• Weed & Turfgrass Science
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• v.6 no.3
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• pp.222-234
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• 2017

Green tides, which was mainly caused by Ulva spp., have been increasing in severity and frequency globally, and have negatively affected on marine ecosystems. This study was conducted to investigate effects of various physical and chemical factors on the death of Ulva australis (ULAUS) and to consider a practical measures useful for alleviating Ulva bloom. Soaking of ULAUS thalli in pure water for 8 hr didn't induce a death, but incubation in 1.0-1.5% salinity for 7 d inhibited sporulation by about 70%. Desiccation gave rise to a serious damage when more than 40-50% of initial fresh weight was lost. ULAUS growth was sensitive to temperature and seriously inhibited from more than $30^{\circ}C$. At $35^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$ and $50^{\circ}C$, treatment time required for 90-95% death of ULAUS thalli was 1 d, 10 min, 30 sec, and 1 sec, repectively. ULAUS growth was seriously inhibited at lower than pH 6.0 and completely dead at pH 4.0. Several compounds for ULAUS control was selected and the chemcals causing a rapid death were oxidants such as hydrogen peroxide and sodium percarbonate. Taken together, our results suggest that low salinities, dryness, pH, high temp. and compounds could be selected for Ulva bloom control, and high temperature and compounds seems to be useful for a development of practical control methods.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.176-182
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• 2016

The purpose of this study was to evaluate the in-vitro efficacy of the active ingredients of dentifrice following treatment time. The whitening effect was evaluated by a change in lightness value relative to the contact time of hydrogen peroxide, by using artificially stained hydroxyapatite discs. The anti-calculus effect was assessed based on the amount of calcium eluted from the human dental calculus by sodium pyrophosphate. Remineralization was evaluated by the Vickers hardness test following the application of sodium fluoride to bovine enamel. In order to view dentinal tubules occlusion, the formation of insoluble calcium salts by bovine dentin specimens was observed using scanning electron microscopy. Change in lightness value (${\Delta}L$) was $5.50{\pm}1.51$ after 1 min of treatment, $5.73{\pm}0.43$ after 3 min, $8.64{\pm}0.24$ after 10 min, $18.93{\pm}0.76$ after 30 min, and $27.35{\pm}0.54$ after 60 min. The amount of calcium eluted from the human dental calculus was $4.23{\pm}0.14ppm$ after 1 min of treatment, $4.51{\pm}0.04ppm$ after 3 min, $12.12{\pm}0.16ppm$ after 10 min, $17.85{\pm}0.81ppm$ after 30 min, and $25.15{\pm}0.32ppm$ after 60 min. The Vickers hardness change value (${\Delta}VHN$) was $1.96{\pm}1.44$ after 1 min, $1.52{\pm}1.06$ after 3 min, $9.06{\pm}0.15$ after 10 min, $10.83{\pm}5.13$ after 30 min, and $12.55{\pm}2.09$ after 60 min. Partial dentinal tubules occlusion was observed at 10 min and complete occlusion was evident at 60 min. In summary, the use of patch type dentifrices for 10, 30, or 60 min were 1.57 to 8.26 times more effective than using the paste type dentifrices for 1 to 3 min. Based on these findings, it is reasonable to expect that the use of patch type dentifrices for 10 min would lead to remineralization, anti-calculus and dentinal tubules occlusion effects, and that use for 30 min would result in a whitening effect.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.979-984
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• 2006

