• Journal of Nutrition and Health
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• v.52 no.5
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• pp.413-421
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• 2019

Purpose: Astragalus membranaceus (AM) is an important traditional medicinal herb. Pharmacological research has indicated that AM has various physiological activities such as antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, and hepatoprotective activities. The bioactive substances responsible for the physiological activities in AM, including many antioxidant substances, change during the roasting process. This study investigated and compared the changes in the antioxidant constituents of AM caused by roasting. Methods: DPPH (1,1-diphenyl-2-picryl hydrazyl) and $ABTS^+$ (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging activities and their total phenolic content (TPC) were measured. High-performance liquid chromatography (HPLC) analysis was performed to confirm any changes in the isoflavonoids of roasted AM (R-AM),. The cell viability of UVB-induced HDF (Human dermal fibroblast) cells treated with AM and R-AM extracts was investigated. The comet assay was used to examine the inhibitory effects of R-AM extracts on DNA damage caused by oxidative stress. Results: The DPPH and $ABTS^+$ radical scavenging activities were $564.6{\pm}20.9$ and $108.2{\pm}3.1$ ($IC_{50}$ value) respectively, from the 2R-AM. The total phenol content was $47.80{\pm}1.40mg$ GAE/g from the 1R-AM. The values of calycosin and formononetin, which are the known isoflavonoid constituents of AM, were $778.58{\pm}2.72$ and $726.80{\pm}3.45{\mu}g/g$ respectively, from the 2R-AM. Treatment of the HDF cells with R-AM ($50{\sim}200{\mu}g/mL$) did not affect the cell viability. Furthermore, the R-AM extracts effectively protected against UVB-induced DNA damage. Conclusion: The findings of this study indicate that R-AM increases its isoflavonoid constituents and protects against UVB-induced DNA damage in HDF cells.

• Journal of Life Science
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• v.22 no.7
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• pp.936-942
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• 2012

Prunus mume has been traditionally used as a medicinal food in Korea, Japan, and China. In particular, this fruit has been reported to have beneficial biological effects on gastritis and gastric ulcers. However, its action in relation to skin whitening has remained unclear. Accordingly, the effects of fruit extract of P. mume related to antioxidation and skin whitening were examined in this study. First, using the MTT assay, it was observed that fruit extract of P. mume below 0.1% has no cytotoxicity in B16-F1 cells as a result of cell viability. Second, the direct scavenging effects and the reducing power of the fruit extract of P. mume were evaluated in vitro on DPPH radicals, hydrogen peroxide, and superoxide. It exhibited high reducing power and scavenging activity on the aforementioned reactive oxygen species. Furthermore, we found that its protective effect against genomic DNA damage related to oxidative stress was increased in a dose-dependent manner. In addition, the fruit extract of P. mume had an inhibitory effect on melanin production induced by L-dopa. In addition, it reduced the expression level of NRF-2, SOD-1, and SOD-2 related to antioxidation in western blot analysis. These results suggest that fruit extract of P. mume could exert a whitening effect through inhibition of melanin production by its antioxidant effect.

• Journal of Life Science
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• v.18 no.12
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• pp.1651-1656
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• 2008

Redox factor-1 (Ref-1) is essential for repair of oxidatively damaged DNA and also govern the reductive activation of many transcription factors. In this study, we examined the effect of overexpressed Ref-1 on AKT activation for nitric oxide (NO) production in mouse aortic endothelial (MAE) cells. Adenoviral-mediated overexpression of Ref-1 enhanced NO production in unstimulated- as well as bradykinin-stimulated MAE cells. Importantly, forced overexpression of Ref-1 induced direct phosphorylation of AKT in cells. And, a PI3K inhibitor wortmannin completely abolished the increase in AKT phosphorylation by stimulation of bradykinin and/or overexpressed Ref-1. In addition, inhibition of AKT activity with HA-tagged activation-deficient AKT suppressed Ref-1-induced endothelial NO synthase (eNOS) phosphorylation and resulted in a corresponding inhibition of unstimulated- and bradykinin-stimulated NO production. These results suggest that Ref-1 stimulates direct phosphorylation of AKT for eNOS enzyme activity in murine endothelial cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.805-813
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• 2005

