• Journal of Life Science
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• v.26 no.12
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• pp.1458-1465
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• 2016

We investigated the neuroprotective effect of an ethanol extract from Asparagus cochinchinensis (AC) against glutamate-induced toxicity in the HT22 hippocampal cell, which is an ideal in vitro model for oxidative stress. The neuroprotective effects of AC in HT22 cells were evaluated by analyzing cell viability, lactate dehydrogenase (LDH), flow cytometry for cell death types, reactive oxygen species (ROS), mitochondria membrane potential (MMP), and Western blot assays. In the cell death analysis, AC treatment resulted in significantly attenuated glutamate-induced loss of cell viability with a decrease in LDH release. AC treatment also reduced glutamate-induced apoptotic cell death. In the ROS and MMP analysis, AC treatment inhibited the elevation of intracellular ROS induced by glutamate exposure and the disruption of MMP. In oxidative stress-related proteins analysis, AC treatment inhibited the expression of poly ADP ribose polymerase and heme oxygenase-1 by glutamate. These results indicate that AC exerts a significant neuroprotective effect against glutamate-induced hippocampal damage by decreasing ROS production and stabilizing MMP. Thus, AC potentially provides a new strategy for the treatment of oxidative stress-related diseases.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.85-96
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• 1993

To investigate the alteration of transferrin receptor (TfR) in the proliferating or transformed liver cells, $^{125}I-transferrin$ binding experiment was carried out in the isolated parenchymal cells (PC) or nonparenchymal cells (NPC) from normal regenerated rat liver after partial hepatectomy and from the liver of 3-methyl-4-dimethyl-aminoazobenzene (3-Me-DAB) treated rat. With the administration of 3-Me-DAB for 8 weeks, the liver tissue showed marked morphologic changes of oval cell proliferation, regenerations of hepatocytes, and atypical proliferations of bile ducts, but these changes were little affected by partial hepatectomy. Transferrin binding values in PC or NPC homogenate from the regenerated liver of normal rat, were increased by 3rd day and diminished to control level at 7th day after partial hepatectomy. With the treatement of 3-Me-DAB for 8 weeks, transferrin binding sites in homogenates were higher than those of normal rat liver and increased by 7th day after partial hepatectomy. Transferrin binding sites (Bmax) in the cell membrane of NPC were higher than those of PC of normal rat liver, but there was no significant difference in Kd values between both groups (5.05, 6.3 nM). In the normal resenerated rat liver, transferrin binding sites in the PC or NPC plasma membrane, were increased by 3rd day and diminished to control level at 7th day after partial hepatectomy. With 3-Me-DAB tratment, transferrin binding sites in both liver NPC and PC plasma membrane were increased about 3 folds, compared to those in each plasma membrane of normal rat liver. And after partial hepatectomy of 3-Me-DAB trated rat, transferrin binding sites were increased by the 3rd day in the NPC plasma membrane but increased by the 7th day in the PC plasma membrane. In the transferrin binding sites of the PC or NPC plasma membrane of 3-Me-DAB treated liver, two kinds of Kd values $(3.1{\sim}4.7\;nM,\;25.4{\sim}54.1\;nM)$ were detected. The present results suggest that 1) TfRs are distributed in the liver PC as well as NPC; 2) Increased TfRs in PC or NPC plasma membrane of normal regenerated liver after partial hepatectomy and 3-Me-DAB treated rat liver, may be due to increased intracellular synthesis; 3) Increased TfRs in normal regenerated liver after partial hepatectomy might be related to the expression of a single type of high affinity site $(Kd,\;3.1{\sim}7.5\;nM)$, but in 3-Me-DAB treated rat liver might be related to the expression of high and low affinity types of receptors $(Kd,\;25.4{\sim}54.1\;nm)$.

