• YAKHAK HOEJI
• /
• v.52 no.2
• /
• pp.117-124
• /
• 2008

The leaves of Perilla frutescens Britt. var. japonica Hara (Labiatae) are often used in gourmet food in several Asian countries. Two kinds of perilla cultivars, Namcheon (NC) and Bora (BR), have been respectively developed in Korea by the pure line of 'deulkkae' from the local variety and by the cross of 'deulkkae' and 'chajogi'. The present study evaluated and compared antioxidant and neuroprotective effects of the fractions prepared from the leaves of the two cultivars using cell-free bioassay systems and primary cultured rat cortical cells. We found that the spirit, chloroform, hexane and butanol fractions from NC and BR leaves inhibited lipid peroxidation initiated in rat brain homogenates by $Fe^{2+}$ and L-ascorbic acid. In contrast, only the spirit and butanol fractions from both cultivars exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Among the fractions tested, the butanol fractions from NC and BR leaves exhibited the most potent antioxidant properties, and the butanol fraction from BR was more potent than the NC fraction. In consistence with these findings, the butanol fractions from both cultivars protected primary cultured cortical cells from the oxidative damage induced by $H_2O_2$ or xanthine and xanthine oxidase, with the BR butanol fraction being more active. The butanol fractions from NC and BR did not produce cytotoxicity in our cultures treated for 24 h at the concentrations of up to $100\;{\mu}g/ml$. Taken together, these results indicate that the leaves of the two cultivars of Perilla frutescens exert antioxidant and neuroprotective effects, and that the butanol fraction from BR leaves exhibits the most potent antioxidative neuroprotection among the fractions tested in this study.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.4
• /
• pp.133-140
• /
• 2008

The purpose of this study is to provide response methods to minimize the damage from chemical terrorism in a naturally ventilated indoor system using several types of dispersion simulations. Three chemical warfare agents such as sarin(GB), phosgene and chlorine gas which have high potential to be used in terror or to be involved with accidents were selected in this simulation. Fire dynamic simulation based on Large Eddy Simulation which is effective because of less computational effort and detailed expression of the dispersion flow was adopted to describe the dispersion behavior of these agents. When the vent speed is 0.005m/s, the heights of 0.1 agent mass fraction are 0.9m for sarin, 1.0m for phosgene and 1.1m for chlorine gas, and the maximum mass fraction are 0.27 for all three agents. However, when the vent speed is increased to 0.05m/s, the heights of 0.1 agent mass fraction become 1.6m for all three agents and maximum mass fraction inside the room increase to 0.70 for sarin, 0.58 for phosgene and 0.53 for chlorine gas. It is shown that molecular weight of the agents has an important role for dispersion, and it is important to install ventilation system with height less than 1.6m to minimize the damage from chemical toxicity.

• Journal of Applied Biological Chemistry
• /
• v.63 no.4
• /
• pp.357-363
• /
• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• Journal of Ginseng Research
• /
• v.48 no.5
• /
• pp.464-473
• /
• 2024

Background: The effects of individual panaxadiol saponin and panaxatriol saponin on rodent models of Parkinson's disease (PD) have been recognized. However, it is not clear whether purified total ginsenosides as an entirety has effect against PD in rat model. This study compared the protective effects of a purified panaxadiol saponin fraction (PDSF), a purified panaxatriol saponin fraction (PTSF), and their mixtures against the rotenone (ROT)-induced PD in rats. Methods: Potential effects of PDSF, PTSF, and their mixtures against motor dysfunction and impairments of nigrostriatal dopaminergic neurons (DN), blood-brain barrier (BBB), cerebrovascular endothelial cells (CEC), and glial cells were measured in the models of ROT-induced PD rats and cell damage. Pro-inflammatory NF-kB p65 (p65) activation was localized in DN and other cells in the striatum. Results: PDSF and PTSF had a dose-dependent effect against motor dysfunction with a larger effective dose range for PDSF. PDSF protected CEC, glial cells, and DN in models of PD rats and cell damage, while PTSF had no such protections. Chronic ROT exposure potently activated p65 in CEC with enhanced pro-inflammatory and decreased anti-inflammatory factors and impaired BBB in the striatum, PDSF almost completely blocked the ROT-induced p65 activation and maintained both anti- and pro-inflammatory factors at normal levels and BBB integrity, but PTSF aggravated the p65 activation with impaired BBB. Furthermore, PTSF nullified all the effects of PDSF when they were co-administrated. Conclusion: PDSF had significant protective effect against the ROT-induced PD in rats by protecting CEC, glial cells, and DN, likely through inhibiting NF-κB p65 in CEC from triggering neuroinflammation, and also directly protecting glial cells and neurons against ROT-induced toxicity. PDSF has great potential for preventing and treating PD.

