• Title/Summary/Keyword: DNA Damage

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Inhibitory Effect of Hot-Water Extract of Paeonia japonica on Oxidative Stress and Identification of Its Active Components (백작약 열수추출물의 산화적 스트레스 억제효과 및 유효성분 동정)

  • Jeong, Ill-Yun;Lee, Joo-Sang;Oh, Heon;Jung, U-Hee;Park, Hae-Ran;Jo, Sung-Kee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.5
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    • pp.739-744
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    • 2003
  • This study was carried out to investigate the antioxidative activity and to identify the active components of hot-water extract of Paeoniajaponica (PJ), which was a main ingredient of a herb mixture preparation recently established as a potent candidate of radioprotector in our laboratory. The water extract was fractionated with CHCl$_3$, EtOAc and n-BuOH. The extract and its fractions showed very low activity in hydroxyl radical scavenging test. In lipid peroxidation test, the extract, EtOAc and water fractions showed moderate inhibition with the ratio above 50%. In DPPH radical scavenging test, the extract, EtOAc and water fraction showed high activity with the ratio above 80%, especially. EtOAc fraction scavenged the radicals as much as synthetic antioxidant (BHA), even at low concentration. It is suggested that mai or partition for antioxidative activity of Paeonia japonica was EtOAc fraction. Subsequently, two active compounds (PJE021-1 and JE024-1) from EtOAc fraction were isolated by using MCI gel and silica gel column chromatography The two compounds inhibited remarkedly the $H_2O$$_2$-induced DNA damage in human peripheral blood lymphocytes, measured by single-cell gel electrophoresis (SCGE). PJE021-1 protected the cells to almost negative control level, dose-dependently. PJE024-1 exhibited a potent inhibition with the ratio of 71% at even low concentration (0.5 $\mu\textrm{g}$/$m\ell$). Finally, their chemical structures were identified as gallic acid (PJE021-1) and (+)-catechin (PJE024-1), respectively, on the basis of the speculation of spectral and physical data.

Clinical Manifestation and Treatment Outcome of Lupus Nephritis in Children (소아 루프스 신염의 임상양상 및 치료결과)

  • Park Jee-Min;Shin Jae-Il;Kim Pyung-Kil;Lee Jae-Seung
    • Childhood Kidney Diseases
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    • v.6 no.2
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    • pp.155-168
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    • 2002
  • Purpose; Systemic lupus erythematosus(SLE) is an autoimmune disease with multi-system involvement and renal damage is a major cause of morbidity and mortality in children. Renal involvement is more common and severe in children than in adults. Therefore, renal biopsy plays a crucial role in planning effective therapy. In this study, we investigated the clinical and pathological findings of lupus nephritis in children to aid clinical care of the disease. Methods: The clinical and pathological data of 40 patients who were diagnosed as SLE with renal involvement in Shinchon Severance Hospital from Jan. 1990 to Sep. 2002 were analyzed retrospectively. Results: The ratio of male to female patients was 1:3 and the median age at diagnosis was 12.1(2-18) years old. FANA(95.0%), anti-ds DNA antibody(87.5%), malar rash(80.0%) were the most common findings among the classification criteria by ARA. Microscopic hematuria with proteinuria(75.0%), nephrotic syndrome(55.0%), and microscopic hematuria alone(15.0%) were the most common renal presentations in the respective order at diagnosis. There were 27 cases with WHO class IV lupus nephritis confirmed by renal biopsy and 3 cases with pathological changes of WHO class type. Different treatment modalities were carried out : prednisolone only in 5 cases, prednisol-one+azat-hioprine in 9 cases, prednisolone+azathioprine+intravenous cyclophosphamide in 14 cases, prednisolone+cyclosporine A+intravenous cyclophosphamide in 12 cases, plasma exchange in 9 cases and intravenous gamma-globulin in 2 cases. The average follow-up period was $51.8{\pm}40.5$ months. During $51.8{\pm}40.5$ months. During follow-up, 4 patients expired. The risk factors associated with mortality were male, WHO class IV and acute renal failure at diagnosis. Conclusion: Renal involvement was noted in 63.5% of childhood SLE, and 67.5% of renal lesion was WHO class IV lupus nephritis which is known to be associated with a poor prognosis. Therefore aggressive treatment employing immunosuppressant during the early stages of disease could be helpful in improving long-term prognosis. But careful attention should be given to optimize the treatment due to unique problems associated with growth, psychosocial development and gonadal toxicity, especially in children.

