantly increased after fermentation. Furthermore, the ROS contents of F3 and F6 were reduced to a greater extent than that of hydrogen peroxide (H2O2) in Clone-9 cells. The MMP integrity, as well as the SOD, CAT, and GPx activity, of F3 and F6 were also increased significantly compared to the H2O2 in Clone-9 cells. Notably, F3 and F6 displayed significant reductions in ROS content, as well as elevate, SOD activity and MMP integrity in Clone-9 cells, when compared with the native FB. These results indicate that the FBs fermented with MP for 3 days (F3), and 6 days (F6) have antioxidant capacity, with possible applications as natural food supplements.

α-Phellandrene enhances the immune response and resistance against Vibrio alginolyticus in white shrimp (Litopenaeus vannamei).

Innate immunity and resistance against Vibrio alginolyticus in white shrimp, Litopenaeus vannamei, that received α-phellandrene were examined. The results indicated that the percent survival of shrimp receiving 4, 8, and 12 µg g-1 α-phellandrene was significantly higher than that of control shrimp after 72 h (p < 0.05). In a separate experiment, the phenoloxidase (PO), respiratory bursts, superoxide dismutase (SOD), and phagocytic and lysozyme activity of L. vannamei receiving 8 and 12 µg g-1 α-phellandrene were significantly higher than those of the other groups upon challenge with V. alginolyticus at 24-60, 36-60, 12-60, 12-72 and 48-72 h, respectively. However, no significant differences in the total haemocyte counts (THC) of L. vannamei receiving any dose of α-phellandrene and of control shrimp were observed at 12-72 h. The expression (mRNA transcripts) of the immune genes prophenoloxidase (proPO), LPS- and ß-1,3-glucan-binding protein (LGBP) and peroxinectin (PE) of shrimp receiving α-phellandrene at 8 and 12 µg g-1 significantly increased after challenge with V. alginolyticus for 72 h (p < 0.05). We conclude that the immune ability and resistance against V. alginolyticus infection increased in L. vannamei receiving >4 µg g-1 α-phellandrene. These results indicated that α-phellandrene plays an important role in the innate immunity of white shrimp.

Construction of a Lactobacillus plantarum Strain Expressing the Capsid Protein of Porcine Circovirus Type 2d (PCV2d) as an Oral Vaccine.

Porcine circovirus type 2 (PCV2) is a pathogenic virus that causes high rates of porcine death, resulting in severe economic losses to the swine industry. In recent years, the prevalence of PCV2d genotype infection in pigs has increased, but most commercially available vaccines were developed against the PCV2a strain and do not ensure complete protection from PCV2d. Here, we first constructed an expression vector for the antigenic ORF2-encoded capsid protein of PCV2d (pLp3050-His6-tag-capsid). We then utilized Lactobacillus plantarum to express the protein at mucosal sites in orally vaccinated mice. After transducing L. plantarum with pLp3050-His6-tag-capsid, the expressed protein could be found in cell wall and cell-free supernatant fractions by Western blotting. Using flow cytometry, we found that L. plantarum cells with surface-displayed capsid protein increased with time after SppIP induction. Finally, mice that were orally immunized 18 times with capsid-expressing L. plantarum showed increased levels of capsid-specific sIgA and virus neutralizing activity at mucosal sites, suggesting mucosal immunity had been stimulated by the vaccine. Overall, our findings demonstrate the feasibility and utility of a PCV2d-based vaccine, which may be of great value in porcine agriculture.

Functional engineered mesenchymal stem cells with fibronectin-gold composite coated catheters for vascular tissue regeneration.

Vascularization of engineered tissues remains one of the key problems. Here, we described a novel approach to promote vascularization of engineered tissues using fibronectin (FN) incorporated gold nanoparticles (AuNP) coated onto catheters with mesenchymal stem cells (MSCs) for tissue engineering. We found that the FN-AuNP composite with 43.5 ppm of AuNP exhibited better biomechanical properties and thermal stability than pure FN. FN-AuNP composites promoted MSC proliferation and increased the biocompatibility. Mechanistically, vascular endothelial growth factor (VEGF) promoted MSC migration on FN-AuNP through the endothelial oxide synthase (eNOS)/metalloproteinase (MMP) signaling pathway. Vascular femoral artery tissues isolated from the implanted FN-AuNP-coated catheters with MSCs expressed substantial CD31 and alpha-smooth muscle actin (α-SMA), displayed higher antithrombotic activity, as well as better endothelialization ability than those coated with all other materials. These data suggested that the implantation of FN-AuNP-coated catheter with MSCs could be a novel strategy for vascular biomaterials applications.