• Applied Chemistry for Engineering
• /
• v.29 no.6
• /
• pp.772-781
• /
• 2018

In this study, we investigated antioxidant, antimicrobial and cytoprotective effects of 50% ethanol extract and ethyl acetate fraction from rhizomes of Belamcanda chinensis (L.) DC. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities ($FSC_{50}$) of the 50% ethanol extract and ethyl acetate fraction were 621.5 and $253.0{\mu}g/mL$, respectively. Total antioxidant capacities ($OSC_{50}$) of the extract and fraction were 13.6 and $3.0{\mu}g/mL$, respectively. Minimum inhibitory concentrations (MIC) of the ethyl acetate fraction for Staphylococcus aureus and Candida albicans were 156, $1,250{\mu}g/mL$, respectively, indicating similar or higher levels of those of using methyl paraben. Cytoprotective effects of the 50% ethanol extract against $^1O_2$-induced cellular damage (${\tau}_{50}$) showed in a dose dependent manner at 4 to $64{\mu}g/mL$. ${\tau}_{50}$ of the 50% ethanol extract, ethyl acetate fraction and (+)-${\alpha}$-tocopherol at $16{\mu}g/mL$ were 36.4, 45.0 and 45.8 min respectively, and the ethyl acetate fraction showed cytoprotective effects similar to (+)-${\alpha}$-tocopherol. In ultraviolet B radiation-induced HaCaT cell damage, the ethyl acetate fraction decreased intracellular reactive oxygen species (ROS) up to 45.9% at $8{\mu}g/mL$. Also in $H_2O_2$-induced HaCaT cell damage, the ethyl acetate fraction significantly increased the cell viability at $0.5{\sim}8.0{\mu}g/mL$. As a result of chemical analyses of the ethyl acetate fraction, the presence of flavonoids and polyphenol such as irisflorentin, irigenin, tectorigenin, resveratrol, iridin and tectoridin were identified. In conclusion, the extract/fraction from rhizomes of B. chinensis can be applied as a natural antioxidant and antimicrobial material to cosmetics.

• Korean Journal of Veterinary Research
• /
• v.34 no.2
• /
• pp.249-258
• /
• 1994

This study was carried out to investigate the inhibitory effects of vitamin E on the oxidative damage of cellular lipids and proteins in free radical reaction induced by $FeCl_3$, and ascorbic acid. In this experiment, a vitamin E treated rat group was administered with 100mg/kg body weight of $dl-{\alpha}-tocophery$ 1 acetate and an untreated rat group was administered with the same volume of corn oil. And then assays of malondialdehyde and carbonyl group in total homogenate, mitochondrial and microsomal fraction of rat liver were carried out at the scheduled time. The results obtained from this study were summarized as follows; 1. Lipid peroxidation levels in vitamin E administered rat liver cells were significantly (p<0.05) decreased at the intervals between 1 hour and 4 hours in liver homogenate, at all times except for 1 hour point in mitochondrial fraction, and also at the intervals between 0.5 hour and 3 hours in microsomal fraction compared with those of the control rat liver cell. 2. Protein oxidation levels in vitamin E administered rat liver cell were also significantly (p<0.05) decreased at the intervals between 1.5 hours and 4 hours in liver homogenate, at over 4 hours in liver mitochondrial fraction, and at the intervals between 0.5 hour and 3 hours in liver microsomal fraction compared with those of the control rat liver cells.