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Effect of Pumpkin, Corn Silk, Adzuki Bean, and Their Mixture on Weight Control and Antioxidant Activities in High Fat Diet-Induced Obesity Rats (호박즙, 옥수수수염차, 팥차 및 혼합물이 식이유도 비만동물모델에서 체중과 항산화 활성에 미치는 영향)

  • Park, Jae-Hee;Lee, Eunji;Park, Eunju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.9
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    • pp.1239-1248
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    • 2016
  • Pumpkin juice (PJ), corn silk tea (CT), and adzuki bean tea (AT) have long been used for treatment of obesity in Korea. This study investigated the efficacy of PJ, CT, AT, and their mixture (PCA) on alteration of body weight and antioxidant metabolism in high-fat diet (HFD)-induced obese rats. After being fed HFD for 4 weeks, SD rats were divided into six groups fed a normal diet (ND), HFD, HFD+PJ [250 mg/kg body weight (BW)], HFD+CT (250 mg/kg BW), HFD+AT (250 mg/kg BW), and HFD+PCA (PJ : CT : AT=1:1:1, 250 mg/kg BW) for another 9 weeks. HFD consumption resulted in total lipid, triglyceride, and total cholesterol accumulation in adipose tissue, which was reduced by administration of PJ, CT, AT, or PCA. The plasma oxygen radical absorbance capacity value and hepatic glutathione peroxidase activity significantly increased compared to the HFD group. The liver thiobarbituric acid reactive substances was significantly lower in the PCA group than the HFD group. HFD-induced DNA damage in hepatocytes, as measured by comet assay, decreased in the PJ, AT, and PCA-supplemented groups. The PCA group exerted a superior antigenotoxic effect compared to other treatments. PCA recovered the concentration of plasma adiponectin, which was reduced by HFD. Adipocyte surface area (%) was significantly higher in the HFD group than the ND group, significantly lower in the PJ and PCA groups than the HFD group, and not significantly different compared with the ND group. Based on the results, supplementation of PJ, CT, AT, and PCA exhibited lipid-lowering effects in adipocytes of HFD-induced obese rats. Furthermore, the PCA group exhibited superior antioxidant activity in all treated groups. This study suggests that a mixed beverage consisting of PJ, CT, and AT may be a significant source of natural antioxidants, which might be helpful in preventing obesity and progress of various oxidative stresses induced by HFD.

HMGB1 Switches Alkylating DNA Damage-Induced Apoptosis to Necrosis (HMGB1에 의한 alkylating DNA 손상에 의해 유도된 세포사멸의 세포괴사로의 전환)

  • Lee, Su-Yeon;Jeong, Eui-Kyong;Jeon, Hyun-Min;Ju, Min-Kyung;Kim, Cho-Hee;Park, Hye-Gyeong;Kang, Ho-Sung
    • Journal of Life Science
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    • v.21 no.7
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    • pp.953-960
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    • 2011
  • Necrosis is characterized by the cell membrane rupture and release of the cellular contents, including high-mobility group box 1 protein (HMGB1), into the extracellular microenvironment. HMGB1 acts as a transcriptional regulator in nuclei, but exerts a pro-inflammatory and tumor-promoting cytokine activity when released into the extracellular space. Its overexpression is associated with tumor progression and chemoresistance. Thus, HMGB1 acts as a clinically important molecule in tumor biology. In this study, we examined whether HMGB1 affects cell death induced by anti-cancer drugs. Here we show that HMGB1 prevented cisplatin (alkylating agent)-induced apoptosis and switched the cell fate to necrosis in MCF-7, MDA-MB231, and MDA-MB361 cells. Similar apoptosis-to-necrosis switch effects of HMGB1 were observed in cells treated with 4-HC, another alkylating agent. In contrast, HMGB1 did not exert any significant effects on docetaxel (DOC)-induced apoptosis in MCF-7 cells. We also show that cisplatin-induced apoptosis was switched to necrosis in MCF-7 multicellular tumor spheroids (MTS) that were cultured for 8 days and had necrotic cores, but DOC-induced apoptosis was prevented without the apoptosis-to-necrosis switch. Finally, the levels of RAGE, a receptor of HMGB1, were increased with extended culture of MTS. These findings demonstrate that HMGB1 switches alkylating agent-induced apoptosis to necrosis, suggesting that the strategy to prevent necrosis occurring as an undesirable action of alkylating agent-based chemotherapy should be delineated to improve the efficacy of chemotherapy for cancer.

