• Analytical Science and Technology
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• v.19 no.1
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• pp.39-44
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• 2006

Puh-erh tea was extracted with water and then fractionated sequentially with n-hexane, ethyl acetate, n-butanol to find antioxidative compounds. The fractions were examined on the antioxidant activity using two different methods, free radical scavenging activity measurement and reductive potential. Those antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole(BHA), butylated hydroxytoluene (BHT), and ${\alpha}$-tocopherol. EA fraction of Pu-erh tea was showed excellent antioxidative activities over BHA and BHT.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.221-228
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• 1999

This study was carried out to extract the natural antioxidants from Bovine bile and to investigate their effects on various antioxidant activities. It also characterized the patterns of antioxidants by GC/FID and GC/MS. The antioxidative activities and chemical structure of the antioxidant were elucidated by examining the effects of biological activity and the analysis of GC/MS. The antioxidant materials extracted from bovine bile were isolated and purified by silica gel column chromatography and TLC. It was confirmed that there were effects of antioxidants such as Xanthine Oxidase(XO) and Glutathione-S-Transferase(GSH-T) on antioxidative activities. When they were compared with BHT, bile extracts showed the relative effects of 51.2% on the antioxidant activity, the inhibition effects of 48.3% on XO activity, and the synergism effects of 85.7% on the GSH-T activity. According to the results of investigation at neuron cell of mouse, the rate of cell activity in the treatment of 6mM glutathione was 96%, While it in the treatment of 140mg of bile extract was 78%. Based on the TLC analysis of EtOAc extracts from the Bovine bile, the antioxidant activity appeared at $R_f$ value, 0.72. These results suggested that the antioxidant may be coprostan 3-ol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.686-692
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• 1992

The present study was carried out to examine the antioxidative actions between the products of amino-carbonyl reaction and commercial antioxidants, and investigate their synergistic effects. Nondialyzable melanoidins exhibited more significantly in the antioxidative action than unfractionated meanoidins did. Also, in the case of unfractionated melanoidins, both glycine and histidine were more effective than aspartic acid for the antioxidative action. There was no significant difference among amino acids in the action of nondialyzable melanoidins. The unfractionated melanoidin was not as good as antioxidative action of the synthetic antioxidants, butylated hydroxytoluene, tert-butyl hydroquinone and ascorbic acid ; however, the one was superior to that of natural antioxidants, ${\alpha}$-tocopherol and lecithin. Otherwise, the action of nondialyzable melanoidin was similar to that of synthetic antioxidant. The synergistic effects were increased in using melanoidin with ${\alpha}$-tocopherol and lecithin except for the systems of fructose-aspartic acid and fructose-glycine in unfractionated melanoidins.

• Journal of Life Science
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• v.32 no.2
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• pp.167-174
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• 2022

In modern society, interest in antioxidants is increasing as the stress caused by oxidants increases. However, the demand for synthetic antioxidants is decreasing because some studies have confirmed that they are harmful when consumed in large quantities; thus, studies on antioxidants derived from natural substances are actively being conducted to replace synthetic antioxidants. Blueberry, known as one of the world's top ten long-lived foods, is a plant of the Vaccinium (Ericaceae) family, and various pharmacological activities of blueberry including antioxidant activity have been studied. Vaccinium oldhamii (VO) is a deciduous broad-leaved shrub in the same genus as blueberries, and in this paper, we summarize the studies on the efficacy analysis of VO extracts and purified products. The content of phenolic compounds in VO fruits was proportional to antioxidant and anti-influenza activity such as the inhibition of NO production, and the total content of polyphenols and anthocyanin was higher than that in blueberries. VO fruit extracts showed anti-inflammatory activity and anti-cancer activity against human acute leukemia; in contrast, VO branch extracts showed anti-inflammatory activity, activity to inhibit osteoclast differentiation and bone resorption due to inflammatory response, and anti-cancer activity against several human cancer cell lines. Compared to blueberries, VO showed higher phenolic compound content, antioxidant activity, and various physiological activities. In addition, VO is considered to have sufficient value as an alternative crop to blueberries, such as it can be grown natively in Korea, with simple mass cultivation and no need to pay royalties for commercialization.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.200-208
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• 2007

Fifty-four natural plants from Jeju Island, Korea were extracted by 70% methanol. The extracts containing the highest total phenolic contents (TPC) (>250 mg gallic acid equivalents/g dry sample) were obtained from Ostrya japonica, Geranium thunbergii, Malus sieboldii, Ardisia japonica, and Agrimonia pilosa. DPPH inhibition activity was greatest in Ardisia crenata at 94.1%. A high correlation was observed between DPPH inhibition activity and TPC ($R^2=0.87$). Tyrosinase inhibition activities of more than 85% were obtained from the extracts of Persicaria filiformis, Rhus javanica, Alnus firma, and Myrica rubra. On the other hand, the P. filiformis and M. rubra extracts each showed more than 90% XOD inhibition activity. The five natural plants with the highest biological activities were also extracted by pressurized liquid (PLE, 100% methanol, 13.6 MPa, $40^{\circ}C$). The DPPH and tyrosinase inhibition activities were almost the same in both the 70% methanol and PLE extracts. The $IC_{50}$ for tyrosinase and elastase inhibition activities in PLE were 802 and 88 ppm in A. japonica, and 959 and 66 ppm in M. rubra, respectively.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.710-714
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• 2006

