• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.47-54
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• 1984

Effect of ascorbic acid on various hepatic ethanol metabolizing enzymes including alcohol dehydrogenase(ADH), the microsomal . ethanol oxidizing system(MEOS), and catalase was quantitatively evaluated in liver microsomal and cytosolic preparation from Sprague-Dowley rats. In present study, ADH activities were no changed significantly by ascorbic acid. The MEOS activity, dependent on NADPH and $O_2$, was affected by azide (inhibitor of catalase) or exogenous catalase. In the presence of ascorbic acid, ethanol oxidation by rat liver microsomal preparation reacted with NADPH-generating system was increased by up to 22.5%, but decreased when liver microsome was reacted with $H_2O_2$ generated by xanthine and xanthine oxidase. Increase in the activity of the MEOS in the presence of ascorbic acid was greater in liver microsomal preparation pretreated with azide. Also ascorbic acid oxidized ethanol nonenzymatically. This ethanol oxidation induced by ascorbic acid was inhibited by OH radical scavengers (thiourea, sodium benzoate), but was not much affected by superoxide dismutase. From these results it was suggested that ascorbic acidcould interact directly with the MEOS, then promote the oxidation of ethanol. And, to some extent, ${\cdot}OH$-radicals or other radicals generated during the spontaneous autooxidation of ascorbic acid may be responsible for the production of acetaldehyde from ethanol.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.155-164
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• 2018

Nypa fruticans Wurmb is a species of palm, which is widely distributed in the mangrove forest of Southeast Asia. Various parts of N. fruticans has been used as a traditional medicinal plant. However, the physiological activities of N. fruticans has not yet been clarified well. Therefore, in this study, the 50% ethanol extract and its aqueous and ethyl acetate fractions of young shoots of N. fruticans were investigated for their antioxidant, cytoprotective effect, and antimicrobial activities. Every sample possessed very high free radical and various ROS scavenging capacities assessed by employing different in vitro assays such as $DPPH^{\cdot}$, $O_2^{{\cdot}-}$, ${\cdot}OH$, and $^1O_2$ scavenging activities. Based on these results, the cytoprotective effect was investigated using the oxidative hemolysis of erythrocyte. We found that the extract and fractions provide a greater protective effect compared with (+)-${\alpha}$-tocopherol. Furthermore, antimicrobial activities were confirmed against skin pathogens by broth microdilution assay. The ethyl acetate fraction had much higher antimicrobial activities than methyl paraben against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Candida albicans. Taken together, our results indicated that the young shoots of N. fruticans may have the potential role as a natural active ingredient through their antioxidant, cytoprotective effect, and antimicrobial activities.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.16-22
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• 2003

Interrelation between the antioxidative activities of 70% ethanol extracts from bran fraction of 23 kinds of colored rice and chuchung as a control were examined. Antioxidative activities were evaluated by assaying reducing power, electron-donation ability to DPPH free radical, scavenging activity of hydroxy radical $({\cdot}OH)$ generated through Fenton reaction and inhibitory activity on lipid peroxidation using linoleic acid autoxidation system, respectively. Among 24 varieties of colored rice LK 1-3-6-12-1-1 had the strongest reducing power followed by Elwee, DZ 78, Jumlalocal-1 and SC-45 in decreasing order. The electron-donating ability to DPPH radical was higher in order of HP 883-1-1-1-B-1-1, HP 833-1-3-1-1-1, LK 2-7-12-1-1 and DZ 78. The hydroxy radical scavenging activity was higher in order of DK-1, IR 1544-38-2-2-1-2-2, SC-5 and SC-45 but LK 2-7-12-1-1 had oxidative effect. In the liaoleic acid autoxidation model system, RGS No 336, LK 1B-2-1-1, LK 1B-4-12-1-1, LK 1A-2-12-1-1, LK 2-7-12-1-1 and HP 883-1-1-1-B-1-1 exhibited strong antioxidative activities but Elwee, Jumlalocal-l and SC-45 showed to have oxidative effects. The rice variety of highest pigment content was Elwee and the next were RGS-No 336, IR 1544-38-2-2-1-2-2 and SC-5 with the order of higher content. The reducing power was correlated with the quantity of the pigment in the ethanolic extract of rice bran and SC-5 showed relatively high antioxidative activity in every results of antioxidative activity tests.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.517-524
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• 2015

