• The Korean Journal of Physiology and Pharmacology
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• 제1권2호
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• pp.221-224
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• 1997

Effects of melatonin on hepatic glutathione-peroxidase (GSH-Px) and glutathione-reductase (GSH-reductase) activities were studied in Sprague-Dawley (SD) rats administered i.p. (10 mg/kg body weight) with melatonin during 15 days. The activity of cytosolic GSH-reductase in the liver was not changed by melatonin. However, melatonin injection increased significantly the activity of liver cytosolic GSH-Px activity compared with those in saline-treated rats. At the same time, plasma GSH-Px was also increased significantly in melatonin-treated rats. Since GSH-Px, a major antioxidative enzyme, removes $H_2O_2$ and lipid peroxides which are formed during lipid peroxidation from cellular membrane, such elevation of heptatic GSH-Px activity may contribute to the improvement of antioxidative effects under oxidative damage in the liver.

• Journal of Ginseng Research
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• 제13권1호
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• pp.5-7
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• 1989

The objective of this study was to investigate the preventive effect of ginseng on acetaldehyde-induced acute toxicity in mice . Compared to the control group, treatment with acetaldehyde inhibited the hepatic cytosolic xanthine oxidise activity with increase in dose. The inhibition of enzyme activity was not changed after dialysis. Pretreatment with ginseng butanol fraction prevented the inhibition of enzyme activity by acetaldehyde. In conjunction with the our previous results (Yakhak Hoeji, 29, 18 (1985)), these results suggest that the most likely mechanism for the observed preventive effects of ginseng against the acetaldehyde-induced acute toxicity may be the decrease hepatic acetaldehyde level.

• BMB Reports
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• 제32권1호
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• pp.67-71
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• 1999

We have investigated the effect of cholestasis on the closely related acyl-CoA:amino acid N-acyltransferase, benzoyltransferase, and phenylacetyltransferase activities in rat liver. Benzoyltransferase and phenylacetyltransferase activities in the liver cytosol, mitochondria, and microsome were investigated for a period of 42 d after common bile duct ligation. Both the mitochondrial and microsomal benzoyltransferases showed significant increase in their activities between the 1st and 7th day after common bile duct ligation, although the cytosolic benzoyltransferase activity did not show a significant change compared to the activities from the sham-operated control. The cytosolic phenylacetyltransferase activity showed a significant increase between the 1st and 2nd day, the mitochondrial activity showed a significant increase between the 2nd and 7th day, and microsomal activity showed a significant increase between the 1st and 7th day, respectively. Enzyme kinetic parameters of hepatic benzoyltransferase were analyzed using benzoyl coenzyme A as a substrate with the preparations from the 1st day post-ligation. Enzyme parameters of hepatic phenylacetyltransferase were also analyzed using phenylacetyl coenzyme A as a substrate with the preparations from the 2nd day post-ligation. The results indicated that although the $K_m$ values of these enzymes were about the same as the sham-operated control, the $V_{max}$ values of both enzymes increased significantly. These results, therefore, suggest that the biosynthesis of benzoyltransferase and phenylacetyltransferase has been induced in response to cholestasis.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1189-1196
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• 1998

The antiatherogenic effect of kimchi ingredients was studied in terms of antioxidative effect against Newzealand white rabbits that fed 1% cholesterol. Experimental groups was fed 8% Baechu (Brassica pekiinensis), or 1% red pepper(Capsium annum), or 1% garlic(Allium sativum) for 12 weeks. Blood samples were drawn every 2 weeks to analyze vitamin E, POV, and TBARS. Hepatic antioxidative enzyme activity, vitamin E, and carotene concentration also were measured. Plasma TBARS and POV level were markedly lowered in both red pepper and garlic fed rabbits(p<0.05) compared to control. Hepatic POV and protein carbonyl values were lowered in the rabbits fed kimchi ingredients compared to control(p<0.05). Plasma vitamin E concentration was increased in the rabbits fed red pepper and garlic compared to control(p<0.05). Hepatic vitamin E concentration was increased in red pepper and garlicfed rabbits compared to control. For the hepatic antioxidative enzyme acitivity, catalase activity was significantly increased in red pepper and garlic fed rabbits compared to control. Therefore, Baechu, red pepper, and garlic exert an antioxidative effect against rabbits fed 1% cholesterol for 3 months.

