• The Korean Journal of Pharmacology
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• v.18 no.1
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• pp.55-63
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• 1982

Lipid peroxidation is the reaction of oxidative deterioration of polyunsaturated lipids and this peroxidation involves the direct reaction of oxygen and lipid to form free radical intermediates, which can lead to autocatalysis. As results of the extensive studies on the lipid peroxidation by many authors, the relationship between lipid peroxidation and the drug metabolizing system as well as the actions of free radicals on the peroxidation was reasonably well known. For a long time, the mechanism of hepatotoxicity of $CCl_4$ was not clearly understood. However, it is now quite well established that $CCl_4$ is activated in vivo to a free radical which is a highly reactive molecule. Therefore, lipid peroxidation which induces the reduction of cytochrome P-450 and aminopyrine demethylase activity is known as decisive event of $CCl_4$ hepatotoxicity. On the other hand, it was also reported that singlet molecular oxygen produces lipid peroxidation in liver microsomes. In this study the effects of benzoyl peroxide on the lipid peroxidation and drug-metabolizing enzyme were examined. Benzoyl peroxide mixed with starch and phosphates etc. is usually used as a food additive for flour bleaching and maturing purpose because of its oxidative property. Albino rats were used for the experimental animals. Benzoyl peroxide was suspended in soybean oil and sesame oil and administered intraperitoneally or orally. TBA value and aminopyrine demethylase activity were determined in liver microsomal fraction and serum. The results were summerized as following. 1) Body weights of animals administered benzoyl peroxide suspension were decreased while that of oil administered group were increased. 2) The activity of aminopyrine demethylase was generally decreased in animals administered oil suspension of benzoyl peroxide. Furthermore, the marked reduction of the enzyme activity was observed in animals administered benzoyl peroxide intraperitoneally. 3) Generally, microsomal TBA values as well as serum TBA were significantly elevated in benzoyl peroxide group in comparison with the control group. However, the more remarkable increase of serum TBA than microsomal TBA was observed in animals administered orally for 6 days. 4) Specifically, the changing pattern of TBA value was notable in serum rather than in liver microsome by intraperitoneal administration of benzoyl peroxide.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1053-1062
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• 2011

Reactive oxygen species (ROS), including singlet oxygen (${O_2}^1$), superoxide anion radical ($O_2{\cdot}^-$), hydroxyl radical ($HO{\cdot}$), peroxyl radical ($ROO{\cdot}$), hydrogen peroxide ($H_2O_2$), and hypochlorous (HOCl), are generated as byproducts of normal cellular metabolism. ROS induce damage to many biological molecules, such as lipids, proteins, carbohydrates, and DNA. It is widely believed that some degenerative diseases caused by ROS can be prevented by the high intake of fruits and vegetables due to their antioxidant activities. Recently, research on natural antioxidants has become increasingly active in various fields. Several assays have been developed to measure the total antioxidant capacity of antioxidants in fruits and vegetables in vitro. These assays include those for DPPH radical scavenging activity, SOD-like activity, total polyphenol content, oxygen radical absorbance capacity, reducing power, trolox equivalent antioxidant capacity (ABTS assay), single-cell gel electrophoresis (comet assay), and a cellular antioxidant activity assay. Because different antioxidant compounds may act through different mechanisms in vitro, no single assay can fully evaluate the total antioxidant capacity of foods. Due to the complexity of the composition of foods, it is important to be able to measure antioxidant activity using biologically relevant assays. In this review, recently used assays were selected for extended discussion, including a comparison of the advantages and disadvantages of each assay and their application to fruits and vegetables.

• Journal of Life Science
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• v.18 no.9
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• pp.1257-1262
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• 2008

Photodynamic therapy (PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species (ROS), which selectively accumulated in target cells. Genistein, soy-derived phytoestrogen, is one of the anticancer agents found in soybean. In the current study, we investigated the effect of photofrin-induced PDT and genistein on apoptotic cell death in head and neck cell line (AMC-HN3) to confirm the photodynamic therapy of genistein. It was determined by MTT assay that the combination group had more cytotoxicity effect than PDT group alone. Combination of photofrin PDT and genistein induced apoptosis more when comparing with PDT alone. Our data also showed that ROS was increased in combination therapy, indicating apoptosis by mitochondrial damage. These results indicated that the combination of photofrin PDT and genistein showed more cytotoxic effect and induced apoptosis in head and neck cancer cell line.

• Journal of the Korean Magnetics Society
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• v.15 no.3
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• pp.167-171
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• 2005

Detailed aspects of the charge disproportionation (CD) transition for a polycrystalline $La_{1/3}Sr_{2/3}FeO_{2.96}$ were studied with the X-ray diffraction, $M\ddot{o}ssbauer$ spectroscopy, and SQUID magnetometer. The crystal structure was found to be rhombohedral with a space group R/3c. The lattice parameters were $a_R=5.4874\;\AA,\;and\;a_R=60.07^{\circ}$, respectively. $M\ddot{o}ssbauer$ spectra were taken within a wide range of temperature from 4.2 K up to room temperature. In the low temperature region, the spectra were comprised of two superimposed sextets which originated from $Fe^{3+}\;and\;Fe^{5+}$, respectively. This was the antiferromagnetic mixed valence state produced by the charges disproportionated into two different species. In the high temperature region, however, only a singlet from $Fe^{3.6+}$ was observed, indicating that it was a paramagnetic averaged valence state. The CD transition occurred in the temperature range from 175 K to 200 K, in which the two phases coexisted. The origin for the CD transition was explained by the thermally generated fast hopping of electrons. Hysteresis loop showed that there existed a strong antiferromagnetic interaction among magnetic ions. As the temperature increased thru the CD transition temperature, it was very likely that the interaction between $Fe^{3+}\;and\;Fe^{5+}$ was replaced by a more stronger one.

