• Toxicological Research
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• v.28 no.2
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• pp.107-112
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• 2012

Polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental pollutants. Recently, it is suggested that neurotoxic effects such as motor dysfunction and impairment in memory and learning have been associated with PCB exposure. However, structure relationship of PCB congeners with neurotoxic effects remains unknown. Since PKC signaling pathway is implicated in the modulation of motor behavior as well as learning and memory and the role of PKC are subspecies-specific, we attempted to study the effects of structurally distinct PCBs on the total PKC activity as well as subspecies of PKC in cerebellar granule cell culture model. Cells were exposed to 0, 25 and 50 ${\mu}M$ of PCB-126, PCB-169, PCB-114, PCB-157, PCB-52 and PCB-4 for 15 min. Cells were subsequently analyzed by [$^3H$] phorbol ester binding assay or immunoblotted against PKC-${\alpha}$ and -${\varepsilon}$ monoclonal antibodies. While non-dioxin-like-PCB (PCB-52 and PCB-4) induced a translocation of PKC-${\alpha}$ and -${\varepsilon}$ from cytosol to membrane fraction, dioxin-like PCBs (PCB-126, -169, -114, -157) had no effects. [$^3H$] Phorbol ester binding assay also revealed structure-dependent increase similar to translocation of PKC isozymes. While PCB-4 induced translocation of PKC-${\alpha}$ and -${\varepsilon}$ was inhibited by ROS inhibitor, the pattern of translocation was not affected in presence of AhR inhibitor. It is suggested that PCB-4-induced PKC activity may not be mediated via AhR-dependent pathway. Taken together, our findings suggest that chlorination of ortho-position in PCB may be a critical structural moiety associated with neurotoxic effects, which may be preferentially mediated via non-AhR-dependent pathway. Therefore, the present study may contribute to understanding the neurotoxic mechanism of PCBs as well as providing a basis for establishing a better neurotoxic assessment.

• BMB Reports
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• v.34 no.2
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• pp.182-187
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• 2001

Phospholiapse D (PLD), and phosphatidic acid generated by it, have been implicated in receptor-mediated intracellular signaling. Carbachol (CCh) is known to activate PLD1, and protein kinase C (PKC) is known to mediate in this signaling pathway In recent reports (Kim et al., 1999b; Kim et al., 2000), we published our observations of the direct phosphorylation of PLD1 by PKC and we described the phosphorylation-dependent regulation of PLD1 activity. In this study, we investigated the phasphorylation and compartmentalization of PLD1 in terms of CCh signaling in M3 muscarinic receptor (M3R)-expressing COS-7 cells. CCh treatment of COS-7 cells transiently coexpressing PLD1 and M3R stimulated PLD1 activity and induced direct phosphorylation of PLD1 by PKC. The CCh-induced activation and phosphorylation of PLD1 was completely blocked upon pretreatment of the cells with PKC-specific inhibitors. We looked at the localization of the PLD1 phosphorylation by PKC and found that PLD1 was mainly located in the caveolin-enriched membrane (CEM) fraction. Based on these results, we conclude that CCh induces the activation and phosphorylation of PLD1 via PKC and that the phosphorylation of PLD1 occurs in caveolae.

• Ocean and Polar Research
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• v.38 no.3
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• pp.185-193
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• 2016

In this study, antioxidative potentials of the crude extract and its four solvent fractions from the Arctic terrestrial plant Ranunculus heperporeus were evaluated by using four different activity tests, including the inhibition of intracellular reactive oxygen species (ROS) and lipid peroxidation in Raw 264.7 cells as well as determining the extent of both the scavenging of peroxynitrite ($ONOO^-$) and the oxidative damage of genomic DNA purified from Raw 264.7 cells. Based on a comparative analysis, n-BuOH, and 85% aq.MeOH solvent fractions showed good scavenging effects on the production of intracellcular ROS and inhibited membrane lipid peroxidation and DNA oxidation. In addition, n-BuOH and 85% aq.MeOH fractions exhibited good scavenging effects on both authentic peroxynitrite and one generated from SIN-1. Among the samples tested, the n-BuOH fraction revealed the strongest antioxidant effect.

