• The Plant Pathology Journal
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• v.39 no.1
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• pp.28-38
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• 2023

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positivesense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host's machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins' role in replicating plant (+)ss RNA viruses.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1457-1466
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• 2012

Antimicrobial peptides (AMPs) exert antimicrobial activity against Gram-positive and Gram-negative bacteria, fungi, and viruses by various mechanisms. AMPs commonly possess particular characteristics by harboring cationic and amphipathic structures and binding to cell membranes, resulting in the leakage of essential cell contents by forming pores or disturbing lipid organization. These membrane disruptive mechanisms of AMPs are possible to explain according to the various structure forming pores in the membrane. Some AMPs inhibit DNA and/or RNA synthesis as well as apoptosis induction by reactive oxygen species (ROS) accumulation and mitochondrial dysfunction. Specifically, mitochondria play a major role in the apoptotic pathway. During apoptosis induced by AMPs, cells undergo cytochrome c release, caspase activation, phosphatidylserine externalization, plasma or mitochondrial membrane depolarization, DNA and nuclei damage, cell shrinkage, apoptotic body formation, and membrane blebbing. Even AMPs, which have been reported to exert membrane-active mechanisms, induce apoptosis in yeast. These phenomena were also discovered in tumor cells treated with AMPs. The apoptosis mechanism of AMPs is available for various therapeutics such as antibiotics for antibiotic-resistant pathogens that resist to the membrane active mechanism, and antitumor agents with selectivity to tumor cells.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.352-373
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• 2003

Rhamnose-rich (RROP-s) and fucose-rich (FROP-s) oligo-and polysaccharides were prepared and extensively characterised by physical and chemical procedures [1,2] and compared to L-fucose. Their biological properties were then studied on human skin fibroblast cell cultures, human skin explant cultures and on hairless rat skin, using a variety of cell-biological, biochemical and computerised morphometrical procedures. Among the most important properties we could establish, the following are of particular interest for the tretment and prevention of age-dependent modifications of human skin (loss of skin-tissue, cells and matrix, wrinkle formation and others) : stimulation of cell proliferation (by $^3$[H]-thymidine incorporation and the MTT test), scavenging of reactive oxygen species (ROS) using several different procedures, and protease (MMP-2 and MMP-9) down-regulation. A topical preparation, using RROP-s and FROP-s, and/or L-fucose, was shown to increase cell proliferation, dermal matrix synthesis, efficient scavenging of ROS-s and to increase also the thickness of dermal tissue when applied for 4 weeks on hairless rat skin, accompanied by the densification of collagen bundles as well as by an increase of elastin synthesis. Using fluorescent labeled FROPs, it could be shown that these oligosaccharides react with cell-membrane receptors and especially with the elastin-laminin-receptor and the fucose-mannose receptor, but they penetrate also in the cell nucleus, suggesting the possibility of a direct action on the regulation of gene expression. When applied to the human skin of a team of voluntary women encompassing all age-groups, the efficiency of FROP-containing preparation could be confirmed using indentometry and computerised evaluation of skin micro-relief, as well as evaluation of periorbital wrinkles. It appears therefore that these preparations correspond to all the requirements of active anti-aging principles.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.200-207
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• 2020

In this study, the effect of calcination temperature on the production of RuTi catalyst in NH₃-SCO (selective catalytic oxidation) was investigated. The RuTi catalyst was prepared using the wet impregnation method, and calcined at 400~600 ℃ for 4 h in air condition. The catalysts were named RuTi x00 where x00 means the calcination temperature. According to XRD (X-Ray diffraction), TEM (transmission electron microscope), H₂-TPR (H₂-temperature programmed reduction) analyses, RuTi x00 catalysts displayed that the dispersion of active metal decreased via increasing the calcination temperature. The catalysts with low dispersion showed a decrease in the surface adsorption oxygen species (O_β) and NH₃ adsorption amount via XPS, and NH₃-TPD analyses. Therefore, the RuTi 400 catalyst was well dispersed in the active metal on TiO₂ surface, and also, the NH₃ removal efficiency was excellent.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.211-219
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• 2024