The objectives of the present study were to investigate the protective effects of Angelica keiskei juice and Oenanthe javanica juice against oxidative damage in LLC-$PK_1$ renal epithelial cells and to evaluate their free radical-scavenging activities. Both A. keiskei juice and O. javanica juice showed a strong in vitro antioxidant activities such as ${\alpha}$, ${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH), nitric oxide (NO), $O_2{^-}$, and ${\cdot}OH$ radical-scavenging activities. The LLC-$PK_1$ cells showed significant lipid peroxidation and cell death due to oxidative stress when it was induced by 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH), sodium nitroprusside (SNP), pyrogallol, and 3-morpholinosydnonimine (SIN-1). Treatment with both A. keiskei juice and O. javanica juice significantly increased cell viability and inhibited lipid peroxidation. These results suggest that A. keiskei juice and O. javanica juice are potential natural antioxidants.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.1-14
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• 1982

The effects of xanthine-xanthine oxidase reaction on brain microsomal $Na^+-K^+-ATPase$ activity were studied to see possible involvement of oxygen free radicals in pathologic change occurring in ischemic state of CNS accompanied by cerebral vascular occlusion or impact injury. When microsomal fraction was incubated with xanthine ana xanthine oxidase, $Na^+-K^+-ATPase$ activity of the fraction was markedly inactivated (80% inactivation) whereas btssl $Mg^{++}-ATPase$ was much less sensitive (less than 10% inactivation) compared to that of $Na^+-K^+-ATPase$. The inactivation was observed only in the presence of both xanthine and xanthine oxidase, not either of them alone, and the extent of inactivation was dependent on the concentration of xanthine. In an attempt to determine which of the oxygen species was responsible for the inactivation, the ability of various scavengers to overcome the inactivation was tested. Superoxide dismutase, catalase and 1,4-diazabicyclo(2,2,2)octane were shown to reverse the inactivation of the ATPase in dose-dependent manner. In contrast, mannitol as well as other $OH{\cdot}$quenchers were ineffective in limiting oxygen radical-induced inactivation. Thus $O_{\bar{2}}{\cdot},\;H_2O_2$ and $^1O_2$ were implicated to be mediators involved in the inactivation. Since oxygen radicals are suspected as being a cause of the peroxidative damaging process in train ischemia, the ATPase inactivation by oxygen radicals may be a possible contributing factor which gives rise to functional derangement of nerve cells observed in the pathologic process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1498-1502
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• 2005

This study evaluated the isolation and identification of biologically active compounds from the ethyl acetate fraction of grape seed extract (Campbell early). Ethyl acetate fraction was further purified with sephadex LP-20 column chromatography. Each biologically active compound for free radical scavenging effect and lipid peroxidation inhibition was isolated and identified with ${1}^H$ and${12}^C$-NMR. Major compounds were identified as (+)-catechin and (-)-epicatechin respectively. The amounts of (+)-catechin and (-)-epicatechin in grape seed were 45.7$\%$ and 35.1$\%$, respectively. The purified (+)-catechin and (-)-epicatechin showed more strong free radical scavenging effects ($RC_{50}$= 11.1 $\mu$g/mL and 10.4 $\mu$g/mL) than ethyl acetate fraction ($RC_{50}$= 15.4 $\mu$g/mL). However, ethyl acetate fraction showed much stronger lipid oxidative inhibition effect than the purified (+)-catechin and (-)-epicatechin.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.579-590
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• 2001

Background : The aging process may be induced, at least in part, by reactive oxygen species(ROS). It has been thought that the lung could be a good source of ROS because it has a high oxygen tension. In the present study, we invetigated the inducibility of the first and last lines against oxidative stress, superoxide dismutases(CujZn-SOD and Mn-SOD) as a scavenger of ${O_2}^-\;{\cdot}$ and metallothionein(MT) as a scavenger of $OH{\cdot}$, respectively, in mouse lungs with age. Methods : Oxidative stress was induced by paraquat, an intracellular superoxide generator, at 1, 4, 8, and 12 months of age and then SODs and MT mRNAs were determined by RT-PCR method. Results : The steady-state level of Mn-SOD mRNA increased from 1 to 8 months but decreased thereafter. However, Mn-SOD mRNA was not induced by paraquat after 1 month. On the other hand, there was no change in the steady-state level of Cu/Zn-SOD mRNA, which decreased abruptly at 12 months of age. Additionally, Cu/Zn-SOD mRNA was not induced by paraquat at any age. There was no change in the steady-state level of MT mRNA with age whereas its inducibility by paraquat was intact at all ages. Conclusion : These results indicate that lack of induction of SODs with age may be one of the causative factors in the aging process while induction of MT may play an important role in the defense against oxidative stress. It is therefore implicated that the tissue antioxidant/prooxidant balance could be one of determinants of mean life span.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.764-769
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• 1999

