• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.638-639
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• 2000

Quinone reductase was purified to electrophoretic homogeneity from bovine liver by using ammonium sulfate fractionation, ion-exchange chromatography, and gel filtration chromatography. The enzyme utilized either NADH or NADPH as the electron donor. The optimum pH of the enzyme was pH 8.5, and the activity of the enzyme was greatly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, dicumarol and cibacron blue 3GA. The enzyme catalyzed the reduction of several quinones and other artificial electron acceptors. Furthermore, the enzyme catalyzed NAD(P)H-dependent reduction of azobenzene or 4-nitroso-N,N-dimethylaniline. The apparent $K_m$ for 1,4-benzoquinone, azobenzene, and 4-nitroso-N,N-dimethylaniline was 1.64mM, 0.524mM and 0.225mM, respectively. The reduction of azobenzene or 4-nitroso-N,N-dimethylaniline by quinone reductase was strongly inhibited by dicumarol or cibacron blue 3GA, potent inhibitors of quinone reductase.

• 대한약리학회지
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• 제16권2호
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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.

• 한국식품위생안전성학회지
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• 제9권3호
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• pp.105-109
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• 1994

Lysosomal enzymes might play a most important role in the pathogenesis od diabetic microangiopathy. Some glycosidases, which participate in the catabolism of glycoprotein, are significantly decreased in diabetic mice. In search of new potential lysosomal enzyme inducers, we examined the effects of crude red-ginseng saponin fraction on N-acetyl-$\beta$-D-glucosaminidase, $\beta$-D-galactosidase and $\alpha$-D-mannosidase activities in the liver and kidney of normal and streptozotocin induced diabetic mice. It was found that i.p. administration of ginseng saponin produced the induction of lysosomal enzymes in the kidney more intensively than in the liver. The obtained results suggest the possibility that ginseng saponin might prevent the diabetic microangiopathy.

• Environmental Analysis Health and Toxicology
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• 제7권1_2호
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• pp.45-51
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• 1992

This study was performed to investigate the effect of Angelicae gigantis Radix extract oil the hepatic detoxifying enzyme activities and lipids. Male sprague-dawley rats were administrated the extracts with benzo(a)pyrene, a hepatotoxic agent, inducing liver damages. Results obtained from this study were as follows: 1. The markedly increased enzyme activities (AST, ALT, LDH, ALP, ${\gamma}$-GTP, GSH-Px) in B(a)P induced groups tended to be decreased by the treatment of the Angelicae gigantis Radix extract. 2. Liver GSH content and lipid peroxide activity were decreased by the administration of the extracts. 3. It tended that the curative effects were better than the protective effects of the extracts.

• 대한본초학회지
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• 제21권2호
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• pp.55-62
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• 2006

Objectives : This study was carried out to investigate the biological activities of methanol extracts of fermented Camellia japonica leaf and flower. Methods : Methanol extracts of fermented Camellia japonica leaf and flower were prepared and a dose of 100 and 400mg/kg/day was administered orally into mice. And after appropriate weeks, changes of serum enzyme activities were investigated to confirm its effects on serum glucose, cholesterol and short term administration safety. Results : Fermented flower extract showed significant decrease of serum level of cholesterol. And showed no toxicity on kidney and liver within the dose of 400mg/kg/day. Conclusion : Thus above result showed no toxicity on kidney and liver in male and female mice.

• Toxicological Research
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• 제13권3호
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• pp.183-186
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• 1997

Acute toxicity of pectenotoxin 2 (PTX2) was examined in mice. Treatment of mice with a toxic dose of PTX2 resulted in clinical signs such as ataxia, cyanosis and an abrupt decrease in body temperature. Histopathological studies revealed that the liver is the major target organ for PTX2. Activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) were significantly elevated by PTX2 administration. Glucose-6-phosphatase activities were not changed by the treatment. The PTX2 treatment decreased relative liver weight without changing the body weight. The effect of PTX2 on hepatic drug metabolizing enzyme system was determined. An ip dose of PTX2 (200 $\mu$g/kg) induced a significant decrease in the hepatic microsomal protein content. Cytochrome P-450 content, cytochrome b$_5$ content, NADPH cytochrome c reductase, aminopyrine N-demethylase activities, or hepatic glutathione content were not altered by PTX2 treatment.