• Journal of Dairy Science and Biotechnology
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• v.25 no.1
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• pp.1-7
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• 2007

A Whey-based medium was formulated with Lactobacillus brevis to investigate whether any functional peptides could derive from whey protein. The optimal concentrations of the ingredients of the medium for the growth of Lactobacillus were determined as 2% whey protein concentrate and 1% glucose and 0.5% yeast extracts. The growth of Lb. brevis was improved with the supplementation of yeast extracts than glucose. The viable cells counts of Lb. brevis reached to 2.0 × 10$^8$CFU/mL in the whey-based medium. The whey protein hydrolysates recovered from the supernatant after centrifugation at 10,000 x g for 10min induced strong inhibitory activity against ACE. When the whey protein hydrolysate were partially purified by a membrane tubing below 8,000Da, the partially purified fraction remained 64.7 ${\pm}$ 3.6% of the ACE inhibition activity of the whey protein hydrolysates and IC$_{50}$ was 38.8 ${\pm}$ 2.2mg/mL. The whey-based medium was proved to be effective in producing ACE inhibitory peptides by lactic bacteria fermented whey protein.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.263-266
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• 2012

Isolation of iron and calcium-binding peptides derived from cottonseed meal protein (CMP) hydrolysates was investigated. The degree of hydrolysis of CMP by Flavourzyme was monitored using trinitrobenzenesulfonic acid method and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Enzymatic hydrolysis of CMP for 12 h was sufficient for the preparation of CMP hydrolysates, and the hydrolysates were membrane-filtered under 3 kDa as a molecular weight. The filtered solution was fractionated using Q-Sepharose fast flow, Sephadex G-15, and reversed phase-high performance liquid chromatography for iron and calcium-binding peptides. As a result, F51 fraction was obtained as the best candidate for calcium and iron chelation, and the isolated iron and calcium-binding peptides can be used as functional food additives, similar to iron and calcium supplements.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.47-60
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• 2007

In this paper, we investigate the natural frequencies and buckling loads of functionally graded material (FGM) plates and shells, using a quasi-conforming shell element that accounts for the transverse shear strains and rotary inertia. The eigenvalue of the FGM plates and shells are calculated by varying the volume fraction of the ceramic and metallic constituents using a sigmoid function, but their Poisson's ratios of the FGM plates and shells are assumed to be constant. The expressions of the membrane, bending and shear stiffness of FGM shell element are more complicated combination of material properties than a homogeneous element. In order to validate the finite element numerical solutions, the Navier's solutions of rectangular plates based on the first-order shear deformation theory are presented. The present numerical solutions of composite and sigmoid FGM (S-FGM) plates are proved by the Navier's solutionsand various examples of composite and FGM structures are presented. The present results are in good agreement with the Navier's theoretical solutions.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.579-585
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• 2015

BACKGROUND/OBJECTIVES: Sonchus asper is used extensively as an herbal anti-inflammatory for treatment of bronchitis, asthma, wounds, burns, and cough; however, further investigation is needed in order to understand the underlying mechanism. To determine its mechanism of action, we examined the effects of an ethyl acetate fraction (EAF) of S. asper on nitric oxide (NO) production and prostaglandin-E2 levels in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. MATERIALS/METHODS: An in vitro culture of RAW264.7 macrophages was treated with LPS to induce inflammation. RESULTS: Treatment with EAF resulted in significant suppression of oxidative stress in RAW264.7 macrophages as demonstrated by increased endogenous superoxide dismutase (SOD) activity and intracellular glutathione levels, decreased generation of reactive oxygen species and lipid peroxidation, and restoration of the mitochondrial membrane potential. To confirm its anti-inflammatory effects, analysis of expression of inducible NO synthase, cyclooxygenase-2, tumor necrosis factor-${\alpha}$, and the anti-inflammatory cytokines IL-$1{\beta}$ and IL-6 was performed using semi-quantitative RT-PCR. EAF treatment resulted in significantly reduced dose-dependent expression of all of these factors, and enhanced expression of the antioxidants MnSOD and heme oxygenase-1. In addition, HPLC fingerprint results suggest that rutin, caffeic acid, and quercetin may be the active ingredients in EAF. CONCLUSIONS: Taken together, findings of this study imply that the anti-inflammatory effect of EAF on LPS-stimulated RAW264.7 cells is mediated by suppression of oxidative stress.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.2
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• pp.181-187
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• 1991

