• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1707-1716
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• 2019

The development of new antimicrobial agents is essential for the effective treatment of diseases such as sepsis. We previously developed a new short peptide, Pap12-6, using the 12 N-terminal residues of papiliocin, which showed potent and effective antimicrobial activity against multidrug-resistant Gram-negative bacteria. Here, we investigated the antimicrobial mechanism of Pap12-6 and a newly designed peptide, Pap12-7, in which the 12^th Trp residue of Pap12-6 was replaced with Val to develop a potent peptide with high bacterial selectivity and a different antibacterial mechanism. Both peptides showed high antimicrobial activity against Gram-negative bacteria, including multidrug-resistant Gram-negative bacteria. In addition, the two peptides showed similar anti-inflammatory activity against lipopolysaccharide-stimulated RAW 264.7 cells, but Pap12-7 showed very low toxicities against sheep red blood cells and mammalian cells compared to that showed by Pap12-6. A calcein dye leakage assay, membrane depolarization, and confocal microscopy observations revealed that the two peptides with one single amino acid change have different mechanisms of antibacterial action: Pap12-6 directly targets the bacterial cell membrane, whereas Pap12-7 appears to penetrate the bacterial cell membrane and exert its activities in the cell. The therapeutic efficacy of Pap12-7 was further examined in a mouse model of sepsis, which increased the survival rate of septic mice. For the first time, we showed that both peptides showed anti-septic activity by reducing the infiltration of neutrophils and the production of inflammatory factors. Overall, these results indicate Pap12-7 as a novel non-toxic peptide with potent antibacterial and anti-septic activities via penetrating the cell membrane.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.6
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• pp.503-508
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• 2014

Spontaneous myometrial contraction (SMC) in pregnant uterus is greatly related with gestational age and growing in frequency and amplitude toward the end of gestation to initiate labor. But, an accurate mechanism has not been elucidated. In human and rat uterus, all TRPCs except TRPC2 are expressed in pregnant myometrium and among them, TRPC4 are predominant throughout gestation, suggesting a possible role in regulation of SMC. Therefore, we investigated whether the TRP channel may be involved SMC evoked by mechanical stretch in pregnant myometrial strips of rat using isometric tension measurement and patch-clamp technique. In the present results, hypoosmotic cell swelling activated a potent outward rectifying current in G protein-dependent manner in rat pregnant myocyte. The current was significantly potentiated by $1{\mu}M$ lanthanides (a potent TRPC4/5 stimulator) and suppressed by $10{\mu}M$ 2-APB (TRPC4-7 inhibitor). In addition, in isometric tension experiment, SMC which was evoked by passive stretch was greatly potentiated by lanthanide ($1{\mu}M$) and suppressed by 2-APB ($10{\mu}M$), suggesting a possible involvement of TRPC4/5 channel in regulation of SMC in pregnant myometrium. These results provide a possible cellular mechanism for regulation of SMC during pregnancy and provide basic information for developing a new agent for treatment of premature labor.

• YAKHAK HOEJI
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• v.48 no.6
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• pp.323-327
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• 2004

Whitening effect, which decreases the skin pigmentation, is the one of important targets in cosmetics. This study was investigated the effects of Scirpi rhizoma on ant ioxidation and melanogenesis. S.rhizoma is a rhizome of Scirpus fluviatilis G. a perennial Cyperaceae species of wide occurrence in Asia, Europe, Africa and North America. S.rhizoma shown scavenging activities of free radicals and reactive oxygen species (ROS) with the IC50 of 638${\mu}g/ml$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 21.7${\mu}g/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. S.rhizoma treatment (48 h) suppressed the biosynthesis of melanin up to 27% and reduced tyrosinase activity up to 31% at 100${\mu}g/ml$ in B16 melanoma cells. S.rhizoma was also able to significantly inhibit tyrosinase and TRP-1 expres- sion in protein level. These results suggest that S.rhizoma inhibited melanin biosynthesis by regulating tyrosinase activity and expression in B16 melanoma cells. Therefore S.rhizoma may be useful as new whitening agent due to the antioxidant effect and the inhibitory effect against melanogenesis.