Although iron is essential for many physiological processes, excess iron can lead to tissue damage by promoting the generation of reactive oxygen species (ROS). There is increasing evidence that ROS might play an important role in the pathogenesis of cardiovascular disease. However, the effects of iron excess on platelet function and the thrombotic response to vascular injury are not well understood. We examined the effects of iron excess-induced oxidative stress and the antioxidants on platelet aggregation. Oxidative stress was accessed by either free iron $(Fe^{+2})$ or hydrogen peroxide $(H_2O_2)$, as well as their combination on washed rabbit platelets (WPs) in vitro. When WPs were stimulated with either $Fe^{+2}$ alone or a subthreshold concentration of collagen, which gave an aggregatory curve with a little effect, and a dose dependent increase in platelet aggregation was observed by increasing concentrations of $Fe^{+2}$ with $H_2O_2$. This aggregation was associated with the iron-catalyzed formation of hydroxyl radicals from $H_2O_2$, and were inhibited by NAD/NADP (proton acceptor), catalase $(H_2O_2\;scavenger)$, tiron (iron chelator), mannitol (hydroxyl radical scavenger), and indomethacin (cyclooxygenase inhibitor), but not by NADH/NADPH (proton donor), superoxide mutase, and aspirin. However, NADH/NADPH, an essential cofactor for the antioxidant capacity by the supply of reducing potentials, showed the effect of an enhanced radical formation, suggesting a role for NADH/NADPH-dependent oxidase. These results suggest that iron $(Fe^{+2})$ can directly interact with washed rabbit platelets and this aggregation be mediated by OH formation as in the Fenton reaction, inhibited by radical scavengers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1304-1308
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• 2006

The present study describes the preliminary evaluation of the antioxidant activity and the cytotoxic effect of Ceramium kondoi. The antioxidant activities and cytotoxic effect of the water extracts were evaluated by total phenolic contents (TPC), DPPH radical scavenging activity (RSA), reducing power (RP), comet assay, and MTT reduction assay. TPC, DPPH RSA, and RP of the extract at the concentration of $1,000{\mu}g/mL$ was $659.2{\mu}M$, 86.0%, and 1.084, respectively, and those were concentration dependent. The $200{\mu}M\;H_2O_2-induced$DNA damage was inhibited by C. kondoi water extract in a dose dependent manner in human leukocytes. The inhibition was by 62.3, 39.8, 24.8% and 16.4% at the concentration of 5, 10, $25{\mu}g/mL$ and $50{\mu}g/mL$, respectively. Cytotoxic activity on HT-29 cells and MCF-7 cells of the C. kondoi water extract at the concentration of $10{\mu}g/mL$ was 49% and 60%, respectively. These results strongly support the possibility of C. kondoi as a source of natural functional materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1139-1145
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• 2006

In this study, antioxidant activities of enzymatic and methanolic extracts from E. cava stem and leave were evaluated by measuring the scavenging activities on 1,1 diphenyl 2 picrylhydrazyl (DPPH), hydroxyl radical, hydrogen peroxide and the inhibitory effects on DNA damage induced by oxidative stress of cells. Enzymatic extracts were prepared by enzymatic hydrolysis of both stem and leave using food grade five different carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, Alcalase). The enzymatic extracts were lower than methanolic extracts in polyphenol contents, but higher in extraction yield by approximately 30%. The enzymatic extracts were superior to methanolic extracts in DPPH and H2O2 scavenging activities and DNA damage protective effect. There were no significant antioxidant activity difference between stem and leave, but the extracts of leave were relatively better than those of stem. In this study it is suggested that E. cava stem as well as its leave would be a good raw materials for antioxidants compound extraction and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.989-995
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• 2009

Extract yield of tartary buckwheat treated with water, 70% ethanol or methanol were about 13.6%, 7.0% and 6.6%, respectively. Extract yield was greatly increased by the treatment of $\alpha$-amylase indicating 95.1% yield. $RC_{50}$ value of DPPH radical scavenging activity with methanol and 70% ethanol extracts were 34.0 $\mu g$/mL, 40.5 $\mu g$/mL, respectively. The DPPH radical scavenging activity increased when it was treated with $\beta$-glucosidase and cellulase, showing $RC_{50}$ value of 24.7 $\mu g$/mL and 25.0 $\mu g$/mL, respectively. In ABTS radical scavenging activity, methanol extract (100 $\mu g$/mL) showed 30% inhibition. In DPPH or ABTS radical scavenging activities, the treatment of $\beta$-glucanase and $\alpha$-amylase shows the highest and the lowest activities, respectively. In $\alpha$-glucosidase inhibitory effect, 70% ethanol extract showed $RC_{50}$ value of 59.9 $\mu g$/mL, but water extract was not inhibitory effective. The $\alpha$-glucosidase inhibitory effect was the highest in multi enzyme treatment. Content of rutin and quercetin in methanol extract showed higher value with 4400.3 mg% and 71.9 mg%, respectively. The 70% ethanol extract of buckwheat contained rutin of 3459.8 mg% and quercetin of 56.9 mg%. In the treatment of $\beta$-glucanase, the rutin content of ethanol extract increased with 5057.4 mg% and multi-enzyme treatment resulted in the modification of rutin glycoside.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.545-551
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• 2017

