• Environmental Analysis Health and Toxicology
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• v.24 no.4
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• pp.303-309
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• 2009

Hepatic antioxidant defense systems were examined in rats treated with tetrabromobisphenol-A (TBBPA), a brominated flame retardant, at the doses of 0, 250, 500 and 1,000 mg/kg for four weeks. Hepatic ratio of glutathione disulfide to glutathione (GSH) and levels of malondialdehyde, oxidative stress markers were not changed in rats treated with TBBPA. Hepatic expression of antioxidant enzymes including GSH peroxdiase-1 (GPX-1)/GSH reductase (GR), alpha-, mu- and pi-class glutathione-S-transferase (GST) and gamma-glutamylcysteine ligase catalytic subunit was determined using immunoblot analysis. Alpha-class GSTs, GPX-1 and GR levels were significantly decreased in rats treated with TBBPA at the dose of 500 or 1,000 mg/kg. These results show that TBBPA results in down-regulation of hepatic expression of antioxidant enzymes related with GSH, suggesting the liver in TBBPA-treated rats may be more sensitive to oxidants.

• Journal of Nutrition and Health
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• v.33 no.1
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• pp.33-41
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• 2000

The purpose of this study was to investigate the effects of vitamin E on antioxidative defense system of liver in acute cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10gm were randomly assigned to one control and three cadmium injected groups. Cadmium injected groups were fed vitamin E free diet(OE-Cd group), 40mg vitamin E per kg diet(40E-Cd group) or 400 mg vitamin E per kg diet(400E-Cd group). Vitamin E level of normal group was 40mg per kg diet. Animals were injected intraperitoneally with 2.0mg Cd$^2$$\^$+//kg bw for 4 days after the rats were fed diets with three different levels of vitamin E for 2 and 4weeks. Activities of superoxide dismutase(SOD), glutathione peroxidase(GSHPx) and glutathione S-transferase(GST) were decreased in cadmium injected groups but those were significantly improved by dietary vitamin I supplementations. Vitamin E contents reduced glutathione(GSH) in the live were decreased in cadmium injected groups, but we., not significantly different among three groups with different levels of vitamin E supplementations. Contents of liver thiobarbituric acid reactive substance (TBARS) of 0E-Cd group were higher than those of 400E-Cd and 400E-Cd groups, but those were markedly alleviated according to vitamin E supplementations. These results indicate that cadmium poisoning in rats causes decreasing antioxidative defense system and increasing peroxidative damage in liver, however can be restored by vitamin E supplements. (Korean J Nutrition 33 (1) : 33-41, 2000)

• BMB Reports
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• v.33 no.3
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• pp.242-248
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• 2000

Phage display of proteins is a powerful tool for protein engineering since a vast library of sequences can be rapidly screened for a specific property. In this study, we develop da new phage display vector that was derived from a pET-25b(+) vector. The pET-25b(+) was modified in order that the expressed protein would have a T7-tag at the amino terminus and GpS (a major coat protein of M13 phage) at the carboxyl terminus. Another vector without the gp8 gene was also constructed. The newly developed phagemid vectors have several advantageous features. First, it is easy to examine whether or not the target proteins are functional and faithfully transported into the periplasmic space. This feature is due to the fact that recombinant proteins are produced abundantly in the pET system. Second, the T7-tag makes it possible to detect any target proteins that are displayed on the surface of filamentous bacteriophage. To verify the utility of the vector, the clones containing the glutathione S-transferase (GST) gene as a target were examined. The result showed that the GST produced from the recombinant vector was successfully transported into the periplasmic space and had the anticipated enzyme activity. Western blot analysis using a T7-tag antibody also showed the presence of the target protein displayed on the surface of the phage. The phages prepared from the recombinant clones were able to bind to glutathione-Sepharose and then eluted with glutathione. These results showed that the new vectors developed in this study are useful for the phage display of proteins.

• BMB Reports
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• v.40 no.6
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• pp.1039-1049
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• 2007

Overdoses of acetaminophen cause hepato-renal oxidative stress. The present study was undertaken to investigate the protective effect of a 43 kDa protein isolated from the herb Cajanus indicus, against acetaminophen-induced hepatic and renal toxicity. Male albino mice were treated with the protein for 4 days (intraperitoneally, 2 mg/kg body wt) prior or post to oral administration of acetaminophen (300 mg/kg body wt) for 2 days. Levels of different marker enzymes (namely, glutamate pyruvate transaminase and alkaline phosphatase), creatinine and blood urea nitrogen were measured in the experimental sera. Intracellular reactive oxygen species production and total antioxidant activity were also determined from acetaminophen and protein treated hepatocytes. Indices of different antioxidant enzymes (namely, superoxide dismutase, catalase, glutathione-S-transferase) as well as lipid peroxidation end-products and glutathione were determined in both liver and kidney homogenates. In addition, Cytochrome P450 activity was also measured from liver microsomes. Finally, histopathological studies were performed from liver sections of control, acetaminophen-treated and protein pre- and post-treated (along with acetaminophen) mice. Administration of acetaminophen increased all the serum markers and creatinine levels in mice sera along with the enhancement of hepatic and renal lipid peroxidation. Besides, application of acetaminophen to hepatocytes increased reactive oxygen species production and reduced the total antioxidant activity of the treated hepatocytes. It also reduced the levels of antioxidant enzymes and cellular reserves of glutathione in liver and kidney. In addition, acetaminophen enhanced the cytochrome P450 activity of liver microsomes. Treatment with the protein significantly reversed these changes to almost normal. Apart from these, histopathological changes also revealed the protective nature of the protein against acetaminophen induced necrotic damage of the liver tissues. Results suggest that the protein protects hepatic and renal tissues against oxidative damages and could be used as an effective protector against acetaminophen induced hepato-nephrotoxicity.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.81-88
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• 2002

