• Journal of Applied Biological Chemistry
• /
• 제53권1호
• /
• pp.8-12
• /
• 2010

The antioxidant activity of hawthorn fruit (Crataegus pinnatifida Bunge var. typica Schneider) extracts was investigated by several in vitro antioxidants properties, including DPPH free radical scavenging activity, total phenolic and flavonoid contents, hydroxyl radical scavenging activity, reducing power activity, iron-chelating capacity and nitrite scavenging activity. Among the extracts in this study, the 70% EtOH extract showed higher antioxidant activity than the others. The $IC_{50}$ value of DPPH free radical scavenging activity was $99.26\;{\mu}g/mL$. Furthermore, the 70% EtOH extract also showed significantly high total phenolic and flavonoids contents and reducing power activity. However, the MeOH extract exhibited stronger effects on hydroxyl radical scavenging activity, iron-chelating capacity and nitrite scavenging activity. All the results implicated that, the hawthorn fruit may has the available potential to be utilize as a potential source of natural antioxidant.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 한국대기환경학회 2001년도 추계학술대회 논문집
• /
• pp.325-326
• /
• 2001

오존은 태양광선의 존재 하에 질소산화물과 VOCs가 관련하여 발생하는 생성물이다. 대기중의 VOCs 는 히드록실 라디칼(hydroxyl radical, OHㆍ)과 같은 자유 라디칼(free radical)과 반응하여 하이드로퍼옥시 라디칼(hydroperoxy radical, HO$_2$ㆍ)과 알킬 퍼옥시 라디칼(alkyl peroxy radical, RO$_2$ㆍ)을 생성해 낸다. 이 퍼옥시 라디칼들은 NO를 NO$_2$ㆍ로 산화시키며 또한 히드록실 라디칼을 재생하며 이 히드록실 라디칼은 다시 VOCs와 반응한다. 그리고, 이때 산화된 NO$_2$는 햇빛에 의해 NO와 자유산소원자(free oxygen atom)로 광분해 되는데, 여기서 생성된 자유산소인자는 산소분자와 반응하여 오존을 생성한다. (중략)

• The Journal of Internal Korean Medicine
• /
• 제17권1호
• /
• pp.265-277
• /
• 1996

Jwagyuyeum and Woogyuyeum, being known to reinforce Kidney-yin and -yang, were tested for the effects of on free radical generating enzyme and lipid peroxidation in rat's kidney. In vitro, levels of lipid peroxide in tissues of brain were proportionally decreased to concentration of extracts prepared from Jwagyuyeum and Woogyuyeum. They were much more decreased, when lipid peroxidation was induced with ferrous iron (Fe+2), In vivo, after both herbs were administered to the rat, levels of lipid peroxide in kidney were decreased only in Jwagyuyeum. The enzyme activities and the ratio of type conversion of xanthine oxidase were decreased only in Jwagyuyeum. But, We can't see special changes in Woogyuyeum. The enzyme activities of aldehyde oxidase was lowered in both herbs, especially Jwagyuyeum was much more done. These results suggest that Jwagyuyeum and Woogyuyeum decrease the activities of free radical generating enzymes such as xanthine oxidase and aldehyde oxidase which form lipid peroxide.

• The Journal of Internal Korean Medicine
• /
• 제16권1호
• /
• pp.62-80
• /
• 1995

Jwagyuyeum and Woogyuyeum, being known to reinforce Kidney-yin and -yang, were tested for the effects of on free-radical generating enzyme and lipid peroxidation. In vitro, levels of lipid peroxide in tissues of liver were proportionally decreased to concentration of extracts prepared from Jwagyuyeum and Woogyuyeum. They were much more decreased, when lipid peroxidation was induced with ferrous iron (Fe+2). In vivo, after both herbs were administered to the rat, levels of lipid peroxide in liver were decreased only in Jwagyuyeum. And, enzyme activities of xanthine oxidase and aldehyde oxidase in liver were not changed. It was guessed that Jwagyuyeum and Woogyuyeum inhibited lipid peroxidation directly, or acted on free radical resolving enzymes which decrease lipid peroxide. Consequently both herbs, particularly in Jwagyuyeum might delay aging.

