• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.226-235
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• 2020

In this paper, we present to evaluate physiological activity of Robinia pseudo-acacia leaf and its skin penetration using liposome and cell penetrating peptide. After extraction with Robinia pseudo-acacia leaf using the distilled water and supercritical, various physiological activities were examined. In antioxidants experiments, the total concentration of polyphenol compounds was determined to be 56.88 mg/g in hydrothermal extract, 45.07 mg/g in supercritical extract. The DPPH radical scavenging ability at 1,000 ㎍/mL was 33.97% in supercritical extract. The scavenging effect on SOD experiment at 500 ㎍/mL was 76.41% in supercritical extract. In the antimicrobial experiments, the hydrothermal extract had no effect, but supercritical extract represented maximum clear zone of 14.00 mm in Staphylococcus aureus strain. Liposome containing the RSE (Robinia pseudo-acacia leaf supercritical extract) reduced particle size and stabilized zeta potential. In the epidermal permeability experiment, it was confirmed that the permeation of liposome containing the RSE and cell penetrating peptides was remarkable.

• 생약학회지
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• 제37권4호
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• pp.307-313
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• 2006

Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.

• 동의생리병리학회지
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• 제27권2호
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• pp.189-195
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• 2013

This study was designed to analyze the effects of methanol extracts and solvent fractions of the young branch of Prunus persica on scavenging activity of ROS, RNS and inhibiting activity of oxidative modification in human LDL induced by copper ion or free radical generator. The scavenging capacities of the fractions on DPPH radical, superoxide radical, nitric oxide and peroxynitrite were exhibited the highest in ethylacetate fraction, followed by butanol fraction. In the copper-induced LDL oxidative modification system, the highest antioxidant activity was revealed in ethylacetate fraction, and butanol fraction exhibited a similar activity. However, solvent fractions of the young branch of Prunus persica showed a relatively low antioxidant activity in the AAPH-mediated LDL oxidation. In addition, ethylacetate and butanol fractions also inhibited the copper-mediated LDL oxidation in the REM assay, which was comparable to that of the positive controls, including EDTA, ascorbic acid and BHT. Futhermore, a content of total phenolics in these two fractions was higher than that of the other fractions. These results indicated that ethylacetate and butanol fractions of the young branch of Prunus persica were useful for the prevention of the free radical- or metal ion-induced oxidative damages.

• 전기학회논문지
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• 제56권5호
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• pp.938-943
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• 2007

In this paper, we show that, in case of piezoelectric micropower generator, just replacing Schottky diodes in the bridge rectifier with ultra-low reverse leakage current diodes improves the mechanical-to-electrical energy conversion efficiency by more than 100%. Experimental and PSPICE simulation results show that, due to the ultra-low leakage current, the charging speed of the circuit employing PAD1 is higher than that of the circuit employing Schottky diodes and the saturation voltage of the circuit employing PAD1 is also higher. This study suggests that , when the internal impedance of source is very large (a few tens of $M{\Omega}$) such that maximum charging current is a few microamperes or less, in order to realize literally the energy scavenging system, ultra-low reverse leakage current diodes should be used for efficient energy conversion. Since low-level vibration is ubiquitous in the environment ranging from human movement to large infrastructures and the mechanical-to-electrical energy conversion efficiency is much more critical for use of these vibrations, we believe that the improvement in the efficiency using ultra-low leakage diodes, as found in this work, will widen greatly the application of piezoelectric micropower generator.

• Food Science and Biotechnology
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• 제16권5호
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• pp.710-714
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• 2007

Ligularia fischeri (LF) has been used to treat jaundice, scarlet-fever, rheumatoidal arthritis, and hepatic diseases. This study was carried out to determine the antioxidant activity of the extract from the leaves of LF by using various established in vitro systems with ${\alpha}$-tocopherol as positive control. The results showed that the ethanol extract of LF (0.05-0.5 mg/mL) displayed a strong free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, ${O_2}^{{\cdot}-}$, and $H_2O_2$ radicals. It was observed that LF extract (1 mg/mL) significantly decreased the levels of malondialdehyde (MDA) to 69 and 89% of control, measured by ferric thiocyanate (FTC) and thiobarbituric acid (TBA) test, respectively. LF extract (0.5-2 mg/mL) was also found to inhibit significantly the amount of malondialdehyde formed from liver homogenate to 69-56% of control. Similarly, in the high $Fe^{2+}/ascorbate$ induction system LF extract (1-2 mg/mL) inhibited carbonyl formation measured by 2,4-dinitrophenylhydrazine reaction to 89-79% of control. Like antioxidant activity, the reducing power of LF extract was excellent at concentration of 0.5-2 mg/mL. These results indicate that LF could be used as a potential source of natural antioxidant.