• Nutritional Sciences
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• 제9권4호
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• pp.259-266
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• 2006

The current study examined the effect of quercetin supplements on the lipid-lowering and antioxidant metabolism in ethanol-fed rats. The control $group(E_8)$ received ethanol only diet for 8 wks, whereas the other group$(E_8Q_4)$ received a diet including quercetin supplementation(0.05% wt/wt) for 4 wks while on the ethanol diet for 8wks. The hepatic alcohol dehydrogenase activity was significantly higher in the $E_8Q_4$ group than in the $E_8$ group. Supplementation with quercetin significantly elevated the HDL- cholesterol concentration, the HDL-C/total-C ratio, and lowered the atherogenic index(AI) compared to the $E_8$ group. The hepatic triglyceride and cholesterol contents were significantly lowered by the quercetin supplement compared to those of the control group. The hepatic HMG-CoA reductase and ACAT activities of the $E_8Q_4$ group were significantly lower than those of the $E_8$ group. The overall potential for antioxidant defense was significantly enhanced by the quercetin supplement, as indicated by a decrease in plasma and hepatic TBARS levels. The hepatic GSH-Px and G6PD activities were significantly higher in the $E_8Q_4$ group compared to the $E_8$ group. The current results suggest that dietary quercetin leads to the inhibition of HMG-CoA reductase and ACAT, which in turn lowers cholesterol levels and normalizes antioxidant enzyme activities.

• BMB Reports
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• 제32권4호
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• pp.331-338
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• 1999

Ethanol catabolism is thought to produce metabolic disorders resulting in alcoholic liver disease. To investigate the mutual effects of ethanol catabolism and cholestasis induced by common bile duct ligation on the activities of carboxylesterase, we have determined the enzyme activities in rat hepatic (cytosolic, mitochondrial, and microsomal) preparations as well as in rat serum using ten animal models: normal rats (group 1), sham-operated rats (group 2), common bile duct-ligated rats (group 3), ethanol-intoxicated rats (group 4), sham-operation plus chronic ethanol-intoxicated rats (group 5), common bile duct-ligated plus chronic ethanol-intoxicated rats at 1.5h and 24h (groups 7A and 7B), and duct-ligated and acute ethanol intoxicated rats at 1.5 h and 24 h (groups 8A and 8B). The $K_m$ and $V_{max}$ values of carboxylesterase from these hepatic preparations of cholestatic rat liver combined with chronic ethanol intoxication were also measured by using ethyl valerate as the substrate from the 14th day post-ligation. Carboxylesterase activities of all hepatic preparations and rat serum (group 3) showed significant decreases compared to the activities from the sham-operated control (group 2). Enzyme kinetic parameters indicated that $V_{max}$ of carboxylesterase from all the hepatic preparations in cholestatic rats (group 3) decreased significantly, although the $K_m$ values were about the same as in the sham-operated control (group 2). When cholestasis was combined with chronic ethanol intoxication (group 6), carboxylesterase activities showed further decrease in all the hepatic preparations and serum compared to the control activity (group 5). The $V_{max}$ also decreased significantly, although $K_m$ values did not change. When common bile duct ligation was combined with acute ethanol intoxication (group 8), the enzyme activities in the rat liver and serum showed significant decrease compared to the activity from acute ethanol-intoxicated rats (group 7). However, quite contrary to this, the activities of serum from acute ethanol intoxication 1.5 h (group 7A) increased significantly compared to the activities in the normal control (group 1). These results, therefore, suggest that the biosynthesis of hepatic carboxyl-esterase seems to decrease when cholestasis is combined with chronic and acute ethanol intoxication, and the decrease in activity is more significant than from cholestasis alone.

