• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.936-942
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• 2012

In the present study, the effects of green tea catechin on microsomal phospholipase $A_2$ ($PLA_2$) activity and the arachidonic acid (AA) cascade in the lungs of microwave exposed rats were investigated. One Sprague-Dawley male rats weighting $100{\pm}10$ g was randomly assigned to the normal group and three were assigned to the microwave exposed groups. The microwave exposed groups were subdivided into three groups according to the levels of dietary catechin supplementation: catechin free diet (MW) group, 0.25% catechin (MW-0.25C) group and 0.5% catechin (MW-0.5C) group. Rats were sacrificed on the 6th day after microwave irradiation (2.45 GHz, 15 min). The lung microsomal $PLA_2$ activity in the MW and MW-0.25C groups was 30% and 15% greater than that of the normal group, respectively, whereas no significant difference between the normal group and MW-0.5C group was observed. The percentage of phosphatidylethanolamine (PE) hydrolyzed in the lung microsome in the MW, MW-0.25C and MW-0.5C group increased by 47%, 18% and 20%, respectively, due to microwave irradiation. The formation of thromboxane $A_2$ ($TXA_2$) in the lung microsome was 50% greater in the MW group than in the normal group. However, the levels of $TXA_2$ in the MW-0.25C and MW-0.5C group were normal. The formation of prostacyclin ($PGI_2$) in the lung microsome was 31% lower in the MW group than in the normal group, while the levels of $PGI_2$ in the MW-0.25C and MW-0.5C group were similar to the normal group. The lung microsomal thiobarbituric acid reactive substances (TBARS) concentration, which can be used as an index of lipid peroxide was 34% greater in the MW group, when compared with the normal group. However, there was no difference between the MW-0.25C, MW-0.5C and normal groups. In conclusion, lung function appeared to be improved by green tea catechin supplementation due to its antithrombus action, which in turn controls the AA cascade system.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.5 s.118
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• pp.54-59
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• 2006

Paperboards used for linerboard of corrugated fiberboard box were coated with different concentrations of polylactic acid (PLA) solution and the effects of harsh environmental conditions such as high humidity and temperature (96% RH at $30^{\circ}C$ for up to 5 days), and freeze-thaw ($-20^{\circ}C$ for a day and then thaw at room temperature for 30 min) conditions on the ring crush (RC) strength of the boards were investigated. One to five percent PLA solutions were coated onto SC manila linerboard ($20{\times}27cm$) using a No. 20 wire bar coater and the ring crush strength was measured using a computer-controlled Advanced Universal Testing System in accordance with TAPPI Test Method T 822 om-93. The RC strength increased significantly when the concentration of coating solution increased and appreciable changes were found when the concentration increased from 0 to 2% (P<0.05). Similar pattern of results was found after 5-day storage at $30^{\circ}C$ and 96% RH. Although such highly humid condition increased moisture content in the samples up to 3.95 from 0.97 times, the RC strength decreased in the range from 29.9 to 48.5%. The freeze-thaw treatment increased the moisture content only up to 1.27% and the reduction in the RC strength ranged from 21.1 to 28.1 %. The results were promising: the samples coated with 5% PLA solution showed 29.9% reduction in the RC strength while that of control was 48.5% during highly humid condition stated above.

• Journal of Acupuncture Research
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• v.21 no.3
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• pp.121-131
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• 2004

