• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.679-687
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• 2018

Korean red pine (Pinus densiflora) is one of the major Pinus species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects. In this study, we investigated if Korean red pine bark extract (KRPBE) could protect neuronal PC-12 cells from oxidative stress and inhibit cholinesterase activity. Analysis of reversed-phase high-performance liquid chromatography results revealed four phenolics in KRPBE: vanillin, protocatechuic acid, catechin, and taxifolin. The total phenolic and flavonoid contents of KRPBE were 397.9 mg gallic acid equivalents/g dry weight (DW) and 248.7 mg catechin equivalents/g DW, respectively. The antioxidant capacities of KRPBE measured using ABTS, DPPH, and ORAC assays were 697.3, 521.8, and 2,627.7 mg vitamin C equivalents/g DW, respectively. KRPBE and its identified phenolics protected against $H_2O_2$-induced oxidative cell death in a dose-dependent manner. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission in synaptic clefts, were inhibited by treatment with KRPBE and its identified phenolics. Taken together, these results suggest that KRPBE and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.222-227
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• 2017

Red ginseng prepared from fresh 6-year-old ginseng treated with colloidal gold nanoparticles was extracted using hot water to evaluate its total phenolic and flavonoid contents, antioxidant capacity, and neuroprotective effects. Water extract of red ginseng treated with gold nanoparticles (WERGGN) had total phenolic and total flavonoid contents of 212.2 mg gallic acid equivalents/$^{\circ}Bx$ and 3.5 mg catechin equivalents/$^{\circ}Bx$, respectively. The antioxidant capacities of WERGGN measured using ABTS, DPPH, and ORAC assays were 272.3, 141.2, and 868.4 mg vitamin C equivalents/$^{\circ}Bx$, respectively. The WERGGN showed protective effects on the viability of neuron-like PC-12 cells against oxidative stress induced by hydrogen peroxide in a dose-dependent manner, partly because of a reduction in intracellular oxidative stress. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission, were inhibited by treatment with WERGGN. These results suggest that WERGGN is useful as a functional material to decrease oxidative stress and neuronal damage.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.358-365
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• 2011

Lespedeza cuneata G. Don is a plant commonly grown in Asian countries, which has been widely used as an oriental medicinal herb to treat diabetes, diarrhea and various other inflammatory diseases. The phenolics of dry leaves of L. cuneata G. Don were extracted by using 80% (v/v) aqueous methanol in assistance with homogenization and sonification. The phenolic extract and its five different fractions (n-hexane, chloroform, ethyl acetate, n-butanol, and water) were used to evaluate the levels of total phenolics, total flavonoids, and antioxidant capacity as well as the inhibitory effect of tyrosinase activity. Ethyl acetate fraction (1 g) had the highest levels of total phenolics at 240.8 mg gallic acid equivalents (GAE), total flavonoids as 90.4 mg catechin equivalents (CE) as well as antioxidant capacity at 523.4 mg vitamin C equivalents (VCE) on ABTS assay and 329.5 mg VCE on DPPH assay among fractions. One g of water fraction contained total phenolics at 133.1 mg GAE, total flavonoids at 34.5 mg CE, and antioxidant capacity at 333.4 mg VCE for ABTS assay and 313.2 mg VCE for DPPH assay. Inhibition of tyrosinase activity of water fraction at 300 ${\mu}g{\cdot}mL^{-1}$ was at 47.2% and 21.1% for L-tyrosine and L-DOPA as its substrate, respectively. On the other hand, ethyl acetate fraction at 300 ${\mu}g{\cdot}mL^{-1}$ showed tyrosinase inhibition of 10.2% for L-tyrosine and 11.9% for L-DOPA. These results suggested that the phenolics from dry leaves of L. cuneata G. Don may be utilized as a potent source of antioxidants and skin whitening agents.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.132-139
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• 2016

The purpose of this study was to investigate the contents of antioxidant compounds and antioxidant activities in teas. A total of 99 teas were tested for their antioxidant activities based on their ability to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. Antioxidant activity was expressed as mg of ascorbic acid equivalents per 100 g tea sample (L-ascorbic acid equivalent antioxidant capacity, AEAC) and was expressed as mg per 1 serving size (free radical scavenging activity, $FSC_{50}$). The total polyphenol contents of the extracts was quantified using the Folin-Ciocalteu method and the total flavonoid contents of the extracts was determined using a modied method of Davis. Vitamin C was analyzed by HPLC method. According to the AEAC value, mate tea, green tea, black tea, oriental raisin tea, chamomile tea and burdock tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of total polyphenol compounds were observed in black tea, green tea and mate tea. The high concentrations of total flavonoid compounds were observed in mate tea, black tea and yam tea and the amount of vitamin C contents were found to be high in citron tea and green tea. As a result, steeping tea was much higher in antioxidant activity than either powdered tea or liquefied tea. According to the study, a high correlation was demonstrated between the total polyphenol contents and antioxidant activities in teas (r = 0.846) and correlations between the total flavonoid contents and antioxidant activities was statistically significant in teas (r = 0.625). It was found that also the proportional relationship established among the total polyphenol content and antioxidant activities. That is, antioxidant activity of teas has been confirmed to have been caused by the total polyphenol.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.150-157
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• 2007