• Journal of Acupuncture Research
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• 제15권2호
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• pp.135-145
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• 1998

Bupleury radix has been used for the treatment of fever, liver disease, inflammation in traditional medicine. The present study was carried out to evaluate the antioxidant effects of Bupleury radix aqua-acupuncture solution (BRAS) in vitro. Oxygen derived free radicals produced in the course of normal aerobic life, such as superoxide anion radical($O_2^-$ ), hydroxyl radicaI( OH), hydrogen peroxide($H_2O_2$) and singlet oxygen($^1O_2$) can attack polyunsaturated fatty acid in cell membranes, enzymes, other cell compounds, and give rise to lipid peroxidation, DNA damage, lipofuscin accumulation, structure alteration of cell membrane and cell death. In this study, antioxidant effects of BRAS on lipid peroxidation were determined according to the method of TBA. BRAS inhibited markedly peroxidation of linoleic acid during the autoxidation, and also inhibited lipid peroxidation induced by hydroxyl radical derived from $H_2O_2-Fe^{2+}$ in rat liver homogenate. And BRAS showed 30% scavenging effect on DPPH radical, also exhibited a 30% inhibitory effect on superoxide generation from xanthine-xanthine oxidase system. In addition, BRAS protected the cell death induced by tert-butyl hydroperoxide(t-BHP) and significantly increased cell viability in the normal rat liver cell(Ac2F).

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.6-9
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• 2006

This study was conducted to evaluate the antioxidant activity of each fraction from Sedum sarmentosum. Antioxidant activity of each fraction was measured using the DPPH radical assay, the ferric thiocyanate (FTC) method, and thiobarbituric acid (TBA) method. The antioxidant activities were then compared with that of BHT(synthetic antioxidant). The ethyl acetate and butanol fractions were found to have significant DPPH radical scavenging activity, with scavenging potencies showing 90.61 % and 87.02%, respectively. Total phenolic compound contents, determined according to the Folin-Denis method, were found to be in the order of ethyl acetate>butanol>ethanol>chloroform>aqueous fraction. From the results, we have been able to establish a positive correlation between the antioxidant activity and the total phenolic compound content of the sample. The antioxidant activity in a linoleic acid system was measured using the ferric thiocyanate (FTC) method and thiobarbituric acid (TBA) method. The ethyl acetate fraction had the highest antioxidant activity among the tested fractions. On the basis of these results, the ethyl acetate fraction provided equivalent or higher antioxidant activity as compared to BHT. These results suggest that Sedum sarmentosum is a potentially useful antioxidant for foods, cosmetics, and medicine.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.193-193
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• 2008

Wearable and ubiquitous micro systems will be greatly growing and their related devices should be self-powered in order to avoid the replacement of finite power sources, for example, by scavenging energy from the environment. With ever reducing power requirements of both analog and digital circuits, power scavenging approaches are becoming increasingly realistic. One approach is to drive an electromechanical converter from ambient motion or vibration. Vibration-driven generators based on electromagnetic, electrostatic and piezoelectric technologies have been demonstrated. Among various generator types proposed so far, piezoelectric generator possesses considerable potential in micro system. To overcome low mechanical-to-electric energy conversion, the piezoelectric device should activate in resonance mode in response to external vibration. Normally, the external vibration excretes at low frequency ranging 0.1 to 200 Hz, whereas the resonant frequencies of the devices are fixed as constant. Therefore, keeping their resonant mode in varying external vibration can be one of important points in enhancing the conversion efficiency. We investigated the possibility of use of multi-bender type piezoelectric devices. To match the external vibration frequency with the device resonant frequency, the various devices with different resonant frequency were chosen.

• Advances in Traditional Medicine
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• 제7권1호
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• pp.65-73
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• 2007

Water and alcohol extracts were prepared from dried and powdered leaves of Thuja orientalis (T. orientalis). The reducing power, total phenolic content, the 1,1-diphenyl-2-picrylhydrazyl scavenging activity, inhibitory effect on Fe (II)-EDTA-$H_{2}O_{2}$ (Fenton reaction system) induced DNA damage and inhibitory effect on human red blood cell (RBC) hemolysis were evaluated in the present study. At a concentration of 200 mg, water and alcohol extracts of T. orientalis inhibited the hydrolysis of DNA by 72.859% and 65.312%, respectively. Water and alcohol extracts of T. orientalis also inhibited 2,2'-Azobis(2-amidinopropane) dihydrochloride induced RBC hemolysis to the extent of 69.30% and 54.55%, respectively. The reducing power and antioxidative activity of water extract was found to be more than that of alcohol extract. This is attributable to the presence of higher amount of phenolic compounds in water extract. The present results indicate that the T. orientalis extracts are rich sources of natural antioxidants and can protect DNA and human red blood cells against free radical induced oxidative damage.

• Molecules and Cells
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• 제26권6호
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• pp.616-620
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• 2008

Maintaining redox balance is one of the crucial requirements for a cell to endure stress from the outside. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) plays an important role in the ascorbate-glutathione cycle; one of the major ROS scavenging systems in most known biological systems. A cDNA clone of the DHAR gene from Oryza sativa (OsDHAR) was isolated and overexpressed in Escherichia coli BL21 (DE3) strain from the pET-28a(+) expression vector. The OsDHAR transformed E. coli cells showed significantly higher DHAR activity and a lower level of ROS than the E. coli cells transformed by an empty pET-28a(+) vector. Also, the DHAR-overexpressing E. coli strain was more tolerant to oxidant- and heavy metal-mediated stress conditions than the control E. coli strain. The results suggest that the overexpressed rice DHAR gene effectively functions in a prokaryotic system and provide protection to various oxidative stresses.