Diphlorethohydroxycarmalol isolated from Pae (Ishige okamurae) protects high glucose-induced damage in RINm5F pancreatic β cells via its antioxidant effects

Pancreatic β cells are very sensitive to oxidative stress and this may play an important role in β cell death in diabetes. The protective effect of diphlorethohydroxycarmalol (DPHC), one of phlorotannin polyphenol compound purified from pae (Ishige okamurae) against high glucoseinduced oxidative stress was investigated using RINm5F pancreatic β cells. High glucose (30 mM) treatment induced RINm5F pancreatic β cells cell death, but DPHC, at concentration 10 or 50 μg/mL, significantly inhibited the high glucose-induced glucotoxicity and apoptosis. Furthermore, treatment with DPHC dose-dependently decreased thiobarbituric acid reactive substances (TBARS), intracellular reactive oxygen species (ROS) generation and nitric oxide level increased by high glucose. In addition, DPHC treatment increased activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) in high glucose pretreated RINm5F pancreatic β cells. DPHC treatment improved the secretory responsiveness following stimulation with glucose. These findings indicate that DPHC might be used as potential nutraceutical agent which will protect the glucotoxicity caused by hyperglycemia-induced oxidative stress associated with diabetes.     

Discrimination of Korean beef from beef of other origin by stable isotope measurements

Beef samples from Korea and from some of the main beef exporting countries (USA, Mexico, Australia, New Zealand) were analysed for carbon, nitrogen and hydrogen isotope ratios of the defatted dried matter. Results showed that the samples from each country investigated could be assigned to a typical isotope signature and can be separated from each other. The main discriminating factors were δ¹³C and δ²H, which mainly reflect feeding of C₃ and C₄-plants and the isotopic composition of the water, respectively, consumed by the cattle. Australian beef showed the largest variation in its isotopic signature, suggesting heterogeneous rearing conditions. By contrast, for beef from New Zealand, Mexico, USA and Korea, each batch had typical signatures with a smaller variability.     

A study on removal efficiency of phenol and humic acid using spherical activated carbon doped by TiO<Subscript>2</Subscript>

This study aimed to find a way to remove organic pollutants, phenol and humic acid in aqueous solutions using TiO₂ spherical activated carbon (Ti-SPAC). The Ti-SPAC was manufactured by resin ion-exchange and a heating process. This method was very effective not only in creating TiO₂ on the surface of the supports evenly, but also in making activated carbon that has highly-developed micro pores. To estimate whether Ti-SPAC has the proper features as a photocatalyst and adsorbent, it was examined in detail by X-ray patterns, SEM image, EDXS, BET, EPMA. The results proved that Ti-SPAC is a very useful material for treating wastewater by photocatalysis and absorption.     

Der f 38 Is a Novel TLR4-Binding Allergen Related to Allergy Pathogenesis from Dermatophagoides farinae

It is difficult to treat allergic diseases including asthma completely because its pathogenesis remains unclear. House dust mite (HDM) is a critical allergen and Toll-like receptor (TLR) 4 is a member of the toll-like receptor family, which plays an important role in allergic diseases. The purpose of this study was to characterize a novel allergen, Der f 38 binding to TLR4, and unveil its role as an inducer of allergy. Der f 38 expression was detected in the body and feces of Dermatophagoides farinae (DF). Electron microscopy revealed that it was located in the granule layer, the epithelium layer, and microvilli of the posterior midgut. The skin prick test showed that 60% of allergic subjects were Der f 38-positive. Der f 38 enhanced surface 203c expression in basophils of Der f 38-positive allergic subjects. By analysis of the model structure of Der p 38, the expected epitope sites are exposed on the exterior side. In animal experiments, Der f 38 triggered an infiltration of inflammatory cells. Intranasal (IN) administration of Der f 38 increased neutrophils in the lung. Intraperitoneal (IP) and IN injections of Der f 38 induced both eosinophils and neutrophils. Increased total IgE level and histopathological features were found in BALB/c mice treated with Der f 38 by IP and IN injections. TLR4 knockout (KO) BALB/c mice exhibited less inflammation and IgE level in the sera compared to wild type (WT) mice. Der f 38 directly binds to TLR4 using biolayer interferometry. Der f 38 suppressed the apoptosis of neutrophils and eosinophils by downregulating proteins in the proapoptotic pathway including caspase 9, caspase 3, and BAX and upregulating proteins in the anti-apoptotic pathway including BCL-2 and MCL-1. These findings might shed light on the pathogenic mechanisms of allergy to HDM.     