Hamcho(Salicorinia herbacea, glasswort), a halophyte, is an annual succulent shrub that grows on coastal wetlands and has been regarded as a functional food for good health. Natural dried red and green Hamcho were extracted with 25% ethanol and water at 70$^{\circ}C$. The antioxidant activities of these four extracts were examined by six different assays, including the measurement of total phenolics, radical scavenging effects on 1,1-diphenyl-2-picrylhydrazyl(DPPH), nitric oxide(NO) and nitrite(NO$_2$) scavenging effects, reducing power, and the inhibitory effect on tyrosinase activity. The total phenolic contents of the four extracts were high at 237 ${\sim}$ 255 mg of gallic acid equivalents per 1 g of dried sample tested. The green Hamcho extracts contained more phenolic compounds than the red Hamcho extracts. When they were compared to tocopherols, the antioxidant activities of the green and red Hamcho powders were significantly higher at the same concentration levels(5 mg and 3 mg, respectively) in a POV test. The inhibition effects of the four extracts at a level of 75 ${\mu}l$ were higher than 98% in the POV test. The red Hamcho 25% ethanol extract showed a high significant effect on DPPH radical scavenging(SC$_{50}$, 90.1 ${\mu}l$). The green Hamcho 25% ethanol extract, however, showed a high significant effect on NO radical scavenging(SC$_{50}$, 6.1 ${\mu}l$). The NO$_2$ radical scavenging effect was assayed at pH 1.2, 4.2 and 6.0, and all the Hamcho extracts scavenged the NO$_2$ radical much more effectively at pH 1.2. The NO$_2$ scavenging effect of the red Hamcho 25% ethanol extract(64%) was as high as that of 5 mM vitamin C at pH 1.2(p<0.05). In the reducing power test, the red Hamcho 25% ethanol extract revealed the highest ferric ion reducing activity among the Hamcho extracts, and its activity was as high as that of 0.33 mg/ml of vitamin C. The four Hamcho extracts showed high tyrosinase inhibition effects of more than 80%, and their activities were higher than 50${\mu}$g of kojic acid. The green and red Hamcho 25% ethanol extracts totally inhibited tyrosinase activity(100%). Therefore, the results suggest that red Hamcho extracts may serve as useful natural antioxidants along with green Hamcho extracts.

• Food Engineering Progress
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• v.14 no.2
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• pp.183-187
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• 2010

Multiple lines of study have shown that Acanthopanax species have anti-oxidant and chemopreventive effect. However, the suitability of Acanthopanax sessilifloru fruit (Ogaza) as a functional food source remains to be investigated. Therefore, we have investigated the effect of Ogaza as an anti-oxidant and anti-inflammatory substance. The phenolic content of Ogaza is 56.1${\pm}$5.2 mg gallic acid equivalents (GAE) per 1 g of Ogaza. The 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging effects of Ogaza extract at 0.25, 0.5, 1, or 2 mg/mL were 34.0, 73.0, 194.3, or 339.7 $\mu g$/mL vitamin C equivalent antioxidnat capacity (VCEAC), respectively. Ogaza extract (1 or 2 mg/mL) inhibited LPS-induced TNF-$\alpha$ production (decrease of 22${\pm}$2% or 19${\pm}$6%, respectively). It also inhibited LPS-induced IL-6 production (decrease of 18${\pm}$2% or 24${\pm}$3%, respectively). In addition, Ogaza extract (0.25, 0.5, 1, or 2 mg/mL) inhibited COX-2 luciferase activity (decrease of 80${\pm}$1%, 83.${\pm}$7%, 96${\pm}$4%, or 98${\pm}$2%, respectively). Overall, these results indicated that Ogaza is promising as a functional food source due to its antioxidant and anti-inflammatory effects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.20-27
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• 2013