In our previous study, a novel herb mixture (HIM-I) of Angelim gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix was developed to protect the intestinal and immune systems and promote its recovery against radiation damage. In this study, a new herbal preparation (HemoHIM) with the high immune modulating activity was developed from HIM-I. HIM-I was fractionated into ethanol fraction (HIM-I-E) and polysaccharide fraction (HIM-I-P). And HemoHIM was prepared by adding HIM-I-P to HIM-I. The protective activities against $\gamma$ -irradiation were compared among HemoHIM, HIM-I and the fractions. HemoHIM and HIM-I significantly decreased the radiation-induced DNA damage in vitro, and scavenged hydroxyl radicals in a dose-dependent manner. HemoHIM showed similar activity to HIM-I. In vitro proliferation assay with mouse lymphocytes and bone marrow cells showed that HIM-I-P was remarkably higher than HIM-I and HIM-I-E in cell proliferating activity. HemoHIM showed higher activity than HIM-I and this might be associated with the higher polysaccharide content. The in vivo protective effects of HemoHIM and HIM-I were investigated in $\gamma$-irradiated mice. HemoHIM increased the surviving intestinal crypts to a similar extent compared with HIM-I. In contrast, HemoHIM appeared to be more effective than HIM-I in endogenous spleen colony formation assay. The recovery of white blood cells and lymphocytes in irradiated mice were significantly enhanced by the administration of HemoHIM. Also HemoHIM administration prolonged the survival of irradiated mice. These results showed that the novel herbal preparation, HemoHIM, effectively protected the self-renewal tissues and immune system, and promoted the survival of irradiated mice. Moreover, in comparison with HIM-I, HemoHIM maintained similar activity in the reduction of oxidative damage of self-renewal tissue but exhibited the higher activity in protection and proliferation of immune and hematopoietic cells. These results suggested that HemoHIM might be more effective than HIM-I in immune modulation as well as radioprotection.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.35-43
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• 2015

In this study, hot water extract from sea buckthorn (Hippophae rhamnoides L.) leaves fermented with Hericium erinaceum mycelium (SBT-HE) was assessed for protection against oxidative modification of biological macromolecules and cell death. Antioxidant activity of SBT-HE was evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, and peroxyl radical scavenging assays. SBT-HE showed 65.06% DPPH radical scavenging activity at $500{\mu}g/mL$, 98.83% ABTS radical scavenging activity at $50{\mu}g/mL$, and 44.03% peroxyl radical scavenging activity at $100{\mu}g/mL$. SBT-HE significantly inhibited DNA strand breakage induced by peroxyl radical. SBT-HE also prevented peroxyl radical-mediated human serum albumin modification. SBT-HE effectively inhibited $H_2O_2$-induced cell death and significantly increased cell survival by 21.59% at $100{\mu}g/mL$. SBT-HE also reduced intracellular reactive oxygen species levels in $H_2O_2$-treated cells. The results suggest that SBT-HE can contribute to antioxidant activity and protect cells from oxidative stress-induced cell injury.

• Journal of Life Science
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• v.31 no.8
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• pp.719-728
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• 2021

