• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.297-301
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• 2012

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the twigs of Taxillus delavayi (Loranthaceae) was found to show potent radical scavenging activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of two phenolic compounds, catechin (1) and galloyl catechin (2), as active principles. Their structures were elucidated by spectroscopic studies. These two compounds showed the significant antioxidative effects on DPPH, and riboflavin- and xanthin-originated superoxide quenching activities. And these two compounds also showed strong nitric oxide radical scavenging effects. In riboflavin- and xanthin-originated superoxide quenching activities and nitric oxide radical scavenging effect, compound 2 showed better antioxidant activities than vitamin C.

• Korean journal of food and cookery science
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• v.24 no.3
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• pp.349-357
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• 2008

In an effort to augment extractability of carnosine and anserine at the levels of pro-oxidants such as iron and protein in Tuna boiled extracts(Skipjack, Yellowfin and Bigeye), we assessed the effects of heated and ion exchange chromatography(IEC) and ultrafiltration(UF) using a MW 500 cut-off(500 MWCO). We also evaluated the antioxidant activity of these extracts processed as free radical scavengers and reducing agents. Tuna boiled extracts of dark and ordinary muscle protein and total iron were reduced, whereas carnosine and anserine concentrations and antioxidant activity were increased. The carnosine and anserine concentrations of the ion exchange and permeate UF(IEC-UF) extracts were higher than those observed in the heated and permeate UF(heat-UF), whereas the protein and total iron contents were lower than that observed in the heat-UF. The quantity of carnosine and anserine in ordinary muscle was higher than that detected in dark muscle. HPLC analysis and SDS-PAGE were shown to removes the effect of UF on high molecular weight impurities in the tuna boiled extracts. The major free amino acids(FFAs) from Skipjack, Yellowfin and Bigeye tuna IEC-UF extracts were anserine, histidine and carnosine. These three peptides constituted more than 80～85%. of the detected amino acid. The IEC-UF treated ordinary muscle extracts evidenced the highest levels of DPPH radical scavenging activity and the highest levels of reducing power among the various extracts. The IEC-UF extracts evidenced a DPPH radical scavenging effect equal to that of 1mM ascorbic acid.

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.1-11
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• 1984

The present study was performed to determine oxygen metabolites involved in cell-free MPO/$H_2O_2/Cl^-$ system by observing the effects of their scavengers on NADH oxidation and ethylene production from methional by the action of MPO prepared from human leukocytes. It was clearly demonstrated that NADH was oxidized by the cell-free MPO/$H_2O_2/Cl^-$ system as evidenced by complete inhibition of the oxidation of the substrate in the presence of eiher azide or catalase, or by omitting $Cl^-$. The MPO-mediated oxidation of NADH was completely abolished by a $^1O_2$ quencher, DABCO but not by $OH{\cdot}$ scavengers, mannitol, benzoate, formate and methanol. In ethylene assay, no ethylene was detected from methional in the MPO/$H_2O_2/Cl^-$ system with evident production of the gas by xanthine-oxidase and $Cu^{++}-H_2O_2$ systems which are suggested to generate $OH{\cdot}$. From the results obtained, it is concluded that $^1O_2$ is a major mediator with exclusion of $OH{\cdot}$ involvement in the cell-free MPO-mediated oxidation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1512-1515
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• 2004

In this study, we investigated in vitro nitric oxide (NO) scavenging effect on nine herbal extracts using an NO donor S-nitroso-N-acetylpenicillamine (SNAP) compared with vitamin C. All herbal extracts effectively reduced the generation of NO radicals in a dose-dependant manner and over 65% in 10h. Especially, Ephedrae herba, Carthami flos and Lonicerae flos declined over 75% of NO scavenging effect, suggested that the herbal extracts are the powerful free radical scavengers and may be effective in clinical applications.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.332-333
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• 2008

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.137-139
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• 2013

Free radical scavengers in the bisdemethoxycurcumin (BDMC), demethoxycurcumin (DMC) and curcumin of turmeric (Curcuma longa) were screened, identified, quantified and isolation using coupled off-line-2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and on-line screening high-performance liquid chromatography (HPLC)-ABTS assay. There was a very small margin of error between the off-line-ABTS method and the on-line screening HPLC-ABTS method.