STUDY ON MUTATION OF P53 AND EXPRESSION OF MDM-2 IN DMBA INDUCED CARCINOMA OF HAMSTER BUCCAL POUCH (DMBA로 유도된 햄스터 협낭암종에서 p53 유전자 변이와 mdm-2 단백의 발현에 관한 연구)

  • Park, Yong-Sun;Kim, Kyung-Wook;Lee, Jae-Hoon;Kim, Chang-Jin
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.5
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    • pp.373-384
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    • 2001
  • Cellular proliferation is an intricately regulated process mediated by the coordinated interactions of critical growth control genes. Two of these factors in mammalian cells are the p53 and mdm-2 genes. A protein product of the mem-2 oncogene has been recently shown to associate with the protein encoded by the tumor suppressor gene p53. The p53 tumor suppressor protein is stabilized in response to DNA damage and other stress signals and causes the cell to undergo growth arrest or apoptosis, thus preventing the establishment of mutations in future cellular generations. Mutation or loss of p53 is a very common event in tumor progression. It occurs in about 50% of all tumors analysed including of colon, lung, breast and liver. The cellular mdm-2 gene, which has potential transforming activity that can be activated by overexpression, is amplified in a significant percentage of human sarcoma and in other mammalian tumors. Proteins encoded by the mdm-2 gene are able to bind to the p53 protein and, when overexpressed, can inhibit p53's transcriptional activation function, thus mdm-2 can act as a negative regulator of p53 function. Experimental study was performed to observe the relationship between p53 gene mutation and mdm-2 protein expression and apply the results to the clinical activity. 36 golden syrian hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek(control side) was treated with mineral oil as the same manner to the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were examined for histology and immunohistochemistry observation, and were completely dissected by microdissection and DNA from both tissue were isolated by proteins K/phenol/chloroform extraction. Segments of the hamster p53 exons 5, 6, 7 and 8 were amplified by PCR using the oligonucleotide primers, and then confirmational change was observed by SSCP respectively. The results were as follows : 1. Dysplasia at 6 weeks, carcinoma in situ at 8 weeks and invasive carcinoma from 10 weeks could be observed in experimental groups. 2. p53 mutations were detected in 10 of the 36(28%) and the exons 6(6 of the 10 : 60%) was the most hot spot area among the highy conserved region(exons 5, 6, 7 & 8). 3. Immunohistochemical study confirmed 22 of the 36(61%) of p53 expression involving 10 of p53 mutations. 4. mdm-2 expression of was showed in 3 of the 36(8%) involving 1 of the 22 of p53 expression and 2 of the 14 of p53 non-expression. From the above results, mutation of p53 gene or expression of p53 protein may have the influence of the DMBA induced carcinoma of hamster buccal pouch but the expression of mdm-2 protein may not have relationship with tumorigenesis.

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EFFECT OF NERVE GROWTH FACTOR GENE INJECTION ON THE NERVE REGENERATION IN RAT LINGUAL NERVE CRUSH-INJURY MODEL (백서 설신경 압박손상모델에서 신경성장인자 유전자 주입이 신경재생에 미치는 영향)