• 생명과학회지
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• 제6권3호
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• pp.159-164
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• 1996

Effects of 1% dietary orotic acid on triglyceride metabolism were examined in SD-rats and Kud: ddY mice. When rats were fed semisynthetic diet containing 1% orotic acid and n-6 polyunsaturated fatty acid (linoleic acid), the hepared diet. In contrast to rats which respond to orotic acid consumption with increases in hepatic triglyceride content, mice did not so respond. The rats-limiting step in triglyceride synthesis is catalyzed by the enzyme phosphatic acid phosphohydrolase (EC3.1.3.4) which is present in the liver cytosol and microsomes of rats fed oroic acid diet. This finding suggests that the activity of this enzyme may play a tole in the fatty liver formation in rats.

• 한국식품영양과학회지
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• 제27권5호
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• pp.968-972
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• 1998

Allium tuberosum Rotter(Liliaceae) is a perennial herb of which leaves are used for food. Leek has been reported to have pharmacological effects including alleviations of abdominal pain, diarrhea, hematemesis, snakebite, and asthma. To investigate the effect of dietary leek supplementation on the drug-metaboizing enzymes, quinone reductase(QR) and arylhydrocarbon hydroxylase(AHH) activities in the liver, stomach, small intestine and lung, and on the plasma testosterone and dihydrosterone hormone levels, mice were fed 2% and 5% leek diets for 8 weeks. Quinone reductase, an anticarcinogenic enzyme, was significantly induced in stomach, small intestine, and lung but slightly lowered in hepatic tissue in the experimental groups compared to control group. Arylhydrocarbon hydroxylase activity, involved in bioactivation of procarcinogens, was significantly decreased in liver and lung. Leek feeding led to the reduction in the plasma level of dihydrotestosterone which is associated with the incidence of prostate cancer. These findings support the potential chemopreventive activity of leek supplementation.

• Journal of Ginseng Research
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• 제27권1호
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• pp.1-10
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• 2003

In present study, we examined whether or not the pretreatment of Korean Red Ginseng (KRG) could protect hepatotoxicity induced by carbon tetrachloride (CCl$_4$) and D-galatosamine (GalN). For this study, we not only tested activity of various plasma enzymes (AST, ALT, SDH, LDH), which are used as indicators of liver disease, but also checked the change of liver components such as lipid, glutathione and cytochromes content, and several liver enzyme activity. Pretreatment of KRG for two weeks significantly reduced the elevated plasma enzyme activities induced by CCl$_4$ and GalN. Pretreatment of KRG also restored the hepatic enzymes, malonedialdehyde formation, and depletion of reduced glutathione content induced by CCl$_4$ and GalN to near normal level. However, ${\gamma}$-glutamylcysteine synthetase activity was lot affected by KRG. These results suggest that KRG shows the hepatoprotective effect by reducing lipid peroxidation, by reducing the activity of free radical generating enzymes, and by preserving the hepatic glutathione.

• Toxicological Research
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• 제11권1호
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• pp.23-29
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• 1995

Microsomes from human liver sample HL 110 oxidized aflatoxin $B_1$ $(AFB_1)$ to $AFB_1$ exo-8, 9-epoxide which was detected as a glutathione (GSH) conjugate with excess GSH S-transferase and to aflatoxin $Q_1$ ($AFB_1$; 3$\alpha$-hydroxyafiatoxin $B_1$), and testosterone to 6$\beta$-hydroxytestosterone. Anti-P450 3A4 nearly completely inhibited all of the reactions. Some fiavonoids inhibited all of the reactions. While other fiayonolds stimulated 8, 9-epoxidation and inhibited 3$\alpha$-hydroxylation. Gestodene inhibited all of the reactions when gestodene was metabolized by human liver microsomal P450 3A4 prior to adding substrate. But, ges-todene was added in the enzyme mixtures in the presence of $AFB_1$, it could not inhibit 8, 9-epoxidation of $AFB_1$. Nifedipine and troleandomycin inhibited both of the reactions of $AFB_1$ but only 3$\alpha$-hydroxylation was inhibited by the oxidation product of nifedipine. Although, troleandomycin was known as a mechanism-based inhibitor, the chemical did not show any detectable inhibitory effect on 6$\beta$-hydroxylation of testosterone. The results suggest that there are several different substrate-binding sites on P450 3A4.