• Food Science and Biotechnology
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• v.17 no.2
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• pp.313-318
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• 2008

This study was conducted to evaluate in vitro antioxidative and antimicrobial properties of ethanolic extracts from Allium victoriallis L. var. platyphyllum (AVP) with 6 different parts. The antioxidative activities of these samples were determined using the 4 separate methods that involved reducing power, DPPH, hydrogen radical scavenging, and lipid peroxidation with use of a $\beta$-carotene/linoleic acid system. The leaf part ethanolic extracts (1,000 ppm) showed the strongest inhibitory potential for reducing power, DPPH, and hydroxyl radicals to 99.8, 49.4, and 52.8%, respectively. Inhibition values of linoleic oxidation were calculated as 58.0, 39.5, and 38.0% for seed, flower, and leaf ethanolic extracts (1,000 ppm), respectively, from AVP. In addition, the ethanolic extracts of the root part showed the most effective antimicrobial activity. The inhibition zones of the root ethanolic extracts ($200\;{\mu}g/disc$) of AVP against Bacillus cereus and Staphylococcus aureus were 17 and 14 mm, respectively. In a micro-dilution assay, B. cereus, S. aureus, and Vibrio parahaemolyticus exhibited sensitivity to root part ethanolic extracts with an minimum inhibition concentration (MIC) value of 20, 28, and 18 mg/mL, respectively. Therefore, the AVP extracts may be suitable as antimicrobial and antioxidative agents in the food industry.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.269-276
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• 2009

Overproduction of reactive oxygen species (ROS), including nitric oxide (NO), could be associated with the pathogenesis of various diseases such as cancer and chronic inflammation. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are known to play key roles in the development of these diseases. Cedrela sinensis leaves have been used in Asian countries as a traditional remedy for enteritis, dysentery and itching. In the present study, we investigated the anti-inflammatory effects of Cedrela sinensis leaves in lipopolysaccharide (LPS)- stimulated RAW 264.7 macrophages. Powder of C. sinensis leaves was extracted with 95% ethanol and fractionated with a series of organic solvents including n-hexane, dichloromethane, ethyl acetate, n-butanol, and water. The dichloromethane (DCM) fraction strongly inhibited NO production possibly by down-regulating iNOS and COX-2 expression, as determined by Western blotting. Hydrogen peroxide-induced generation of reactive oxygen species (ROS) was also effectively inhibited by the DCM fraction from C. sinensis leaves. In addition, C. sinensis inhibited LPS-mediated p65 activation via the prevention of IκB-$\alpha$ phosphorylation. Furthermore, mitogen-activated protein kinases (MAPKs) such as ERK 1/2 and p38 were found to affect the expression of iNOS and COX-2 in the cells. Taken together, our data suggest that leaves of C. sinensis could be used as a potential source for anti-inflammatory agents.

• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.432-443
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• 2017

Maltodextrin and citric acid are two types of natural materials with the potential as an eco-friendly binder. Maltodextrin is a natural substance rich in hydroxyl groups and can form hydrogen bonds with lignoselulosic material, while citric acid is a polycarboxylic acid which can form an ester bond with a hydroxyl group at lignoselulosic material. The combination of maltodextrin and citric acid as a natural binder materials supposed to be increase the ester bonds formed within the particleboard. This research determined to investigate the bonding properties of a new adhesive composed of maltodextrin/citric acid for nipa frond particleboard. Maltodextrin and citric acid were dissolved in distillated water at the ratios of 100/0, 87.5/12.5, 75/25 and 0/100, and the concentration of the solution was adjusted to 50% for maltodextrin and 60% citric acid (wt%). This adhesive solution was sprayed onto the particles at 20% resin content based on the weight of oven dried particles. Particleboards with a size of $25{\times}25{\times}1cm$, a target density $800kg/m^3$ were prepared by hot-pressing at press temperatures of $180^{\circ}C$ or $200^{\circ}C$, a press time of 10 minute and board pressure 3.6 MPa. Physical and mechanical properties of particleboard were tested by a standard method (JIS A 5908). The results showed that added citric acid level in maltodextrin/citric acid composition and hot-pressing temperature had affected to the properties of particleboard. The optimum properties of the board were achieved at a pressing temperature of $180^{\circ}C$ and the addition of only 20% citric acid. The results also indicated that the peak intensity of C=O group increased and OH group decreased with the addition of citric acid and an increase in the pressing temperature, suggesting an interreaction between the hydroxyl groups from the lignocellulosic materials and carboxyl groups from citric acid to form the ester groups.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.203-210
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• 2017

