• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.165-174
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• 2003

Cr (Ⅵ) - containing compounds are well-established carcinogens, although the mechanism for chromium - induced carcinogenesis is still not well understood. The reduction of Cr (Ⅵ) to its lower oxidation states, par ticularly Cr (V) and Cr (IV), is an important step for the production of chromium-mediated reactive oxygen species (ROS). The persistent oxidative stress during the reduction process may play a key role in the mechanism of Cr (Ⅵ) -induced carcinogenesis. This paper summarizes recent studies on (1) the reduction of Cr (Ⅵ) to Cr (III) occur by a multiplicity of mechanisms depending on the nature of reducing agents including ascorbate, diol-and thiol-containing molecules, certain flavoenzymes, cell organelles, intact cells, and whole animals; (2) free-radical production with emphasis on hydroxy radical generation via Fenton or Haber-Weiss type reactions; and (3) free radical - induced cellular damage, such at DNA strand breaks, hydroxylation of 2'-deoxyguanosine, and activation of nuclear transcription factor kB.

• Food Science and Biotechnology
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• 제15권2호
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• pp.312-316
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• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• 한국해양바이오학회지
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• 제2권3호
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• pp.187-191
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• 2007

The radical scavenging activity of methanol extracts of seaweeds and their active compounds, alginic acid, fucoidan and phloroglucinol, were investigated under in vitro. Among methanol extracts of seaweeds (sea mustard, sea tangle, seaweed papulosa, fusiforme, sea lettuce, purple laver and chlorella), seaweed papulosa and sea tangle showed strong scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical (${\cdot}OH$). In addition, under in vitro, the scavenging activities on DPPH radical of alginic acid and fucoidan, which are active compounds of brown algae, and phloroglucinol, the active compound from Ecklonia species, were evaluated and compared. Fucoidan and phloroglucinol showed strong DPPH scavenging effect, in particular, phloroglucinol had strongest activity among the active compounds. On the other hand, alginic acid did not exert DPPH scavenging activity. From the present study, we could confirm the antioxidative activity of seaweeds and its active compounds.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.719-730
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• 2014

노루궁뎅이 버섯균사체(Hericium erinaceum)를 인진쑥(Artemisia capillaris)에 배양하여 조제한 AC-HE 열수 추출물이 생체고분자의 산화적 손상과 세포사멸을 보호할 수 있는 지를 관찰하였다. AC-HE의 항산화 활성을 DPPH radical, ABTS radical, peroxyl radical 소거활성 측정을 통해 알아보았다. 그 결과 DPPH radical 소거활성은 $500{\mu}g/mL$ 농도에서 61.73%, ABTS radical 소거활성은 $250{\mu}g/mL$ 농도에서 97.39%, peroxyl radical 소거활성은 $100{\mu}g/mL$ 농도에서 44.18%로 나타났다. AC-HE은 DNA의 산화적 손상을 효과적으로 억제하였다. 또한 생체고분자물질인 사람의 혈청단백질의 산화적 손상을 억제하였다. 세포에 $H_2O_2$를 처리하였을 때 세포생존율에 비하여 발효물을 $100{\mu}g/mL$ 농도로 전 처리한 세포생존율은 11.47% 증가했으며, 발효물을 $50{\mu}g/mL$ 농도로 처리했을 경우 세포내 ROS의 축적이 유의적으로 감소되었다. 따라서 AC-HE은 항산화 활성뿐만 아니라 산화적 스트레스에 의해 야기되는 세포 독성에 대한 보호 작용이 뛰어난 것으로 사료되었다.

