• Toxicological Research
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• v.26 no.4
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• pp.321-327
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• 2010

The ability of 80% ethanol extracts from five medicinal plants, Aralia continentalis, Paeonia suffruticosa, Magnolia denudata, Anemarrhena asphodeloides, and Schizonepeta tenuifolia, to neutralize hydroxyl radical, peroxyl radical and peroxynitrite was examined using the total oxyradical scavenging capacity (TOSC) assay. Peroxyl radical was generated from thermal homolysis of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (ABAP); hydroxyl radical by an iron-ascorbate Fenton reaction; peroxynitrite by spontaneous decomposition of 3-morpholinosydnonimine N-ethylcarbamide (SIN-1). The oxidants generated react with $\alpha$-keto-$\gamma$-methiolbutyric acid (KMBA) to yield ethylene, and the TOSC of the substances tested is quantified from their ability to inhibit ethylene formation. Extracts from P. suffruticosa, M. denudata, and S. tenuifolia were determined to be potent peroxyl radical scavenging agents with a specific TOSC (sTOSC) being at least six-fold greater than that of glutathione (GSH). These three plants also showed sTOSCs toward peroxynitrite markedly greater than sTOSC of GSH, however, only P. suffruticosa revealed a significant hydroxyl radical scavenging capacity. Seven major active constituents isolated from P. suffruticosa, quercetin, (+)-catechin, methyl gallate, gallic acid, benzoic acid, benzoyl paeoniflorin and paeoniflorin, were determined for their antioxidant potential toward peroxynitrite, peroxyl and hydroxyl radicals. Quercetin, (+)-catechin, methyl gallate, and gallic acid exhibited sTOSCs 40~85 times greater than sTOSC of GSH. These four components also showed a peroxynitrite scavenging capacity higher than at least 10-fold of GSH. For antioxidant activity against hydroxyl radical, methyl gallate was greatest followed by gallic acid and quercetin. Further studies need to be conducted to substantiate the significance of scavenging a specific oxidant in the prevention of cellular injury and disease states caused by the reactive free radical species.

• The Journal of Korean Medicine
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• v.23 no.4
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• pp.55-63
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• 2002

Objectives: Peroxynitrite ($ONOO^{-}$), formed from the reaction of superoxide <${\cdot}O_2^{-}$) and nitric oxide (NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA. It has been implicated in diseases such as aging process, Alzheimer's disease, rheumatoid arthritis, cancer and arteriosclerosis. Due to the lack of endogenous enzymes responsible for $ONOO^{-}$ inactivation, developing a specific $ONOO^{-}$ scavenger is of considerable importance. The aim of this study was to evaluate $ONOO^{-}$ scavenging activity and its mechanism in Cheonga-hwan (CAH). Methods: The $ONOO^{-}$ scavenging activity in CAH was assayed by measuring oxidized dihydrorhodamine 123 (DHR 123) by fluorescence. The scavenging efficacy was expressed as $IC_{50}$, showing the concentration of each sample required to cause 50% inhibition of DHR 123 oxidation. In a separate study, the protective effect of CAR on $ONOO^{-}$-induced nitration of bovine serum albumin (BSA) was investigated using immunoassay with a monoclonal anti-nitrotyrosine antibody, and a horseradish peroxidase-conjugated anti-mouse secondary antibody from sheep. Results: CAH showed potent scavenging activities of $ONOO^{-}$, NO and ${\cdot}O_2^{-}$. The data demonstrated that CAH led to decreased $ONOO^{-}$-mediated nitration of tyrosine through electron donation. CAH showed significant inhibition on nitration of bovine serum albumin by $ONOO^{-}$ in a dose-dependent manner. Conclusions: CAH can be developed as an effective peroxynitrite scavenger for the prevention of the $ONOO^{-}$ involved diseases.