• Journal of Life Science
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• v.25 no.9
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• pp.984-992
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• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Journal of Life Science
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• v.19 no.5
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• pp.598-606
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• 2009

Oxidative stress by free radicals is a major cause of neuronal cell death. Excitotoxicity in hypoxia/ischemia causes an increase in reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP), resulting in dysfunction of the mitochondria and cell death. Pinelliae Rhizoma (PR) is a traditional medicine for incipient stroke. We investigated the effects of PR Water-Extract on the modulation of ROS and MMP in a hypoxic model using cultured rat cortical cells. PR Water-Extract was added to the culture medium at various concentrations (0.25${\sim}$5, 5.0 ${\mu}g/ml$) on day in vitro 12(DIV12), given a hypoxic shock (2% $O_2$/5% $CO_2$, $37^{\circ}C$, 3 hr), and cell viability was assessed on DIV15 by Lactate Dehydrogenase Assay (LDH assays). PR Water-Extract showed a statistically significant effect on neuroprotection (10${\sim}$15% increase in viability; p<0.01) at 1.0 and 2.5 ${\mu}g/ml$ in normoxia and hypoxia. Measurement of ROS production by $H_2DCF-DA$ stainings showed that PR Water-Extract efficiently reduced the number and intensity of ROS-producing neurons, especially at 1 hr post shock and DIV15. When MMP was measured by JC-1 stainings, PR Water-Extract efficiently maintained high-energy charged mitochondria. These results indicate that PR Water-Extract protects neurons in hypoxia by preventing ROS production and preserving the cellular energy level.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.13-19
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• 2011

Semen cryopreservation induces the formation of reactive oxygen species (ROS), and the ROS cause sperm damage. We aimed to investigate the effects of the antioxidative enzyme catalase (CAT) on sperm quality and ROS during cryopreservation. Sperm rich fractions collected from five Duroc boars were cryopreserved in freezing extender with (200 or 400 U/mL) or without CAT (control). After thawing, sperm motility, viability, normal morphology, plasma membrane integrity, mitochondrial function and intracellular ROS were evaluated. CAT significantly improved total sperm motility at a concentration of 400 U/mL (P < 0.05), but didn't improve progressive sperm motility, viability, morphological defects, plasma membrane integrity and mitochondrial function in frozen-thawed boar sperm. In evaluation of ROS, CAT had no effect on reduction in ${\cdot}O_2$, but scavenged $H_2O_2$ in viable frozen-thawed boar sperm at concentrations of 200 and 400 U/mL (P < 0.05). In conclusion, CAT was not enough to improve quality of frozen-thawed sperm, but can reduce $H_2O_2$ generation in viable boar sperm during cryopreservation.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.321-326
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• 1993

Membrane separation technology with polymeric membranes for the effective separation and energy conservation has emerged to be a new technology for separation in recent years. In this research, the reverse osmosis process was applied to the concentration process of clarified apple juices. The changes of concentration and permeate flux of apple juice in this process were measured at different membrane characteristics, operating pressures, temperature and flow rate. And the changes of quality were also measured at different pressures. The prediction model for the permeate flux based on these data was established. Generally, the osmotic pressure increased as the concentration of the feed increased in the RO process, which caused a reduction of permeate flux. The changes of permeate flux were not much dependent on temperature and flow rate, but very much dependent on pressure. The most effective factor in increased permeate flux was found to be the operating pressure, followed by temperature and flow rate. The final prediction model for the permeate flux was developed by the $SPSS^x$ computer program. The result showed that recovery of sugar was not affected by processing pressures, but the percentage recovery of total flavor was increased with increasing pressure.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.193-198
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• 2013

In general, boron recovery of 40-90% could be achieved by Reverse Osmosis (RO) membranes in neutral pH condition. As an emerging technology, Forward Osmosis (FO) membrane has attracted growing interest in wastewater treatment and desalination. The objective of this study is to evaluate the possibility of the boron removal in radioactive liquid waste by FO. In this study, the performance of FO was investigated to remove boron in the simulated liquid waste as the factors such as pH, osmotic pressure, ionic strength of solution, etc. The pH of feed solution is a major operating parameter which strongly influences to the permeation of boron and more than 80% of boron content can be separated when conducted at pH values less than 7. The water flux is not influenced but the boron flux and permeation rate tends to decrease in the low salt concentration of 1,000 mg/L. The boron flux increases linearly, but the permeation ratio of reducing boron is nearly constant even with changes in the draw solution concentration.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.308-318
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• 2022

