• Natural Product Sciences
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• v.24 no.2
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• pp.119-124
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• 2018

Two triterpenoids, arjunolic acid (1), belleric acid (2), five phenylethanoids, martynoside (3), orobanchoside (4), 3,4-dihydroxyphenethylalcohol-6-O-caffeoyl-${\beta}$-$\text\tiny{D}$-glucoside (5), leucosceptoside B (6), lunariifolioside (7), four phenolic acids, ferulic acid (8), syringic acid (9), vanillic acid (10), 4-hydroxybenzoic acid (11), and one lignan, (+)-syringaresinol-${\beta}$-$\text\tiny{D}$-glucoside (12), were isolated from the roots of P. umbrosa. All isolated compounds were explored for their antioxidant potential in the DPPH and ABTS assays. In DPPH assay, compound 5 showed high antioxidant capacity. Compounds 3, 4, 6, and 7 displayed considerable antioxidant activities. In addition, compounds 5-7 exhibited potential antioxidant capacities in the ABTS assay.

• Food Science and Preservation
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• v.22 no.5
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• pp.721-726
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• 2015

Phellinus baumii has been used in traditional oriental medicine for the treatment of various cancer types, such as lung cancer, ovarian cancer and malignant melanoma. It has strong anti-cancer, anti-inflammatory and antioxidant activities due to its polysaccharides including glucan, schizophyllan, heteroglycan and lentinan, as well as its polyphenolics such as protocatechuic acid, caffeic acid, coumaric acid. ${\beta}$-Glucan and polyphenolics may be the most important activ ecompounds in P. baumii. Therefore, researchers have focused on these two compounds to improve their contents in extracts. In this study, P. baumii was extracted with hot-water and ethanol at different pH conditions, and their ${\beta}$-glucan contents, antioxidant activity and antioxidant contents were determined. Extraction yield was highest for the 60% ethanol extract at pH 4. The ${\beta}$-glucan contents of the hot-water extract at pH 7 was higher than those of the ethanol extracts. The antioxidant contents and antioxidant activities of the ethanol extracts were higher than those of the hot-water extracts. Extraction with 60% ethanol at pH 7 was appropriate with respect to the antioxidant capacities.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.4
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• pp.667-671
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• 2015

This study investigated the antioxidant capacities and inhibitory activity of peeled lotus root (Nelumbo nucifera) as a food material on angiotension-converting enzyme (ACE). The antioxidant effects on total polyphenol and total flavonoid contents were not signicant. However, DPPH radical scavenging activity decreased from 85.07% to 80.70% by peeled treatment. SOD-like activity decreased from 20.84% to 17.97%, and ACE inhibitory activity decreased from 53.4% to 50.1% by peeled treatement. Thus, consumption of non-peeled lotus root should increase.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.206-213
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• 2017

BACKGROUN/OBJECTIVES: Although studies have revealed that black garlic is a potent antioxidant, its antioxidant mechanism remains unclear. The objective of this study was to determine black garlic's antioxidant activities and possible antioxidant mechanisms related to nuclear factor erythroid 2-like factor 2 (Nrf2)-Keap1 complex. METHODS/MATERIALS: After four weeks of feeding rats with a normal fat diet (NF), a high-fat diet (HF), a high-fat diet with 0.5% black garlic extract (HF+BGE 0.5), a high-fat diet with 1.0% black garlic extract (HF+BGE 1.0), or a high-fat diet with 1.5% black garlic extract (HF+BGE 1.5), plasma concentrations of glucose, insulin,homeostatic model assessment of insulin resistance (HOMA-IR) were determined. As oxidative stress indices, plasma concentrations of thiobarbituric acid reactive substances (TBARS) and 8-isoprostaglandin $F2{\alpha}$ (8-iso-PGF) were determined. To measure antioxidant capacities, plasma total antioxidant capacity (TAC) and activities of antioxidant enzymes in plasma and liver were determined. The mRNA expression levels of antioxidant related proteins such as Nrf2, NAD(P)H: quinone-oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), glutathione reductase (GR), and glutathione S-transferase alpha 2 (GSTA2) were examined. RESULTS: Plasma glucose level, plasma insulin level, and HOMA-IR in black garlic supplemented groups were significantly (P < 0.05) lower than those in the HF group without dose-dependent effect. Plasma TBARS concentration and TAC in the HF+BGE 1.5 group were significantly decreased compared to those of the HF group. The activities of catalase and glutathione peroxidase were significantly (P < 0.05) increased in the HF+BGE 1.0 and HF+BGE 1.5 groups compared to those of the HF group. The mRNA expression levels of hepatic Nrf2, NQO1, HO-1, and GSTA2 were significantly (P < 0.05) increased in the HF with BGE groups compared to those in the HF group. CONCLUSIONS: The improvements of blood glucose homeostasis and antioxidant systems in rats fed with black garlic extract were related to mRNA expression levels of Nrf2 related genes.

• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.86-94
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• 2018

This study was designed to evaluate the antioxidant activities and protective effects on PC12 cells of the extract of Epimedium koreanum and its main constituents icariin and icariside I. After screening the seven identified flavonoid glycosides from E. koreanum through DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay, E. koreanum, Icariin and Icariside I exhibited significant effect on radical scavenging activity. E. koreanum, icariin and icariside I were examined using DPPH, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (ferric reducing ability power) assay. In all antioxidant assays, E. koreanum, icariin and icariside I showed high radical scavenging activities in a dose-dependent manner. Protective effects against $H_2O_2-induced$ PC12 cells were assessed with MTT assay. The results indicated that cell viability and protection on PC12 cells of icariside I and icariin increased dose dependently. These study results suggest that E. koreanum, icariin and icariside showed high antioxidant capacities and cell protective effects. Icariside I, one of the metabolites of icariin, may be a new and effective flavonoid compound as a functional component.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.3
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• pp.207-214
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• 2016

This study investigated the effects of ginger (Zingiber officinale Roscoe) on antioxidant and antiproliferative activities in A2058 human melanoma cells. The antioxidant and antiproliferative activities of 70% ethanol extracts of Zingiber officinale Roscoe were identified based on DPPH and ABTS free radical scavenging capacities. Treatment of cells with Zingiber officinale Roscoe at concentrations of 0, 0.2, and 0.4 mg/mL for 24 hours significantly reduced cell viability as determined by Hoechst 33258 nuclear staining, apoptosis analysis, and Western blotting analysis, respectively. In our study, 70% ethanol extracts of Zingiber officinale Roscoe exhibited antioxidant activity and inhibited A2058 cell growth in a dose-dependent manner. Concomitant activation of the mitochondria-dependent apoptotic pathway of A2058 human melanoma cells by Zingiber officinale Roscoe extracts was mediated via modulation of Bax and Bcl-2 expression, which activated cleavage of caspases-3, caspases-9, and poly ADP-ribose polymerase. The findings of study indicate that Zingiber officinale Roscoe extracts induce apoptosis in A2058 human melanoma cells, and this phenomenon occurs via the death receptor-mediated and intrinsic pathways.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.31-31
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• 2022

Plant-derived antioxidants are used as a healthy diet and are known to inhibit various human diseases. In this study, we investigated free radical scavenging and antioxidant activity of extracts from three plants (Ammannia multiflora, Ammannia coccinea and Salix gracilistyla) with the most DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity from 196 plant extracts inhabiting along Nakdong River in Republic of Korea. The three extracts also have strong total antioxidant activity. Moreover, the extracts inhibited hydrogen peroxide (H₂O₂)-induced reactive oxygen species production and depolarized mitochondrial membrane potential in RAW264.7 macrophages. In zebrafish larvae, 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescent intensity, induced by H₂O₂, was markedly reduced by the extracts of A. multiflora, A. coccinea and S. gracilistyla. Meanwhile, the extracts were upregulated Nrf2 and HO-1 expression, and an HO-1 inhibitor reversed the extract-induced oxidative responses both in vivo and in vitro. The data suggest that the extracts of A. multiflora, A. coccinea, and S. gracilistyla exert potential free radical scavenging and antioxidant capacities both in vivo and in vitro by activating the Nrf2/HO-1 signaling pathway.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.80-91
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• 2014

The aim of this study was to establish the superiority of ohmic heating over conventional heating for the sterilization of mulberry juice. Heat treatment of fresh juice significantly reduced the concentration of soluble solids, lowered the pH, and lowered the reducing sugar content (p<0.01). Color measurements showed decreases in the L and a values and increases in the b, H and C values after heat treatment, although the total color differences were smaller after ohmic heating than after conventional heating of fresh juice. The antioxidant capacities, such as reducing power, FRAP, and DPPH, decreased in the order of fresh juice, ohmically heated juice and conventionally heated juice. Furthermore, the anthocyanin, flovonoid, and total antioxidant capacities of the juices significantly decreased in the same order. Sensory evaluations showed no difference between fresh and ohmically heated mulberry fruit juice excluding off-flavor, whereas conventionally heated juice received significantly lower evaluations. The microbial counts were zero in the juice after either heat treatment. Thus, ohmic heat treatment can be effectively used to sterilize fresh mulberry juice to obtain good shelf life with minimal physicochemical, color, antioxidant and sensory deterioration.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.223-230
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• 2017

The purposes of this study were to produce polysaccharides from red pepper stems using different extraction methods and evaluate their chemical composition, in vitro biological capacities, and rheological properties. Two polysaccharides were extracted from red pepper stems using an autoclave and alkali treatments, and the extracts were named PAU and PAL, respectively. The contents of total phenolics and flavonoids were significantly higher in PAU than those in PAL. PAU exhibited greater scavenging activities on 2,2-diphenyl-1-picrylhydrazyl radicals, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radicals, superoxide radicals, and nitrite compared to PAL, suggesting that PAU served as better antioxidants. Similarly, in vitro inhibitory abilities against carbohydrate hydrolyzing enzymes of PAU were higher than those of PAL. Steady shear rheological analysis demonstrated that PAU showed higher psuedoplastic shear-thinning behavior compared to PAL. Based on the results from dynamic shear rheological properties, it was found that both samples had predominantly viscous behavior rather than elastic behavior.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.686-694
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• 2013

Shade treatment of Synurus deltoides (Aiton) Nakai was carried out with 0, 35, and 55% shading net, and samples were marked as no shade, 35% shade, and 55% shade, respectively. We examined in vitro antioxidant and anti-inflammatory capacities using a 1,1-diphenyl-2-2-pricylhydrazyl (DPPH) radical scavenging assay, a reducing power assay, a total antioxidant assay, a metal chelating assay, a superoxide radical scavenging assay, and a nitric oxide inhibition assay. As a result, no shade and 35% shade possessed higher DPPH radical scavenging activity and reducing power ability than that of 55% shade. Notably, no shade had significantly higher total phenolic and flavonoid contents than those in the other samples. No shade exhibited significantly higher total antioxidant activity than that of 35% shade and 55% shade. However, the chelating ability of 55% shade was significantly greater than that of no shade and 35% shade; 55% shade also showed significantly higher anti-inflammatory capacity than that of no shade or 35% shade.