• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.165-170
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• 2007

Pyungwi-san(PWS) have been using as a basic prescription of digestive disorder in Korean traditional medicine. This study was performed to examine the in vitro antioxidant activity of the extract using different antioxidant tests including by 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging, superoxide anion radical scavenging, metal chelating hydrogen peroxide scavenging, lipid peroxydation protective effect and scavenging effect of nitric oxide and peroxynitrite. Herbal-acupuncture solution of PWS(PWS-HS) exhibited a concentration-dependent inhibition of DPPH radical adduct formation and it showed dose-dependent free radical scavenging activity onto superoxide anions. In addition, the result of metal chelating hydrogen peroxide scavenging and ammonium thiocyanate experiments showed that PWS-HS was an active scavenger of hydroxyl radicals. Furthermore, it was also found to be effective in scavenging nitric oxide and peroxynitrite, well-known cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.35-39
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• 2002

The significance of cell ploidy and repair ability for the radioprotective efficiency of cysteamine was studied in DNA repair - proficient and repair - deficient yeast cells irradiated $^{60}C0\;\gamma-rays.$ Results have been obtained for the cell survival of two groups of yeasts-diplont and haplont cells, both in haploid and diploid states. For diploid Saccharomyces cerevisiae yeast cells, the correlation between the radio-protective action of cysteamine and the cell repair capacity was demonstrated. Such a correlation was not clearly expressed for haploid yeast cells. In addition, evidence was obtained indicating that the degree of the radioprotective action was independent of the number of chromosome sets in haplont yeast Pichia guilliermondii cells and in some radiosensitive mutants defective in the diploid-specific recovery. It is concluded on this basis that the radioprotective action may involve the cellular recovery process, which may be mediated by a recombination-like mechanism, for which the diploid state is required. The results obtained clearly show that the radioprotective effect was dependent on DNA repair status and indicate that the mechanism of the radioprotective action may be realized on the level of primary radiation damage production as well as on the level of postradiation recovery from potentially lethal radiation damage.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.271-278
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• 2001

Oxidative stress and methylglyoxal (MG), a reactive dicarbonyl metabolites produced by enzymatic and non-enzymatic reaction of normal metabolism, induced aldose reductase (AR) expression in rat aortic smooth muscle cells (SMC). AR expression was induced in a time-dependent manner and reached at a maximum of 4.5-fold in 12 h of MG treatment. This effect of MG was completely abolished by cyclohemide and actinomycin D treatment suggesting AR was synthesized by de novo pathway. Pretreatment of the SMC with N-acetyl-L-cysteine significantly down-regulated the MG-induced AR mRNA. Furthermore, DL-Buthionine-(S,R)-sulfoximine, a reagent which depletes intracellular glutathione levels, increased the levels of MG-induced AR mRNA. These results indicated that MG induces AR mRNA by increasing the intracellular peroxide levels. Aminoguanidine, a scanvenger of dicarbonyl, significantly down-regulated the MG-induced AR mRNA. In addition, the inhibition of AR activities with statil, an AR inhibitor, enhanced the cytotoxic effect of MG on SMC under normal glucose, suggesting a protective role of AR against MG-induced cell damages. These results imply that the induction of AR by MG may contribute to an important cellular detoxification of reactive aldehyde compounds generated under oxidative stress in extrahepatic tissues.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.157-163
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• 2008

Formation of ${\beta}$-amyloid $(A{\beta})$ fibrils has been identified as one of the major characteristics of Alzheimer's disease (AD). Inhibition of $A{\beta}$ fibril formation in the CNS would be attractive therapeutic targets for the treatment of AD. Several small compounds that inhibit amyloid formation or amyloid neurotoxicity in vitro have been known. Citrate has surfactant function effect because of its molecular structure having high anionic charge density, in addition to the well-known antibacterial and antioxidant properties. Therefore, we hypothesized that citrate might have the inhibitory effect against $A{\beta}$ fibril formation in vitro and have the protective effect against $A{\beta}$-induced neurotoxicity in PC12 cells. We examined the effect of citrate against the formation of $A{\beta}$ fibrils by measuring the intensity of fluorescence in thioflavin-T (Th-T) assay of between $A{\beta}_{25-35}$ groups treated with citrate and the control with $A{\beta}_{25-35}$ alone. The neuroprotective effect of citrate against $A{\beta}$-induced toxicity in PC12 cells was investigated using the WST-1 assay. Fluorescence spectroscopy showed that citrate inhibited dose-dependently the formation of $A{\beta}$ fibrils from ${\beta}$-amyloid peptides. The inhibition percentages of $A{\beta}$ fibril formation by citrate (1, 2.5, and 5 mM) were 31%, 60%, and 68% at 7 days, respectively in thioflavin-T (Th-T) assay. WST-1 assay revealed that the toxic effect of $A{\beta}_{25-35}$ was reduced, in a dose-dependent manner to citrate. The percentages of neuroprotection by citrate (1, 2.5, and 5 mM) against $A{\beta}-induced$ toxicity were 19%, 31 %, and 34%, respectively. We report that citrate inhibits the formation of $A{\beta}$ fibrils in vitro and has neuroprotective effect against $A{\beta}$-induced toxicity in PC12 cells. Neuroprotective effects of citrate against $A{\beta}$ might be, to some extent, attributable to its inhibition of $A{\beta}$ fibril formation. Although the mechanism of anti-amyloidogenic activity is not clear, the possible mechanism is that citrate might have two effects, salting-in and surfactant effects. These results suggest that citrate could be of potential therapeutic value in Alzheimer's disease.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.284-291
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• 2013