Diallyl trisulfide inhibits cell migration and invasion of human melanoma a375 cells via inhibiting integrin/facal adhesion kinase pathway.

Melanoma is the leading cause of death from skin disease due to its propensity for metastasis. Studies have shown that integrin-mediated focal adhesion kinase (FAK) signal pathway is implicated in cell proliferation, survival and metastasis of tumor cells. Our previous results indicated that diallyl trisulfide (DATS) provided its antimelanoma activity via inducing cell cycle arrest and apoptosis. The aim of this study was to explore DATS mediated antimetastatic effect and the corresponding mechanism in human melanoma A375 cells. We found that DATS exhibited an inhibitory effect on the abilities of migration and invasion in A375 cells under noncytotoxic concentrations analyzed by wound healing assays and Matrigel invasion chamber system. DATS attenuated invasion of A375 cells with characteristic of decreased activities and protein expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9. Moreover, DATS exerted an inhibitory effect on cell adhesion of A375 cells, which is in correlation with the change in integrin signaling pathway. Results of Western blotting showed that DATS decreased the levels of several integrin subunits, including α4, α5, αv, ß1, ß3 and ß4. Subsequently, DATS induced a strong decrease in total FAK, phosphorylated FAK Tyr-397,-576, -577, and disorganized F-actin stress fibers, resulting in a nonmigratory phenotype. These results suggest that the antimetastatic potential of DATS for human melanoma cells might be due to the disruption of integrin/FAK signaling pathway.

Magnetite nanoparticle interactions with insulin amyloid fibrils.

Accumulation of amyloid fibrils is one of the likely key factors leading to the development of Alzheimer's disease and other amyloidosis associated diseases. Magnetic nanoparticles (NPs) have been developed as promising medical materials for many medical applications. In this study, we have explored the effects of Fe3O4 NPs on the fibrillogenesis process of insulin fibrils. When Fe3O4 NPs were co-incubated with insulin, Fe3O4 NPs had no effect on the structural transformation into amyloid-like fibrils but had higher affinity toward insulin fibrils. We demonstrated that the zeta potential of insulin fibrils and Fe3O4 NPs were both positive, suggesting the binding forces between Fe3O4 NPs and insulin fibrils were van der Waals forces but not surface charge. Moreover, a different amount of Fe3O4 NPs added had no effect on secondary structural changes of insulin fibrils. These results propose the potential use of Fe3O4 NPs as therapeutic agents against diseases related to protein aggregation or contrast agents for magnetic resonance imaging.

Nanoscale characterization illustrates the cisplatin-mediated biomechanical changes of B16-F10 melanoma cells.

Cells reorganize their membrane biomechanical dynamics in response to environmental stimuli or inhibitors associated with their physiological/pathological processes, and disease therapeutics. To validate the biophysical dynamics during cell exposure to anti-cancer drugs, we investigate the nanoscale biological characterization in melanoma cells undergoing cisplatin treatment. Using atomic force microscopy, we demonstrate that the cellular morphology and membrane ultrastructure are altered after exposure to cisplatin. In contrast to their normal spindle-like shape, cisplatin causes cell deformation rendering cells flat and enlarged, which increases the cell area by 3-4 fold. Additionally, cisplatin decreases the topography height values for both the cytoplasmic and nuclear regions (by 40-80% and 60%, respectively). Furthermore, cisplatin increases the cytoplasmic root mean square roughness by 110-240% in correlation with the drug concentration and attenuates the nuclear RMS by 60%. Moreover, the cellular adhesion force was enhanced, while the Young's modulus elasticity was attenuated by ∼2 and ∼2.3 fold, respectively. F-actin phalloidin staining revealed that cisplatin enlarges the cell size through enhanced stress fiber formation and promotes cytoskeletal reorganization. Immunoblot analyses further revealed that the activities of focal adhesion proteins, such as FAK and c-Src, are upregulated by cisplatin through phosphorylation at tyrosine 397 and 530, respectively. Collectively, these results show that cisplatin-treated melanoma cells not only exhibit the upregulation of FAK-mediated signaling to enhance the cytoskeleton mechanical stretch, but also promote the cytoskeletal rearrangement resulting in 43% decrease in the cell modulus. These mechanisms thus promote the malignancy and invasiveness of the melanoma cells.