Objective : The purpose of this study was investigation how the bee venom(BV) prevents inflammation in human cell. Methods : we induced inflammation on human synoviocyte cell by lipopolysaccharide(LPS) and sodium nitroprusside(SNP), treated the bee venom and melittin on this cell, surveyed the expression of Nisotric oxide(NO), inducible nitric oxide synthase(iNOS), Cyclooxygenease-2(COX-2), cytolic phospholipase $A_2(cPLA_2)$, Prostaglandin $E_2(PGE_2)$ and nuclear factor-${\kappa}B$(NF-${\kappa}B$), and got below conclusions. Results : Compared with control 1. Expressions of LPS-induced $PGE_2$(BV 1, $5{\mu}g/m{\ell}$) and SNP-induced PGE2(BV 0.5, 1, $5{\mu}g/m{\ell}$)were decreased significantly. 2. Expressions of LPS-induced NO(BV 0.5, 1, $5{\mu}g/m{\ell}$) and SNP-induced NO(BV 1, $5{\mu}g/m{\ell}$)were decreased significantly. 3. Expressions of LPS-induced COX-2(BV 1, $5{\mu}g/m{\ell}$) and SNP-induced COX-2(BV $5{\mu}g/m{\ell}$)were decreased significantly. 4. Expressions of LPS-induced iNOS(BV 0.5, 1, $5{\mu}g/m{\ell}$) and SNP-induced iNOS(BV $5{\mu}g/m{\ell}$) were meanless by all dose. 5. Expressions of LPS-induced $cPLA_2$(BV 1, $5{\mu}g/m{\ell}$) and SNP-induced cPLA2(BV 1, $5{\mu}g/m{\ell}$)were decreased significantly. 6. Expressions of LPS-induced NF-${\kappa}B$(BV $5{\mu}g/m{\ell}$, melittin $5{\mu}g/m{\ell}$) and SNP-induced NF-${\kappa}B$(BV 0.5, 1, $5{\mu}g/m{\ell}$, melittin 5, $10{\mu}g/m{\ell}$)were decreased significantly. 7. Expressions of LPS-induced NF-${\kappa}B$ binding activity (BV $1{\mu}g/m{\ell}$, melittin $5{\mu}g/m{\ell}$, melittin $5{\mu}g/m{\ell}$+ DTT 20mM) were decreased significantly. Conclusion : The bee venom treatments on synoviocyte showed significant changes in LPS and SNP induced NO, iNOS, COX-2, cPLA2, PGE2 and NF-${\kappa}B$, these results suggest that bee venom is effective to inflammations and establish the process of bee venom therapy, so we expect active use of bee venom to control the inflammation.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.464-470
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• 2008

Background: This study examined the role of neutrophilc oxidative stress in an $O_2-induced$ acute lung injury (ALI). Methods: For 48 h, experimental rats were exposed to pure oxygen (normobaric hyperoxia) in a plastic cage. Forty-eight hours after $O_2$ breathing, the rats were sacrificed and the parameters for ALI associated with neutrophilic oxidative stress were assessed Results: Normobaric pure oxygen induced ALI, which was quite similar to ARDS. The $O_2-induced$ neutrophilic oxidative stress was identified by confirming of the increase in lung myeloperoxidase, BAL neutrophils, malondialdehyde (MDA), cytosolic phospholipase $A_2$ ($cPLA_2$) activity in the lung, histological changes and BAL cytospin morphology. Conclusion: In part, ALI-caused by oxygen is affected by neutrophils especially by the generation of free radicals.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.125-131
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• 2015

Phenyllactic acid (PLA) which is known as antimicrobial compound can be synthesized through the reduction of phenylpyruvic acid (PPA) by lactate dehydrogenase (LDH) of lactic acid bacteria (LAB). LAB producing PLA was isolated from Korea Kimchi and identified to Lactobacillus plantarum SJ21 by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. plantarum SJ21 was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against four fungal pathogens (Rhizoctonia solani, Aspergillus oryzae, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23mM in CFS when L. plantarum SJ21 was grown in MRS broth containing 5mM PPA for 16 h. PLA production also could be promoted by the supplement of PPA and phenylalanine in MRS broth, but inhibited by the supplement of 4-hydroxyphenylpyruvic acid and tyrosine as precursors. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. plantarum SJ21 with average growth inhibitions ranging from 27.32% to 69.05% (p<0.005), in which R. solani was the most sensitive to 69.05% and followed by B. cinerea, C. aculatum, and A. oryzae. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range from $0.35mg\;mL^{-1}$ (2.11 mM) to $0.7mg\;mL^{-1}$ (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens was not affected by heating or protease treatment. However, pH modification in CFS to 6.5 caused an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS were caused by acidic compounds like PLA or organic acids rather than proteins or peptides molecules.