Soluble forms of YlCrh1p and YlCrh2p, cell wall proteins of Yarrowia lipolytica, have beta-1,3-glycosidase activity

Crh1p and Crh2p of Saccharomyces cerevisiae are cell wall proteins covalently attached to cell wall glucan and are thought to be putative glycosidases involved in cell wall remodelling. We investigated whether YlCrh1p and YlCrh2p, the Yarrowia lipolytica proteins homologous to ScCrh1p and ScCrh2p, had the required glycosidase activity for cell wall biosynthesis and maintenance. Ylcrh1Delta and Ylcrh2Delta mutants showed sensitivity to compounds that interfere with cell wall construction. Soluble forms of YlCrh1p and YlCrh2p that lacked the C-terminal consensus sequence for GPI anchoring showed glycosidase activity on laminarin, a substrate carrying beta-1,3-glycosidic linkage. Our study suggests that the YlCrh1p and YlCrh2p may participate in cell wall biosynthesis and remodelling through their beta-1,3-glycosidase activity.     

Bioactive compounds extracted from Gamtae (Ecklonia cava) by using enzymatic hydrolysis, a potent α-glucosidase and α-amylase inhibitor, alleviates postprandial hyperglycemia in diabetic mice

This study was designed to investigate whether the brown alga gamtae (Ecklonia cava) may inhibit α-glucosidase and α-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. For that purpose, we prepared an enzymatic hydrolysate from gamtae (EHG) by using the carbohydrase, Celluclast. EHG evidenced prominent inhibitory effect against α-glucosidase and α-amylase. The IC₅₀ values of EHG against α-glucosidase and α-amylase were 0.62 and 0.59 mg/mL, respectively, which evidenced the higher activities than that of acarbose. EHG did not exert any cytotoxic effect in human umbilical vein endothelial cells (HUVECs) at various concentrations (from 0.25 to 2 mg/mL). The increase of postprandial blood glucose levels were significantly suppressed in the EHG administered group than those in the streptozotocin-induced diabetic or normal mice. Moreover, the area under curve (AUC) was significantly reduced via EHG administration (6,102 vs. 10,425 mg·min/dL) in the diabetic mice as well as it delays absorption of dietary carbohydrates. These result indicated that EHG might be a potent inhibitor for α-glucosidase and α-amylase.     

Preparation,characterization and photocatalytic activity evaluation of micro- and mesoporous TiO2/spherical activated carbon

The influences of heat-treatment temperature and activation time on the properties of TiO₂ supported on spherical activated carbon (TiO₂/SAC) were investigated. Nano-sized TiO₂ was dispersed on the spherical activated carbon with the size of 10–30 nm. Some anatase phase of TiO₂ was transformed to rutile phase of TiO₂ with an increase of heat-treatment temperature. All of the TiO₂/SAC photocatalysts had microporous structure, with the mesopore volume increasing over an activation time of 6 h. The TiO₂/SAC photocatalysts obtained at activation times of 6 h and 9 h were observed synergistic effects between adsorption and photocatalysis in the removal of humic acid.     

A comparison of fenton oxidation and photocatalyst reaction efficiency for humic acid degradation

There have been many studies on the use of photocatalysts as an advanced oxidation process (AOP) to oxidize and degrade organic-based contaminants. This research group has previously reported a production process of Ti based spherical activated carbon and the characteristics of the product. This paper further examines the process of fenton oxidation and the process of Ti-spherical carboneous material (Ti-SCM) photolysis to evaluate their respective advantages and disadvantages. Non-biodegradable humic acid (HA) was chosen for the purpose of the study to observe the degradation. It is demonstrated that fenton oxidation is fast and efficient in a low organic viscous solvent. Ti-SCM is not greatly affected by variation of the pH level and the process is also fast and efficient. Moreover, the process's retention rate of catalysts and its reusability were greater than that of fenton oxidation, which required pH balancing and produced sludge.     

Photocatalytic degradation of azo dye using TiO2 supported on spherical activated carbon

TiO₂ supported on spherical activated carbon (TiO₂/SAC) was prepared through an ion-exchange method followed by a heat-treatment process. The adsorption characteristic of TiO₂/SAC was evaluated using azo dye methyl orange (MO) as a target substance, and the photocatalytic degradation of MO under UV irradiation was also discussed. A synergistic effect of both the adsorption capacity of activated carbon and the photoactivity of TiO₂ on the removal of MO from aqueous solution was observed. Experimental results revealed that the photocatalytic degradation of MO improved with increasing photocatalyst dosage and followed a pseudo-first order kinetic. After five-cycle runs, TiO₂/SAC still exhibited relatively high photocatalytic characteristic for the degradation of MO. Besides, the prepared TiO₂/SAC can be helpful in the easy separation of photocatalyst from solution after photocatalysis of MO. Furthermore, the use of liquid chromatography/mass spectrometry (LC/MS) technique, identified three intermediates as degradation products during the photocatalytic reaction of MO with TiO₂/SAC.