• Advances in Traditional Medicine
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• v.10 no.4
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• pp.304-309
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• 2010

Scutellaria pinnatifida A. Hamilt. (Lamiaceae) is an endemic Turkish herb. This plant is also endemic to Iran, and grows abundantly in other central and western Asian countries. Several species of the Scutellaria are known for their traditional uses in the treatment of hypertension, arteriosclerosis, inflammatory diseases, hepatitis, allergy, cancer and diarrhoea. Free-radical-scavenging property, antibacterial activity and brine shrimp toxicity of the n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of S. pinnatifida were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtitre plate based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts exhibited free-radical-scavenging property, with the $RC_{50}$ values of 0.362 and 0.127 mg/ml, respectively. Among the solid-phase extraction fractions of the MeOH extract, the 50% aqueous-MeOH fraction showed the highest level of free-radicalscavenging activity ($RC_{50}$ = 0.039 mg/ml). While the DCM extract showed low level of antibacterial activity against Bacillus subtilis and ampicillin-resistant Escherichia coli, the MeOH extract was active against B. cereus, B. subtilis, E. coli and ampicillin-resistant E. coli. However, the minimum inhibitory concentrations (MIC) of the MeOH extract against these bacterial strains were >10 mg/ml. None of the extracts showed any significant toxicity towards brine shrimps ($LD_{50}$ = > 1.00 mg/ml).

• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.8-11
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• 2011

In this study, we assessed the free radical scavenging and xanthine oxidase inhibitory activities of extracts isolated from the dried roots and stems (including leaves) of Angelica dahurica. The irritation response from these extracts was also assessed to determine potential cosmetic use. Both sources of A. dahurica extracts exhibited radical scavenging properties to different extents. The free radical scavenging potency ($EC_{50}$) of the stems (including leaves) of A. dahurica was 243.33 ${\mu}g/mL$, which is significantly lower (p<0.01) than that observed of the roots (1,161.79 ${\mu}g/mL$). The inhibition values ($EC_{50}$) of xanthine oxidase were as follows: 435.19 ${\mu}g/mL$ (roots) and 434.66 ${\mu}g/mL$ (stems). We noted no significant differences between the two plant parts with regard to ability to inhibit xanthine oxidase activity. After the application of A. dahurica extracts to rabbits for skin and eye irritation tests, no negative effects were observed; therefore, the extracts are considered to be non-irritating to the skin and eye.

• Korean Journal of Pharmacognosy
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• v.41 no.3
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• pp.180-184
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• 2010

The antioxidant activity of Desmodium oldhami (Leguminosae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of D. oldhami showed the strong antioxidant activity. Five compounds, kaempferol-3-O-rhamnopyranoside (afzeline) (1), quercetin-3-O-[$\alpha$-L-rhamnopyranosyl($1{\rightarrow}6$)-$\beta$-Dglucopyranoside] (rutin) (2), kaempferol-3-O-glucopyranoside (astragalin) (3), genistein-7-O-$\beta$-D-glucopyranoside (genistin) (4), kaempferol-3-O-rutinoside (5) were isolated from the active ethyl acetate soluble fraction of D. oldhami through repeated silica gel and Sephadex LH-20 column chromatography. Among them, compound 2 showed the most significant antioxidative effect on DPPH free radical scavenging test. Compounds 1-5 are reported for the first time from this plant.

• Journal of Ginseng Research
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• v.35 no.1
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• pp.60-68
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• 2011

The chemical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity changes of ginsenoside $Rb_1$-glycine and ginsenoside $Rg_1$-glycine mixtures by Maillard reaction were investigated to identify the role of Maillard reaction in the increased antioxidant activity of ginseng by heat-processing. The DPPH radical scavenging activity of $Rg_1$-glycine mixture was more strongly increased by heat-processing than that of $Rb_1$-glycine mixture. From the analyses of ginsenosides, $Rb_1$ was gradually changed into 20(S)-$Rg_3$, 20(R)-$Rg_3$, $Rk_1$ and $Rg_5$ by heat-processing. $Rg_1$ was gradually changed into 20(S)-$Rh_1$, 20(R)-$Rh_1$, $Rk_3$ and $Rh_4$ by heat-processing. However, the generation of these less-polar ginsenosides was not related to the increased DPPH radical scavenging activity of $Rb_1$-glycine and $Rg_1$-glycine mixtures because their DPPH radical scavenging activities were already significantly increased when dried at $50^{\circ}C$, which temperature induce no structural changes of ginsenosides. In the comparison of browning compound levels of $Rg_1$-glycine and $Rb_1$-glycine mixtures, the extents of Maillard reaction were positively correlated with their increased free radical scavenging activities. Based on the chemical and DPPH radical scavenging activity changes of $Rg_1$-glycine and $Rb_1$-glycine mixtures by heat-processing, we clearly identified that the increased free radical scavenging activity of ginsenoside is mediated by the Maillard reaction between sugar moiety of ginsenoside and amino acid.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1025-1035
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• 2017