• Research in Plant Disease
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• v.14 no.1
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• pp.15-20
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• 2008

Three isolates of Cucumber mosaic virus (CMV) were isolated from weed hosts showing typical mosaic symptoms, and some properties of the viruses were investigated. CMV isolates, designated as Is-CMV, Jd-CMV and Pla-CMV from Isodon inflexus, Jeffersonia dubia and Phryma leptostachya var. asiatica, respectively, were identified and characterized by biological reaction in several host plants, serological property, dsRNA analysis, reverse transcription-polymerase chain reaction (RT-PCR), restriction fragment-length polymorphism (RFLP). All isolates systemically infected in Nicotiana benthamiana, Cucurbita pepo cv. Black beauty and Cucumis sativus, and did not reveal any differences in these host plants between the isolates. However, remarkable difference in the symptoms was found between the CMVs in Capsicum annuum. Is-CMV induced an asymptomatic symptoms, while Jd-CMV and Pla-CMV produced severe mosaic symptoms in C. annuum plants. In dsRNA analysis, all isolates revealed four major bands with estimated molecular size of 3.4, 3.2, 2.1 and 1.0 kbp. The cDNAs of coat protein gene of the isolates were amplified by RT-PCR using a genus-specific single pair primers that designed to amplify a DNA fragment of approximately ranging from 938 to 966 bp. By restriction mapping analysis using RFLP of the RT-PCR products as well as by serological properties of gel diffusion test, the CMV isolates belong to a typical members of CMV subgroup IA. This is the first report on the occurrence of CMV in the three weed hosts.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.102-109
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• 2018

In the present study, a variety of polylactide (PLA) articles (n = 211) were tested for migration of lead (Pb), cadmium (Cd) and arsenic (As) into the food simulant (4% v/v acetic acid). Pb, Cd, and As were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Migration tests were performed at $70^{\circ}C$ and $100^{\circ}C$ for 30 min. The amounts of Pb, Cd, and As increased at $100^{\circ}C$ for 30 min compared with levels at $70^{\circ}C$. However, the migration at both conditions was very low. The maximum level of Pb at $100^{\circ}C$ for 30 min corresponded to 1% of the migration limit. The estimated daily intakes (EDI) based on safety evaluation ranged from $2.5{\times}10^{-5}$ to $2.0{\times}10^{-3}{\mu}g/kg\;bw/day$ for Pb, Cd, and As. The EDI calculated from migration of Pb at $100^{\circ}C$ for 30 min in PLA was the maximum value, $2.0{\times}10^{-3}{\mu}g/kg\;bw/day$, which corresponded to 0.055% of provisional tolerable weekly intake (PTWI, $25{\mu}g/kg\;bw/week$). The data from this study represent a valuable source for science-based safety control and management of hazardous heavy metals migrating from polylactide food contact materials.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.126-135
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• 2001