The antioxidant and antimicrobial activities of three kinds of strawberry ethanol extracts from Robus corchorifolius L. f. (RCL), Rubus parvifolius L. var. parvifolius (RPL), and Duchesnea chrysantha Miq. (DCM) were investigated. The RPL was highest (P<0.05) in phenolic, flavonoid, and anthocyanin contents. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities of RPL and DCM extracts were higher than that of RCL (P<0.05). Hydrogen peroxide scavenging activity of RPL was high compared to DCM and RCL (P<0.05). RCL exhibited a significant (P<0.05) potent antioxidant activity in nitric oxide radical inhibition. Inhibition diameter zone (nearest mm) of extracts against the test bacteria ranged from 11.5 in RCL to 12.5 in DCM against Staphylococcus aureus, from 10.5 in RCL to 13.5 in DCM against Streptococcus pneumoniae, from 8.5 in DCM to 10.5 in RCL against Escherichia coli, and the same inhibition of 10 mm in three of the extracts against Klebsiella pneumoniae. However, there was no inhibition against fungi Aspergillus niger and Candida albicans. Three of the extracts had the same minimum inhibitory concentration values of 12.50, 12.50, and $6.25{\mu}g/mL$ against S. aureus, K. pneumoniae, and S. pneumoniae, respectively. On the other hand, MIC values of 12.50, 12.50, and $6.50{\mu}g/mL$ were recorded for RPL, DCM, and RCL against E. coli, respectively. The result of present study revealed that extracts from three kinds of strawberries could be potential candidates as antioxidant and antimicrobial sources for functional food industries.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.102-102
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• 2016

Water, which is most abundant in Earth surface and very closely related to all forms of living organisms, has a simple molecular structure but exhibits very unique physical and chemical properties. Even though tremendous effort has been paid to understand this nature's core substance, there amazingly still lefts much room for scientist to explore its novel behaviors. Especially, as the scale goes down to nano-regime, water shows extraordinary properties that are not observable in bulk state. One of such interesting features is the formation of nanoscale bubbles showing unusual long-term stability. Nanobubbles can be spontaneously formed in water on hydrophobic surface or by decompression of gas-saturated liquid. In addition, the nanobubbles can be generated during electrochemical reaction at normal hydrogen electrode (NHE), which possibly distorts the standard reduction potential at NHE as the surface nanobubble screens the reaction with electrolyte solution. However, the real-time evolution of these nanobubbles has been hardly studied owing to the lack of proper imaging tools in liquid phase at nanoscale. Here we demonstrate, for the first time, that the behaviors of nanobubbles can be visualized by in situ transmission electron microscope (TEM), utilizing graphene as liquid cell membrane. The results indicate that there is a critical radius that determines the long-term stability of nanobubbles. In addition, we find two different pathways of nanobubble growth: i) Ostwald ripening of large and small nanobubbles and ii) coalescence of similar-sized nanobubbles. We also observe that the nucleation and growth of nanoparticles and the self-assembly of biomolecules are catalyzed at the nanobubble interface. Our finding is expected to provide a deeper insight to understand unusual chemical, biological and environmental phenomena where nanoscale gas-state is involved.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.311-320
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• 2016

Kava (Piper methysticum, P. methysticum) is used as traditional herbal medicine for urogenital diseases, rheumatisms, gastrointestinal problems, respiratory irritations, and pulmonary pains. We identified a flavokavain C (FKC) from P. methysticum, which showed anti-inflammatory activity on nuclear factor ${\kappa}B$ (NF-${\kappa}B$)-dependent nitric oxide (NO) production and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. FKC inhibited accumulation of reactive oxygen species (ROS), such as hydrogen peroxide, and was able to dose-dependently reduce the LPS-induced NO production and the expression of various inflammation-associated genes (iNOS, IL-$1{\beta}$, IL-6) through inhibition of NF-${\kappa}B$ and MAPKs (ERK and JNK). In conclusion, these results indicate that FKC may have the potential to prevent inflammation process including NF-${\kappa}B$ and MAPKs pathways, and it could be applicable to functional cosmetics for anti-inflammation and antioxidant properties.