The purpose of this study is to evaluate the biomechanical properties of fractured adjacent soft tissue during closed reduction after forearm fracture using the finite element method. To accomplish this, a finite element (FE) model of the forearm including soft tissue was constructed, and the material properties reported in previous studies were implemented. Based on this, nine finite element models with different fracture types and fracture positions, which are the main parameters, were subjected to finite element analysis under the same load and boundary conditions. The load condition simulated the traction of increasing the fracture site spacing from 0.4 mm to 1.6 mm at intervals of 0.4 mm at the distal end of the radioulnar bone. Through the finite element analysis, the fracture type, fracture location, and displacement were compared and analyzed for the fracture site spacing of the fractured portion and the maximum equivalent stress of the soft tissues adjacent to the fracture(interosseous membrane, muscle, fat, and skin). The results of this study are as follows. The effect of the major parameters on the fracture site spacing of the fractured part is negligible. Also, from the displacement of 1.2 mm, the maximum equivalent stress of the interosseous membrane and muscle adjacent to the fractured bone exceeds the ultimate tensile strength of the material. In addition, it was confirmed that the maximum equivalent stresses of soft tissues(fat, skin) were different in size but similar in trend. As a result, this study was able to numerically confirm the damage to the adjacent soft tissue due to the fracture site spacing during closed reduction of forearm fracture.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.251-260
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• 1998

Cromakalim (BRL 34915), known as an airway smooth muscle relaxant, inhibited the releases of mediators in the antigen-induced mast cell activation. It has been suggested that cromakalim, in part, inhibited mediator releases by inhibiting the initial increase of 1,2-diacylglycerol (DAG) produced by the activation of the other phospholipase system which is different from phosphatidylcholine-phospholipase D pathway. The aim of this study is to further examine the inhibitory mechanism of cromakalim on the mediator release in the mast cell activation. Guinea pig lung mast cells were purified by using enzyme digestion and percoll density gradient. In purified mast cells prelabeled with $[^3H]PIP_2$, phospholipase C (PLC) activity was assessed by the production of $[^3H]$insitol phosphates. Protein kinase C (PKC) activity was assessed by measuring the protein phosphorylated from mast cells prelabeled with $[{\gamma}-32P]ATP$, and Phospholipase $A_2\;(PLA_2)$ activity by measuring the lyso-phosphatidylcholine produced from mast cell prelabeled with 1-palmitoyl-2-arachidonyl $phosphatidyl-[^{14}C]choline$. Histamine was assayed by fluorometric analyzer, and leukotrienes by radioimmunoassay. The PLC activity was increased by activation of the passively sensitized mast cells. This increased PLC activity was decreased by cromakalim pretreatment. The PKC activity increased by the activation of the passively sensitized mast cells was decreased by calphostin C, staurosporine and cromakalim, respectively. The $PLA_2$ activity was increased in the activated mast cells. The pretreatment of cromakalim did not significantly decrease $PLA_2$ activity. These data show that cromakalim inhibits histamine release by continuously inhibiting signal transduction processes which is mediated via PLC pathway during mast cell activation, but that cromakalim does not affect $PLA_2$ activity related to leukotriene release.

• Genomics & Informatics
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• v.2 no.3
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• pp.121-125
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• 2004

The purpose of this study was to investigate the use of decision tree for the classification of antimicrobial peptides. The classification was based on the activities of known antimicrobial peptides against common microbes including Escherichia coli and Staphylococcus aureus. A feature selection was employed to select an effective subset of features from available attribute sets. Sequential applications of decision tree with 17 nodes with 9 leaves and 13 nodes with 7 leaves provided the classification rates of $76.74\%$ and $74.66\%$ against E. coli and S. aureus, respectively. Angle subtended by positively charged face and the positive charge commonly gave higher accuracies in both E. coli and S. aureusdatasets. In this study, we describe a successful application of decision tree that provides the understanding of the effects of physicochemical characteristics of peptides on bacterial membrane.