Background: Recently, plant-derived exosome-like nanoparticles (PDENs) have been isolated, and active research was focusing on understanding their properties and functions. In this study, the characteristics and molecular properties of ginseng root-derived exosome-like nanoparticles (GrDENs) were examined in terms of skin protection. Methods: HPLC-MS protocols were used to analyze the ginsenoside contents in GrDENs. To investigate the beneficial effect of GrDENs on skin, HaCaT cells were pre-treated with GrDENs (0-2 × 10⁹ particles/mL), and followed by UVB irradiation or H₂O₂ exposure. In addition, the antioxidant activity of GrDENs was measured using a fluorescence microscope or flow cytometry. Finally, molecular mechanisms were examined with immunoblotting analysis. Results: GrDENs contained detectable levels of ginsenosides (Re, Rg1, Rb1, Rf, Rg2 (S), Gyp17, Rd, C-Mc1, C-O, and F2). In UVB-irradiated HaCaT cells, GrDENs protected cells from death and reduced ROS production. GrDENs downregulated the mRNA expression of proapoptotic genes, including BAX, caspase-1, -3, -6, -7, and -8 and the ratio of cleaved caspase-8, -9, and -3 in a dose-dependent manner. In addition, GrDENs reduced the mRNA levels of aging-related genes (MMP2 and 3), proinflammatory genes (COX-2 and IL-6), and cellular senescence biomarker p21, possibly by suppressing activator protein-1 signaling. Conclusions: This study demonstrates the protective effects of GrDENs against skin damage caused by UV and oxidative stress, providing new insights into beneficial uses of ginseng. In particular, our results suggest GrDENs as a potential active ingredient in cosmeceuticals to promote skin health.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.222-238
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• 1995

Inflammatory cells may produce active species of oxygen in antimicrobial defense. While such species can directly damage surrounding tissue, their major secondary role may be to mediate important components of the inflammatory response. Superoxide dismutase, antioxidant, have significant anti-inflammatory properties in rheumatoid arthritis, ischemic tissue injury and gastrointestinal disease. Increased oxidative product formation diseases. And superoxide dismutase produced by Porphyromonas Gingivalis is resistant to killing by polymorphonuclear leukocyte. The purpose of this study was to investigate on the effects of superoxide dismutase in 3T3 fibroblast and in experimental gingivitis in the rats. The effect of superoxide dismutase(SOD) to cell morphology and cell activity was measured in cultured mouse 3T3 fibroblast. After experimental gingivitis were induced by lipopolysaccharide(LPb) and bovine serum albumin(BSA), injection of SOD were done. WBC count and histologic findings were observed at 1, 2, 3, and 7 days. The results were as follows; 1. There was a little difference between LPS treated groups and SOD treated groups in 3T3 fibroblast morpholoy. 2. There was no difference between only SOD treated groups (except SOD 150U at 3days) and control in 3T3 fibroblast activity. 3. LPS $0.5{\mu}g/ml$ and SOD treated groups (except 150U) had decreased 3T3 fibroblast activity and no significant difference at 3 days. 4. LPS $5.0{\mu}g/ml$ and SOD treated groups were significantly increased cell activity of 3T3 fibroblast than control group at 1 day(P<0.05). 5. In LPS induced gingivitis, the number of leukocytes in SOD treated was significantly decreased than in saline treated at 1 day(P<0.05). 6. In histopathologic findings of LPS or BSA induced gingivitis, inflammatorycell infiltration in SOD treated groups were less than in saline treated group at 1, 2 and 3 days.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.128-139
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• 2003

Juglans sinensis Dode has been reported to have antioxidant activity. However, the effect of Juglans sinensis Dode aquacupuncture(JS) on reactive oxygen species(ROS)-induced alterations in membrane transport function in renal tubular cells. This study was performed to evaluate the effect of JS on the organic hydroperoxide t-butylhydroperoxide(tBHP)-induced inhibition of $Na^+$-dependent phosphate($Na^+$-Pi) uptake in opossum kidney (OK) cells, an established renal proximal epithelial cell line. tBHP inhibited $Na^+$-Pi uptake in a time-dependent manner. The inhibitory effect of tBHP was prevented by JS over concentration range of 0.05-1mg/100ml in a dose-dependent manner. Kinetic studies showed that tBHP caused an decrease in Vmax for $Na^+$-Pi uptake without any a significant change in Km. $Na^+$-dependent phosphonoformic acid binding, a irreversible inhibitor of renal $Na^+$-Pi uptake, was decreased by tBHP treatment. The reduction in Vmax and phosphonoformic acid binding by tBHP was prevented by JS. tBHP induced lipid peroxidation and its effect was completely inhibited by JS and antioxidant N,N'-diphenyl-p-phenylenediamine. These data suggest that the oxidant inhibits phosphate uptake by a reduction in the number of active carrier across the membrane. JS may prevent oxidant-induced inhibition of membrane transport function by a mechanism similar to antioxidants in renal epithelial cells. Although the precise constituents remain to be explored, JS may be employed as a useful candidate herb for drug development to prevent and treat oxidant-mediated renal failure.

