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Research Trends of Foreign Countries on Geological Evaluation of Abiotic Hydrogen Productivity: A Review (비생물기원 수소 생산성의 지질학적 평가 관련 해외 연구 동향: 리뷰 논문)

  • Jeong, Seongwoo;Kim, Taeyong;Ko, Kyoungtae;Yang, Minjune
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.627-642
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    • 2022
  • The world's long reliance on fossil fuels (e.g., oil, coal, and natural gas) is severely changing its environment and climate. Energy research has focused on developing hydrogen as the most promising energy carrier and a key technology for sustainable energy development. Hydrogen can be classified as gray, blue, green, and otherwise according to the raw materials and methods used for production and processing. For the development of hydrogen energy, geologists are attempting to identify the mechanism of abiotic hydrogen generation by serpentinization or hydrothermal alteration. Teams in the United States, France, and Australia have researched laboratory-scale hydrogen production through water-rock interactions under various conditions, whereas there has been almost no research on abiotic hydrogen in South Korea. This paper reviews the current state of international research on hydrothermal alteration and offers suggestions for future investigations of abiotic hydrogen production in South Korea.

Suppressive Effects on Lipid Accumulation and Expression of Interleukin-1β-Mediated Inducible Nitric Oxide Synthase in 3T3-L1 Preadipocytes by a Standardized Commercial Noni Fruit Juice (Noni Fruit Juice의 3T3-L1 지방전구세포 분화 억제 및 인터루킨-1β 유도 Inducible Nitric Oxide Synthase 염증유전자 발현 감소 효과)

  • Byeong-Churl Jang
    • Journal of Korean Medicine for Obesity Research
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    • v.23 no.1
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    • pp.1-9
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    • 2023
  • Objectives: Noni fruit juice (NFJ) is liquor extracted from Morinda citrifolia (noni) fruit and has been used as an herbal remedy in many countries. However, the NFJ's anti-adipogenic and anti-inflammatory effects on adipocytes are poorly understood. The purpose of this study was to explore the commercially standardized NFJ effects on lipid accumulation throughout 3T3-L1 preadipocytes differentiation and interleukin-1β (IL-1β)-mediated inducible nitric oxide synthase (iNOS) expression in 3T3-L1 preadipocytes. Methods: Cellular lipid accumulation and triglyceride (TG) content in differentiating 3T3-L1 preadipocytes were assessed subsequently via the Oil Red O staining and AdipoRed assay. MTS assay was used to examine NFJ cytotoxicity in (differentiating) 3T3-L1 preadipocytes. Immunoblotting and reverse transcriptase polymerase chain reaction analysis were used to measure the expression levels of target protein and mRNA in (differentiating) 3T3-L1 preadipocytes, respectively. Results: NFJ treatment at 150 μL/mL led to a substantial reduction of fat accumulation and TG content during 3T3-L1 adipogenesis with no discernable impact on the cell viability. Of note, while NFJ treatment (150 μL/mL) largely inhibited the CCAAT/enhancer-binding protein-α (C/EBP-α) and peroxisome proliferator-activated receptor-β (PPAR-β) protein expressions, it did not influence PPAR-γ in differentiating 3T3-L1 preadipocytes. Of interest, treatment with IL-1β at 20 ng/mL for 4 hours elicited in firm induction of iNOS mRNA expression in 3T3-L1 preadipocytes. However, NFJ treatment at 100 or 200 μL/mL greatly attenuated the IL-1β-induced iNOS mRNA expression in 3T3-L1 preadipocytes. Conclusions: NFJ has anti-adipogenic and anti-inflammatory effects on (differentiating) 3T3-L1 preadipocytes which are in part intervened via control of the expression of C/EBP-α, PPAR-β, and iNOS.

The Community Structure of Macrozoobenthos and Its Spatial Distribution in the Subtidal Region off the Namhaedo Island, South Coast of Korea (남해도 주변 조하대 해역의 대형저서동물 분포)