• Progress in Medical Physics
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• v.16 no.2
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• pp.104-109
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• 2005

Photodynamic therapy (PDT) is one of the expectable current cure operation methods. Tumor tissue is treated by abundant oxygen in a body and generated singlet or free radical from exterior laser diode and photosensitizer. Current problem of PDT is the low penetration power of the light beam in a deep seated large tumor and solid tumor thus results in low treatment outcome. In the study, we tried to develop interstitial photodynamics therapy treatment to solve this problem. As the accurate determination of light dosimetry in biological tissue is one of the most important factors affecting the effectiveness of PDT, parameters used in this study are the optical property of biological tissue. Since biological tissues have large scattering coefficient to visible light the penetration depth of a biological tissue in visible light region is only $15\~20$ mm. We showed that it is possible to measure fluence rate and penetration depth within the biological tissues by Monte Carlo simulation very well. Based on the MC simulation study, the effectiveness of interstitial photodynamic therapy on tumor control in solid tumor was proved through in vivo animal experiment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.300-307
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• 1987

The present study was investigated on the DNA damage by the peroxidation of polar and non-polar lipid fractionated from mackerel lipid to elucidate the DNA damage mechanism by fish oil peroxidation. The degree of DNA damage by polar lipid peroxidation became greater with the increase of its concentration, and such DNA damage was induced below 100 millieq./kg in POV for 4 days incubation. Among the polar lipid peroxidation products, singlet oxygen $^1O_2$ and superoxide anion ${\cdot}O_2^-$ greatly affected to the DNA damage than hydrogen peroxide $H_2O_2$ and hydroxyl radical ${\cdot}OH$. Non-polar lipid peroxidation also induced the DNA damage with the increase of its concentration, but such effect was lower than the case of total lipid and polar lipid. And, the effects of active crygens on the DNA damage by non-polar lipid peroxidation was the same as in the case of total and polar lipid peroxidation.

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.452-460
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• 1991

The chemical evidence for involvement of singlet oxygen during photoirradiation for 2-ethylanthracene [2-EA] and 9-phenylanthracene [9-PA] was based on the rapid decomposition of 1,3-diphenylisobenzofuran [DPBF] in methanol-water mixture and aqueous CTAB, and SDS micellar solutions. The average microenvironmental polarities of 2-EA and 9-PA were estimated by UV spectroscopic characteristics sensitive to the polarity of solvent. When 2-EA and 9-PA were solubilized in aqueous CTAB, SDS and Brij 35 solutions, their average microenvironmental polarities were polar, and their microenvironmental polarity parameter showed little dependence on the ionic properties of the micelles. The average microenvironmental polarity of 2-EA was similar to the polarity of 40% (w/w) aqueous ethanol, and that of 9-PA was similar to the polarity between 30 and 40% (w/w) aqueous ethanol. It was found that the greater part of these species might be distributed at the surface of micelles when they were solubilized in aqueous micellar solutions. The methanol-water mixture solution appeared to have characteristics more favorable for photooxidation reaction than aqueous micellar solutions.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.405-416
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• 1995

The testis and the epididymis of sexually mature male bats were examined to investigate the process of spermiogenesis of Korean long-fingered bat (Miniopterus schreifersi fulignosus) using electron microscope. The ultrastructural findings were analysed on the basis of Lee's method (1992). Especially, we focused on the acrosome formation. The results are as follows: The spermiogenesis of the Korean long-fingered bat can be divided into ten phases on the basis of ultrastructural differentiation; three "Golgi" phases of early, mid and late stages, two "cap" and two "acrosome" phases respectively composed of early and late phases, one "maturation phase and two "spermiation" phases of early and late phases. The axoneme of sperm in the cauda epididymis is composed of nine outer dense fiber and a central singlet. The number 1, 5, 6, and 9 outer dense fibers are larger than others. In the Golgi phases, small vesicles are separated from Golgi vesicles and then appear to fuse into a large vesicle, and finally it contacd with the outerside of the nucleus. It suggests that proacrosomal material could be made in the cytoplasm before the Golgi vesicle formation and then it could be transferred into the Golgi vesicle and condensed more and more, and finally form acrosome, just as Lee;s suggestion (1992).m acrosome, just as Lee;s suggestion (1992).

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.395-399
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• 1997

Meat model emulsions ware prepared with salt-soluble protein and soybean oil. Effects of water-soluble protein (WSP) on the meat model emulsion treated with/without BHT during 8 day storage $5^{\circ}C$ under both dark and light illumination were studied by measuring POV and TBA. An emulsion without BHA and WSP was used as a control. Under light storage, there was no significant difference in peroxide values between the control and the sample treated with BHA except the 2nd day of storage. However, TBA values of the sample treated with BHA were significantly (p<0.05) lower than those of control except the 4th day of storage. TBA and POV of the samples treated with WSP and WSP + BHA were higher than control after 4th day of storage under light. That is, water soluble protein, which was composed mainly of myoglobin, increased lipid oxidation under light storage. The similar trends were also shown in the samples stored under dark. These results suggested that acceleration of lipid oxidation of the meat model emulsions by water soluble protein (WSP) under both light and dark might not be due to the singlet oxygen formation, but due to superoxide anion formed.