• Journal of Korean Society for Atmospheric Environment
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• v.8 no.2
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• pp.121-127
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• 1992

This study was carried out to investigate the features of air pollutants in rainwater and trace their transported trajectories from other countries. Chemical analysis data of rainwater and suspended particulates collected at Seoul, Kanghwa, and Taean for three years were used to evaluate the effects of long-range transport of air pollutants. Scavenging theory on washout and rainout effect during a rainy period was applied to estimate whether pollutants in the precipitation were long-range transported or not. On the other hand, precipitation weighted surface wind were evaluated to analyze the effect from local sources on atmospheric concentrations. As a result, contribution of air pollutants caused by anthropogenic sources in the precipitation which was identified to be long range transported was confirmed significantly high and trajectory of these pollutants was to be equivalent to 850mb isobar. Although concentration of acidifying components increased in the precipitation, neutralization by alkaline soil components such as $Ca^{2+}$ and $Mg^{2+}$ was conspicuous especially during Yellow-sand period.

• CELLMED
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• v.4 no.4
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• pp.26.1-26.9
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• 2014

Reactive oxygen species are known to mediate various pathological conditions associated with malaria. In this study, the antioxidant potential of Clerodendrum violaceum leaf extracts, an indigenous antimalarial remedy, was evaluated. Total phenol, flavonoid, selenium, vitamins C and E contents of Clerodendrum violaceum leaf extracts were determined. The free radical scavenging activities of the extracts against DPPH, superoxide anion and hydrogen peroxide coupled with their reducing power were also evaluated in vitro. Moreover, responses of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in a rodent malaria model to a 4-day administration of Clerodendrum violaceum leaf extracts were also evaluated. The methanolic extract was found to contain the highest amounts of antioxidant compounds/element and also demonstrated the highest free radical scavenging activity in vitro. The results showed a significant decrease (p < 0.05) in SOD and CAT activities with a concurrent significant (p < 0.05) increase in GPx and GR activities in both erythrocytes and liver of untreated Plasmodium berghei NK65-infected animals compared to the uninfected animals. The extracts were able to significantly increase (p < 0.05) SOD and CAT activities and significantly reduce (p < 0.05) GPx and GR activities in both the liver and erythrocytes compared to those observed in the untreated infected animals. The results suggest the augmentation of the antioxidant system as one of the possible mechanisms by which Clerodendrum violaceum extract ameliorates secondary effects of malaria infection, alongside its antiplasmodial effect in subjects.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.1
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• pp.55-66
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• 1993

The characteristics of the flow processes in the cylinder of the two-stroke cycle engines have become the subject of increasing and attention owing to the simplicity and the higher power per unit weight of the two-stroke cycle engine. Among the many factors which influence on the scavenging flow, the port angle is important factor. Hence, four different type models with one inlet-port and two side-ports are studied to show the effect of port angle on the laminar scavenging flow. When the inlet-port axial is relatively larger than the side-port axial angle, it is showed that the fresh charge penetrate into the burned gas and displace it first toward the cylinder head and then toward the exhaust port. When the inlet-port axial angle is much less than the side-port axial angle, the fresh charge through the inlet-port directly move toward the exhaust port. The result showed that the model A may suppress the generation of vortices in the vicinity of inlet and side prots which restrict the sufficient supply of fresh charge and obstruct the perfect displacement of all combustion products.

• Mycobiology
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• v.44 no.4
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• pp.291-301
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• 2016

Culinary mushroom Pleurotus pulmonarius has been popular in Asian countries. In this study, the anti-oxidant, cholinesterase, and inflammation inhibitory activities of methanol extract (ME) of fruiting bodies of P. pulmonarius were evaluted. The 1,1-diphenyl-2-picryl-hydrazy free radical scavenging activity of ME at 2.0 mg/mL was comparable to that of butylated hydroxytoluene, the standard reference. The ME exhibited significantly higher hydroxyl radical scavenging activity than butylated hydroxytoluene. ME showed slightly lower but moderate inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase than galantamine, a standard AChE inhibitor. It also exhibited protective effect against cytotoxicity to PC-12 cells induced by glutamate ($10{\sim}100{\mu}g/mL$), inhibitory effect on nitric oxide (NO) production and inducible nitric oxide synthase protein expression in lipopolysaccharide-stimulated RAW 264.7 macrophages, and carrageenan-induced paw edema in a rat model. High-performance liquid chromatography analysis revealed the ME of P. pulmonarius contained at least 10 phenolic compounds and some of them were identified by the comparison with known standard phenolics. Taken together, our results demonstrate that fruiting bodies of P. pulmonarius possess antioxidant, anti-cholinesterase, and inflammation inhibitory activities.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.322-327
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• 2018