The present study examined the lipid lowering and antioxidant activity of Paecilomyces tenuipes. Eight week-old male Sprague-Dawley rats were fed one of the three diets, a reference diet without cholesterol addition (NC), a high fat (17 g/ 100 g)-high cholesterol (1 g/100 g) diet (HC) and a HC diet supplemented with 3% P. tenuipes (PT) for 30 days. Total lipid and total cholesterol were reduced significantly by 33 and 37%, respectively, in the PT diet group compared with controls. A similar reduction was found for low density lipoprotein (LDL) cholesterol levels, while plasma high density lipoprotein (HDL) cholesterol and triglyceride (TG) concentrations were not significantly different among groups. Hepatic total lipid and total cholesterol levels, but not hepatic TG levels, were significantly decreased in the PT group compared to the HC group. The administration of P. tenuipes increased the plasma total antioxidant potential and decreased the levels of lipid peroxidation. These results suggest that P. tenuipes exerts significant health benefits through the modulation of physiological functions including a variety of atherogenic lipid profiles and antioxidants in hypercholesterolemia.

• Culinary science and hospitality research
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• v.9 no.4
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• pp.1-12
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• 2003

This study was conducted to evaluating the antioxidative activities of waffle by natural antioxidants combination (tocopherol, rosemary extract and tea polyphenol) and packaging. Waffle stored at $25^{\circ}C$ and 35$^{\circ}C$ for 70 days were evaluated for acid value, peroxide value and Q$_{10}$ value. Tocopherol, either alone or with rosemary and tea polyphenol, was highly effective in inhibiting lipid oxidation of waffle at $25^{\circ}C$ and 35$^{\circ}C$. Especially among them, rosemary extract exhibited the best synergistic effect, as determined by peroxide value measurement. Waffle was then packaged under the following packing materials (OPP/DL/VMCPP, PET/DL/VMCCP). As the temperature condition, the modified atmosphere decrease in waffle package and increase peroxide value. This result indicated that the PET package was more effective in reducing oxidation than the OPP package.

• Culinary science and hospitality research
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• v.23 no.8
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• pp.90-97
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• 2017

This study investigated optimal extraction conditions for application of Hippophae rhamnoides leaves as a natural antioxidant. Hippophae rhamnoides leaves were extracted using ethanol at various concentrations (0, 30, 50, and 70%) and extraction times (4, 8, and 12 hrs) at $70^{\circ}C$ and then evaluated for extraction yield (22.51%), total phenolic contents (84.21~149.25 mg/g), total flavonoid contents (63.10~124.14 mg/g), as well as antioxidant activities DPPH, ABTS radical scavenging activity, reducing power, and FRAP. Antioxidant activities (DPPH, ABTS radical scavenging activity, reducing power) were correlated with total phenolic and flavonoid contents. 70% EtOH extracts for 12 h at $70^{\circ}C$ showed the highest total phenolic and flavonoid contents with strong antioxidant activities, and that the leaves of Hippophae rhamnoides could be considerd as a candidate of new functional antioxidant agents. This extract could be a good source for natural antioxidants and good health food. This work offers would be useful for chemical and biological studies of natural plants and its products.

• Natural Product Sciences
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• v.20 no.3
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• pp.176-181
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• 2014

The antioxidant activities of 29 components isolated from the aerial parts of Artemisia iwayomogi were evaluated in vitro and in cell culture. Among the tested compounds, 2, 6, 8, 10, 13, and 14 exhibited the greatest peroxyl radical-scavenging activities in the oxygen radical absorbance capacity (ORAC) assay, and 2, 10, and 14 also showed significant reducing capacities. However, all compounds showed weak metal chelating activities. Their cellular antioxidant activities were evaluated in HepG2 cells. At $10{\mu}M$, compounds 6, 8, and 14 exhibited stronger protection against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress than compounds 2, 10, and 13. Moreover, Compounds 2 and 8 were more effective in protecting against $Cu^{2+}$-induced oxidative stress than compounds 6, 10, 13, and 14 at $10{\mu}M$. These results suggest that the phenolic compounds in A. iwayomogi have the potential to be developed as natural antioxidants for the treatment of oxidative stress-related diseases.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.436-441
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• 2009

The final bio-metabolites of lipid peroxidation (LPO) such as 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) have been suggested to mediate the oxidative stress-linked pathological incidences. Natural phytochemicals such as polyphenolic compounds in green tea have been known in preventing the LPO induced cellular growth inhibition and apoptosis. We investigated that green tea ethanol extracts (GTE) inhibit LPO-induced apoptosis in ECV 304 cells. GTE had time- or dose-dependent anti-apoptotic effects as evidenced by changes in cell morphology, MTT assay, DNA fragmentation, LPO production, and the Western blotting for apoptotic expression. In the 4-HNE-induced apoptosis model, GTE $10-20{\mu}g/mL$ decreased cell death through decreasing LPO production. GTE protected 4-HNE induced apoptosis, as evidence with down regulation of mitochondrial signaling such as cytochrome C and caspase-3 activity. GTE increased bcl2, survival signaling protein, compared to 4-HNE alone within 6 hr incubation. Since polyphenols in GTE are effective antioxidants in endothelial ECV 304 cells, we suggested that natural polyphenols might be anti-atherosclerotic.