• KSBB Journal
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• v.19 no.1
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• pp.57-61
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• 2004

A peroxynitrite is formed when superoxide and nitric oxide exist at near eqimolar ratio in biological systems. Although not a free radical by chemical nature, peroxynitrite is a powerful oxidant having a wide array of tissue damaging effects ranging from lipid oxidation and inactivation of enzymes and ion channels through protein oxidation and nitration to inhibition of mitochondrial respiration. During our search for new antioxidizing components from natural resources, twenty salt marsh plants were screened for their ONOO and DPPH radical scavenging activities. Among them, methanol extract of Rosa rugosa, lxeris tamagawaensis, Erigeron annus, Tetragonia tetragonoides, Imperata cylindrica, and Suaeda japonica inhibited more than 85% of peroxynitrite produced by 3-morpholinsydnonimine (SIN-1) at a concentration of 5 $\mu\textrm{g}$/$m\ell$. In addition, Rosa rugosa, Artemisia capillaris, Erigeron annus and Ixeris tamagawaensis showed significant scavenging effect against DPPH (1,1-diphenyl-2-picrylhydrazyl radical).

• Ocean and Polar Research
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• v.29 no.2
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• pp.187-191
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• 2007

In this study, antioxidant activities of acetone/dichloromethane and methanol extracts of Arctic seaweeds were investigated. The antioxidant properties of both extracts of arctic seaweed were evaluated using two different peroxynitrite tests, including scavenging power on authentic peroxynitrite and inhibitory activities on peroxynitrite generation from 3-morpholinosydnonimine (SIN-1) producing superoxide anion and nitric oxide simultaneously in vitro. At concentration of $10\;{\mu}g/ml$, the acetone/dichloromethane and methanol extracts of Odonthalia dentata exhibited 54.6 and 64.2% inhibition against peroxynitrite generation from SIN-1 while they exhibited 24.3 and 23.0% scavenging activities on authentic peroxynitrite, respectively. On the other hand, the acetone/dichloromethane extract of Polysiphonia stricta exhibited 61.8% inhibition only against the induced peroxynitrite from SIN-1. Furthermore, the crude extracts of Odonthalia dentata and Polysiphonia stricta were fractionated into n-hexane, 85% aq. MeOH, n-BuOH, and $H_2O$ fractions, successively, and only 85% aq. MeOH fraction exhibited the best inhibition.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.625-627
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• 2002

From the leaves of Brassica juncea, an radical scavenging isorhamnetin 7-Ο-glucoside on peroxynitrite and 1,1-diphenyl-2-picrylhydrazyl (DPPH) was isolated and characterized based on the spectroscopic evidence. The compound showed the peroxynitrite and DPPH scavenging activities with $IC_{50}$ values of 2.07$\pm$0.17 and 13.3 $\mu$M, respectively. Penicillamine and L-ascorbic acid as positive control exhibited radical scavenging activities with $IC_{50}$ values of 3.17$\pm$0.39 and 12.78 $\mu$M, respectively.

• Ocean and Polar Research
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• v.26 no.1
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• pp.59-64
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• 2004

As a part of our search for novel antioxidants from the seaweeds, we have investigated radical scavenging effect for their crude extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, authentic peroxynitrite, and 3-morpholinsydnonimine (SIN-1), a peroxynitrite-generating species in vitro. Thirty-four seaweeds were screened for $ONOO^-$ and DPPH radical scavenging activities. A potent inhibitory effect against peroxynitrite generated by SIN-1 at $5{\mu}g/ml$ of methanol extracts was observed in order of Ishige okamurae(95.3%), Sargassum hemiphyllum(90.2%), Symphyocladia latiuscula(89.6%), Porphyra suborbiculata(86.7%), and Gelidium amamsii(85.9%), Also, a significant scavenging effect against direct authentic peroxynitrite was revekaled for methanol extracts of Ishige okamurae(66.2%) and Sargassum hemiphyllum(55.2%) and the acetone/methylene chloride(1:1) extract of Gigatina tenella (61.0%). In our measurement for evaluating the capacity to scavenge the stable free radical of DPPH, acetone/methylene chloride(1:1) extracts of Symphyocladia latiuscula, Gloiopeltis furcata, and Sargassum thunbergii and the methanol extract of Sargassum sp. showed an inhibitory potency of 85.8%, 82.8%, 74.1%, and 64.0%, respectively.