• 대한예방한의학회지
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• 제19권3호
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• pp.141-154
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• 2015

Objective : In this paper, we investigated the anti-oxidative capacities and protective effects of water extract of palmul-tang (PMT) against Ultraviolet B(UVB)-induced oxidative damage in human keratinocytes(HaCaT). Method : To evaluate the anti-oxidative activities of PMT, we measured scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation and reducing power of PMT. To give an oxidative stress to HaCaT cells, UVB was irradiated with $40mJ/cm^2$ to HaCaT cells. To detect the protective effects of PMT against UVB, we measured cell viability, apoptotic bodies and reactive oxygen species(ROS) generation. Results : PMT showed the anti-oxidative activities by scavenging DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation. Also PMT showed high reducing values. The UVB-induced oxidative conditions led to the cell apoptosis. However, treatment with PMT reduced oxidative stress conditions, including inhibition of cell apoptosis and expression of ROS. Conclusion : PMT had anti-oxidative activities and exhibited protective effects against UVB on HaCaT cells. PMT would be useful for the development of cosmetics treating UVB-induced skin aging.

• Toxicological Research
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• 제17권
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• pp.83-88
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• 2001

Most reactive oxygen species (ROS) are free radicals and implicated in the development of a number of disease processes including artherosclerosis, neurodegenerative disorders, aging and cancer. ROS are byproducts of a number of in vivo metabolic processes and are formed deliberately as part of nor-mal inflammatory response. On the other hand, ROS are generated either as by products of oxygen reduction during xenobiotic metabolism or are liberated as the result of the futile redox cycling of the chemical agents including several chemical carcinogens. A better understanding of the mechanisms of free radical toxicity may yield valuable clue to risks associated with chemical exposures that leading to the development of chronic diseases including cancer. The molecular biology of ROS-mediated alterations in gene expression, signal transduction and carcinognesis is one of the important subjects in free radical toxicology. Epidemiological studies suggest that high intake of vegetables and fruits are associated with the low incidence of human cancer. Many phytopolyphenols such as tea polyphenols, curcumin, resveratrol, apigenin, genistein and other flavonoids have been shown to be cancer chemopreventive agents. Most of these compounds are strong antioxidant and ROS scavengers in vitro and effective inducers of antioxidant enzymes such as superoxide dismutatse, catalase and glutathione peroxidase in vivo. Several cellular transducers namely receptor tyrosine kinase, protein kinase C, MAPK, PI3K, c-jun, c-fos, c-myc, NFkB, IkB kinase, iNOS, COX-2, Bcl-2, Bax, etc have been shown to be actively modulated by phyto-polyphenols. Recent development in free radical toxicology have provided strong basis for understanding the action mechanisms of cancer chemoprevention.

• 동의생리병리학회지
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• 제29권6호
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• pp.475-484
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• 2015

In this paper, we studied the anti-oxidative capacities and protective effects of water extract of Gagam-Danguieumja(GDE) against Ultraviolet B(UVB)-induced oxidative damage in human keratinocytes(HaCaT). To evaluate the anti-oxidative activities of GDE, we measured scavenging activities on DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation and reducing power of GDE. To detect the protective effects of GDE against UVB, we irradiated with 40 mJ/㎠`s UVB to HaCaT cells then we measured reactive oxygen species(ROS) generation, apoptotic bodies and cell viability using DCFH-DA assay, Hoechst 33342 staining and MTT assay. GDE showed the anti-oxidative activities by scavenging DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation. Also GDE showed high reducing values. GDE reduced oxidative stress conditions by inhibition of ROS expression. Also the cell apoptosis by UVB-induced oxidative conditions was decreased by GDE treatment. These results could suggest that GDE had anti-oxidative activities and exhibited protective effects against UVB on HaCaT cells. GDE would be useful for the development of cosmetics treating UVB-induced skin aging.

• 생약학회지
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• 제29권1호
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• pp.28-34
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• 1998

It has been known that diseases related with aging or cancer result, at least in part, from free radicals, and antioxidants may reduce or prevent the abnormalities associated with free radical formation via its scavenging action. Thus, this study was carried out to investigate the antioxidative and antimicrobial activities of nut species for the purpose of developing antioxidant from natural products. Antioxidant activities of four kinds of nuts such as chestnut, groundnut, walnut and acorn were examined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The extracts from chestnut hull and acorn barnyard millet showed strong antioxidative activities among 10 samples tested. Because of their highest antioxidative activity among 10 samples, radical scavenging effects of 4 different extract compartments (Hexane, EtOAc, BuOH and $H_2O$ extracts) from chestnut hull and acorn barnyard millet, were further examined by DPPH method. EtOAc and BuOH extracts exhibited antioxidative activities similar to those of natural, tocopherol or synthetic antioxidants, BHA. These findings demonstrates that major fraction of the antioxidative activity of chestnut hull or acorn barnyard millet was the EtOAc and BuOH extract compartments. However, antimicrobial activities against food-related bacteria and yeasts was relatively weak.

