• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.203-208
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• 1991

The present study was undertaken in order to elucidate the effects of pretreatment with nicotinamide on changes in the hepatic metabolizing enzyme system inducted by streptozotocin (STZ). In rats, STZ(50mg/kg) administered by tail vein caused a significant rise in hepatic aniline hydroxylase and a decrease in aminopyrine N-demethylase when compared to control (p<0.05). Pretreatment with nicotinamice inhibited these effects (p<0.05). Similarly, STZ induced changes in hepatic microsomal cytochrome P-450 activity were inhibited by pretreatment with nicotinamide (p<0.05). However, changes in UDP-glucuronyl transferase and sulfortransferase activity were not significantly different(p>0.05). Pretreatment with nicotinamide also prevented STZ induced increases in glutathion S-tranferase activity when compared to the control(p<0.05). There results suggest that nicotinamide pretreatment suppresses STZ-induced changes in the hepatic metabolizing enzyme system.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.121-128
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• 1993

This study was intended to clarify the protective mechanism of diallyl disulfide on the carbon tetrachloride-induced hepatotoxicity in mice. It was observed that a powerfully increment of serum alanine aminotransferase activity and hepatic lipid peroxide content after carbon tetrachloride injection were markedly inhibited by the pretreatment of diallyl disulfide (20mg/kg) for 5 days. It was also observed that hepatic aminopyrine demethylase and xanthine ocidase as free radical generating enzymes as well as superoxide dismutase and catalase activities as free frdical scavenging enzymes and hepatic glutathione content were not changed by the pretreatment with diallyl disulfide. But, treatment with diallyl disulfide did signifiantly increase cytosolic glutathione S-transferase activity. However, glutathione S-transferase activity in the presence of diallyl disulfide was not affected in vitro. Therefore, it is concluded that mechanism for the observed preventive effect ofdiallyl disulfide against the carbon tetrachloride-induced hepatotoxicity can be due to the engancement of glutathione S-transferase activity.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.196-200
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• 1989

The methanolic extract of the Rhizome of Curcuma zedoaria exhibited a significant prolongation of hexobarbital (HB)-induced hypnosis. Through liquid chromatography of an ether soluble fraction. monitoring by bioassay, three sequiterpenes, germacrone (A), curzerenone (B) and germacrone epoxide (C) were isolated as active consituents. A single treatment (100-200 mg/kg, i.p.) of each compound showed not only a significant prolongation of HB-induced sleeping time but also a significant inhibition of aminopyrine N-demethylase activity in mice, and further exhibited a typical type I binding spectra with oxidized rat hepatic cytochrome P-450 induced by phenobarbital. All of the compounds provoked a sleep episode at a subhypnotic dose of HB, implying that they possess CNS depressant properties.

• Natural Product Sciences
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• v.8 no.1
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• pp.18-22
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• 2002

Inhibitory effects of the essential oils obtained from ten herbs were tested on acetaminophen-induced lipid peroxidation in the rat. The oil of Artemisia princeps var. orientalis buds (AP-oil) showed the most significant hepatic malondialdehyde value which was comparable to those of ascorbic acid and methionine. This was warranted by the protective effect on hepatic glutathione depletion. Overview of the data on the activities of hepatic microsomal enzymes, aminopyrine N-demethylase and aniline hydroxylase led to the notice that the suppressed activities of those enzymes are mainly responsible for the anti-lipid peroxidation. The interpretation of GC-MS data on the AP-oil revealed the ingredient of cineol, thujone, carvone, borneol, camphor and terpineol.

• Toxicological Research
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• v.13 no.3
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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.

• The Korean Journal of Pharmacology
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• v.18 no.1
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• pp.65-72
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• 1982

It has been known that retinoids are intrinsically of critical importance for control of premalignant epithelial cell differentiation. In the absence of retinoids, normal cellular differentiation and growth does not occur in epithelia such as those of trachea and bronchi. Furthermore, it was also reported that retinoid deficiency enhanced susceptibility to chemical carcinogenesis in the respiratory system, in the bladder, and in the colon of the experimental animal. In 1974, Bollag examined the effects of synthetic retinoids in prevention of development of cancer and demonstrated synthetic retinoids to have more favorable therapeutic index than retinoic acid for causing regression of skin papilloma in mice. Therefore, it was assumed that this anticarcinogenic effect of vitamin A derivatives could be due to modification of the metabolism of the carcinogenic polycyclic hydrocarbon, which must first be activated to exert their effect. Hill and Shih reported that vitamin A compounds and analogs had inhibitory effect on drug metabolizing enzyme from liver and lung tissue of mouse and hamster. Lucy suggested that the chemoprevention effect of vitamin A derivatives is due to reaction with molecular oxygen, and it is possible that inhibition of hydroxybenzpyrene formation is a result of this property. On the other hand, butylated hydroxytoluene which is a potent antioxidant strongly inhibited the formation of mammary tumor induced by dimethylbenranthracene. Also, it was observed that this antioxidant inhibited cancer induction in rats by N-2-fluo-renylacetamide. The purpose of this experiment was to investigate the effect of vitamin A derivatives such as retinoic acid and retinoid on drug-metabolizing enzyme and to determine whether riboflavin tetrabutylate or vitamin E could prevent of modify any changes induced by vitamin A delivatives in the rats. The results obtained were as followings. 1) Body weight was significantly reduced by retinoic acid, but not by retinoid. 2) Retinoic acid markedly increased liver weight while retincid showed no effect on liver weight. Treatment of riboflavin tetrabutylate did not affect retinoic acid-induced change in both body weight and liver weight. 3) Both retinoic acid and retinoid remarkably decreased the activity of aminopyrine demethylase. Pretreatment of riboflavin tetrabutylate, however, prevented inhibitory effect of retinoic acid on the enzyme activity. 4) No significant effect of vitamin E on aminopyrine demethylase was observed in both groups treated with retinoic acid and retinoid.