In this study, the antibacterial and antioxidative activities of Epimedium koreanum Nakai were investigated for applications as cosmetic ingredients. Minimum inhibitory concentrations (MICs) of fraction-bacterium, that showed high antibacterial activity from disc diffusion assay on human skin pathogens, were tested. The ethyl acetate fraction on Staphylococcus aureus, Bacillus subtilis, Propionibacterium acnes and 50% ethanol extract on S. aureus exhibited higher antibacterial activities than methyl paraben, well known as a preservative. The DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activities of 3 fractions of E. koreanum Nakai were lower than (+)-${\alpha}$-tocopherol, known as a typical antioxidant. From the results of the scavenging activities of various ROS generated in $Fe^{3+}-EDTA/H_2O_2$ systems ($OSC_{50}$), 50% ethanol extract ($OSC_{50}=2.46{\pm}0.06{\mu}g/ml$) and aglycone fraction ($OSC_{50}=1.45{\pm}0.02{\mu}g/ml$) showed high activities similar to L-ascorbic acid ($OSC_{50}=1.50{\pm}0.85{\mu}g/ml$), used as reference. The cellular protective effects (${\tau}_{50}$) on photohemolysis by $^1O_2$ generated by photosensitization reaction were tested. The cellular protective effect of 50% ethanol extract (${\tau}_{50}=37.0{\pm}0.3$ min) was similar to (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.0{\pm}1.8$ min), used as reference. In particular, the ${\tau}_{50}$ of aglycone fraction results were $165.9{\pm}7.2$ min. This is a high cellular protective effect, more than 4 times that of (+)-${\alpha}$-tocopherol. These results indicate that E. koreanum Nakai extract, and its fractions, could be utilized as a cosmetic ingredient possessing antibacterial and antioxidative activities.

• Journal of Life Science
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• v.31 no.2
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• pp.126-136
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• 2021

Oxidative stress causes injury to and degeneration of retinal pigment epithelial (RPE) cells. It is involved in several retinal disorders and leads to vision loss. In the present study, we investigated the effect of 14 kinds of natural compounds and two kinds of synthetic compounds on oxidative stress-induced cellular damage in human PRE cell lines (ARPE-19). From among them, we selected five kinds of compounds, including auranofin, FK-509, hemistepsin A, honokiol, and spermidine, which have inhibitory effects against hydrogen peroxide (H2O2)-mediated cytotoxicity. In addition, we found that four kinds of compounds (excluding auranofin) have protective effects on H2O2-induced mitochondrial dysfunction. Furthermore, the expression of phosphorylation of histone H2AX, a sensitive marker of DNA damage, was markedly up-regulated by H2O2, whereas it was notably down-regulated by FK-506, honokiol, and spermidine treatment. Meanwhile, five kinds of candidate compounds had no effect on H2O2-induced intracellular reactive oxygen species (ROS) levels, suggesting that the five candidate compounds have protective effects on oxidative stress-induced cellular damage through the ROS-independent pathway. Taken together, according to the results of H2O2-mediated cellular damage―such as cytotoxicity, apoptosis, mitochondrial dysfunction, and DNA damage―spermidine and FK-506 are the natural and synthetic compounds with the most protective effects against oxidative stress in RPE. Although further studies on the identification of the mechanism responsible are required, the results of the present study suggest the possibility of using spermidine and FK-506 to suppress the risk of retinal disorders.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.525-531
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• 2013

Purpose: To identify the apoptosis caused by Proparacaine hydrochloride (PPC), a topical anesthesia, applied to conjunctival cell lines and determine whether pigallocatechin-gallate (EGCG), has protective effects on. Methods: The conjunctival cell lines were treated with 0.5% of Alcaine$^{(R)}$, 0.5% of PPC and 0.01% of Benzalkonium chloride (BAC) for 15 minutes, respectively in order to investigate the effects of topical anesthesia on cells, and followed by cultured for 12 and 24 hours. The recovery effects were investigated by measuring level of cellular proliferation inhibiting using MTT assay and LDH assay. The conjunctival cell lines were pre-treated with EGCG $10{\mu}M$ for 3 hrs and post-treated with 0.5% PPC for 15 mins in order to investigate whether EGCG has protective effects, flow cytometry were performed in order to observe apoptosis. Results: A result of the additional culture of 12 and 24 hours and again immediately after the treatment for 15 minutes 0.5% of Alcaine$^{(R)}$, 0.5% of PPC, the 0.01% of BAC, cell viability was not increased in all groups (p<0.05). The cell viabilities were higher than in cells 3 hours post-treated with $10{\mu}M$ of EGCG and pre-treated PPC 0.5% (68.2%), compared to cells ($32.2{\pm}2.0%$) treated only with 0.5% of PPC. PPC 0.5% also induced apoptosis in the treated group was reduced by the addition of EGCG. Conclusions: It is considered that the EGCG has cell protective effects when it is added to PPC, a topical anesthesia, by improving cell viability and inhibiting apoptosis.