  • Gao, En-Feng;Chung, Hun-Jong;Ahn, Kang-Min;Kim, Soung-Min;Kim, Yun-Hee;Jahng, Jeong-Won;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.5
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    • pp.375-395
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    • 2006
  • Purpose: Lingual nerve (LN) damage may be caused by either tumor resection or injury such as wisdom tooth extraction, Although autologous nerve graft is sometimes used to repair the damaged nerve, it has the disadvantage of necessity of another operation for nerve harvesting. Moreover, the results of nerve grafting is not satisfactory. The nerve growth factor (NGF) is well-known to play a critical role in peripheral nerve regeneration and its local delivery to the injured nerve has been continuously tried to enhance nerve regeneration. However, its application has limitations like repeated administration due to short half life of 30 minutes and an in vivo delivery model must allow for direct and local delivery. The aim of this study was to construct a well-functioning $rhNGF-{\beta}$ adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with enhanced and extended secretion of hNGF from the injured nerve by injecting $rhNGF-{\beta}$ gene directly into crush-injured LN in rat model. Materials and Methods: $hNGF-{\beta}$ gene was prepared from fetal brain cDNA library and cloned into E1/E3 deleted adenoviral vector which contains green fluorescence protein (GFP) gene as a reporter. After large scale production and purification of $rhNGF-{\beta}$ adenovirus, transfection efficiency and its expression at various cells (primary cultured Schwann cells, HEK293 cells, Schwann cell lines, NIH3T3 and CRH cells) were evaluated by fluorescent microscopy, RT-PCR, ELISA, immunocytochemistry. Furthermore, the function of rhNGF-beta, which was secreted from various cells infected with $rhNGF-{\beta}$ adenovirus, was evaluated using neuritogenesis of PC-12 cells. For in vivo evaluation of efficacy of $rhNGF-{\beta}$ adenovirus, the LNs of 8-week old rats were exposed and crush-injured with a small hemostat for 10 seconds. After the injury, $rhNGF-{\beta}$ adenovirus($2{\mu}l,\;1.5{\times}10^{11}pfu$) or saline was administered into the crushed site in the experimental (n=24) and the control group (n=24), respectively. Sham operation of another group of rats (n=9) was performed without administration of either saline or adenovirus. The taste recovery and the change of fungiform papilla were studied at 1, 2, 3 and 4 weeks. Each of the 6 animals was tested with different solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) by two-bottle test paradigm and the number of papilla was counted using SEM picture of tongue dorsum. LN was explored at the same interval as taste study and evaluated electro-physiologically (peak voltage and nerve conduction velocity) and histomorphometrically (axon count, myelin thickness). Results: The recombinant adenovirus vector carrying $rhNGF-{\beta}$ was constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. GFP expression was observed in 90% of $rhNGF-{\beta}$ adenovirus infected cells compared with uninfected cells. Total mRNA isolated from $rhNGF-{\beta}$ adenovirus infected cells showed strong RT-PCR band, however uninfected or LacZ recombinant adenovirus infected cells did not. NGF quantification by ELISA showed a maximal release of $18865.4{\pm}310.9pg/ml$ NGF at the 4th day and stably continued till 14 days by $rhNGF-{\beta}$ adenovirus infected Schwann cells. PC-12 cells exposed to media with $rhNGF-{\beta}$ adenovirus infected Schwann cell revealed at the same level of neurite-extension as the commercial NGF did. $rhNGF-{\beta}$ adenovirus injected experimental groups in comparison to the control group exhibited different taste preference ratio. Salty, sweet and sour taste preference ratio were significantly different after 2 weeks from the beginning of the experiment, which were similar to the sham group, but not to the control group.

A Novel Synthesized Tyrosinase Inhibitor, (E)-3-(4-hydroxybenzylidene) chroman-4-one (MHY1294) Inhibits α-MSH-induced Melanogenesis in B16F10 Melanoma Cells (신규 합성물질 (E)-3-(4-하이드록시벤질리딘)크로마논 유도체의 티로시나아제 효소활성 저해 및 멜라닌 생성 억제 효과)

  • Jeon, Hyeyoung;Lee, Seulah;Yang, Seonguk;Bang, EunJin;Ryu, Il Young;Park, Yujin;Jung, Hee Jin;Chung, Hae Young;Moon, Hyung Ryong;Lee, Jaewon
    • 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.

