• Journal of Life Science
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• v.29 no.2
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• pp.173-180
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• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• 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.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.349-354
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• 2008

Superoxide dismutase (SOD) activities were investigated from the portions of shoots and roots in accordance with developmental stage and in response to environmental stress and antioxidants using Rhodiola-seedlings. The rates of SOD activities were revealed highly at the portion of roots and its tip of seedlings in the latter stages rather than the initial stages. SOD activities of seedlings in the initial stages treated with sodium chloride and cadmium as environmental stressors showed the decrease by 15 and 30% with respect to the control, respectively. However, in spite of stressor-treatments, the activities in the roots were increased according to the growth period showing a maximum rate of up to 45%. Also, SOD activities of the seedling treated with ascorbic acid as a antioxidant were increased by 46% of control value, but this was similar to the rate revealed in the presence of stressors. These results suggest that SOD activities in Rhodiola-seedlings may be related with the important defence-system against injurious environments.

• Journal of Haehwa Medicine
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• v.23 no.1
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• pp.105-114
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• 2014

Objectives : In this study, the antioxidant activities of the 80% ethanol and hot water extracts of Euphorbia supina Rafinesque were investigated. Methods : We measured total phenol contents, flavonoid contents, 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The production of reactive oxygen species was measured in LPS-induced RAW 264.7 cells using flow cytometry system. Results : The content of phenol in the hot water extract was $65.529{\pm}0.462mg/g$ and $126.932{\pm}1.894mg/g$ in the 80% ethanol extract, and that of flavonoid in the hot water extract was $16.063{\pm}0.471mg/g$ and $29.159{\pm}1.963mg/g$ in the ethanol extract. The 80% ethanol extract also showed higher DPPH and ABTS radical scavenging activities ($90.8{\pm}1.0%$ and $92.5{\pm}0.7%$) than the hot water extract ($81.5{\pm}0.5%$ and $91.5{\pm}0.2%$). The production of reactive oxygen species(ROS) was reduced dose-dependently by 80% ethanol and hot water extract at concentration of 1, 10 and $100{\mu}g/m{\ell}$ of RAW 264.7 cells. Conclusion : According to these results, the 80% ethanol extract of Euphorbia supina Rafinesque has a good anti-oxidative effects than the hot water extract. Thus, the 80% ethanol extract of Euphorbia supina Rafinesque may serve as useful natural antioxidants.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1104-1113
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• 2014

The effects of feeding pelleted citrus pulp (PCP) as a natural antioxidant source on the performance and milk quality of dairy cows fed highly polyunsaturated fatty acid (FA) diets were evaluated. Four lactating Holstein cows were assigned to a $4{\times}4$ Latinsquare. Treatments, on a dry matter (DM) basis, were i) control diet; ii) 3% soybean oil; iii) 3% soybean oil and 9% PCP and; iv) 3% soybean oil and 18% PCP. When cows fed on citrus pulp, the DM intake tended to decrease. The total tract apparent digestibility of DM and ether extract decreased when cows fed on the control diet compared to other diets. Cows fed PCP had higher polyphenols and flavonoids content and higher total ferric reducing antioxidant power (FRAP) in milk compared to those fed no pelleted citrus pulp. Cows fed 18% PCP showed higher monounsaturated FA and lower saturated FA in milk fat compared with cows fed the other diets. The lowest n-6 FA proportion was in milk fat from cows fed control. The present study suggests that pelleted citrus pulp added to 9% to 18% DM increases total polyphenols and flavonoids concentration, and the FRAP in milk.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.714-722
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• 2019

Oxidative DNA damage negatively affects humans and the research is currently ongoing to find ways to reduce oxidative stress. Oxidative stress has been identified as a key factor in triggering various diseases. Thus, its alleviation is important for human health. Broussonetia kazinoki (B. kazinoki) has been used in traditional Korean medicine as a dermatological therapy to treat burns, pruritus, and acne. B. kazinoki is generally segregated into peeled root (PR), root bark (RB), peeled stem (PS), and stem bark (SB). To assess these components for their antioxidant activity and protection against DNA damage, their ethyl acetate fractions were examined by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assay. As a result of confirming the expression of factors involved in attenuating DNA damage, the protective effect of SB on oxidative stress suppressed the expression of p-p53 and γ-H2AX. Additionally, the levels of p53 and H2AX mRNA were significantly downregulated. In conclusion, these results indicated that the SB component of B. kazinoki had the potential to be used as an effective natural antioxidant compared to the other parts of the plant.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.524-530
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• 2019