Curcuma longa L. (CL) is widely used as a spice and coloring agent in several foods, such as curry and mustard, as well as cosmetics and drugs. In this study, we investigated the protective effects of CL extracted with various solvents [methanol (MC), ethanol (EC), acetone (AC)] on $H_2O_2-induced$ DNA damage in human leukocytes along with total polyphenol contents (TPC) and antioxidant properties. The antioxidant effects of CL were determined by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and superoxide dismutase (SOD)-like activity. The preventive effect of CL on oxidative stress-induced DNA damage and DNA repair capacities were assessed using comet assay. MC showed the highest TPC (11.17 g gallic acid equivalents/100 g) and antioxidant properties among the solvent extracts. The $SC_{50}$ for DPPH RSA was MC: 35.0 > AC: 45.8 > EC: $57.8{\mu}g/mL$ and SOD-like activity was MC: 46.6 > EC: 141.5 > AC: $296.4{\mu}g/mL$. In the comet assay, the $ED_{50}$ value of MC showed the highest inhibition ($86.7{\mu}g/mL$) of $H_2O_2-induced$ DNA damage, followed by AC ($110.0{\mu}g/mL$) > EC ($115.8{\mu}g/mL$). Analysis of the percentage of damaged cells showed that repair capacity significantly decreased at 4, 8, and 12 h from $H_2O_2-induced$ oxidative stress in each extract. After 12 h, level of DNA damage recovery was similar to the negative control level. These results suggest that CL has potential antioxidant activity and a protective effect against oxidation-induced DNA damage, and the methanol extract of CL was the most effective.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1164-1170
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• 2017

Protaetia brevitarsis larvae (PBL) has recently been registered as a temporary food in Korea, and this study evaluated the application potential of PBL proteins as health functional food materials. Protein hydrolysates were prepared from PBL powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and based on the results from the peptide content and SDS-PAGE analyses, PBL treated with alcalase or flavourzyme showed a high degree of hydrolysis (HD) value, whereas the HD value of those treated with neutrase, bromelain, or papain was minimal. The protein hydrolysates showing a high HD value were separated further into the fractions of >3 kDa and <3 kDa by a centrifugal filter system and then lyophilized, and according to the $RC_{50}$ values of the protein hydrolysates (<3 kDa) obtained from three different antioxidant analyses; the alcalase hydrolysates showed the highest antioxidant activity. Therefore, the alcalase hydrolysates were tested further for their inhibitory effects on the peroxidation of linoleic acid by measuring the thiobarbituric acid values. The results showed that the peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation, but a pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited the linoleic acid peroxidation in a dose-dependent manner for 6 days. Our current studies are focused on the identification of active peptide sequences from alcalase hydrolysates.