• KSBB Journal
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• v.19 no.1
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• pp.67-71
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• 2004

An antioxidant activity of Rosa rugosa extract and its solvent-partitioned fractions was determined not only by measuring lipid peroxide produced when a mouse liver homogenate was exposed to the air at 37$^{\circ}C$, using thiobarbituric acid (TBA) but also by evaluating the free radical scavenging effect against DPPH radical, authentic peroxynitrite, and 3-morpholinsydnonimine (SIN-1). All its partitioned fractions including crude extract showed potent scavenging effect against DPPH radical, peroxynitrite, and lipid peroxidation. n-BuOH fraction, in particular, was found to be the most effective in DPPH radical scavenging ability as well as inhibition against lipid peroxidation. The 15% aqueous MeOH fraction also showed a strong potency which was slightly lower than n-BuOH fraction. Based on these results, we suggest that Rosa rugosa could be useful for preventing an oxidative damage.

• Natural Product Sciences
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• v.9 no.2
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• pp.73-79
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• 2003

To discover the sources with antioxidative activity in traditional medicines, 100 extracts of Korean medicinal plants were screened for their scavenging effect on peroxynitrite $(ONOO^{-})$ and total reactive oxygen species (ROS). The potency of total ROS scavenging activity was shown in the extracts of 25 plants, and 4 of their species, Macleaya cordata R. Br., Salvia plebeia R. Br., Cassia tora L. and Angelica gigas Nakai, had a greater effect with $IC_{50}$ values of $1.7{\pm}0.36$, $4.3{\pm}1.08$, $4.9{\pm}0.17$ and $5.8{\pm}1.01\;{\mu}g/ml$, respectively, than that of trolox, positive control $(7.61{\pm}0.12\;{\mu}g/ml)$. Another 35 extracts exhibited inhibitory effect of below 50 percent at $100\;{\mu}g/ml$ of sample concentrations on total ROS, while the rest observed total ROS generators rather than scavengers. The peroxynitrite scavenging activities were observed in the greater part of the plants tested. Five of them, Schisandra chinensis Baill, Campsis grandiflora (Thunb.) K. Schum., Cedrela sinensis A. Juss., Pleuropterus multiflorus Turcz. and Veronica linariaefolia Pall represented scavenging activities on peroxynitrite twice as strong with $IC_{50}$ Values of $0.48{\pm}0.10$, $0.59{\pm}0.15$, $0.60{\pm}0.10$, $0.64{\pm}0.10$ and $0.91{\pm}0.23\;{\mu}g/ml$, respectively, as that of penicillamine $(1.72{\pm}0.05\;{\mu}g/ml)$, positive control. Consequently, 25 species of the entire plants tested, exhibited scavenging activities on total ROS and $ONOO^{-}$, Salvia plebeia R. Br., Macleaya cordata R. Br., Cassia tora L. and Angelica gigas Nakai exerted potent scavenging activities on both radicals.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.13-18
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• 2006

The antioxidant activity of the extract of Erigeron annuus was assessed by means of two different in vitro tests: bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test) and the scavenging of authentic peroxynitrite in company with peroxynitrite generation from 3-morpholinosydnonimine (SIN-1). In both tests, the 85% aq. MeOH and n-BuOH soluble fractions of the crude extract showed a significant scavenging effect on peroxynitrite and DPPH radical in comparison to L-ascorbic acid. And bioassay-guided fractionation of the n-BuOH soluble fraction led to the isolation of three compounds: Apigenin (1), quercetin-3-O-glucoside (2), and caffeic acid (3). The structures of the isolated compounds were elucidated on the basis of their spectroscopic data and their antioxidant activities were measured by determining their capacity to scavenge peroxynitrite and the DPPH radical.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.376-381
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• 2009

The compositional analysis and the peroxynitrite ($ONOO^-$) scavenging assay were undertaken to demonstrate beneficial dietary effect of lettuce (Lactuca sativa L., Compositae). Quinic acid derivatives of the seven cultivars were qualitatively and quantitatively analyzed by HPLC to lead to the finding of 3,4-di-O-caffeoyquinic acid and 3-O-p-coumaroylquinic acid and their contents ranged over 2.72-4.47 mg/g and 8.97-23.26 mg/g, respectively. A cultivar Hacheong had the highest quantity of quinic acid derivatives. The peroxynitrite scavenging effect of the five cultivars (Jangsu, Gosina 27, Gopung, Yeolpungjeogchima, and Mipungjeogchugmyeon) were ranged over 7.45-8.26${\mu}g$/ml as $IC_{50}s$ while those of Hacheong and Mihong had less effect ($IC_{50}$ >10 ${\mu}g$/ml).