• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.568-577
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• 2012

The objective of this study was to investigate the antioxidative capacity of ethanol extracts from Rumex crispus L. The concentration of R. crispus L. extract at which DPPH radical scavenging activity was inhibited by 50% was 2.15 mg/mL, which was lower than that of ${\alpha}$-tocopherol (0.43 mg/mL), as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.47 and 2.33 mM Trolox equivalents, respectively, which were higher than those of ${\alpha}$-tocopherol. Superoxide scavenging activities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 21.5 and 78.9%, respectively, which were not significantly (p>0.05) different from those of catechin. Oxygen radical absorbance capacities of R. crispus L. extract at concentrations of 20 and 100 ${\mu}g/mL$ were 62.5 and 156.4 ${\mu}M$ Trolox equivalents, respectively, which were lower than those of ascorbic acid. Cupric reducing antioxidant capacities of R. crispus L. extract at concentrations of 0.1 and 1 mg/mL were 0.28 and 1.88 mM Trolox equivalents, which were similar or significantly (p<0.05) higher than those of ${\alpha}$-tocopherol, respectively. R. crispus L. extract prevented supercoiled DNA strand breakage induced by hydroxyl radical and peroxyl radical. Total phenolic contents of R. crispus L. extract at concentrations of 0.5 and 5 mg/mL were 0.58 and 3.85 mM gallic acid equivalents, respectively. R. crispus L. extract at concentration of 0.1 and 0.5 mg/mL inhibited 0.2 mM tert-butyl hydroperoxide-induced cytotoxicity by 38.5 and 63.5%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-inhibiting effects of R. crispus L. extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.460-469
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• 2017

The aim of this work was to study the comparison of anti-oxidative activity in a single serving size of commercial coffees and teas. Commercial regular coffees and teas, including, brand regular coffees ($BC_A$, $BC_B$, $BC_C$, $BC_D$, and $BC_E$), green tea ($GT_A$, $GT_B$, $GT_C$, and $GT_D$), black tea ($BT_A$, $BT_B$, and $BT_C$), pu-erh tea ($PT_A$, $PT_B$, and $PT_C$), chamomile tea ($CT_A$, $CT_B$, and $CT_C$), peppermint tea ($P_A$, $P_B$, and $P_C$), polygonatum odoratum tea ($POT_A$, $POT_B$, and $POT_C$), and jujube tea ($JT_A$, $JT_B$, and $JT_C$) were assayed for the levels of ascorbic acid, caffeine, total content of polyphenols and flavonoids, and ability to scavenge free radicals, using two in vitro antioxidant assays. The scavenging abilities of $BC_A$ and $BC_C$ were $664.91{\pm}48.87mg$ ascorbic acid equivalent/serving size and $624.36{\pm}16.18mg$ ascorbic acid equivalent/serving size, respectively. The four beverage samples ($BC_A$, $BC_C$, $GT_D$, and $BT_A$) significantly reduced the production of reactive oxygen species (ROS) and intracellular oxidative stress induced by $H_2O_2$. These results suggest that the beverages possess significant radical scavenging ability, which may be due to the presence of antioxidants. Furthermore, the significant reducing level of ROS evidences the potential antioxidant effects of these beverages in human cells.

• Journal of Life Science
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• v.31 no.5
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• pp.488-495
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• 2021

The aim of this study was to investigate the possible antioxidant effect of Spirodela polyrhiza (SP) on rats fed a high fat and high cholesterol diet supplemented with either 5% (SPA group) or 10% (SPB group) SP for 4 weeks. The hepatic SOD activity of the HF group significantly decreased compared to that of the N group, but that of the SPA and SPB groups significantly increased. The GPx activity of the SPA and SPB groups in the liver was significantly greater than that of the HF group, and the hepatic catalase activity of the SPA and SPB groups significantly increased compared to the HF group. The hepatic superoxide radical content of the mitochondria and microsomes of the HF group significantly increased compared to that of the N group, but the contents were reduced in the group that took SP powder. The hepatic hydrogen peroxide content in the cytosol and mitochondria of the SP powder group was lower than in the HF group. The carbonyl content in the mitochondria and microsomes of the SPA and SPB groups was significantly lower than in the HF group. The TBARS values in the liver significantly decreased in the SPA and SPB groups. Spirodela polyrhiza was thus effective in reducing oxidative stress by regulating the hepatic antioxidant enzymes and the free radicals in rats fed high fat and high cholesterol diets.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.15-25
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• 2023