• Journal of Embryo Transfer
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• v.30 no.1
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• pp.7-15
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• 2015

The objective of this study was to investigate the efficiency of nicotinic acid on sperm cryosurvival and fertilization ability in frozen-thawed boar semen. Boar semen was collected by glove-hand method and was frozen using freezing solution treated to 0, 5, 10 and 20 mM of nicotinic acid. The frozen sperm for sperm characteristic analysis was thawed such as viability, acrosome reaction, and mitochondrial integrity. The frozen-thawed sperm was estimated by SYBR14/PI double staining for viability, FITC-PNA/PI double staining for acrosome reaction and Rhodamine123/PI double staining for mitochondrial integrity using a flow cytometry. The embryo was estimated in vitro development and DCFDA staining for reactive oxygen species assessment. As results, frozen-thawed sperm viability was significantly higher in 5 and 10 mM ($61.1{\pm}1.5%$,$64.7{\pm}2.0%$) of nicotinic acid than other groups (0 mM, $52.1{\pm}2.3%$; 20 mM, $47.8{\pm}5.1%$, P<0.05). The live sperm with acrosome reaction was significantly higher in 5 and 10 mM of nicotinic acid ($26.1{\pm}1.8%$, $24.9{\pm}1.5%$) than other groups (0 mM, $35.3{\pm}0.8%$; 20 mM, $36.5{\pm}1.9%$, P<0.05). The live sperm with mitochondrial integrity was significantly higher in 5 and 10 mM ($84.2{\pm}3.6%$, $88.4{\pm}2.3%$) of nicotinic acid than other groups (0 mM, $77.3{\pm}4.4%$; 20 mM, $73.3{\pm}3.6%$, P<0.05). Blastocyst rate of in vitro development was significantly higher in 10 mM ($17.0{\pm}1.3%$) of nicotinic acid than other groups (0 mM, $9.4{\pm}0.5%$; 5mM, $12.6{\pm}0.8%$; 20 mM, $5.0{\pm}1.0%$, P<0.05). Moreover, total cell number was higher in 5 and 10 mM ($53.6{\pm}2.9%$, $57.9{\pm}2.8%$) of nicotinic acid than other groups (0 mM, $41.0{\pm}1.4%$; 20 mM, $23.2{\pm}2.8%$, P<0.05). Hydrogen peroxide in embryos was lower in 5 mM nicotinic acid ($0.7{\pm}0.1%$) than other groups (0 mM, $1.0{\pm}0.1%$; 10mM, $0.9{\pm}0.0%$; 20 mM, $1.4{\pm}1.0%$, P<0.05). In conclusion, nicotinic acid-treated semen improves cryosurvival and quality of spermatozoa. Also, the fertilized oocytes with nicotinic acid improve quality of embryo and blastocyst formation.

• Journal of Nutrition and Health
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• v.52 no.1
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• pp.26-35
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• 2019

Purpose: The aim of this study was to estimate the antioxidant activities of 50%, 70%, and 100% ethanol extracts of Lycium barbarum leaf and chlorophyll removal extract. Methods: The antioxidant activities were estimated by measuring total polyphenol content and by assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfate) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). In addition, reactive oxygen species (ROS) production, DNA fragmentation, and antioxidant enzyme (superoxide dismutase and catalase) activities of the extracts were measured in hydrogen peroxide ($H_2O_2$)-stressed HepG2 cells. Results: The total polyphenol content, DPPH and ABTS radical scavenging activities, and FRAP value of the extracts increased in an ethanol concentration-dependent manner. The antioxidant activities of the chlorophyll-removal extracts were much higher than those of the chlorophyll-containing extracts. Cytotoxicity was not observed in HepG2 cells with extracts up to $1,000{\mu}g/mL$. All extracts inhibited ROS production in a concentration-dependent manner from $31.3{\mu}g/mL$ and inhibited DNA damage at $250{\mu}g/mL$. The SOD and catalase activities of cell lines treated with the extracts and $H_2O_2$ were similar to those of normal cells, indicating a strong protective effect. Conclusion: Lycium barbarum leaf extracts had high antioxidant activities and protected $H_2O_2$-stressed HepG2 cells. Since the chlorophyll-removal extract exhibited higher antioxidant activities than the chlorophyll-containing ones and the cytoprotective effect was similar, chlorophyll removal extract of Lycium barbarum leaf could be developed as ingredients of functional food and cosmetics.