• ALGAE
• /
• 제21권1호
• /
• pp.149-156
• /
• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• Natural Product Sciences
• /
• 제9권2호
• /
• pp.80-82
• /
• 2003

Since reactive oxygen radicals play an important role in carcinogenesis and other human diseases including neurodegenerative states, antioxidants present in natural products have received considerable attention for alleviation of these disease states. Therefore, in order io identify antioxidants in plant extracts, fifty-seven methanolic extracts derided from indigenous Korean plants were primarily assessed for potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. As a result, nine plant extracts were found to exhibit the DPPH free radical scavenging activity in the criteria of $IC_{50}<40\;{\mu}g/ml$. In particular, the extracts of Melioma oldhami $(IC_{50}=0.1\;{\mu}g/ml)$, Myrica rubra $(IC_{50}=16.2\;{\mu}g/ml)$, Sympolocos paniculata $(IC_{50}=23.0\;{\mu}g/ml)$, Carpinus laxiflora $(IC_{50}=25.1\;{\mu}g/ml)$, and Cleyera japonica $(IC_{50}=26.2\;{\mu}g/ml)$ showed a potent radical scavenging activity. Further study for the identification of active compounds from these lead extracts might be warranted.

• Journal of Physiology & Pathology in Korean Medicine
• /
• 제20권4호
• /
• pp.980-984
• /
• 2006

In order to examine the effect of oxygen free radicals on the vascular endothelial cells, cell viability was measured by XTT assay after bovine pulmonary vascular endothelial cell line(BPVEC) was treated only with hydrogen peroxide. In addition, the antioxidant effect of allopurinol on cells treated with hydrogen peroxide was examined by colormetric assay. in this study, the BPVEC treated with hydrogen peroxide showed the significantly decreased cell viability compared with control. Whereas, the viability of cells treated with hydrogen peroxide and allopurinol has significantly increased when compared with that of cells treated only with hydrogen peroxide. These results suggested that hydrogen peroxide, one of the oxygen free radicals showed cytotoxic effect and allopurinol has protective effect on oxygen free radical-induced cytotoxicity.

• The Journal of Korea CHUNA Manual Medicine
• /
• 제1권1호
• /
• pp.91-102
• /
• 2000

To prove the effect of Yukmijihwngwon(YMJHW) and Taeyoungjeon(TYJ) extract on the Meridian of Human body and Active oxygen experimentally, ORS & Free Radical of extract and precipitate of YMJHW and TYJ was measured. The results were summarized as follows; 1. TYJ extract, as a result of measuring QRIS, had a considerable effect on the function of pituitary gland, the 4th cervical vertebra and the 1 st lumbar vertebra. 2. TYJ precipitate, as a result of measuring QRIS, had a considerable effect on the function of liver, uterus, and vertebra. 3. YMJHW extract, as a result of measuring QRIS, had a considerable effect on the function of lung, adrenalin gland, bladder, prostate gland, ovaria, the 2nd cervical vertebra, the 3rd cervical vertebra, the 5th cervical vertebra, the 6th cervical vertebra, the 2nd lumbar vertebra, the 4th lumbar vertebra and the 5th lumbar vertebra. 4. YMJHW precipitate, as a result of measuring QRIS, had a considerable effect on the function of spleen, lung, kidney, adrenal gland, bladder, ovaria, the 2nd cervical vertebra, the 6th cervical vertebra, the 7th cervical vertebra, the 2nd lumbar vertebra, the 5th lumbar vertebra, sacrum, and knee joint. 5. As a result of measuring Free Radical, the level of TYJ is higher than YMJHW. It is thiut that's because of Duchung and roasted Gamcho. 6. As an order of QRIS levels, YMJHW precipitate is the highest, YMJHW extract is next, TYJ extract and TYJ precipitate. These results suggested that TYJ and YMJHW be usefully applied for suppressing of abnormal Meridian and noxious oxygen, preventing and curing all the disease.

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

• Journal of Applied Biological Chemistry
• /
• 제43권3호
• /
• pp.156-160
• /
• 2000

The possible mechanism of the DNA strand breaking activity of the hot-water extract of Fructus Chaenomelis (dried fruit of Chaenomeles sinensis) in a closed circular duplex replica form DNA (RFI DNA) was studied through agarose gel electrophresis under various conditions. Induction of DNA strand scission by the hot-water extract of C. sinensis occurred in dose and time-dependent manners. $Cu^{2+}$ was indispensable for the induction of DNA strand breakage. Exogeneous chelating agents inhibited the DNA breaking activity, conforming the catalytic action of $Cu^{2+}$ on generation of free radicals responsible for oxidative damage. Antioxidant enzymes and some radical scavengers were used to investigate the major radical species triggering the DNA strand scission, demonstrating that a highest inhibitory activity was found in the presence of catalase, while less in the presence of tiron (a scavenger for superoxide radical), 2-aminoethyl-isothiuroniumbromide-HBr, cysteamine (scavengers for hydroxyl radical), and 1,4-diazabicyclo [2,2,2] octane (a scavenger for singlet oxygen) in decreasing order. The findings implied that oxygen radical species generated in presence of transition divalent cation during the oxidation of some compounds contained in the hot-water extract of C. sinensis is mainly responsible for inducing genotoxicity.