Epidermal growth facter(EGF)는 내열성이 강하고 분자량이 6045 dalton인 단쇄상의 polypeptide로써, Cohen에 의해 생쥐의 악하선에서 처음 발견된 이래, 여러학자들에 의해 많은 연구가 되어왔다. 인체의 EGF는 urogastrone이라고도 불리우며, 인체의 소변에서 처음 검출되었고 분자구조 및 생리작용이 생쥐의 EGF와 매우 유사한 것으로 판명되었다. EGF의 자세한 작용기전은 확실히 규명되어있지는 않지만 세포의 증식과 분화를 촉진시키며 위산의 분비를 억제시킨다고 알려져 있다. 또한 EGF receptor는 분자량이 170,000${\sim}$180,000dalton인 세포표면의 polypeptide로써 인체, 쥐, 닭, 소 등의 세포막조직에 특이하게 결합되어 있다. 최근 수년동안 몇몇 학자들에 의해 EGF가 배아와 태아 및 태반의 성장을 촉진시키고 chorionic gonadotrophin과 placental lactogen의 분비를 증진하는데 기여할 것이라고 가정되어 왔다. 그러나 아직까지 배아착상에 대한 EGF의 작용여부에 관해서는 발표된 문헌이 없어 저자는 radioreceptor assay를 이용하여 EGF receptor binding과 토끼의 배아착상과의 관계를 규명하고자 임신경과에 따른 착상부위와 비착상부위의 자궁 및 태아측 태반과 모체측 태반을 분리취득하고 receptor binding assay를 시행하여 다음과 같은 결론을 얻었다. 1. 전임신군과 비임신군의 자궁조직의 membrane fraction으로부터 specific한 EGF receptor binding이 관찰되었다. 2. 착상전 임신 3일에 자궁조직의 EGF receptor수는 4.72 +0.16($10\;mol/{\mu}g$)로 비임신시보다 의의있게 증가되어 있었고(p<0.01), 착상시기인 임신 7일에는 착상된 부위에서 20.33+6.58로 훨씬 더 높은 측정치를 나타내었다(p<0.05). 3. 착상이후 가장 먼저 취득된 임신 14일의 태아측 태반은 모체측 태반의 1.39+0.49에 비해 훨씬 높은 11.94+1.97의 EGF receptor 측정치를 보였다 (p<0.01). 4. 이상의 소견들로 보아 EGF가 토끼의 배아착상에 밀접한 관련이 있을 것으로 추측되며, 이러한 착상전후의 EGF의 작용은 태아측으로부터 일 것으로 예상된다.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.470-477
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• 1995

Flavonoids from Scutellariae Radix possessed a dual function both as an anti-inflammatory agent and an enhancer of cellular activity in gingival fibroblast. The purpose of this study was to evaluate on the toxicity of ethanolic extract from the root of Scutellariae Radix Georgi and its flavonoids, Wogonin, Baicalein, and Baicalin were isolated and purified by the following method. The crude drug was extracted with ethyl acetate and the residue was dissolved in ethyl alcohol. The ethyl alcohol soluble fraction was separated, concentrated, and then chromatographed on a silica gel column. The acute oral LD 50 in rats was determined for EtOH ex. of Scutellariae Radix and three compounds were evaluated with a single oral gavage at three graded dosage levels. The acute intravenous LD 50 was determined with a single intravenous injection via the jugular vein at three graded dosage levels. Groups of 5 male and 5 female rats, 6 week of age at the start of the study, were fed diets containing 3 graded dosage levels for 14 days. Groups of 5 male and 5 female hamster received O.5ml of the test article at once in a day for 5 days to the buccal cheek pouch for two minutes each. The acute oral LD50 for EtOH ex. of Scutellariae Radix is 1430mg/kg, and for Wogonin 1320mg/kg, for Baicalein 1250mg/kg, for Baicalin 1330mg/kg. The acute intravenous toxicity of EtOH ex. of Scutellariae Radix and its extracts was found to be 27mg/kg body weight No toxic effects were observed in rats fed up to 200mg/kg of EtOH ex. of Scutellariae Radix, Wogonin, Baicalein and Baicalin in the diet for 14 days. The acute Mucouse Membrane LD 50 in hamsters was found to be greater than 100mg/kg. These results suggested that EtOH ex. of Scutellariae Radix and its flavonoids are safe for oral care products using limited amount of extract.

• BMB Reports
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• v.33 no.3
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• pp.279-284
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• 2000

Using fluorescence probes, 2-(9-anthroyloxy) stearic acid (2- AS) and 12-(9-anthroyloxy) stearic acid (12-AS), we determined the differential effects of local anesthetics (tetracaine-HCI, bupivacaine-HCI, lidocaine-HCI, prilocaine-HCI and procaine-HCI) on the differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total phospholipid fraction liposome that is extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were$0.051{\pm}0.001$ and $0.096{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. Local anesthetics in a dosedependent manner decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer, but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior, but have significant ordering effects on the surface region of the liposome outer monolayer.