• The Korea Journal of Herbology
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• v.27 no.4
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• pp.73-80
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• 2012

Objectives : Under normal condition melanin protects the skin from extracellular stimuli including ultraviolet (UV)-induced oxidative skin damages, but excess production and accumulation of melanin can induce hyperpigmentation causing esthetic problems. Therefore, in this study we tried to search for natural skin whitening materials from marine natural resources. Methods : Water and ethanol extracts of marine natural resources were prepared from Porphyra thalli (PT), Laminariae thallus (LT), Ostreae concha (OC), Sargassum thallus (ST), Undaria thallus (UT), Codium thalli (CT), Enteromorpha thalli (ET), Syngnathoides biaculeatus (SB), and Hippocampus coronatus (Hc). Their effects against UVB and ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis were investigated based on melanin formation in B16 mouse melanoma cells. The mRNA and protein expression of enzymes involved in the melanogenic process were further examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. Results : Water extract of Ostreae concha (OCW/E) effectively inhibited UVB and ${\alpha}$-MSH-induced melanin production in B16 melanocytes, which seemed to be mediated by inhibition of mRNA expression of tyrosinase and tyrosinase-related protein 1 (TRP-1). In another experiment, ethanol extracts from Porphyra thalli (PTE/E), Laminariae thallus (LTE/E), Sargassum thallus (STE/E), Undaria thallus (UTE/E), Codium thalli (CTE/E), Syngnathoides biaculeatus (SBE/E), and Hippocampus coronatus (HcE/E) significantly suppressed UVB and ${\alpha}$-MSH-induced melanin formation. Furthermore, ethylacetate fraction isolated form LTE/E (LTE/EEt) decreased UVB and ${\alpha}$-MSH-elevated extracellular melanin levels via inhibition of tyrosinase protein expression. Conclutions : These results suggest that marine natural resources such as Porphyra thalli, Laminariae thallus, Ostreae concha, Sargassum thallus, Undaria thallus, Codium thalli, Syngnathoides biaculeatus and Hippocampus coronatus have anti-melanogenic effects, thereby exhibiting high potentials to be utilized as one of the ingredients for the development of new whitening functional cosmetics.

• Journal of the Korean Chemical Society
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• v.41 no.6
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• pp.304-312
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• 1997

Acetolactate synthase(ALS) is the common enzyme in the biosynthetic of valine, leucine, and isoleucine, and is the target of several classes of structually unrelated herbicides, including sulfonylureas, imidazolinones, and triazolopyrimidines. In an effort to develop new and desirable herbicides, we have synthesized 4,6-dimethoxypyrimidine derivatives, and examined their inhibitory activities on pea ALS. The most active compound was found to be K11570 and $IC_{50}$ value for K11570 was 0.2 ${\mu}M.$ The inhibition of pea ALS by K11570 was biphasic, showing increased inhibition with incubation time. The K11570 showed mixed-type inhibition with respect to substrate pyruvate. Dual inhibition analysis of K11570 versus sufonylurea herbicide Ally and feedback inhibitor leucine revealed that three inhibitors were competitive for binding to ALS. The arginine modified enzyme showed decreased inhibition by K11570, sufonylurea Ally, and leucine, in constrast to, tryptophan modification did not affect on the sensitivity of ALS to the inhibitors.

• Food Science of Animal Resources
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• v.37 no.3
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• pp.402-409
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• 2017

A novel peptide having free radical scavenging activity was separated, using an on-line high-performance liquid chromatography (HPLC) - ABTS screening method, from bovine skim milk fermented by Lactococcus lactis SL6 (KCTC 11865BP). It was further purified using reverse phase-HPLC (RP-HPLC) and sequenced by RP-HPLC-tandem mass spectrometry. The amino acid sequence of the identified peptide was determined to be Phe-Ser-Asp-Ile-Pro-Asn-Pro-Ile-Gly-Ser-Glu-Asn-Ser-Glu-Lys-Thr-Thr-Met-Pro-Leu-Trp (2,362 Da), which is corresponding to the C-terminal fragment of bovine ${\alpha}_{s1}$-casein (f179-199). The hydroxyl radicals scavenging activity ($IC_{50}$ $28.25{\pm}0.96{\mu}M$) of the peptide chemically synthesized based on the MS/MS data showed a slightly lower than that of the natural antioxidant Trolox ($IC_{50}$ $15.37{\pm}0.52{\mu}M$). Furthermore, derivatives of the antioxidant peptide were synthesized. The antioxidative activity of the derivatives whose all three proline residues replaced by alanine significantly decreased, whereas replacement of two proline residues in N-terminal region did not affect its antioxidative activity, indicating that $3^{rd}$ proline in C-terminal region is critical for the antioxidative activity of the peptide identified in this study. In addition, N-terminal region of the antioxidant peptide did not show its activity, whereas C-terminal region maintained antioxidative activity, suggesting that C-terminal region of the peptide is important for antioxidative activity.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1634-1638
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• 2002