Melanin pigments are abundantly distributed in mammalian skin, hair, eyes, and nervous system. Under normal physiological conditions, melanin protects the skin against various environmental stresses and acts as a physiological redox buffer to maintain homeostasis. However, abnormal melanin accumulation results in various hyperpigmentation conditions, such as chloasma, freckles, senile lentigo, and inflammatory pigmentation. Tyrosinase, a copper-containing enzyme, plays an important role in the regulation of the melanin pigment biosynthetic pathway. Although several whitening agents based on tyrosinase inhibition have been developed, their side effects, such as allergies, DNA damage, mutagenesis, and cytotoxicity of melanocytes, limit their applications. In this study, we synthesized 4-chromanone derivatives (MHY compounds) and investigated their ability to inhibit tyrosinase activity. Of these compounds, (E)-3-(4-hydroxybenzylidene)chroman-4-one (MHY1294) more potently inhibited the enzymatic activity of tyrosinase (IC₅₀ = 5.1±0.86 μM) than kojic acid (14.3±1.43 μM), a representative tyrosinase inhibitor. In addition, MHY1294 showed competitive inhibitory action at the catalytic site of tyrosinase and had greater binding affinity at this site than kojic acid. Furthermore, MHY1294 effectively inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis and intracellular tyrosinase activity in B16F10 melanoma cells. The results of the present study indicate that MHY1294 may be considered as a candidate pharmacological agent and cosmetic whitening ingredient.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.701-710
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• 2008

The wild simulated ginseng (WSG) has been effectively used in folk medicine as a remedy against hepatic disease, hypertension and arthritic disease. However, there is still lack of scientific proof about its antioxidant capability. The present study has been conducted to evaluate the protective role of the WSG ethanol extract in the CCl4-induced oxidative stress and resultant hepatic disfunction in ICR mice. The electron donating abilities and IC50 of WSG etnanol extract were 76.86 ${\pm}$ 1.06% and 33.3 ${\mu}g$/mL (that of ascobic acid was 16.5 ${\mu}g$/mL), respectively. Total antioxidant status of WSG extract was 2.13 ${\pm}$ 0.06 mmoL/mg, while the values of ascorbic acid and BHT were 3.63 ${\pm}$ 0.06 and 3.12 ${\pm}$ 0.02, respectively. ICR mice (aged 3weeks) were fed for 4 weeks on AIN-93M diet and had free access to food and water. The animals were divided into three groups: normal group (intraperitoneally (i.p) injected with PBS at 100 ${\mu}L$/mouse), group C; CCl4-induced and without any treatment. (i.p injected only PBS, 100 ${\mu}L$ /mice), group G; CCl4-induced and treated with WSG (i.p injected with 5 mg WSG extract per mouse, suspended in 100 ${\mu}L$ phosphate buffer). After the i.p. injection of WSG or PBS (5 times for 7weeks), all mice were administered CCl4 in olive oil at the last day of the experiment, except for normal group. The normal group was administered only olive oil. Determination of plasma triglyceride, total cholersterol, fasting glucose and GPT activity was performed using automatic blood analyzer. To evaluate the protective effect against the oxidative stress, DNA fragmentation and TBARS were determined in blood leucocytes and RBC and hepatocyte, respectively. Body and organs weights and food intake did not show significant differences among the groups. Blood total cholesterol of group G was similar to that of normal group, which was the lowest in group C. The fasting blood glucose level was the highest in normal group (205.20 ${\pm}$ 135.24), which were decreased in group C (134.2 ${\pm}$ 79.31) and group G (126.48 ${\pm}$ 77.05). TBARS values in a red blood cell and hepatic tisuue homogenate were lower in group G comparing to the group C. DNA% in tail, tail length (TL) and tail moment (TM) of blood leucoocytes showed the highest values in group C (20.11 ${\pm}$ 2.47, 17.36 ${\pm}$ 2.58, 94.11 ${\pm}$ 12.29) and they were significantly diminished in group G (9.63 ${\pm}$ 1.19, 7.04 ${\pm}$ 1.50, 38.64 ${\pm}$ 7.60). In conclusion, wild simulated ginseng might be a protective agent against the oxidative stress.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.1-8
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• 2013