• Advances in Traditional Medicine
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• v.5 no.1
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• pp.16-20
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• 2005

Grewia tiliaefolia is commonly used in India and several other countries for its ethnomedical properties. The antioxidant effect of 50% methanol extract of Grewia tiliaefolia bark was investigated by in-vitro and in-vivo methods. The extract exhibited $IC_{50}$ value of $51.40{\pm}3.98\;{\mu}g/ml$ in DPPH assay. In the in vivo experiments, the treatment was given at 250 and 500 mg/kg body weight doses orally for seven days and catalase, SOD, TBA-RS and ascorbic acid levels were estimated. Both the doses caused a significant increase in the levels of catalase in the liver and kidney, and SOD in the liver, kidney and blood serum. A significant decrease in the level of TBARS was also observed. These results suggest potent antioxidant nature of the extract.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.331-337
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• 2019

Digitaria exilis L. is an under-utilized crop with high nutritional and medicinal values. It thrives in and is well-adapted to arid areas with low soil nutrients. Using biochemical markers, this study investigates the mechanisms by which D. exilis responds to osmotic stress. Three accessions Dinat Iburua (DIN), Jakah Iburua (JAK) and Jiw Iburua (JIW) were collected from National Cereal Research Institute, Niger State. Two accessions, NG/11/JD/061 and NG/11/JD/062 were also collected from National Centre for Genetic Resources and Biotechnology, Ibadan. Murashige and Skoog medium of approximately 1.2 L was supplemented with polyethylene glycol 6000 to create osmotic pressures of -9.29, -13.93, -20.13, -26.32, -32.51, and 0 MPa (control). Sterilized seeds were inoculated in the medium and placed in the growth room for 4 weeks. Proline accumulation was significantly high in all JAK plants under osmotic stress. Proline and ascorbate peroxidase (p<0.05) activities were directly correlated, thus reinforcing the survivability of JAK during stress. Catalase (CAT) activity was also significantly induced in JAK under osmotic stress, which synergistically improved its tolerability. As a result, >50% of OH-, H₂O₂, and NO radicals were scavenged. However, other accessions including DIN, NG061, NG062, and JIW showed variations in their responses to different levels of osmotic stress, although not significant. Therefore, JAK possesses a well-equipped free radical quenching system that is protected by the accumulation of the osmolyte proline; therefore, accession JAK is considered osmotolerant. CAT and superoxide dismutase activities were osmostabilized against oxidative stress by proline.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.845-854
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• 1998

Background: S-2-(3 aminoprophlamino) ethylphosphorothioic acid(WR-2721) is one of the radical scavenging thiols. We tested its protective effects in the reperfused heart. Material and Method: The experimental setup was the constant pressure Langendorffs perfusion system. We investigated the radical scavenging properties of this compound in isolated rat hearts which were exposed to 20 minutes ischemia and 20 minutes reperfusion. Four experimental groups were used:group I, control, Amifostine 50 mg(1 mL) peritoneal injection 30 minutes before ischemia(group II), Amifostine 10 mg(0.2 mL) injection during ischemia through coronary artery(group III),and Amifostine 50 mg(1 mL) peritoneal injection 2 hrs before ischemia(group IV). The experimental parameters were the levels of latate, CK-MB, and adenosine deaminase(ADA) in frozen myocardium, the quantity of coronary flow,and left ventricular developed pressure, and it's dp/dt. Statistical analysis was performed using repeated measured analysis of variance and student t-test. Result: The coronary flow of group II and IV were less than group I and III at equilibrium state but recovery of coronary flow at reperfusion state of group II, III, and IV were more increased compared with group I. The change of systolic left ventricular devoloping pressure of group II and IV were less than control group at equilibrium state, which seemed to be the influence of the pharmacological hypotensive effect of amifostine. But it was higher compared with group I at reperfusion state. The lactic acid contents of group II were less than control group in frozen myocardium.(Group I was 0.20 0.29 mM/g vs Group II, which was 0.10 0.11 mM/g). The quantity of CK-MB in myocardial tissue was highest in group IV (P=0.026 I: 120.0 97.8 U/L vs IV: 242.2 79.15 U/L). The adenosine deaminase contents in the coronary flow and frozen myocardium were not significantly different among each group. Conclusion: Amifostine seemed to have significant cardioprotective effect during ischemia and reperfusion injuries of myocardium.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.919-922
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• 2004

The effect of an extract of Dalbergiae Lignum and four components that were isolated from the extract on the anticarcinogenic phase II marker enzyme, quinone reductase (QR), was investi-gated. Of the solvent extracts of Dalbergiae Lignum, the CH$_2$CI$_2$ fraction was the most potent in inducing QR activity, with a CD value (the concentration required to double the QR activity) of 29.5 $\mu$/mL. The CH$_2$CI$_2$ extract was further separated into six compounds, four of which were identified as 4-methoxydalbergione, latifolin, 4＇,6-dihydroxy-7-methoxyflavanone, and obtusafu-ran. Obtusafuran ［CD ＝ 1.1 $\mu$M； chemopreventive index (CI) ＝ 101.9］ and latifolin (CD ＝ 1.7 $\mu$M； CI ＝ 154.6) displayed potent QR inducing activity and high chemopreventive indices. Lati-folin and 4-methoxydalbergione were identified as strong DPPH-scavengers with half-maximal free radical scavenging concentrations of 15.9 and 17.2 $\mu$M, respectively.