  • LIM, HYUN-SIG;CHOI, JIN-WOO;CHOI, SANG-DUK
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.21 no.1
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    • pp.11-23
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    • 2016
  • An ecological study on subtidal macrobenthic fauna was conducted off the Namhaedo Island, south coast of Korea from July 2012 to April 2013. A total of 247 species of macrobenthos occurred with a mean density of $1,027ind./m^2$ and a mean biomass of $148.7g/m^2$. Polychaetes was the richest and most abundant faunal group that comprised 37% in both total species number and density whereas echinoderms were biomass-dominant faunal group that accounted for 44% of the mean biomass. There was a seasonal variation in the species richness and abundance of macrobenthos with more species in winter and higher density in spring. Mean faunal density was relatively high at the stations near Namhaedo Island, but gradually decreased toward offshore stations. The most dominant species in terms of density was an amphipod species, Eriopisella sechellensis which occurred as a top ranker during three seasons except spring recorded the fourth rank. E. sechellensis showed its high density at the near shore stations of Namhaedo Island, but this species did not occur around the entrance of Gwangyang and Saryang Bays where Theora fragilis and Lumbrineris longifolia showed high densities. In particular, Tharyx sp., recorded high density between Gwangyang Bay entrance and offshore after Sea Prince oil spill, did not occur in the same area during this study period. The bottom temperature and sorting value of the surface sediments were highly correlated to the spatial distribution of macrobenthic fauna from the Bio-Env analysis. From the cluster analysis, the study area has five station groups with more similar faunal affinities from inner area toward offshore area. Based on the SIMPER analysis T. fragilis, Magelona japonica, E. sechellensis, L. longifolia and Paraprionospio cordifolia were mainly contributed to the classification of station groups. From the BPI, benthic communities in the entrance of Gwangyang Bay and Saryang Bay were considered to be in a slightly polluted condition in contrast to the normal healthy community at the offshore of Namhaedo Island. These results suggested that the benthic community of this area should be regularly monitored to assess the health status of this benthic ecosystem.

Mycelial Culture of Lentinus edodes Alleviates Rat Liver Toxicity Induced by Carbon Tetrachloride and Ethanol (표고버섯균사체의 사염화탄소 및 알콜로 처리된 흰쥐 간기능 보호 효과)

  • Ha, Yeong-L.;Kim, Young-S.;Ahn, Chae-R.;Kweon, Jung-M.;Park, Cherl-W.;Ha, Young-K.;Kim, Jeong-O.
    • Journal of Life Science
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    • v.20 no.1
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    • pp.133-141
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    • 2010
  • The protective effect of a mixed powder from solid-cultured and liquid-cultured Lentinus edodes mycelia (2:1, w/w) (designate LED) on the carbon tetrachloride ($CCl_4$)- and ethanol-induced hepatotoxicity of male Sprague-Dawley (SD) rat was investigated. In the $CCl_4$-induced rat hepatotoxicity experiment, rats of 4 groups (6 rats/group) were administere with Normal (0.2 ml distilled water), Control (0.2 ml distilled water), LED (LED 200 mg/kg BW + 0.2 ml distilled water), and Silymarin (200 mg/kg BW + 0.2 ml distilled water), p.o., daily for 2 weeks. Afterwards, all groups except for the Normal group were subjected to abdominal injection with $CCl_4$ ($CCl_4$ : corn oil, 1:1 v/v; 0.5 ml/kg BW). For the ethanol- induced rat hepatotoxicity experiment, rats were divided into 5 groups (5 rats/group): Normal; Pair-fed control (PFC); Control (ethanol); LED (ethanol + LED 200 mg/kg BW); and Silymarin (ethanol + silymarin 200 mg/kg BW). Rats of the Normal and PFC groups were fed a basal liquid diet, and rats of the Control, LED, and Silymarin groups were fed a liquid ethanol diet containing LED or Silymarin. Eight weeks later, blood and liver samples were collected to analyze biomarkers. In $CCl_4$-induced SD rats, LED elevated hepatic superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH peroxidase) activities and thiobarbituric reactive substances (TBARS) were reduced, resulting in the reduction of glutamate-oxalate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and lactic dehydrogenase (LDH) activities in plasma. Similar results of these enzymes and biochemical markers in both liver tissues and plasma were seen in ethanol-induced hepatotoxicity of SD rats. In addition, elevated alcohol dehydrogenase (ADH) activity and reduced expression of cytochrome p450 mixed monooxygenase enzyme (CYP2E1) were seen in liver tissues from ethanol-treated rats by LED treatment. These effects of LED were similar to those of Silymarin. In in vitro experiments, LED showed antioxidant activity in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) system and mouse liver mitochondria system induced by NADPH/$Fe^{2+}$ and cumine hydroperoxide (CuOOH). These results indicate that LED protected SD rat hepatotoxicity, induced by $CCl_4$ and ethanol, through its antioxidative activity and might be useful as a material for protection from hepatoxicity in humans.