Proximate composition, total phenolics and total flavonoids level, DPPH radical scavenging activity, and cytotoxicity were determined in the methanol extracts of different plant parts of Youngia sonchifolia at reproductive growth stage. Crude protein and crude fat were present as the highest amount in flowers, and crude fiber in the stems and roots. The highest content of phenolics [mg ferulic acid equivalents (FAE) $kg^{-1}$ dry weight (DW)] was found in flowers (highest) and followed by leaves, stems and roots (lowest). Flavonoids [mg rutin equivalents $kg^{-1}$ DW] level, however, showed the highest in leaf extracts and lowest in root extracts. The antioxidant potential of the methanol extracts from the plants dose-dependently increased DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity (%). DPPH radical scavenging activity were highest in root extracts ($IC_{50}=1,135.6\;mg\;kg^{-1}$) and followed by leaf, stem and flower extracts. By way of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, methanol extracts of roots showed the highest anticancer activity on human cancer cell line Calu-6 for human pulmonary carcinoma ($IC_{50}=196.3\;mg\;kg^{-1}$) and HCT-116 for human colon carcinoma ($IC_{50}=623.6\;mg\;kg^{-1}$).

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.539-543
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• 2015

A hardy kiwifruit is a good source of phenolics and antioxidants. This study was aimed at investigating the effects of hot air drying at three different temperatures (35, 50, and $70^{\circ}C$) for 24 h on the total phenolic and flavonoid contents and the antioxidant capacity of hardy kiwifruits of Actinidia arguta ${\times}$ A. deliciosa cv. Mansoo. Dried kiwifruit extracts were produced using 80% (v/v) aqueous ethanol under homogenization. Hot air drying lowered the total phenolic and flavonoid contents and decreased the antioxidant capacity in the dried kiwifruits compared with their fresh counterparts. The results also revealed high positive linear correlations of antioxidant capacity with total phenolic and flavonoid contents, indicating that phenolics are the major contributors to antioxidant capacity. Our results suggested that an optimal drying process must be determined for industrial application in order to obtain dried kiwifruits with increased antioxidant capacity for consumers.

• Food Science and Preservation
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• v.23 no.4
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• pp.553-559
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• 2016

The purpose of this study was to determine the content of phenolics and various anthocyanin compounds, and antioxidant and anticancer activities of the extracts from pomergranates, which were produced in two different regions including Goheung, Korea and California, USA. These pomergrantes were divided into juice, pericarp, and seed parts and each part was extracted with 95% methanol. Content of total phenolics [mg chlorogenic acid equivalents/kg DW] was highest in pericarp, followed by juice and seeds from pomergrantes in both regions. The anthocyanins identified in pomegranate fruit were cyanidin-3,5-diglucoside chloride (Cy3,5G), cyanidin-3-O-glucoside chloride (Cy3G), delphini din-3,5-di-O-glucoside chloride (Dp3,5G), delphinidin-3-O-glucoside chloride (Dp3G), pelargonidin-3,5-di-glucoside chloride (Pg3,5G), and pelargonidin-3-glucoside chloride (Pg3G). Among these, cyanidin-3,5-diglucoside chloride (Cy3,5G) was the major anthocyanin in California pomegranate fruit juice and Goheung pomegranate fruit pericarp. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was dose-dependently increased, and was higher in pericarp part than juice or seed parts from pomergrantes in both regions. By MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, pericarp extracts from pomergrantes in both regions showed the highest anticancer activity, which was higher on Calu-6 for human pulmonary carcinoma than SNU-601 for human gastric carcinoma. Correlation between polyphenols and anticancer activity on Calu-6 was determined to be in the range of $r^2=0.8904$ to 0.9706.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.538-543
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• 2017

Astringent persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) peel with the astringency removed, which is a by-product of dried persimmon (gotgam), was investigated for its antioxidant and neuroprotective properties. A mixture of peel and 40% (v/v) aqueous ethanol was subjected to ultrasonication and then thermal and nonthermal treatments, to produce thermally-treated and nonthermally-treated persimmon peel extracts (TPE and NTPE, respectively). The total phenolic and flavonoid contents and the antioxidant capacity of TPE was approximately 1.3-1.8 times higher than those of NTPE. TPE resulted in the increased viability of neuronal PC-12 cells compared with NTPE. Furthermore, intracellular oxidative stress in PC-12 cells was more decreased by treatment with TPE than NTPE. Cholinesterases, such as acetylcholinesterase and butyrylcholinesterase, were more inhibited by treatment with TPE than NTPE. These results suggest that TPE is useful as a functional material to decrease oxidative stress in neuronal cells and to inhibit cholinesterases.