• 한국해양바이오학회지
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• 제1권3호
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• pp.170-177
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• 2006

본 연구는 제주산 해조류의 생리활성을 대량검색하기 위해 HTS 기법을 이용한 실험과정의 제어 및 관리를 위한 자동화 시스템을 구축하고자 DPPH 라디칼을 이용하여 HTS를 이용한 자동화 시스템을 구축하고 제주산 해조류의 DPPH 라디칼 소거활성을 대량 검색하고자 하였다. 그 결과 HTS를 위한 효율적인 검색방법을 개발하였고 DPPH 라디칼 소거활성이 높은 해조류를 검색하게 되었다. 녹조류의 경우 납작파래 (20G6)의 $20^{\circ}C$ 추출물(1 mg/ml)에서 약 60%이 DPPH 라디칼 소거활성을 보였을 뿐 나머지 해조류에서는 40% 미만이 낮은 활성만을 보였다. 갈조류의 경우 꽈배기 모자반 (20B17), (70B17), 참그물바탕말 (70B1), 큰잎모자반 (70B16)과 감태 (70B26)에서 DPPH 라디칼 소거활성이 우수하였다. 홍조류 중에서는 왜떨기나무붉은실 (20R24)에서 가장 우수한 DPPH 라디칼 소거활성을 나타내었고 갈래잎 (20R17), 굵은참우뭇가사리 (20R18), 부채분홍잎 (20R23) 또한 높은 소거활성을 보였다. 따라서 우수한 효과를 나타내었던 해조류를 대상으로 용매분획 및 활성물질의 분리, 정제를 통해 해조류 유래의 기능성 신소재를 개발한다면, 해조류의 고부가가치화 및 HTS기술의 보편화에 큰 영향을 미칠 것으로 판단된다.

• Journal of Applied Biological Chemistry
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• 제64권1호
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• pp.69-74
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• 2021

만성 알코올 섭취는 산화적 스트레스 및 치매와 같은 신경퇴행성질환을 발병시킨다. 본 연구는 홍화씨 추출물의 in vitro 항산화 활성과 ethanol로 손상을 유도한 신경교세포에서의 보호 효과를 확인하기 위해 수행되었다. 홍화씨 추출물은 50, 100, 250, 500 ㎍/mL의 농도에서 농도 의존적으로 in vitro에서 1,1-diphenyl-2-prcrylhydrazy (DPPH), hydroxyl radical (·OH), superoxide radical 및 nitric oxide radical 소거능이 증가하였다. 특히 DPPH 및 ·OH radical 소거능 측정 결과, 각각 500 ㎍/mL, 100 ㎍/mL의 농도에서 80% 이상의 radical 소거능을 나타내었다. 홍화씨 추출물의 신경교세포 보호 효과를 확인하기 위해, C6 신경교세포에 500 mM ethanol을 처리하여 산화적 손상을 유도하였다. Ethanol을 처리한 C6 신경교세포는 세포 생존율의 감소 및 reactive oxygen species (ROS) 생성량이 증가하여 세포 손상을 나타내었다. 반면 홍화씨 추출물을 처리하였을 때 세포 생존율 증가 및 ROS 생성 억제를 통해 ethanol로 유도된 신경교세포 손상에 대한 보호 효과를 나타내었다. 본 연구를 통해, 홍화씨는 알코올로 유도된 신경교세포의 산화적 스트레스에 대한 보호 효과가 있는 것으로 사료된다.