Optimization of Lactobacillus acidophilus cultivation using taro waste and evaluation of its biological activity.

In this study, taro waste (TW) was utilized for Lactobacillus acidophilus BCRC 14079 cultivation and the anti-tumor and immune-modulatory properties of heat-killed cells (HKCs), cytoplasmic fraction (CF), and exopolysaccharide (EPS) were evaluated. The optimum liquefaction enzyme dosage, temperature, and time determined by Box-Behnken design response surface methodology (BBD-RSM) were 9 mL/L of α-amylase, 79.2 °C, and 5 h of reaction, respectively. The optimum temperature and reaction time for saccharification were determined as 60 °C and 3 h. The optimum medium, CGMY1 medium, constitutes of TW hydrolysate containing 37 g/L of glucose, 25 g/L of corn gluten meal (CGM), and 1 g/L of yeast extract (YE). Results of MTT assay showed that HKCs and EPS from CGM medium exhibited the highest anti-proliferative in HT-29 (IC50 of HKCs, 467.25 µg/mL; EPS, 716.10 µg/mL) and in Caco-2 cells (IC50 of EPS, 741.60 µg/mL). Luciferase-based NF-ΚB and COX-2 systems indicated HKCs from CGM medium stimulated the highest expression of luciferin in both systems. The luciferase activities by using 100 and 500 µg/mL of HKCs from CGM were 24.30- and 45.83-fold in NF-ΚB system and 11.54- and 4.93-fold in COX-2 system higher than the control. In conclusion, this study demonstrated the potential of TW medium for L. acidophilus cultivation and the production of non-viable probiotics with enhanced biological activities.

Differential regulation of protein expression in response to polyunsaturated fatty acids in the liver of apoE-knockout mice and in HepG2 cells.

BACKGROUND: Polyunsaturated fatty acids (PUFAs) are nutrients necessary for life. The liver is the essential metabolic center, which aids in maintaining health via diverse biological actions. In the present work, a proteomics study was conducted with an aim to provide new insights into PUFA-regulated hepatic protein expression in apoE-knockout mice. Additionally, we investigated how n-3 PUFAs influence cytokine-challenge by using HepG2 cells as a model. RESULTS: Through the proteomic analysis using 2-dimensional electrophoresis and mass spectrometry, we found that 28, 23, 14, and 28 hepatic proteins were up-regulated at least a two-fold difference in intensity compared with the control group in mice treated with the docosahexaenoic acid, eicosapentaenoic acid, arachidonic acid, and linoleic acid, respectively. In contrast, 12 hepatic proteins were down-regulated with a ratio value of less than 0.5 compared to their control counterparts by these four fatty acids. All of the altered proteins were then sorted according to their biochemical properties related to metabolism, redox stress/inflammation, enzymatic reactions, and miscellaneous functions. The results provide evidence that PUFAs may act as either pro-inflammatory or anti-inflammatory agents. Cytokine-challenged HepG2 cells were used to reveal the anti-inflammatory function of n-3 PUFAs. The results showed that interleukin (IL)-1ß combined with IL-6 induced C-reactive protein (CRP) mRNA expression and its protein secretion by HepG2 cells. The CRP promoter activity was significantly increased in the IL-6-treated cells, whereas IL-1ß alone had no effect. However, IL-1ß and IL-6 acted synergistically to further enhance CRP promoter activities. Furthermore, n-3 PUFAs inhibited nuclear factor-κB (NF-κB) activation and the phosphorylation of the nuclear signal transducer and activator of transcription 3 (STAT3) during cytokine-induced CRP production. CONCLUSION: This study indicates that PUFAs induced changes in the hepatic protein profile in vivo. Furthermore, n-3 PUFAs exert their anti-inflammatory properties through differential molecular mechanisms in hepatic cells. These results provide novel information regarding the roles of PUFAs in the liver at the tissue and cellular levels.

Porosity-controlled eggshell membrane as 3D SERS-active substrate.

We report on the fabrication of a surface-enhanced Raman scattering (SERS) platform, comprised of a three-dimensional (3D) porous eggshell membrane (ESM) scaffold decorated with Ag nanoparticles (NPs). Both native and treated ESM were used, where the treated ESM pore size and fiber crossing density was controlled by timed exposure to hydrogen peroxide (H2O2). Ag NPs were synthesized in situ by reduction of silver nitrate with ascorbic acid. Our results demonstrate that H2O2-treated Ag-ESM provides a more densely packed 3D network of active material, which leads to consistently higher SERS enhancement than untreated Ag-ESM substrates.