Effects of Fetal Calf Serum and Gonadotropins Supplemented to the Medium on Maturation and Fertilization In Vitro of Porcine Follicular Oociytes (성선(性腺)자극호르몬과 우태아혈청(牛胎兒血淸)첨가가 돼지난포란(卵胞卵)의 체외성숙(體外成熟) 및 체외수정(體外受精)에 미치는 영향)

  • Kim, Kyu Hyon;Jung, Bum Sik;Park, Soo Bong;Park, Hang Kyun
    • Current Research on Agriculture and Life Sciences
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    • v.8
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    • pp.45-50
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    • 1990
  • This study was carried out ot investigate the effects of fetal calf serum (FCS) and gonadotropins supplemented to the medium on maturation and fertilization in vitro of porcine follcular oocytes. Ovaries were obtained from gilts at local slaughter-house. Oocyte-cumulus complexes were recovered by puncturing the ovarian follicles(3~5 mm in diameter). The complexes from individual ovaries were pooled in a $0.4m{\ell}$ droplet of medium covered with paraffin oil, then washed twice in fresh droplet and cultured for 36hrs in culture media according to experimental conditions. Boar epididymal spermatozoa were capacitated by preincubation for 4hrs in m-KRB medium and the preincubated spermatozoa were insemenated in the fertilization medium containing the cultured oocytes. The results obtained in this study are summarized as follows: 1. The maturation rates of oocytes cultured in m-KRB and m-KRB supplemented to 10% FCS were 82 and 37%, respectively. When PMSG, hCG. and PMSGt hcG($10Iu/m{\ell}$) were added to the media supplemented to 10% FCS, the maturation rates were 66, 58 and 68%, respectively. 2. Expansion of cumulus cells was not occured in m-KRB and m-KRB supplemented to 10% FCS. However, when PMSG, hCG and PMSG+hCG($10Iu/m{\ell}$) were added to m-KRB supplemented to 10% FCS, the expansion rates of cumulus cell layers were 92, 13 and 91%, respectively. 3. When oocytes were mltured in m-KRB, the rates of penetration and formation of male pronucle: were 93 and 7%, respectively. By adding FCS and gonadotropin to m-KRB, the penetration and formation of male pronuclei were 100 80%, respectively.

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Effects of Soil Organic Matter Content on Activity Change, Vertical Migration, and Persistence of Two Nematicides, Carbofuran and Ethoprophos, to Root-Knot Nematode, Meloidogyne incognita (토양중 유기물함량 차이에 따른 고구마뿌리혹선충(Meloidigyne incognita)에 대한 Carbofuran과 Ethoprophos의 효력변동, 수직이동성 및 잔효성조사)

  • Song, Cheol;Hwang, In-Taek;Jang, Kyoung-Soo;Cho, Kwang-Yun
    • Korean journal of applied entomology
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    • v.38 no.1
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    • pp.47-52
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    • 1999
  • Effects of organic matter content in soil on activity. vertical migration. and persistence of two nernaticides. carbofuran and ethoprophos. to root-knot nematode, Mrloitlog!~iei ~lcognita.w ere investigated. As the organic matter content increased. activity of the nernaticides tended to be reduced. Both nematicides exhibited control values of more than 80'k' to M. iix.o,yilit~iln 0-2 cm depth soil layer from the surface. regi~rdless of organic matter content in soil. In 2-4 cm depth soil layer. however. the control value of the neniaticides varied with the organic niatter content in soil. The control value of carbofuran in the soil layer was ranged from I0 to 30'2,. depending on the soil organic niatter content. In contrast. ethoprophos had no control value against M. i/ic.o,ytlitcr in the \oil layer, except that the nematicide had a control value of 30% when the organic matter content was 0.4%. Furthermore. ethoprophos had no effect on controlling M. i/ic.o,gtiitrr in soil layer of below 4cm. whereas control values of carbofuran were approximately from 5 to 20% in all test soils having different organic matter contents. These results indicate that carbofuran has more vertical migration effect than ethoprophos. Persistence of the two neniaticides was also decreased with increasing soil organic matter content. Half life of carbofuran was 2-3 weeks in soil containing 0.4% organic matter, whereas it was found to be I week in soils containning 0.8 ant1 1.6% of organic matter. On the other hand. activity of ethoprophos was reduced to half in 3-3 weeks and in 2-3 weeks in soil containing 0.4 and 0.8%, and 1.6%) of organic matter, respectively. However, no activity of the both nernaticides was found in soil containing 3.2% of organic matter.