Myriophyllum spicatum L. has been used as an ornamental in ponds and aquariums, and as a folk remedy for inflammation and pus. Nevertheless, the biological activity and underlying mechanisms of anti-inflammatory effects are unclear. This study is aimed at investigating the antioxidative and anti-inflammatory activities of ethanol extract of Myriophyllum spicatum L. (EMS) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Antioxidant activity of EMS was assessed by radical-scavenging effects on ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. As inflammatory response parameters produced by LPS-stimulated RAW 264.7 cells were quantified to assess the anti-inflammatory activity of EMS. Our results showed that EMS increased FRAP and DPPH radical-scavenging activity. In EMS-treated RAW 264.7 cells, the production of NO, PGE₂, TNF-α and IL-1β was significantly inhibited at the non-cytotoxic concentration. In addition, EMS significantly attenuated LPS-stimulated the toll-like receptor (TLR) 4/myeloid differentiation protein (MyD) 88 signaling pathway, and inhibited nuclear translocation of nuclear factor-kappa B(NF-κB). Positive correlations were noted between anti-inflammatory activity and antioxidant activity. In conclusion, it was indicated that EMS suppresses the transcription of inflammatory factors by inhibiting the TLR4/MyD88/NF-κB signaling pathway, thereby suppressing LPS-stimulated inflammation in RAW 264.7 cells. This study highlights the potential role of EMS against inflammation and associated diseases.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1265-1276
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• 1998

Background : Nitric oxide(NO) is an endogenously produced free radical that plays an important role in regulating vascular tone, inhibition of platelet aggregation and white blood cell adhesion to endothelial cells, and host defense against infection. The highly reactive nature of NO with oxygen radicals suggests that it may either promote or reduce oxidant-induced cell injury in several biological pathways. Oxidant injury and interactions between pulmonary vascular endothelium and leukocytes are important in the pathogenesis of acute lung injury, including acute respiratory distress syndrome(ARDS). In ARDS, therapeutic administration of NO is a clinical condition providing exogenous NO in oxidant-induced endothelial injury. The role of exogenous NO from NO donor or the suppression of endogenous NO production was evaluated in oxidant-induced endothelial injury. Method : The oxidant injury in cultured rat lung microvascular endothelial cells(RLMVC) was induced by hydrogen peroxide generated from glucose oxidase(GO). Cell injury was evaluated by $^{51}$chromium($^{51}Cr$) release technique. NO donor, such as S-nitroso-N-acetylpenicillamine(SNAP) or sodium nitroprusside(SNP), was added to the endothelial cells as a source of exogenous NO. Endogenous production of NO was suppressed with N-monomethyl-L-arginine(L-NMMA) which is an NO synthase inhibitor. L-NMMA was also used in increased endogenous NO production induced by combined stimulation with interferon-$\gamma$(INF-$\gamma$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and lipopolysaccharide(LPS). NO generation from NO donor or from the endothelial cells was evaluated by measuring nitrite concentration. Result : $^{51}Cr$ release was $8.7{\pm}0.5%$ in GO 5 mU/ml, $14.4{\pm}2.9%$ in GO 10 mU/ml, $32.3{\pm}2.9%$ in GO 15 mU/ml, $55.5{\pm}0.3%$ in GO 20 mU/ml and $67.8{\pm}0.9%$ in GO 30 mU/ml ; it was significantly increased in GO 15 mU/ml or higher concentrations when compared with $9.6{\pm}0.7%$ in control(p < 0.05; n=6). L-NMMA(0.5 mM) did not affect the $^{51}Cr$ release by GO. Nitrite concentration was increased to $3.9{\pm}0.3\;{\mu}M$ in culture media of RLMVC treated with INF-$\gamma$ (500 U/ml), TNF-$\alpha$(150 U/ml) and LPS($1\;{\mu}g/ml$) for 24 hours ; it was significantly suppressed by the addition of L-NMMA. The presence of L-NMMA did not affect $^{51}Cr$ release induced by GO in RLMVC pretreated with INF-$\gamma$, TNF-$\alpha$ and LPS. The increase of $^{51}Cr$ release with GO(20 mU/ml) was prevented completely by adding 100 ${\mu}M$ SNAP. But the add of SNP, potassium ferrocyanate or potassium ferricyanate did not protect the oxidant injury. Nitrite accumulation was $23{\pm}1.0\;{\mu}M$ from 100 ${\mu}M$ SNAP at 4 hours in phenol red free Hanks' balanced salt solution. But nitrite was not detectable from SNP upto 1 mM The presence of SNAP did not affect the time dependent generation of hydrogen peroxide by GO in phenol red free Hanks' balanced salt solution. Conclusion : Hydrogen peroxide generated by GO causes oxidant injury in RLMVC. Exogenous NO from NO donor prevents oxidant injury, and the protective effect may be related to the ability to release NO. These results suggest that the exogenous NO may be protective on oxidant injury to the endothelium.

• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.21-30
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• 2000

Background: The purpose of the present study was to investigate the effect of exercise on the activities of antioxidant enzymes, super oxide dismutase(SOD), glutathione peroxidase(GPX) and catalase(CAT) of skeletal muscle(gastrocnemius) and liver in streptozotocin(STZ) induced diabetic rats. The malondialdehyde(MDA) concentration was also measured as an index of lipid poroxidation of tho tissues by exercise-induced oxidative stresses in diabetic rats. Material and Methods: Male Sprague-Dawley rats were randomly divided into control and STZ-induced diabetic rats. The STZ in citrate buffer solution was injected twice at S days intervals intraperitoneally(50, 70 mg/kg respectively). On the 28th day after the first STZ injection, the diabetic animals were randomly divided into pre- and post-exercise groups, The exercise was introduced to the rats of post-exercise group by treadmill running until exhaution with moderate intensity ($V_{O2max}$: 50-70%) of exercise. The duration of average running time was 2 hours and 19 minutes. Results: The blood glucose concentration was increased(p<0.001) and plasma insulin concentration was decreased(p<0.001) in the diabetic rats. The glycogen concentration in the muscle and liver was decreased by exhaustive exercise in the diabetic rats(p<0.001), In the skeletal muscle, the activities of GPX was increased(p<0.05) and the activities of SOD and CAT were not changed in the diabetic rats compare to those of the control rats. The activities of GPX was not changed by exercise but the activities of SOD(p<0.01) and CAT(p<0.01) were decreased by exercise in the diabetic rats, The concentration of MDA was not changed by exercise in diabetic rats, and the values of pre-exercise and post-exercise diabetic rats were not different from the value those of control rats, In the liver, the activities of SOD was decreased(p<0.01), and the activities of GPX and CAT were not changed in diabetic rats compared to the values of control rats, The activities of SOD, GPX and CAT were not changed by exercise in diabetic rats but the activity of SOD seemed to decrease slightly, The MDA concentration was increased in the diabetic rats compared to the values of control rats(p<0.001), but there was no change of MDA concentration by exercise in diabetic rats, Conclusions: In summary, exhaustive physical exercise did not seem to impose oxidative stress on the skeletal muscle because of due to oxygen free radicals, regardless of the decrease in SOD and CAT in the diabetic rats, In liver tissue, the tissue damage by oxidative stress was observed in diabetic rats but the additional tissue damage by exhaustive physical exercise was not observed.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.723-735
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• 1998

Background : Vitamin C has been reported to have a role in the decrease of airway hyperresponsiveness in animal models. This data is based on some metabolic actions of vitamin C, such as promotion of histamine degradation, producing more $PGE_2$ than $PGF_{2\alpha}$ in cyclooxygenase pathway, decrease of smooth muscle contraction, and acting as reducing agent of oxidant. It has been also known that heavy smokers have lower blood levels of vitamin C than nonsmokers and this deficiency in heavy smokers have been explained by several mechanisms, such as increased oxidation by oxidants and free radicals, increased biosynthesis of catecholamine and serotonin released by nicotine, and inadequate dietary intake. In this study, We attempted to assess effect of vitamin C on bronchial hyperresponsiveness in heavy smokers who have bronchial hyperresponsiveness and role of vitamin C on bronchial hyperresponsiveness. Method: To assess acute effect of vitamin C on airway hyperresponsiveness, blood sample for vitamin C level and spirometry, methacholine challenge test were done in 17 smokers and 8 nonsmokers, and one hour after oral administration of vitamin C 3 g, blood sample for vitamin C level and spirometry, methacholine challenge test were repeated. To assess chronic effect of vitamin C on airway hyperresponsiveness, after daily administration of vitamin C 1 g for one week in 17 smokers, blood sample for vitamin C level and spirometry, methacholine challenge test were done. To assess role of vitamin C, after oral administration of vitamin C 3 g plus indomethacin 100 mg in 12 of 15 smokers who were reactive to methacholine challenge test, spirometry and methacholine challenge test were done and after oral intake of indomethacin 100 mg in 12 smokers who were reactive to methacholine challenge test, spirometry and methacholine challenge test were repeated. Result: There were no significant differences in whole blood vitamin C levels between smokers($1.17{\pm}0.22$ mg/dL) and nonsmcikers($1.14{\pm}0.19$ mg/dL) (p>0.05). Fifteen of the 17 smokers(88.2%) were reactive to methacholine challenge test and 10 of the 15 smokers who were reactive to methacholine challenge test were less than 8 mg/dL in $PC_{20}FEV-2$, and 7 of the 8 nonsmokers(87.5%) were nonreactive to methacholine challenge test There were significant decrease in bronchial responsiveness after oral administration of vitamin C 3 g in 13 of the 15 smokers who were reactive to methacholine challenge test This significant decrease persisted with maintenance daily administration of 1 g for one week. $PC_{20}FEV-2$ were not correlated to vitamin C levels in smokers. After oral administration of indomethacin 100 mg, significant reduction of bronchial responsiveness that occured after oral administration of vitamin C 3 g in smokers were attenuated. Conclusion: Although there were no significant differences in whole blood vitamin C levels between smokers and nonsmokers. heavy smokers have significant increase in bronchial responsiveness than nonsmokers. This bronchial hyperresponsiveness of heavy smokers can be attenuated by vitamin C supplement. Disappearance of vitamin C effect by indomethacin supplement may suggest that vitamin C exert its effect via alteration of arachidonic acid metabolism.