Methanol extract of Salvia miltiorrhiza Bunge (Labiatae) root was investigated to research the anti-oxidative activity, by using a Caenorhabditis elegans model system. The methanol extract of this plant showed significant DPPH radical scavenging and superoxide quenching activities. Ethyl acetate soluble fraction of the methanol extract that showed the most potent DPPH radical scavenging and superoxide quenching activities. The ethyl acetate fraction was tested on its activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance in C. elegans. Furthermore, in order to see if regulation of stress-response genes is responsible for the increased stress tolerance of the ethyl acetate fraction treated C. elegans, we checked SOD-3 expression using a transgenic strain. Consequently, the ethyl acetate fraction of S. miltiorrhiza root increased the catalase and SOD activities in a dose-dependent manner in C. elegans. Besides, the ethyl acetate fraction-treated CF1553 worms showed higher SOD-3::GFP intensity than the non-treated ones.

• Natural Product Sciences
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• v.26 no.4
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• pp.268-278
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• 2020

In this study, we investigated the chemical profile and effects of RW0117 (Artemisia argyi 65 .5 % ethanol extract) on gastric lesions in rats. We optimized and validated a method to obtain the chemical profile of RW0117. We then investigated the antioxidant and anti-inflammatory effects in vitro, and the protective effects on gastric lesions in vivo. The IC50 of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging considering the antioxidant effects of RW0117 was 166.55 ㎍/mL, and the IC50 of nitric oxide scavenging considering the anti-inflammatory effects was 41.16 ㎍/mL. Oral administration of RW0117 at lower concentrations (25, 50, 100 mg/kg) had similar or greater effects than the daily intake conversion concentration (115mg/kg) of a health functional food (Avexol®) in the acetic acid-induced ulcer and the ethanol-induced gastric injury rat models. In addition, oral administration of RW0117 increased the expression of prostaglandin E2, which enhances the protective effect in the gastric mucosa in the ethanol-induced gastric injury rat model. These results suggest that RW0117 may have potential therapeutic uses in the protection of the gastric mucosa.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.865-872
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• 2002

In the course of the investigations of natural antioxidants, we examined the antioxidant activities of the methanol (MeOH) extracts of some selected Prunus species, including P. buergeriana, P. davidiana, P padus, P. pendula for. ascendens, P. sargentii, P. serrulata var. spontanea and P. yedoensis by three methods as represented by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, total ROS (reactive oxygen species) and the peroxynitrite ($ONOO^-$) scavenging activity tests. We also evaluated the activities of the organic solvent-soluble fractions, including the dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), n-butanol (n-BuOH) fractions and the water ($H_2O$) layer of P. serrulata var. spontanea leaves. By means of bioassay-directed fractionation, we isolated eleven known flavonoids (1-11) from the EtOAc soluble fraction of the MeOH extract of the Prunus serrulata var. spontanea leaves, exhibiting strong antioxidant activity and characterized as prunetin (1), genistein (2), quercetin (3), prunetin $4'-O-{\beta}-glucopyranoside$ (4), kaempferol $3-O-{\alpha}-arabinofuranoside$ (5), prunetin $5-O-{\beta}-glucopyranoside$ (6), kaempferol $3-O-{\beta}-xylopyranoside$ (7), genistin (8), kaempferol $3-O-{\beta}-glucopyranoside$ (9), quercetin $3-O-{\beta}-glucopyranoside$ (10) and kaempferol $3-O-{\beta}-xylopyranosyl-(1{\rightarrow}2)-{\beta}-glucopyranoside$ (11). Compounds 3 and 10 showed good activities in all tested model systems. Compounds 2 and 8 showed scavenging activities in the DPPH and $ONOO^-$ tests, while compounds 5, 7, 9 and 11 were active in the $ONOO^-$ and ROS tests. On the other hand, compounds 1, 4 and 6 did not show any activities in the tested model systems.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.362-370
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• 1999