• 대한의생명과학회지
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• 제11권4호
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• pp.473-479
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• 2005

Possible mechanism of decreased catechol-O-methyltransferase (COMT) activity in cholestatic rat liver was studied. Hepatic and serum COMT activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in this hepatic enzyme were also measured. The activities of cytosolic, mitochondrial and mircosomal COMT as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum COMT activity increased slightly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the COMT in the liver. The elevated activity of the serum COMT is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• 환경생물
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• 제22권4호
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• pp.559-564
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• 2004

The effects of intra-peritoneal injection of inorganic mercury on haemato-logical parameters and hepatic oxidative stress enzyme activities were studied in common carp, Cyprinus carpio. The fish were injected thrice intra-peritoneally with mercuric chloride TEX>$(5,\;10mg\;Hg\;kg\;b.W.^{-1})$. After exposure of three different mercury concentrations a physiological stress response was exerted on C. carpio by causing changes in the blood status such as erythropenia in blood and oxidative stress in liver. Red blood cell counts, hemoglobin concentration and hematocrit level were reduced in most cases by inorganic mercury. Remarkable low level of serum chloride, calcium and osmolality were also observed in the mercury- exposed fish. However, serum magnesium and phosphate were not altered by exposure to mercury. An increased activity of hepatic glutathione peroxidase was observed in the lowest treatment group of carp $(1mg\;Hg\;mg\;b.w.^{-1})$, hence, hepatic catalase and glutathione peroxidase of carp exposed to higher concentration of mercury $(5,\;10mg\;Hg\;kg\;b.W.^{-1})$ showed significant reduction in such activities.

• Journal of Nutrition and Health
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• 제37권3호
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• pp.169-175
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• 2004

This study was performed to investigate the effect of acorn supplementation on the lipid profile and redox antioxidant enzyme activities in obese rat. Obesity in the rats was induced by feeding diet contained 10％ lard and 0.5％ cholesterol for 4 week. After 4 weeks, rats were divided into the following 5 groups; high fat diet (Control), high fat diet plus 10％ Acorn powder (APlO％), high fat diet plus 20％ Acorn powder (AP20％), high fat diet plus 0.2％ Acorn extract (AE0.2％), high fat diet plus 0.5％ Acorn extract (AE0.5％). Total food intake and food efficiency ratio (FER) was not significantly different by acorn powder and extract supplementation. But, body weight was decreased by 20％ acorn powder. Acorn powder and extract supplementation for 4 weeks tend to decrease total cholesterol and triglyceride level on the serum and hepatic tissue. There was no significant difference in hepatic glutathione (GSH) content among all the groups. The hepatic GST activity in acorn supplemented groups was lower than that of control. Glutathione peroxidase and catalase activities were higher in acorn supplemented groups than that of control. Hepatic TBARS levels of experimental groups were also significantly lower than that of control group. Our finding suggest that acorn powders and extract might have potential role for improving lipid profiles and antioxidant enzyme activities in obese rats.

• Natural Product Sciences
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• 제10권4호
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• pp.182-189
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• 2004

To find the action mechanism of the MeOH extract (LFS) of Ligularia fischeri var. spiciformis herbs (Compositae) and its active component, 3,4-dicaffeoylquinic acid (DCQA) on antihepatotoxicity, the effect was investigated on hepatic lipid perxodation and drug-metabolizing enzyme activities in acetaminophen-treated rat. Pretreatment with 250 mg/kg LFS (p.o.) and 10 mg/kg DCQA (p.o.) significantly decreased hepatic lipid peroxidation caused by acetaminophen injection. Further, LFS and DCQA inhibited hepatic microsomal enzyme activation such as hepatic P-450 cytochrome $b_5$, aniline hydroxylase and aminopyrine N-demethylase, suggesting that the two substances might effectively prevent the metabolic activation or scavenge electrophilic intermediates capable of causing hepatotoxicity. Both LFS and DCQA increased hepatic glutathione content and glutathione reductase activity, indicating that both resultantly prevented hepatotoxicity via antioxidative mechanism. Therefore, it was found that LFS had antihepatotoxicity based on the antioxidative action of DCQA.