Quantification of endogenous amino acid loss at the terminal ileum is an essential means for calculation of the true amino acid digestibility of a feedstuff. Since nitrogen appeared in the determined diet or not could shift the results very much, also, none of digestibility markers could be recovered with 100% rate at the terminal ileum, the objectives of the present study were: (1) to determine endogenous amino acid losses when fed either a casein diet or a protein-free diet and (2) to examine the reliability of chromic oxide or acid insoluble ash in the protein-free diet. Six ileal-cannulated pigs ($65{\pm}1.85 kg$ BW) with a simple T-cannula in the terminal ileum were used in a replicated $3{\times}3$ Latin square designed trial, after allowed a 14 d recuperation period. Each test period ran for 12 days comprised of a 10 d adjustment period and a 2 d collection period. The endogenous AA losses of His, Ile, Lys, Cys, Thr, Val, Trp, Asp, Glu, and Ser from pigs fed the casein diet were significantly higher than those of the protein-free diet (p<0.05). No significant difference was found in the amount of endogenous amino acid loss when determined with the different markers in the protein-free diet (p>0.05). These data suggest that endogenous amino acid loss could be underestimated when a protein-free diet is used. A direct effect of dietary peptides on the endogenous amino acid loss was found when the casein diet was fed. Our results also indicate that acid insoluble ash can be used as an inert marker as an alternative to chromic oxide when measuring endogenous amino acid loss.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6613-6618
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• 2013

To evaluate the relationship between alcohol drinking, XRCC1 codon 194 and 399 polymorphisms and risk of colorectal cancer, we conducted a case-control study with 315 colorectal cancer cases (105 colon, 210 rectal) and 439 population-based controls in Jiangsu Province of China. The XRCC1 codon 194 and 399 genotypes were identified using polymerase chain reaction and restrictrion fragment length polymorphism methods (PCR-RFLP). A structured questionnaire was used to elicit detailed information. Odds ratios (ORs) were estimated with an unconditional logistic model. In this study no significant differences were observed among the studied groups with regard to the genotype distribution of the XRCC1 codons 194 and 399 and the risk of colorectal cancer did not appear to be significantly influenced by genotype alone, whereas alcohol consumption showed a positive association (P for trend <0.01). When combined effects of XRCC1 polymorphisms and alcohol consumption were analyzed, we found that the 194Trp or 399Gln alleles further increased the colorectal cancer risk due to high alcohol intake. These findings support the conclusion that colorectal cancer susceptibility may be altered by gene-environment interactions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.1
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• pp.35-42
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• 2018

TRPA1 and TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels. TRPA1 and TRPV1 are often co-expressed in sensory neurons and play an important role in mechanical hyperalgesia and allodynia during neuropathic pain. Scutellariae Radix was reported to possess anti-inflammation properties and similar patterns of therapeutic action against different diseases. also Baicalin(a known principal constituent of Scutellaria Radix) was shown to down-regulate the mRNA expression levels of TRPV1. In this study, we observed the effects of Scutellariae Radix extract(SRE) in neuropathic pain induced SD rats via modulation of TRPV1 and TRPA1. Oral administration of a Scutellaria Radix extract(in doses of 300mg/kg, SRE(300)) showed a meaningful increase in the withdrawal threshold of mechanical allodynia and showed a meaningful decrease in the expression of c-fos compared to the control group. SRE(100) and SRE(300) showed a meaningful decrease in the expression of TRPV1 level compared to the control group. These results suggest that Scutellariae Radix extract could decrease mechanical allodynia by down-regulate the TRPV1 on the model of neuropathic pain.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.431-437
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• 2014

Synthetic compounds that are used in the clinic to regulate skin hyperpigmentation, such as arbutin, hydroquinone, and kojic acid, are only moderately effective. But, their use is limited by side effects. As part of an effort to overcome the limitations, we developed resveratrol-enriched rice (RR) using genetic engineering technique. Each of resveratrol and rice has been reported to produce anti-melanogenic effects. Therefore, we hypothesized that RR would show more anti-melanogenic effects than those of resveratrol or rice alone. Anti-melanogenic effect of RR was done by using melan-a mouse melanocytes. The depigmenting efficacy was then observed following topical application of the RR to UVB-stimulated hyperpigmented dorsal skin of guinea pigs. Treatment with RR extract resulted a $21.4{\pm}0.7%$ decrease in tyrosinase expression at melan-a cells. Colorimetric analysis showed a significantly lower depigmenting value by day 9 following treatment with RR in UVB-irradiated guinea pigs the dorsal skin (p<0.01), indicating that RR produced a depigmentation effect. By staining with Fontana-Masson stain, we found that the RR-treated group had more effect histopathologically in epidermal melanin production than resveratrol or rice alone-treated group. RR was associated with reduction in the levels of microphthalmia-associated transcription factor (MITF), and downregulation of tyrosinase and tyrosinase-related protein (TRP-2) expression, leading to inhibit epidermal melanin production by western blot analysis. This study suggests that the resveratrol-enriched rice may be a promising candidate in regulating skin pigmentation with UVB exposure.