• Journal of Life Science
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• v.18 no.1
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• pp.129-135
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• 2008

Paraquat (1,1-dimethyl 4,4' -dipyridium dichloride; PQ) is a kind of herbicide. Terminalia chebulae (TC) has been used as a medicine in China and in Korea for treating illnesses such as diarrhea, collapsed anus, spasmodic, diphtheria, asthma etc.. This study was to examin new physiological activities of methanol extract of TC (TCM) on the toxicity of PQ. It was observed biochemical effects on the toxicity of PQ in kidney and lung tissues after treatment orally administered 100, 200, 300 mg/kg of TCM daily for two weeks. In the experiment related to the toxicity of PQ, we got following results: renal and pulmonary lipid peroxide contents, activities of aminopyrine N-demethylase, aldehyde oxidase and xanthine oxidase were significantly increased in control group as compared with normal group, in the treatment of TCM the values were decreased as compared with control group. Activities of superoxide dismutase, catalase and glutathione peroxidase which are free radical scavenging enzymes were also increased in control group as compared with normal goup, but were decreased in TCM group as compared with control group. Collagen content and glucose-6-phosphatase activity in lung tissue were increased in control group as compared with normal, but was decreased in TCM group as compared with control group. From these results, we concluded that TCM can playa role as an effective agent to decrease toxicity of PQ.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.304-310
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• 1995

This study was done to investigate the effect of vitamin C on hepatic biliary and microsomal function during ischemia and reperfusion. Rats were treated with vitamin C(20, 100, 400, 1600 mg/kg) or with vehicle(saline) and then subjected to 60 min no-flow hepatic ischemia in vivo. Control animals were time-matched sham ischemic animals. After 1 or 5 hr of reperfusion, bile was collected, blood was obtained from the abdominal aorta, and liver microsomes were isolated. In vehicle-treated ischemic rats, serum ALT and AST levels peaked at 5 hr and were significantly attenuated by vitamin C 20 mg/kg and 100 mg/kg treatment. Similarly, hepatic wet weight-to-dry weight ratio was decreased in the vehicle-treated ischemic group. Vitamin C 20 mg/kg and 100 mg/kg treatment minimized the increase in this ratio. Lipid peroxidation was elevated in vehicle-treated ischemic group, but this elevation was also inhibited by vitamin C 20 mg/kg and 100 mg/kg treatment. Bile flow and cholate output, but not bilirubin output, were markedly decreased by ischemia/reperfuzion. Vitamin C 20 mg/kg and 100mg/kg treatment restored the secretion but vitamin C 1600 mg/kg reduced the cholate output. Cytochrome P-450 content was decreased by ischemia/reperfusion and restored by vitamin C 20 mg/kg and 100 mg/kg treatment to the level of sham operated group but decreased by vitamin C 1600 mg/kg. Aminopyrine N-demethylase activity was decreased and aniline p-hydroxylase activity was increased by ischemia/reperfusion. The changes in the activities of aminopyrine were prevented by vitamin C 20 mg/kg and 100 mg/kg treatment, but not by 400 mg/kg and 1600 mg/kg treatment. Our findings suggest that ischemia/reperfusion diminishes hepatic secretory functions as well as microsomal drug metabolizing systems, small doses(20, 100 mg/kg) of vitamin C significantly ameliorates and large doses(400, 1600 mg/kg) of vitamin C aggravated these ischemia/reperfusion-induced changes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.702-708
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• 1993

The study was attempted to elucidate the mechanism of GE-132(100mg/kg, p.o. for 6 weeks) on the metabolism of bromobenzene (460mg/kg, i.p. bid, for 2 days), which has potent carcinogenicity, mutagenicity and hepatotoxicity. It showed that activities of cytochrome p-450, aminopyrine demethylase and aniline hydroxylase, which have epoxide generating property, were not changed by GE-132 treatment. On the other hand, epoxide hydrolase was not changed but that glutathione S-transferase was significantly increased by GE-132 treatment. And also ${\gamma}-glutamylcysteine$ synthetase was not changed following the GE-132 treatment, but the activity of glutathione reductase was significantly increased. The level of hepatic glutathione which was decreased by bromobenzene recovered markedly by GE-132 pretreatment. It is concluded that the mechanism for the observed effect of GE-132 on bromobenzene metabolism is due to the induction of glutathione S-transferase.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.261-269
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• 1998

Concomitant administration of a single acute dose of ethanol (4 g/kg) protected mice from the hepatocellular injury observed upon administration of a large dose of acetaminophen (400 mg/kg). This was evidenced by the normal histological appearances of liver sections and by the lowered serum aminotransferase activities in mice treated with ethanol and acetaminophen together. In the mice treated with acetaminophen alone, along with the hepatic necrosis, the hepatic microsomal aminopyrine N-demethylase activity was decreased. However, co-administration of ethanol prevented this acetaminophen dependent inhibition on the microsomal mixed function oxidase activity. Pharmacokinetic studies indicated that the concentration of un-metabolized drug in the blood was increased in the ethanol treated mice. Furthermore, upon co-administration of ethanol, although the biliary levels of acetaminophen metabolites (glucuronide, sulfate and cysteine conjugates) were decreased, the level of unmetabolized acetaminophen was increased. Our findings suggest that co-administration of an acute dose of ethanol reduces the degree of hepatocellular necrosis produced by a large dose of acetaminophen and this ethanol dependent protection is, in major part, afforded by suppression of the hepatic microsomal mixed function oxidase activity catalyzing the metabolic activation of acetaminophen.