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Anti-obesity effect of EGCG and glucosamine-6-phosphate through decreased expression of genes related to adipogenesis and cell cycle arrest in 3T3-L1 adipocytes (Adipogenesis관련 유전자발현감소와 Cell Cycle Arrest를 통한 EGCG와 Glucosamine-6-Phosphate의 Anti-Obesity 효과)

  • Kim, Kkot Byeol;Jang, Seong hee
    • Journal of Nutrition and Health
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    • v.47 no.1
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    • pp.1-11
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    • 2014
  • Purpose: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. Methods: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expres-sion level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. Results: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG $60{\mu}M$ and PGlc $200{\mu}g/m$ compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. Conclusion: Combination treatment of EGCG and PGlc inhibited adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.

A Study on the Dietary Quality Assessment among the Elderly in Jeonju Area (전주지역 노인의 식사의 질 평가에 관한 연구)

  • 김인숙;유현희;서은숙;서은아;이형자
    • Journal of Nutrition and Health
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    • v.35 no.3
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    • pp.352-367
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    • 2002
  • In order to assess the quality of dietary intake among the elderly, a survey was conducted during Jucy-August, 1999, of 230 subjects who were 65 years or older and who were living in Jeonju City. Results of the analysis of the data are as follows : Regarding Dietery Variety Score (DVS), the average number of food items consumed per person was significantly higher for males (19.6) than for females (17.7). The intake of plant food was higher than animal food for both sexes the proportion of plant versus animal foods consumed by fresh weight was 85 : 15 for males and 89 : 11 for females. Diet Diversity Score (DDS) is determined by how many from five food groups (cereal, meat, dairy, vegetable and fruit) consumed per day while Korean Diet Diversity Score (KDDS) is determined by how many from five different food groups (cereal, meat, vegetable, dairy and oil) consumed per day. The subjects'average DDS and KDDS were 4.0 and 3.5 for males, and 3.7 and 3.2 for females, respectively. Overall, the distribution of DDS was lower than that of KDDS. The average Meal Balance Score (MBS : Apply the KDDS at breakfast, lunch and dinner) was 9.1 for malts and 8.1 for females. Average daily caloric intake for males and females was 1,740 kcal and 1,433 kcal, which was 84.0% and 80.9% of the RDA, respectively. Average daily protein intake for males and females, at 67 g and 49 g (100.7% and 88.3% of the RDA), respectively, was satisfactory. However, intakes of calcium and vitamin A were below 75% of the RDA (calcium : 62.7% for males and 55.3% for females ; vitamin A : 60.7% for males and 53.9% far females). The average proportional contribution of protein/fat/carbohydrate (PFC) to total calorie intake was 15.8 : 15.7 : 68.5 for males and 13.8 : 13.2 : 73.0 for females. Distribution of energy for each meal (breakfast : lunch : afternoon snack : dinner : night snack) was 29.2 : 32.4 : 5.0 : 31.2 : 2.2 among males and 30.5 : 33.5 : 4.5 : 28.6 : 2.91 among females. The Index of Nutritional Quality (INQ) was above 1 for protein, phosphorus, iron, vitamin B$_1$, niacin, and vitamin C. However, the INQ of calcium and vitamin A were below 1 among both males and females, and the INQ of vitamin B$_2$was below l among females. The Nutrient Adequacy Ratio (NAR = nutrient intake %RDA) was below 1 for all nutrients, and the NAR of vitamin A were the lowest among 9 nutrients (protein, calcium, phosphorus, iron, vitamin A, vitamin B$_1$, vitamin B$_2$, niacin, vitamin C) for both males and females, with values of 0.52 and 0.42, respectively. The second and third lowest NAR values were for calcium(males: 0.68: females: 0.54) and vitamin B$_2$(males: 0.77: females: 0.67). Values of Mean Adequacy Ratio (MAR = sum of 9 NARs/9) for males (0.82) were higher than for females (0.73). These results indicate that the intakes of calcium and vitamin A were severely inadequate. The results of a stepwise multiple regression analysis, where the DVS or MAR were the dependent variables and the DDS, KDDS, and MBS were independent variables, indicated that DDS is a more useful variable than KDDS in determining the quality of meals of the elderly.