In this study, the hot water extract from Mulberry (Morus alba) Leaves fermented with Hericium erinaceum mycelium (MA-HE) was assessed for antioxidant activity. Radical scavenging activity of MA-HE evaluated using 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid)(ABTS) radical. MA-HE showed 63% DPPH radical scavenging activity at $500{\mu}g/mL$ and 98.27% ABTS radical scavenging activity at $250{\mu}g/mL$. MA-HE was shown to significantly inhibited DNA strand breakage induced by free radical. MA-HE also inhibited free radical-mediated human serum albumin modification. MA-HE effectively inhibited $H_2O_2$ induced cell death and significantly increased of the 8% cell survival at $100{\mu}g/mL$. MA-HE decreased intracellular reactive oxygen species (ROS) levels in $H_2O_2$-treated cells. The results suggested that MA-HE can contribute to antioxidant and protected cells from oxidative stress-induced cell injury.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.529-533
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• 2005

In the course of searching for hepatoprotective agents from natural products, six compounds were isolated from the MeOH extract of the leaves of Juglans sinensis, as guid ed by their DPPH free radical scavenging activity. The structures were determined as juglanoside B (1), quercetin 3-O-${\alpha}$-L-arabinofuranoside (avicularin, 2), quercetin 3-O-${\alpha}$-L-arabinopyranoside (guaijaverin,3), quercetin 3-O-${\alpha}$-L-rhamnopyranoside (quercitrin,4), (+)-catechin (5) and quercetin 3-O-${\beta}$- D-galactopyranoside (hyperin,6). Compounds 2-6 showed significant DPPH free radical scavenging effects. An evaluation for the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity was conducted, and compounds 1, 2, and 5 showed protective effects against nitrofurantoin-induced cytotoxicity, and compound 5 also exhibited a moderate protective effect on amiodarone-induced cytotoxicity in Hep G2 cells.

• Natural Product Sciences
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• v.11 no.3
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• pp.119-122
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• 2005

In the course of searching for hepatoprotective agents from natural products, four compounds were isolated from the MeOH extract of Sanguisorbae Radix, as guided by their DPPH free radical scavenging activity. The structures were determined as 4,5-dimethoxy-3-hydroxybenzoic acid methyl ester (1), (+)-gallocatechin (2), methyl $6-O-galloyl-{\beta}-D-glucopyranoside$ (3), and pomolic acid $3-O-[{\alpha}-L-arabinopyranoside]-28-O-[{\beta}-D-glucopyranosyl]$ ester (ziyu-glycoside I) (4). Compounds 2 and 3 showed significant DPPH free radical scavenging effects, exhibiting $IC_{50}$ values of 11.4 and $13.0\;{\mu}M$, respectively. L-Ascorbic acid was used as a positive control and exhibited the $IC_{50}$ value of $50.3\;{\mu}M$. In evaluation of the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity, compound 2 showed the significant hepatoprotective effect with the $EC_{50}$ value of $91.84\;{\pm}\;11.0\;{\mu}M$ on tacrine-induced cytotoxicity in Hep G2 cells, while silybin, a positive control, exhibited $EC_{50}$ value of $122.4\;{\pm}\;12.5\;{\mu}M$.

• ALGAE
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• v.21 no.1
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.324-326
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• 2003

The methanol (MeOH) extract and ist fractions of Taraxacum mongolicum (Compositae) were examined for their scavenging effects on 1,1-diphenyl-2- phenylhydrazyl (DPPH) and superoxide radicals, and hepatoprotective effects on tacrine-induced cytotoxicity in human hepatoma cell line, Hep G2 cells. Both methylene chloride $(CH_2Cl_2)$ and butanol (n-BuOH) soluble fractions of the MeOH extract showed the free radicals scavenging and hepatoprotective effects. From these results, it is suggested that hepatoprotective effect of these fractions partly relies on their free radical scavenging activity.