COP9 signalosome (CSN), which is originally identified as the regulator of the photomorphogenic development in plant, is highly conserved protein complex in diverse eukaryotic organisms. Most eukaryotic CSN complex is composed of 8 subunits, which is structurally and functionally similar to the lid subunit of 26S proteasome and eIF3 translation initiation complex. CSN play important functions in the regulation of cell cycle and checkpoint response by controlling Cullin-Ring E3 ubiquitin ligases (CRL) activities. CSN exhibits an isopeptidase activity which cleaves the neddylated moiety of cullin components. In fission yeast, S-phase cell cycle progression was delayed and the sensitivity to g-ray or UV was increased in CSN1 and CSN2 deletion mutants, indicating that yeast CSN is also involved in the checkpoint regulation. CSN in fungal system more closely resembles that of the higher organisms in the structure and assembly of their components. Functionally, CSN is associated with the regulation of conidiation rhythms in Neurospora crassa and the sexual development in Aspsergillus nidulans. Recent studies also revealed that CSN functions as an essential cell cycle regulator, playing key roles in the regulation of DNA replication and DNA damage response in Aspergillus. Overall, CSN of microorganisms, such as fission yeast and fungi, share functionally common aspects with higher organisms, implying that they can be useful tools to study the role of CSN in the CRL-mediated diverse cellular activities.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.83-91
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• 2012

Quorum sensing (QS) is a cell-to-cell communication system, which is used by many bacteria to regulate diverse gene expression in response to changes in population density. Bacteria recognize the differences in cell density by sensing the concentration of signal molecules such as N-acyl-homoserine lactones (AHL) and autoinducer-2 (AI-2). In particular, QS plays a key role in biofilm formation, which is a specific bacterial group behavior. Biofilms are dense aggregates of packed microbial communities that grow on surfaces, and are embedded in a self-produced matrix of extracellular polymeric substances (EPS). QS regulates biofilm dispersal as well as the production of EPS. In some bacteria, biofilm formations are regulated by c-di-GMP-mediated signaling as well as QS, thus the two signaling systems are mutually connected. Biofilms are one of the major virulence factors in pathogenic bacteria. In addition, they cause numerous problems in industrial fields, such as the biofouling of pipes, tanks and membrane bioreactors (MBR). Therefore, the interference of QS, referred to as quorum quenching (QQ) has received a great deal of attention. To inhibit biofilm formation, several strategies to disrupt bacterial QS have been reported, and many enzymes which can degrade or modify the signal molecule AHL have been studied. QQ enzymes, such as AHL-lactonase, AHL-acylase, and oxidoreductases may offer great potential for the effective control of biofilm formation and membrane biofouling in the future. This review describes the process of bacterial QS, biofilm formation, and the close relationship between them. Finally, QQ enzymes and their applications for the reduction of biofouling are also discussed.

• Journal of Life Science
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• v.28 no.4
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• pp.454-464
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• 2018

Black soybeans are used as food sources as well as for traditional medicines because they contain an abundance of natural phenolic compounds. In this study, total phenolic contents (TPCs) of Korean black seed coat soybean varieties Socheongja (SCJ), Socheong 2 (SC2) and Cheongja 2 (CJ2) as well as their antioxidant capacities were investigated. Among them, TPCs were abundantly present in the order of CJ2$H_2O_2$-stimulated HaCaT human keratinocytes. Our results revealed that treatment with SCJ and SC2 prior to $H_2O_2$ exposure significantly increases the viability of HaCaT cells, indicating that the exposure of HaCaT cells to SCJ and SC2 conferred a protective effect against oxidative stress. SCJ and SC2 also effectively inhibited $H_2O_2$-induced apoptotic cell death through the blocking of mitochondrial dysfunction. SCJ and SC2 also attenuated the phosphorylation of Histone H2AX. Furthermore, they effectively induced the levels of thioredoxin reductase (TrxR) 1, a potent antioxidant enzyme, which is associated with the induction of nuclear transcription factor erythroid-2-like factor 2 (Nrf2); however, the protective effects of SCJ and SC2 were significantly reversed by Auranofin, a TrxR inhibitor. These results indicate that they have protective activity through the blocking of cellular damage related to oxidative stress via the Nrf2 signaling pathway. In conclusion, our study indicated that SCJ and SC2 might potentially serve as novel agents for the treatment and prevention of skin disorders caused by oxidative stress.