Effect of the surface chemistry of insulin fibrils on the aggregation rate.

Structure transition cascade: Insulin fibrils undergo a secondary structural transition-from the α-rich to the ß-rich form-upon progressively increasing the incubation time from 0.5 to ten hours. Atomic force microscopy measurements show that the fibril surface chemistry changes from hydrophilic to hydrophobic and the aggregation rate increases fivefold.

Preconditioning somatothermal stimulation on Qimen (LR14) reduces hepatic ischemia/reperfusion injury in rats.

BACKGROUND: In human beings or animals, ischemia/reperfusion (I/R) injury of the liver may occur in many clinical conditions, such as circulating shock, liver transplantation and surgery and several other pathological conditions. I/R injury has a complex pathophysiology resulting from a number of contributing factors. Therefore, it is difficult to achieve effective treatment or protection by individually targeting the mediators. This study aimed at studying the effects of local somatothermal stimulation preconditioning on the right Qimen (LR14) on hepatic I/R injury in rats. METHODS: Eighteen male Sprague-Dawley rats were randomly divided into three groups. The rats were preconditioned with thermal tolerance study, which included one dose of local somatothermal stimulation (LSTS) on right Qimen (LR14) at an interval of 12 h, followed by hepatic ischemia for 60 min and then reperfusion for 60 min. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been used to assess the liver functions, and liver tissues were taken for the measurements such as malondialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxidase dismutase (SOD), and myeloperoxidase (MPO). RESULTS: The results show that the plasma ALT and AST activities were higher in the I/R group than in the control group. In addition, the plasma ALT and AST activities decreased in the groups that received LSTS. The hepatic SOD levels reduced significantly by I/R injury. Moreover, the hepatic MPO activity significantly increased by I/R injury while it decreased in the groups given LSTS. CONCLUSIONS: Our findings show that LSTS provides a protective effects on the liver from the I/R injury. Therefore, LSTS might offer an easy and inexpensive intervention for patients who have suffered from I/R of the liver especially in the process of hepatotomy and hepatic transplantation.

Phytoconstituent-derived zingerone nanoparticles disrupt the cell adhesion mechanism and suppress cell motility in melanoma B16F10 cells.

Combining phytochemicals and nanotechnology to improve the unfavorable innate properties of phytochemicals and develop them into potent nanomedicines to enhance antitumor efficacy has become a novel strategy for cancer chemoprevention. Melanoma is the most aggressive, metastatic, and deadly disease of the primary cutaneous neoplasms. In this study, we fabricated phytoconstituent-derived zingerone nanoparticles (NPs) and validated their effects on cell adhesion and motility in melanoma B16F10 cells. Our data indicated that zingerone NPs significantly induced cytotoxicity and anti-colony formation and inhibited cell migration and invasion. Moreover, zingerone NPs dramatically interfered with the cytoskeletal reorganization and markedly delayed the period of cell adhesion. Our results also revealed that zingerone NPs-mediated downregulation of MMPs (matrix metalloproteinases) activity is associated with inhibiting cell adhesion and motility. We further evaluated the effects of zingerone NPs on Src/FAK /Paxillin signaling, our data showed that zingerone NPs significantly inhibited the protein activities of Src, FAK, and Paxillin, indicating that they play important roles in zingerone NP-mediated anti-motility and anti-invasion in melanoma cells. Accordingly, the phytoconstituent-zingerone NPs can strengthen the inhibition of tumor growth, invasion, and metastasis in malignant melanoma. Altogether, these multi-pharmacological benefits of zingerone NPs will effectively achieve the purpose of melanoma prevention and invasion inhibition.

Kumquat peel-derived biochar to support zeolitic imidazole framework-67 (ZIF-67) for enhancing peracetic acid activation to remove acetaminophen from aqueous solution.

This study presents the synthesis of a novel composite catalyst, ZIF-67, doped on sodium bicarbonate-modified biochar derived from kumquat peels (ZIF-67@KSB3), for the enhanced activation of peracetic acid (PAA) in the degradation of acetaminophen (APAP) in aqueous solutions. The composite demonstrated a high degradation efficiency, achieving 94.3% elimination of APAP at an optimal condition of 200 mg L-1 catalyst dosage and 0.4 mM PAA concentration at pH 7. The degradation mechanism was elucidated, revealing that superoxide anion (O2•-) played a dominant role, while singlet oxygen (1O2) and alkoxyl radicals (R-O•) also contributed significantly. The degradation pathways of APAP were proposed based on LC-MS analyses and molecular electrostatic potential calculations, identifying three primary routes of transformation. Stability tests confirmed that the ZIF-67@KSB3 catalyst retained an 86% efficiency in APAP removal after five successive cycles, underscoring its durability and potential for application in pharmaceutical wastewater treatment.