Kelp (Saccharina japonica) contains various bioactive compounds, including vitamins, minerals (especially iodine and potassium), alginic acid, fucoxanthin, and various antioxidants. Kelp is mainly used as a dried product. The purpose of this study was to investigate the stabilities of antioxidant capacities and fucoxanthin of kelp by different conventional drying conditions including hot air drying at 70℃ and natural drying methods. Fucoxanthin, total phenolic contents, and total antioxidant capacity by ABTS, DPPH, and FRAP assays were significantly decreased after 5 to 10 h of hot air drying at 70℃. The assay values were also significantly decreased by 50% after 2 days of drying due to ultraviolet exposure. The findings demonstrate that heat and ultraviolet exposure during drying of kelp could affect the degradation of bioactive compounds, especially fucoxanthin and polyphenols. Optimal conditions should be considered during kelp drying and storage.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.427-435
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• 2019

Background: A growing interest in health has increased the need for the development of potent antioxidant materials known to play a role in various physiological activities. Currently research and development of non-toxic natural antioxidants with high activity is ongoing. Methods and Results: In this study, we measured 2,2'-azinobis- (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability of 10 plant essential oils, selecting samples of Dendranthema indicum, Dendranthema zawadskii, and Citrus sunki essential oils. The samples were analyzed using liquid chromatography (LC) and the radical scavenging activity on LC-based systems with the same conditions. In the LC-mass spectroscopy (MS)/MS analysis of the active compound peak, 2-methoxy-4-vinylphenol with a molecular weight of 150.1 g/mol was identified in C. sunki essential oils. Eugenol or isoeugenol with a molecular weight of 164.1 g/mol as identified in D. indicum and D. zawadskii essential oils as radical scavenging active compounds. Conclusions: In the LC-based measurement system, the active ingredient can be identified by simultaneously conducting profile analysis and the radical scavenging activity of essential oil samples. In addition, LC-MS/MS analysis of the active compound peaks can be performed under the same separation conditions to obtain data that can identify the active compounds in the sample.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.116-123
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• 2001

The non-enzymatic antioxidants and antioxidant enzyme from the extracts of Parthenocissus tricuspidata PLANCH. were examined in order to utilize natural product for cerchemopreventive agents. The antioxidant potential and enzyme activities on plant positions in the extracts of Parthenocisuss tricuspidata PLANCH. showed considerable differences. The antioxidant activity of the leaf extracts by Ethyl acetate fractions of Parthenocisuss tricuspidata PLANCH. was the highest among three positions ($7.57\mu\textrm{g}/m\ell$). The highest activities showed in S-5 (in leaf), S-4 (in stem) and S-3 (in root) fraction by Silicagel column chromatography and the antioxidant activity showed, in purified extract of each positions, $7.06\mu\textrm{g}/m\ell$ (in leaf), $6.99\mu\textrm{g}/m\ell$ (in stem) and $12.39\mu\textrm{g}/m\ell$ (in root) respectively. The activities of DPPH by LH-20 column chromatography revealed much higher than those by silica-gel column chromatography. These were identified as the phenolic compounds known as antioxidant compounds such as Benzoic acid(Gallic acid), 1-methyl-3-(2-phenylethen) benzene, phloroglucinol and 1,2-dihydroxy-4-(1-propyl)benzene by GC/MS. POD activities in the stem and root were higher than in the leaf. SOD activity was highest in the leaf, stem and root activity was comparatively low. Especially, SOD activity in leaf was over 2 times higher than root.

• Korean journal of food and cookery science
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• v.30 no.1
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• pp.33-40
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• 2014

The purpose of this study was to examine the antioxidative activity of feral haw (Crataegus pinnatifida BUNGE) seed extracts using 70% methanol, 70% ethanol, chloroform:methanol (CM, 2:1, v/v), n-butanol and ethyl acetate (EA). The total phenol content of the five extracts ranged from 37.29 mg/g to 55.53 mg/g. Moreover, the content was high in the 70% methanol and, 70% ethanol extracts, but low in the n-butanol extract. On the contrary, the total flavonoid content decreased in the order of n-butanol (2.93 mg/g), EA (2.67 mg/g), 70% methanol (1.00 mg/g), 70% ethanol (0.88 mg/g) and CM (0.67 mg/g) extracts. The $NO_2$ radical scavenging activity, antioxidant activity by ${\beta}$-carotene bleaching assay and, superoxide dismutase (SOD) like ability decreased in the order of 70% methanol, 70% ethanol, CM, EA and, n-butanol extracts; further, a similar tendency was also observed in the total phenol contents. Overall, these results indicated that the antioxidative activity of feral haw seeds was closely related to the total phenol and flavonoid contents. Therefore, haw seeds might be usefully applied to natural antioxidants as well as functional foods.