Propolis, a natural resinous compound collected from honey bees, contains many biochemical constituents(wax, flavonoids, phenolic compounds, etc.) and has been used in traditional medicines as early as 300 B.C. It was been demonstrated that ethanol, acetylsalicylic acid, ischemia reperfusion, non-steroidal antiin-flammatory drugs and stress induce gastric lesions by promoting the generation of reactive oxygen metabolites. Therefore, some drugs that are capable of scavenging or inhibiting the generation of reactive oxygen radicals might be expected to prevent the gastric mucosal injury. The aim of this study was 1) to examine the antiulcer effect of propolis, 2) to investigate the mechanism of action by determining gastric acid secretion, lipid per-oxidation, mucus content and proton pump ($H^+$/$K^+$-ATPase) activity on gastric mucus in varios experimental models, and finally, 3) to isolate and identify the pure compounds that exert antiulcer activity. Step 2-1 and 2-3 sub-sub fraction shoed a significant reduction of severity of gastirc damage at the dose of 25 mg/kg in various experimental models. We isolated 4 sub-sub-sub fractions by flash column chromatography of Step 2-1 sub-sub fraction and one sub-sub-sub fraction by recrystalization of Step 2-3 sub-sub fraction. The protective effects of propolis sub-sub-sub fraction manifested sifnificant effects in HCl-ethanol induced gastric erosion model and aspirin induced gastric ulcer model. These results showed that the gastric mucosal protective effect of propolis might result from the increase of mucus secretion, free radical scavenging effect as well as the reduction of acid secretion in accordance with the reduction of $H^+$/$K^+$-ATPase activitv. Three compounds were isolated and identified from sub-sub fraction of propolis which showed antiulcer effects. Subsequently, these compounds were identified as a flavonoid, namely, 2-acetoxy-5,7,-dihydroxy-flavanone, galangin and chrysin.

• Preventive Nutrition and Food Science
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• v.17 no.3
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• pp.177-183
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• 2012

Interruption of blood flow through coronary arteries and its subsequent restoration triggers the generation of a burst of reactive oxygen species (ROS), leading to myocardial cell death. In this study, we determined whether a methanol extract of Cassia mimosoides var. nomame Makino could prevent myocardial ischemia-reperfusion injury. When radical scavenging activity of the extract was measured in vitro using its ${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical quenching ability, the extract showed an activity slightly lower than that of ascorbic acid. Three days after oral administration of the extract (400 mg/kg/day) to rats, myocardial ischemia/reperfusion injury was generated by 30 min of ligation of the left anterior descending coronary artery (LAD), followed by 3 hr reperfusion. Compared with the vehicle-treated group, administration of the extract significantly reduced infarct size (IS) (ratio of infarct area to area at risk) in the extract-treated group by 28.3%. Reduction in the cellular injury was mediated by attenuation of Bax/Bcl-2 ratio by 33.3%, inhibition of caspase-3 activation from procaspase-3 by 40%, and subsequent reduction in the number of apoptotic cells by 66.3%. These results suggest that the extract attenuates myocardial injury in a rat model of ischemia-reperfusion by scavenging ROS, including free radicals, and consequently blocking apoptotic cascades. Therefore, intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic myocardial injury.

• Food Science and Preservation
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• v.13 no.2
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• pp.119-124
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• 2006

This study was conducted to optimize roasting process of Job's tears for utilization as food Optimal condition for masting was investigated with changes in temperature and time by response surface methodology. The qualities of water extract such as browning degree, polyphenol and DPPH radical scavenging ability were affected more by roasting temperature than time. The values increased with temperature and time proportionally. The response variables were more significant with temperature than time and the established polynomial model was suitable (P>0.05) model by Lack-of-Fit analysis. Optimal roasting conditions with the limit of $0.2{\sim}0.3$ browning degree, $2.0{\sim}2.5{\mu}g/mL$ polyphenol, $30{\sim}40%$ scavenging ability and $0{\sim}100$ hue angle were $215^{\circ}C$ and 32 min.