Redox-active π-conjugated organometallic monolayers: pronounced Coulomb blockade characteristic at room temperature.

We report the electrical transport characteristics of a series of molecular wires, fc-C≡C-C6H4-SAc (fc = ferrocenyl; Ac = acetyl) and AcS-C6H4-C≡C-(fc)n-C≡C-C6H4-SAc (n = 2, 3), consisting of multiple redox-active ferrocenyl centers. The self-assembled monolayers of these molecular wires on Au surfaces were comprehensively characterized by electrochemistry and conductive atomic force microscopy techniques. Characterization of the wires revealed that electron transport is made extremely efficient by the organometallic redox states. There is a strong electronic coupling between ferrocenyl moieties, and superior electron-transport ability exists through these semirigid molecular wires. Standard rate constants for the electron transfer between the electrode and the ferrocenyl moieties were measured for the monolayers by a potential-step chronoamperometry technique. The electron conduction through the molecular wires was estimated using the monolayers as a bridge from the Au(111) metal surface to the gold tip of a conductive atomic force microscope (CAFM). Using the CAFM, Coulomb blockade behavior arising from the capacitive charging of the multinuclear redox-active molecules was observed at room temperature. The conductance switching was mediated by the presence of various ferrocenyl redox states and each current step corresponded to a specific redox state.

Docosahexaenoic acid and eicosapentaenoic acid reduce C-reactive protein expression and STAT3 activation in IL-6-treated HepG2 cells.

C-reactive protein (CRP), an acute phase protein in humans, is predominantly produced by hepatocytes in response to interleukin-6 (IL-6). Several epidemiological studies have reported that dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) is inversely associated with serum CRP concentration. However, the molecular mechanism by which n-3 PUFAs reduce the serum CRP level in HepG2 cells remains unclear. The aims of this study were to examine the effect of the n-3 PUFAs, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), on the modulation of IL-6-induced CRP expression and to explore its possible mechanisms. We demonstrated that DHA and EPA inhibited IL-6-induced CRP protein and mRNA expression, as well as reduced CRP promoter activity in HepG2 cells. Knockdown of Signal Transducer and Activator of Transcription 3 (STAT3) and CCAAT box/Enhancer-Binding Protein ß (C/EBPß) by small interfering RNAs (siRNAs) significantly decreased IL-6-induced CRP promoter activity. Gel electrophoresis mobility shift assays (EMSA) showed that pretreatment with DHA and EPA decreased IL-6-induced STAT3 DNA binding activity but not C/EBPß. By western blot analysis, DHA and EPA inhibited IL-6-induced STAT3 phosphorylation but not ERK1/2 or C/EBPß. The suppression of the phosphorylation of STAT3 by DHA and EPA was further verified by immunofluorescence staining. Taken together, our results demonstrate that DHA and EPA are able to reduce IL-6-induced CRP expression in HepG2 cells via an inhibition of STAT3 activation. This mechanism, which explains the inhibitory effect of n-3 PUFAs on the CRP expression, provides new insights into the beneficial anti-inflammatory effect of n-3 PUFAs.

Susceptibility of Vibrio parahaemolyticus to disinfectants after prior exposure to sublethal stress.

In the present study, Vibrio parahaemolyticus 690 in phosphate buffered-saline containing 3% NaCl was subjected to sublethal stresses: heat shock at 42 °C for 15 min, acid adaptation at pH 5.0 for 30 min, or cold shock at 20 °C for 4 h. The effect of sublethal stress on the susceptibility of V. parahaemolyticus to a chlorine-containing disinfectant (Clidox-S) and a quaternary ammonium compound (Quatricide) at 25 and 40 °C was investigated. It was found that the sublethal stresses examined enhanced the resistance of V. parahaemolyticus 690 to both disinfectants. Depending on the kinds of sublethal stress, V. parahaemolyticus 690 showed various degrees of enhanced resistance to disinfectants. Furthermore, the phenomenon of enhanced resistance to the disinfectants was more marked at 40 than at 25 °C.