This study was designed to investigate the effects of sea tangle (Laminaria japonica) extract (Dasi-Ex group: dry base $4.0\%$) and fucoidan-added (Fuco-I, II, III group: fucoidan of $1,0\%,\;2.0\%,\;3.0\%$ added to Dasi-Ex) drinks on the formation of oxygen radicals and scavenger enzyme activities of stressed mice. ICR male mice (20 $\pm$2 g) were fed experimental diets and these drinks instead of water for 18 days including 4 days of sociopsychological stress. Dasi-Ex and Fuco-I, II and III groups resulted in a marked decreases $20\~40\%$ in basal oxygen radical (BOR) formation, and $15\~25\%$ in induced oxygen radical (IOR) formation compared with control group. Hydroxyl radical formations were significantly inhibited about $10\%$ in Dasi-Ex group, while remarkably inhibited $30\~40\%$ in Fuco-I, II and III groups. lipid peroxide (ISO) levels in Dasi-Ex group were not significantly different from those of control group, tut Fuco-I, II and III groups resulted in a significant decreases about $10\%$ in LPO levels compared with control group, Dasi-Ex, Fuco-I, II and III groups resulted in a marked decreases ($31\%,\;36\%,\;39\%$ and $42\%$, respectively) in oxidized protein levels through production of carbonyl group. Significant differences in nitric oxide (NO) levels in Dasi-Ex group were not obtained, but NO levels were slightly inhibited about $7\%$ in Fuco-I and II groups and $20\%$ in Fuco-III group compared with control group. Significant differences in superoxide dismutase (SOD) and catalase (CAT) activities in Dasi-Ex and Fuco-I groups were not obtained, but Fuco-II and III groups resulted in a significant increases $25\~40\%$ in SOD activities, and about $10\%$ in CAT activities compared with control group. These results suggest that the sociopsychological stress and aging process could be effectively inhibited by biological activity of sea tangle and fucoidan components.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.3
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• pp.127-132
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• 2010

Reactive oxygen species (ROS), which include hydrogen peroxide ($H_2O_2$), the superoxide anion (${O_2}^-{\cdot}$), and the hydroxyl radical ($OH{\cdot}$), are generated as by-products of oxidative metabolism in cells. The cerebral cortex has been found to be particularly vulnerable to production of ROS associated with conditions such as ischemia-reperfusion, Parkinson's disease, and aging. To investigate the effect of ROS on inhibitory GABAergic synaptic transmission, we examined the electrophysiological mechanisms of the modulatory effect of $H_2O_2$ on GABAergic miniature inhibitory postsynaptic current (mIPSCs) in mechanically isolated rat cerebral cortical neurons retaining intact synaptic boutons. The membrane potential was voltage-clamped at -60 mV and mIPSCs were recorded and analyzed. Superfusion of 1-mM $H_2O_2$ gradually potentiated mIPSCs. This potentiating effect of $H_2O_2$ was blocked by the pretreatment with either 10,000-unit/mL catalase or $300-{\mu}M$ N-acetyl-cysteine. The potentiating effect of $H_2O_2$ was occluded by an adenylate cyclase activator, forskolin, and was blocked by a protein kinase A inhibitor, N -(2-[p-bromocinnamylamino] ethyl)-5-isoquinolinesulfonamide hydrochloride. This study indicates that oxidative stress may potentiate presynaptic GABA release through the mechanism of cAMP-dependent protein kinase A (PKA)-dependent pathways, which may result in the inhibition of the cerebral cortex neuronal activity.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.258-264
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• 2011

The Korean edible mountainous vegetable, byeongpungssam, Cacalia firma Komar. (CFK) is a wild plant found in the intermountain areas in Korea. The aim of this study was to investigate its free radical scavenging activity using 1,1-diphenyl-2-picryl-hydrazyl, 2,2-azinobis(3-ethylbenozothiazoline- 6-sulfonic acid) diammonium salt, ferric reducing/antioxidant power assays, an electron spin resonance spectroscopy. We also examined its protective effect against oxidative DNA damage using agarose electrophoresis of ethanol extract of CFK. The protective activity of the extract against the DNA damage induced by HO${\cdot}$ radicals was compared to epicatechin, ascorbic acid and trolox as reference antioxidant compounds. Total phenolic content in the extract was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents. Total polyphenolic content of the extract was measured in the leaves ($161.53{\pm}1.07{\mu}g/g$) and shoot ($142.45{\pm}0.56{\mu}g/g$). The antioxidant potential of the extracts against some radicals and DNA damage by HO${\cdot}$ radicals showed over 60%, respectively.