• Smart Structures and Systems
• /
• v.23 no.2
• /
• pp.173-184
• /
• 2019

The main objective of this study is to evaluate the true fracture energy and monitor the damage progression in steel fibre reinforced concrete (SFRC) specimens using acoustic emission (AE) features. Four point bending test is carried out using pre-notched plain and fibre reinforced (0.5% and 1% volume fraction) - concrete under monotonic loading. AE sensors are affixed at different locations of the specimens and AE parameters such as rise time, AE energy, hits, counts, amplitude and duration etc. are obtained. Using the captured and processed AE event data, fracture process zone is identified and the true fracture energy is evaluated. The AE data is also employed for tracing the damage progression in plain and fibre reinforced concrete, using both parametric- and signal- based techniques. Hilbert - Huang transform (HHT) is used in signal based processing for evaluating instantaneous frequency of the acoustic events. It is found that the appropriately processed and carefully analyzed acoustic data is capable of providing vital information on progression of damage on different types of concrete.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.05a
• /
• pp.89-92
• /
• 2001

Drop weight impact tests were performed to investigate the impact behavior of carbon fiber/epoxy composite laminates reinforced by short fibers and other interleaving materials. Characterization techniques, such as cross-sectional fractography and scanning acoustic microscopy, were employed quantitatively to assess the internal damage of some composite laminates. Scanning electron microscopy was used to observe impact damage and fracture modes on specimen fracture surfaces. The results show that composite laminates experience various types of fracture; delamination, intra-ply cracking, matrix cracking and fiber breakage depending on the interlayer materials. Among the composite laminates tested in this study, the composites reinforced by Zylon fibers showed very good impact damage resistance with medium level of damage, while the composites interleaved by poly(ethylene-co-acrylic acid) (PEEA) film is expected to deteriorate the bulk strength due to the reduction of fiber volume fraction, even though the damaged area is significantly reduced.

• Korean Journal of Food Science and Technology
• /
• v.32 no.2
• /
• pp.461-468
• /
• 2000

To investigate the antigenotoxicity of Korean mistletoe using Comet assay, the crude extract was divided into 4 fractions, i.e. fraction I (MW range over 14,000), fraction II $(8,000{\sim}14,000)$, fraction III $(3,500{\sim}8,000)$, and fraction IV (below 3,500) by molecular weight fractionation. In the non-tumoral 3T3 cells, fraction IV could reduce DNA damage induced by MNNG in a dose dependent pattern while fraction I and III which were known to contain lectins and viscotoxins, respectively, did not show the activity. By heat treatment, the antigenotoxic activity of faction IV, though was gradually diminished according to heating time, was found to be maintained significantly. From the Sephadex G-25 gel filtration chromatography, a more purified fraction responsible for the activity of faction IV was obtained from the latter part of total elute. Therefore, it was concluded that the antigenotoxic components of Korean mistletoe were water soluble substances of MW below 1,000 and there is a possibility of utilization as a material of functional foods for chemoprevention.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.109.2-110
• /
• 2003

The neuroprotective effect of solvent fraction of native edible plant MK-104 in the mice administered with kainate was evaluated using behavioral sign, neuronal injuries and biomarkers of oxidative stress. Mice, ICR male, were administered with the BFME through a gavage for 4 days consecutively, and on the 3rd day, kainate (450 mg/kg) was i.p. administered. The fraction(400 mg/kg) delayed the onset time of neurobehavioral change (p<0.01), reduced the severity of convulsion and lethality (p<0.05), and restored the level of GSH and lipid peroxidation in brain to control value. A similar protective action was also expressed by fraction-I (200 mg/kg), which showed a prominent protection against the neuronal damage in hippocampal CA1 and CA2 regions (p<0.01) caused by kainate injection. of TBARS value. Based on these results, BFME-I is suggested to contain a functional agent to prevent against oxidative stress in the brain of mice.