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.10-16
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• 2000

In general, acid rain is unbuffered solution with low ionic strength and high resistance. Therefore during the pH measurement of acid rain, error can be occurred due to the liquid junction potential difference between the sample and the standard solution. Actually the average conductivity of rain in Taeduk Science Town during 1998 is 12.8 ${\mu}S/cm$, while that of pH standmd solutions is about 5,980 ${\mu}S/cm$. There is a large difference in ionic strength. To compensate the bias due to residual liquid junction potentials, a quality control standard(QCS) of dilute sulfuric acid, which has the conductivity and pH values simikw to rain, was prepared. The pH of QCS solution was determined using the hydrogen electrode system without liquid junction, and compensation has been made for the bias terms by performing the pH measurements with glass electrode. On the basis of this compensation method, the pH vaiues of rain in Taeduk Science Town during 1998 were measured.

• Food Science and Preservation
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• v.12 no.3
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• pp.267-274
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• 2005

Oxidant stress is a well-known pivotal parameter for the degenerative immune diseases including asthma, atopic dermatitis, and rhinitis. In order to screen for anti-asthma agents effectively, we first established the infrastructure of high throughput screening(HTS) for anti-oxidant agents from agricultural products and/or oriental medicine library extracted with water, methanol, dimethyl sulfoxide, ethyl acetate and juice, Using the screening system, we found that Chaenomelis langenariae, Rhus javanica L., Camellia sinensis, Helianthus annuus and Angelica utilis Makino had strong anti-oxidant activity. Moreover, Helianthus annuus, Rehmannia glutinosa Libo and Angelica utilis Makino have protection activities by treatment of an oxidant hydrogen peroxide. Together, these results suggest that screened agents could be potential agents against asthma, although the in vivo studies should be clearly tested.

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.133-142
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• 2018

Objectives: The pathogenic Vibrios genus denotes halophilic bacteria that are distributed in aquatic environments, including both sea and freshwater. Vibrio cholerae, Vibrio vulnificus, and Vibrio parahaemolyticus are the most important species since they can be potent human pathogens and leading causes of septicemia, wound infections, and seafood borne gastroenteritis. The recent emergence of a potential pandemic clone, V. cholera serotype O1 and the cholera outbreak in South Korea in 2016 indicates the importance of consistent surveillance of pathogenic Vibrio genus within coastal areas. Methods: The present study was undertaken to determine where and how vibrios live in the aquatic environment adjacent to coastal areas of South Korea. For this survey, a total of 838 samples were obtained at 35 different sites in South Korean coastal areas during the period from January 2016 to December 2016. Pathogenic vibrios was determined using the real-time PCR method, and its clones were isolated using three selective plating media. We also monitored changes in seawater and atmospheric temperature, salinity, turbidity, and hydrogen ion concentration at the collection points. Results: The total isolation rates of V. vulnificus, V. cholera (non-pathogenic, non-O1, non-O139 serogroups), and V. parahaemolyticus from seawater specimens in 2016 were 14.2, 13.48, and 67.06%, respectively. Conclusions: The isolation rates of pathogenic vibrios genus showed a positive correlation with temperature of seawater and atmosphere but were negatively correlated with salinity and turbidity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2005.04a
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• pp.53-60
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• 2005

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting $1\%$ of the population above the age of 65 and is characterized by a selective loss of dopaminergic neurons in the substantia nigra pars compacta. Although the underlying cause of dopaminergic cell death or the mechanism by which these cells degenerate is still not clearly understood, oxidative stress, mitochondrial dysfunction, and protein misfolding are thought to play important roles in the dopaminergic degeneration in PD. Tetrahydrobiopterin (BH4) is synthesized exclusively in the monoaminergic, including dopaminergic, cells and serves as an endogenous and obligatory cofactor for syntheses of the potential oxidative stressors dopamine and nitric oxide. In addition to its contribution toward the syntheses of these two potentially toxic molecules, BH4 itself can directly generate oxidative stress. BH4 undergoes oxidation during the hydroxylation reaction as well as nonenzymatic autooxidation to produce hydrogen peroxide and superoxide radical. We have previously suggested BH4 as an endogenous molecule responsible for the dopaminergic neurodegeneration. BH4 exerts selective toxicity to dopamine-producing cells via generation of oxidative stress, mitochondrial dysfunction, and apoptosis. BH4 also induces morphological, biochemical, and behavioral characteristics associated with PD in vivo. BH4 as well as enzyme activity and gene expression of GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis pathway, are readily upregulated by cellular changes such as calcium influx and by various stimuli including stress situations. This points to the possibility that cellular availability of BH4 might be increased in aberrant conditions, leading to increased extracellular BH4 subsequent degeneration. The fact that BH4 is specifically and endogenously synthesized in dopaminergic cells, Is readily upregulated, and generates oxidative stress-related cell death provides physical relevance of this molecule as an attractive candidate with which to explain the mechanism of pathogenesis of PD.