Application of Plant Flavonoids as Natural Antioxidants in Poultry Production (가금 생산에서 천연 항산화제로서 식물성 Flavonoids의적용)

  • Kang-Min, Seomoon;In-Surk, Jang
    • Korean Journal of Poultry Science
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    • v.49 no.4
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    • pp.211-220
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    • 2022
  • Poultry are exposed to extremely high levels of oxidative stress as a consequence of the excessive production of reactive oxygen species (ROS) induced by endogenous and exogenous stressors, such as high-stocking densities, thermal stress, environmental and feed contamination, along with factors associated with intensive breeding systems. Oxidative stress promotes lipid peroxidation, DNA damage, and inflammation, which can have detrimental effects on the health of birds. During the course of evolution, birds have developed antioxidant defense mechanisms that contribute to maintaining homeostasis when exposed to endogenous and exogenous stressors. The primary antioxidant defense systems are enzymatic and non-enzymatic in nature and play roles in protecting cells from ROS attack. Recently, plant flavonoids, which have been established to reduce oxidative stress, have been attracting considerable attention as potential feed additives. Flavonoids are a group of polyphenolic compounds that can be stabilized by binding structural compounds with ROS, and can promote the elimination of ROS by inducing the expression of antioxidant enzymes. However, although flavonoids can contribute to reducing lipid peroxidation and thereby enhance the antioxidant capacity of birds, they have low solubility in the gastrointestinal tract, and consequently, it is necessary to develop a delivery technology that can facilitate the effect intestinal absorption of these compounds. Furthermore, it is important to determine the dietary levels of flavonoids by assessing the exact antioxidant effects in the gastrointestinal tract wherein the concentrations of dietary flavonoids are highest. It is also necessary to examine the expression of transcriptional factors and vitagenes associated with the efficient antioxidant effects induced by flavonoids. It is anticipated that the application of flavonoids as natural antioxidants will become a particularly important field in the poultry industry.

Effect of Natural Product Extracts on Inhibition of Macrophage and Basophil (천연물 추출물이 대식세포 및 호염구 활성 억제에 미치는 영향)

  • Park, Jaehyun;Jang, Jimin;Cha, Sang-Ryul;Baek, Hyosin;Lee, Jooyeon;Lee, You-Hui;Ryu, Semin;Yang, Se-Ran
    • Journal of Food Hygiene and Safety
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    • v.37 no.3
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    • pp.189-197
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    • 2022
  • Asthma is a chronic inflammatory disease characterized by recurring symptoms, airflow obstruction, and bronchial hyper-responsiveness. The onset of asthma for most patients begins early in life, and current asthma treatment with anti-inflammatory agents can have adverse effects, eventually leading to impaired quality of life. In the pathogenesis of asthma, macrophages and basophils play a vital role during progression. Macrophages not only induce inflammation by secreting inflammatory cytokines but also promote DNA damage and mucus production through nitric oxide (NO) production. Basophils enhance eosinophil recruitment and aggravate asthma through the FcεRIα receptor with high affinity for histamine and IgE. Therefore, in this study, we investigated whether the activation of macrophages and basophils is suppressed by the individual extracts of 28 natural products. RAW 264.7 cells (mouse macrophages) were treated with the natural products in LPS, and 4 natural product extracts resulted in decreased NO production. In β-hexosaminidase assay using RBL-2H3 cells (rat basophils), 19 natural product extracts decreased β-hexosaminidase production. In NO production and β-hexosaminidase assay using macrophages and basophils, 3 natural product extracts (Plantago asiatica, Centella asiatica, and Perilla frutescens var. japonica) significantly inhibited NO production and β-hexosaminidase release. Overall, we examined the inhibitory effects of 28 natural product extracts on macrophage and basophil activity, and the findings demonstrated the potential of natural product extracts for treating asthma and macrophage- and basophil-related diseases.

Antioxidant and Cytoprotective Effects of Socheongja and Socheong 2, Korean Black Seed Coat Soybean Varieties, against Hydrogen Peroxide-induced Oxidative Damage in HaCaT Human Skin Keratinocytes (HaCaT 인간 피부 각질세포에서 과산화수소 유도 산화 손상에 대한 소청자 및 소총2호의 항산화 및 세포보호 효능)

  • Choi, Eun Ok;Kwon, Da Hye;Hwang, Hye-Jin;Kim, Kook Jin;Lee, Dong Hee;Choi, Yung Hyun
    • 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.