The First North Korean Painting in the Collection of the National Museum of Korea: Myogilsang on Diamond Mountain by Seon-u Yeong (국립중앙박물관 소장 산률(山律) 선우영(鮮于英) 필(筆) <금강산 묘길상도>)

  • Yi, Song-mi
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.97
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    • pp.87-104
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    • 2020
  • Myogilsang on Diamond Mountain, signed and dated (2000) by Seon-u Yeong (1946-2009), is the first work by a North Korean artist to enter the collection of the National Museum of Korea (fig. 1a). The donor acquired the painting directly from the artist in Pyeongyang in 2006. In consequence, there are no issues with the painting's authenticity.This painting is the largest among all existing Korean paintings, whether contemporary or from the Joseon Dynasty, to depict this iconography (see chart 1. A Chronological List of Korean Myogilsang Paintings.) It is ink and color on paper, measures 130.2 × 56.2 centimeters, and is in a hanging scroll format. Since this essay is intended as a brief introduction of the painting and not in-depth research into it, I will simply examine the following four areas: 1. Seon-u Yeong's background; 2. The location and the traditional appellation of the rock-cut image known as Myogilsang; 3. The iconography of the image; and 4) A comparative analysis of Seon-u Yeong's painting in light of other paintings on the same theme. Finally, I will present two more of his works to broaden the understanding of Seon-u Yeong as a painter. 1. Seon-u Yeong: According to the donor, who met Seon-u at his workshop in the Cheollima Jejakso (Flying Horse Workshop) three years before the artist's death, he was an individual of few words but displayed a firm commitment to art. His preference for subjects such as Korean landscapes rather than motifs of socialist realism such as revolutionary leaders is demonstrated by the fact that, relative to his North Korean contemporaries, he seems to have produced more paintings of the former. In recent years, Seon-u Yeong has been well publicized in Korea through three special exhibitions (2012 through 2019). He graduated from Pyeongyang College of Fine Arts in 1969 and joined the Central Fine Arts Production Workshop focusing on oil painting. In 1973 he entered the Joseon Painting Production Workshop and began creating traditional Korean paintings in ink and color. His paintings are characterized by intense colors and fine details. The fact that his mother was an accomplished embroidery specialist may have influenced on Seon-u's choice to use intense colors in his paintings. By 1992, he had become a painter representing the Democratic People's Republic of Korea with several titles such as Artist of Merit, People's Artist, and more. About 60 of his paintings have been designated as National Treasures of the DPRK. 2. The Myogilsang rock-cut image is located in the Manpok-dong Valley in the inner Geumgangsan Mountain area. It is a high-relief image about 15 meters tall cut into a niche under 40 meters of a rock cliff. It is the largest of all the rock-cut images of the Goryeo period. This image is often known as "Mahayeon Myogilsang," Mahayeon (Mahayana) being the name of a small temple deep in the Manpokdong Valley (See fig. 3a & 3b). On the right side of the image, there is an intaglio inscription of three Chinese characters by the famous scholar-official and calligrapher Yun Sa-guk (1728-1709) reading "妙吉祥"myogilsang (fig. 4a, 4b). 3. The iconography: "Myogilsang" is another name for the Bhodhisattva Mañjuśrī. The Chinese pronunciation of Myogilsang is "miaojixiang," which is similar in pronunciation to Mañjuśrī. Therefore, we can suggest a 妙吉祥 ↔ Mañjuśrī formula for the translation and transliteration of the term. Even though the image was given a traditional name, the mudra presented by the two hands in the image calls for a closer examination. They show the making of a circle by joining the thumb with the ring finger (fig. 6). If the left land pointed downward, this mudra would conventionally be considered "lower class: lower life," one of the nine mudras of the Amitabha. However, in this image the left hand is placed across its abdomen at an almost 90-degree angle to the right hand (fig. 6). This can be interpreted as a combination of the "fear not" and the "preaching" mudras (see note 10, D. Saunders). I was also advised by the noted Buddhist art specialist Professor Kim Jeong-heui (of Won'gwang University) to presume that this is the "preaching" mudra. Therefore, I have tentatively concluded that this Myogilsang is an image of the Shakyamuni offering the preaching mudra. There is no such combination of hand gestures in any other Goryeo-period images. The closest I could identify is the Beopjusa Rock-cut Buddha (fig. 7) from around the same time. 4. Comparative analysis: As seen in , except for the two contemporary paintings, all others on this chart are in ink or ink and light color. Also, none of them included the fact that the image is under a 40-meter cliff. In addition, the Joseon-period paintings all depicted the rock-cut image as if it were a human figure, using soft brushstrokes and rounded forms. None of these paintings accurately rendered the mudra from the image as did Seon-u. Only his painting depicts the natural setting of the image under the cliff along with a realistic rendering of the image. However, by painting the tall cliff in dark green and by eliminating elements on either side of the rock-cut image, the artist was able to create an almost surreal atmosphere surrounding the image. Herein lies the uniqueness of Seon-u Yeong's version. The left side of Seon-u's 2007 work Mount Geumgang (fig. 8) lives up to his reputation as a painter who depicts forms (rocks in this case) in minute detail, but in the right half of the composition it also shows his skill at presenting a sense of space. In contrast, Wave (fig. 9), a work completed one year before his death, displays his faithfulness to the traditions of ink painting. Even based on only three paintings by Seon-u Yeong, it seems possible to assess his versatility in both traditional ink and color mediums.