• Food Science and Preservation
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• v.18 no.1
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• pp.65-71
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• 2011

We explored the effect of extracts of dried Platycodon grandiflorum on production of reactive oxygen species (ROS), glutathione (GSH) and nitric oxide (NO). To determine antioxidant activity in the presence of $H_2O_2$-induced oxidative stress, DCFH-DA (dichlorodihydrofluorescin diacetate) assay was employed. Acetone/methylene chloride (A+M) and methanolic (MeOH) extracts of P. grandiflorum reduced intracellular ROS levels. Of the various tested fractions, n-BuOH fraction showed the highest protective effect in terms of lipid peroxide production. Total GSH levels were measured after treatment of HT1080 cells with the A+M and MeOH extracts, and other solvent fractions, at various concentration. The A+M extacts and 85% (v/v) aqueous MeOH fraction significantly increased GSH levels (p<0.05). When lipopolysaccharide (LPS)-induced NO production was evaluated, all tested crude extracts, and fractions thereof, significantly reduced NO production (p<0.05), and the n-BuOH and 85% (v/v) aqueous MeOH fractions (at 0.05 mg/mL) showed the strongest inhibitory effects. The results showed that the n-BuOH fraction inhibited both cellular oxidation and NO production, and this fraction may thus contain valuable active compounds.

• Journal of Life Science
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• v.20 no.9
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• pp.1365-1372
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• 2010

We investigated the inhibitory effects of solvent extracts from dried yam on $H_2O_2$-induced oxidative stress and growth of cancer cell lines (HT1080 human fibrosarcoma and HT-29 human colon cancer cells). Yam (Dioscoreacea) has been recognized as a healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-proliferation, and anti-mutagenic activities, as well as its ability to decrease blood glucose and cholesterol levels. In order to determine the protective effect on $H_2O_2$-induced oxidative stress, DCFH-DA (dichlorodihydrofluorescin diacetate) assay was conducted. Acetone with methylene chloride (A+M) extract of dried yam appeared to reduce the levels of intracellular reactive oxygen species (ROS) with dose responses. Among the fractions, 85% aq. methanol fraction showed the highest protective effect on production of lipid peroxides. Inhibitory effects of A+M and methanol (MeOH) extracts on the growth of HT1080 and HT-29 cancer cells increased in a dose dependent manner. The treatments of n-hexane, 85% aq. methanol and n-butanol fractions (${\geqq}0.5$ mg/ml concentrations) significantly inhibited the growth of both cancer cells (p<0.05). From these results, 85% aq. methanol fraction showed inhibitory effects on cellular oxidation and growth of human cancer cells, suggesting that this fraction may contain active compounds of dried yam.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.727-733
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• 1996

2-(Allylthio)pyrazine is effective in selectively suppressing constitutive and inducible expression of cytochrome P450 2E1. The effect of 2-(allylthio)pyrazine against potentiat ed chemical injury was studied in rats. Vitamin-A pretreatment of rats substantially increased carbon tetrachloride hepatotoxicity, as supported by an ~4-fold increase in serum alanine aminotransferase (ALT) activity. Concomitant pretreatment of rats with 2-(allylthio)pyrazine at the daily dose of 200mg/kg resulted in a 76% decrease in vitamin-A-potentiated hepatotoxicity, which supported the possibility that 2-(allylthio)pyrazine protects the liver against chemical-induced hepatic injury by the mechanism associated with Kupffer cell inactivation. Pyridine pretreatment caused substantial enhancement in carbon tetrachloride hepatotoxicity. 2-(Allylthio)pyrazine treatment of rats reduced the pyridine-potentiated toxicity in a dose-dependent manner. Animals treated with both pyridine and 2-(allylthio)pyrazine prior to intoxicating dose of CCl$_4$ resulted in 85% and 47% decreases in pyridine-increased triglycerides and cholesterol levels in the liver. The protective effect of 2-(allylthio)pyrazine on the DNA strand breakage induced by benzenetriol was assessed by measuring the conversion of supercoiled ${\Phi}x$-174 DNA to the open relaxed form. 2-(Allylthio)pyrazine blocked the benzenetriol-induced conversion of supercoiled DNA to open circular form in a dose-dependent manner. The presence of 2-(allylthio)pyrazine at the doses from I to 10mM in the incubation mixture containing 5 ${\mu}$M benzenetriol completely protected benzenetriol-induced DNA strand breakage with the EC50 for the 2-(allylthio)pyrazine blocking being noted as ~220 ${\mu}$M, whereas allyl disulfide exerted protecting effect at relatively high concentrations (i.e. ~850 ${\mu}$M), suggesting that 2-(allylthio)pyrazine effectively scavenges the reactive oxygen species. These results provide evidence that 2-(allylthio)pyrazine blocks vitamin A- or pyridine-potentiated CCl$_4$ hepatotoxicity and that the agent is active in protecting DNA by scavenging the reactive oxygen species.