• YAKHAK HOEJI
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• v.56 no.2
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• pp.99-107
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• 2012

The protective effect of AI-1367 (Alnus japonica extract) on liver injury was investigated. Primary rat hepatocyte intoxication was induced by tert-butyl hydroperoxide (tBH), carbon tetrachloride ($CCl_4$), or D-glactosamine (D-GalN). Liver injury was induced by $CCl_4$, D-GalN or MCD (methionine choline deficient)-diet in mouse. The cellular leakage of lactate dehyrogenase and cell viability followed by the treatment of hepatotoxicants were significantly improved by AI-1367 treatment at a concentration range of 5~50 ${\mu}g/ml$ for tBH, 5~50 ${\mu}g/ml$ for D-GalN, and 5~100 ${\mu}g/ml$ for $CCl_4$, respectively. Treatment with AI-1367 (20, 10, 5 mg/kg, p.o.) on liver injury induced by subcutaneous injection of $CCl_4$ or D-GalN reduced significantly the levels of aspartate transaminase and alanine transaminase in serum. Histological observations revealed that fatty acid changes, hepatocyte necrosis and inflammatory cell infiltration in $CCl_4$ (D-GalN)-induced liver injury was improved by administration of AI-1367. AI-1367 treatment (10, 5, 2.5 mg/kg, p.o.) also significantly recovered the body weight change and serum levels of aspartate transaminase, alanine transaminase and triglyceride in liver injury induced by MCD diet. From these results, AI-1367 shows protective effects against tBH, $CCl_4$, D-GalN, or MCD diet-induced hepatotoxicity in vitro or in vivo.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.3
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• pp.359-367
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• 2014

This study analyzed phytochemicals, including various carotenoids, tocopherol and L-ascorbic acid, in green, yellow and orange paprikas (GP, YP and OP) and measured the preventive effects of lipophilic extracts from different colored paprikas on the blockage of gap junctional intercellular communication (GJIC), which is known as a cellular event associated with tumor promotion. Main carotenoids were lutein and ${\beta}$-carotene in GP, lutein, ${\beta}$-carotene, capsanthin, violaxanthin, ${\beta}$-carotene and capsorubin in YP, and lutein, ${\beta}$-carotene, cryptoxanthin and zeaxanthin in OP. Total carotenoid contents were $65.54{\pm}15.87$ mg/100 g dw in OP, $11.98{\pm}0.69$ mg/100 g dw in YP and $10.30{\pm}1.43$ mg/100 g dw in GP. Tocopherol contents were highest in GP compared with in YP and OP, whereas L-ascorbic acid contents were very high in all paprikas. We determined the non-cytotoxic levels of paprika extracts by MTT assay, which showed less formation of reactive oxygen species (ROS) induced by $500{\mu}M$ $H_2O_2$ for 1h. Finally, we showed that pretreatment of paprika extracts prevented inhibition of GJIC induced by $500{\mu}M$ $H_2O_2$ by the scrape-loading/dye-transfer technique. In conclusion, each colored paprika has unique phytochemicals and showed a protective effect on inhibition of GJIC.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.116-122
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• 2015

Keratinocytes are first barrier against outer challenges on skin. However, it is still largely unknown about effective protectors against ultraviolet B (UVB), and oxidative stress in human keratinocyte, HaCaT cells. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a role in the pathogenesis of skin disorders. Therefore, the purpose of this study was to evaluate the effect of Portulaca oleracea 70% EtOH extracts against hydrogen peroxide (H₂O₂)-induced oxidative stress in human keratinocytes, HaCaT cells. P. oleracea 70% EtOH extracts showed the potent protective effects on H₂O₂-induced toxicity by induced the expression of HO-1 in human keratinocyte, HaCaT cells. Furthermore, P. oleracea 70 % EtOH extracts caused the nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2) in human keratinocytes, HaCaT cells. In addition, we found that treatment with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) reduced P. oleracea 70% EtOH extracts-induced HO-1 expression, and JNK inhibitor (SP600125) also inhibited protective effects by P. oleracea 70% EtOH extracts. Therefore, these results suggest that P. oleracea 70 % EtOH extracts increases cellular resistance to H₂O₂-induced oxidative injury in human keratinocyte, HaCaT cells, presumably through JNK pathway-Nrf2-dependent HO-1 expression.