Effect of Riboflavin Tetrabutylate on the Activity of Drug Metabolizing Enzyme and Lipid Peroxidation in Liver Microsomes of Rats (Riboflavin Tetrabutylate가 약물대사 효소 및 지질 과산화효소에 미치는 영향)

  • Lee, H.W.;Kim, W.J.;Hong, S.S.;Kwack, C.Y.;Hong, S.U.
    • The Korean Journal of Pharmacology
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    • v.16 no.2 s.27
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    • pp.45-53
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    • 1980
  • Lipid peroxidation in vitro has been identified as a basic deteriorative reaction in cellular mechanism of aging processes, such as air pollution oxidant damage to cell and to the lung, chlorinated hydrocarbon hepatotoxicity. Many experimental evidences were reported by several investigators that lipid peroxidation could be one of the principle causes for the hepatotoxicity produced by $CCl_4$. It is now reasonably established that $CCl_4$ is activated to a free radical in vivo, that lipid peroxidation occurs very quickly in microsomes prepared from damaged livers, that the peroxidation is associated with loss of enzyme activity of microsomes, and that various antioxidants can protect animals against the hepatotoxic effect of $CCl_4$. Recent studies have drawn attention to some other feature of microsomal lipid peroxidation. Incubation of liver microsomes in the presence of NADPH has led to a loss of cytochrome $P_{450}$. However, the presence of an antioxidant prevented lipid peroxidation and preserved cytochrome $P_{450}$. Decrease of cytochrome $P_{450}$ in microsomes under in vitro incubation can be enhanced by $CCl_4 and these changes were parallel to a loss of microsomal polyunsaturated fatty acid and formation of malonaldehyde. The primary purpose of this experiment was to study the effect of riboflavin tetrabutylate on lipid peroxidation, specially, the relationship between lipid peroxidation and drug metabolizing enzyme system which is located in smooth endoplasmic recticulum as well as the effect of ritoflavin tetrabutylate on drug metabolizing enzyme system of animal treated with $CCl_4$. Albino rats were used for experimental animal. In order to induce drug metabolizing enzyme system, phenobarbital was injected intraperitoneally. $CCl_$ and riboflavin tetrabutylate were given intraperitoneally as solution in olive oil. Microsomal fraction was isolated from liver of animals and TBA value as well as the activity of drug metabolizing enzyme were measured in the microsomal fractions. The results are summerized as following. 1) The secobarbital induced sleeping time of $CCl_4$ treated rat was about 2 times longer than that of the control group. However, the pretreatment with riboflavin tetrabutylate inhibited completely the lengthened sleeping time due to $CCl_4$ treatment. Furthermore TBA value was significantly increased in $CCl_4$ treated rat in comparison to control group tut the increase of TBA value was prevented by the pretreatment with riboflavin tetrabutylate. On the other hand, the activity of hepatic drug metabolizing enzyme was decreased in $CCl_4$ group, however, the pretreatment with riboflavin tetrabutylate also prevented the decrease of the enzyme activity caused by $CCl_4$. 2) The effect of riboflavin tetrabutylate on TBA value and the activity of drug metabolizing enzyme in vitro was similar to in vivo results. Incubation of liver microsome from rat in the presence of $CCl_4$, $Fe^{++}$, or ascorbic acid has led to the marked increase of TBA value, however, the addition of riboflavin tetrabutylate in incubation mixture prevented significantly the increase of TBA value, suggesting the inhibition of lipid peroxidation. In accordance with TBA value, the activity of drug metabolizing enzyme was inhibited in the presence of $CCl_4$, $Fe^{++}$, ascorbic acid but the addition of riboflavin tetrabutylate protected the loss of the enzyme activity in microsome under in vitro incubation.

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