Quinacrine (QU), a phospholipase-A2 (PLA-2) inhibitor has been used clinically as a chemotherapeutic adjuvant. To understand the mechanisms leading to its chemotherapeutic effect, we have investigated QU-induced apoptotic signaling pathways in human cervical squamous carcinoma HeLa cells. In this study, we found that QU induced cytochrome c-dependent apoptotic signaling. The release of pro-apoptotic cytochrome c was QU concentration- and time-dependent, and preceded activation of caspase-9 and -3. Flow cytometric FACScan analysis using fluorescence intensities of $DiOC_6$/ demonstrated that QU-induced cytochrome c release was independent of mitochondrial permeability transition (MPT), since the concentrations of QU that induced cytochrome c release did not alter mitochondrial membrane potential (${\blacktriangle}{\Psi}_m$). Moreover, kinetic analysis of caspase activities showed that cytochrome c release led to the activation of caspase-9 and downstream death effector caspase-3, Caspase-3 inhibitor (Ac-DEVD-CHO) partially blocked QU-induced apoptosis, suggesting the importance of caspase-3 in this apoptotic signaling mechanism. Supplementation with arachidonic acid (AA) sustained caspase-3 activation induced by QU. Using inhibitors against cellular arachidonate metabolism of lipooxygenase (Nordihydroxyguaiaretic Acid, NDGA) and cyclooxygenase (5,8,11,14-Eicosatetraynoic Acid, ETYA) demonstrated that QU-induced apoptotic signaling may be dependent on its role as a PLA-2 inhibitor. Interestingly, NDCA attenuated QU-induced cytochrome c release, caspase activity as well as apoptotic cell death. The blockade of cytochrome c release by NDCA was much more effective than that attained with cyclosporin A (CsA), a MPT inhibitor. ETYA was not effective in blocking cytochrome c release, except under very high concentrations. Caspase inhibitor z-VAD blocked the release of cytochrome c suggesting that this signaling event is caspase dependent, and caspase-8 activation may be upstream of the mitochondrial events. In summary, we report that QU induced cytochrome c-dependent apoptotic signaling cascade, which may be dependent on its role as a PLA-2 inhibitor. This apoptotic mechanism induced by QU may contribute to its known chemotherapeutic effects.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.75-84
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• 2023

This study aimed to observe the protective effect of momordicine I, a triterpenoid compound extracted from momordica charantia L., on isoproterenol (ISO)-induced hypertrophy in rat H9c2 cardiomyocytes and investigate its potential mechanism. Treatment with 10 μM ISO induced cardiomyocyte hypertrophy as evidenced by increased cell surface area and protein content as well as pronounced upregulation of fetal genes including atrial natriuretic peptide, βmyosin heavy chain, and α-skeletal actin; however, those responses were markedly attenuated by treatment with 12.5 ㎍/ml momordicine I. Transcriptome experiment results showed that there were 381 and 447 differentially expressed genes expressed in comparisons of model/control and momordicine I intervention/model, respectively. GO enrichment analysis suggested that the anti-cardiomyocyte hypertrophic effect of momordicine I may be mainly associated with the regulation of metabolic processes. Based on our transcriptome experiment results as well as literature reports, we selected glycerophospholipid metabolizing enzymes group VI phospholipase A₂ (PLA2G6) and diacylglycerol kinase ζ (DGK-ζ) as targets to further explore the potential mechanism through which momordicine I inhibited ISO-induced cardiomyocyte hypertrophy. Our results demonstrated that momordicine I inhibited ISO-induced upregulations of mRNA levels and protein expressions of PLA2G6 and DGK-ζ. Collectively, momordicine I alleviated ISO-induced cardiomyocyte hypertrophy, which may be related to its inhibition of the expression of glycerophospholipid metabolizing enzymes PLA2G6 and DGK-ζ

• Polymer(Korea)
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• v.26 no.2
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• pp.174-178
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• 2002

PLLA-POE-PLLA block copolymers were prepared using PLLA and POE with different compositions. Copolymers were obtained in high yield and the polydispersity of the copolymers was very narrow. A dispersed solution of 0.1 g/mL of PLLA-POE-PLLA copolymer was mixed with a dispersed solution of 0.1 g/mL of PDLA-POE-PDLA copolymer. Gel formation was observed from the mixed product obtained at the human body temperature of $37^{\circ}C$. The mixed product comprising PDLA-POE-PDLA and PLLA-POE-PLLA was found to have higher cloud points than that of PLLA-POE-PLLA copolymer. The cloud points decreased with increasing the concentration of the mixed copolymer dispersed solution.