Effect of cyclohexanone treatment on the activities oxygen free radical and cyclohexanone metabolizing enzyme in acute liver damaged rats, was investigated. Acute liver damage was induced in rats with pretreatment of 50% $CCl_4$ in olive oil(0.1ml/100g body wt) intraperitoneally 3 times every other day. Cyclohexanone(1.56g/kg body wt, i.p.) was administered to the animals 24 hours after the last Pretreatment of CC1$_4$. Rats were sacrificed at 4 hours after injection of cyclohexanone. On the basis of liver weight/body weight(％), serum levels alanine aminotransferase activity and hepatic protein content, cyclohexanone treatment to acute liver damaged animals led to the more enhanced liver damage. On the other hand, injection of cyclohexanone to the rats led to the increased activities of hepatic cytochrome P-450 dependent aniline hydroxylase and xanthine oxidase. Furthermore, by treatment of cyclohexanone to the acute liver damaged rats hepatic xanthine oxidase activity was more increased than the $CCl_4$ treated rats. In case of oxygen free radical scavenging system, the hepatic glutathione content and the activities of hepatic glutathione S-transferase, catalase, superoxide dismutase were generally increased by injection of cyclohexanone to rats, and the hepatic glutathione content, catalase and alcohol dehydrogenase activities were more decreased in liver damaged rats by the treatment of cyclohexanone. In conclusion, the cyclohexanone treatment to acute liver damaged rats led to enhancement of liver damage that may be due to oxygen free radical together with cyclohexanone.

• Nutrition Research and Practice
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• v.6 no.3
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• pp.208-212
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• 2012

In the present study, we examined whether four grains including adlay (AD), buckwheat (BW), glutinous barley (GB), and white rice (WR) affect the duration of food residence in the gastrointestinal tract and hepatic enzyme activities in rats fed different combinations of the grains. The rats were raised for 4 weeks on a high fat diet based on the American Institute of Nutrition-93 (AIN-93G) diets containing 1% cholesterol and 20% dietary lipids. Forty male rats were divided into four groups and raised for 4 weeks with a diet containing one of the grains. Corresponding to the dietary fiber contents of the experimental grains, gut transit time was shortest in the rats fed GB and increased in the order of BW, AD, and WR. In addition, the accumulated shortest transit time occurred in the GB group. Gut transit time affected weight gain and major organ weight, as it was closely related to the absorption of nutrients. The level of thiobarbituric acid reactive substance (TBARS) in liver was higher in rats fed WR, AD, BW, and GB, indicating that the other grains decreased oxidative stress in vivo more than WR. Glutathione, glutathione peroxidase, and glutathione S-transferase levels in the AD, BW, and GB groups were significantly higher than those in the WR group. In conclusion, reduced colonic transit time has been implicated in reducing the incidence of colon cancer, as evidenced by populations consuming diets rich in fiber. Whole grains such as AD, BW, and GB may contribute to a significant supply of antioxidants to prevent oxidative stress if they are consumed in large amounts.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.119-123
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• 2002

Antioxidative activities of ethanol extracts of fruits from three cultivars of Prunus mune with different harvest times were determined. Extracts of P. mune cutivar Okyoung showed the strongest activity at 97.5%(compared to BHT) using DPPH or thiocyanate method, although no statistically significant differences were observed among the cultivars. Antioxidative activities of the extracts measured with glutathione-S-transferase method was over 70% of that of BHT. Survival rates of cells in mouse spinal cord culture challenged by superoxide anion were 89, 79, and 62% at 40 mg/ml of Okyoung, Namgo, and Kochunme extracts, respectively, whereas 90% at 6mM glutathion.

• Herbal Formula Science
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• v.9 no.1
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• pp.289-317
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• 2001

The purpose of this study was to reseach the effect of Daesihotang and its component groups on diabetes, free radical and antioxidative defense system in alloxan-induced diabetic rats. The experimental group was divided into three groups: Daesihotang (DS), Soyangyak (DS1), Yangmyungyak (DS2). The results were obtained as follows: The level of glucose, triglyceride, total cholesterol, creatinine in serum were considerablely reduced by Daesihotang. And the level of HDL cholesterol, albumin, total protein in serum were increased by Daesihotang significantly. And the level of BUN has some decreased, but with no significancy. In the study of Daesihotang on free radical scavenging effect in vitro, it has shown that Daesihotang and its components group have significant suppressing effect on peroxidation of linoleic acid on concentration. And in other experiments as scavenging effect of DPPH radical, inhibitory effect of superoxide in xanthine-xanthine oxidase system and inhibitory effect on lipid peroxidation reaction by hydroxy radical in $H_2O_2-Fe^{2+}$ system, Daesihatang have some activity, but with no significancy. In the study of Daesihotang on antioxidative defense system in vivo, the activity of GOT and GPT in serum were significantly increased; and the amounts of lipid peroxide in serum was reduced significantly but in liver no significancy. In hepatic catalase activity, Daesihotang has showed significant effect. In the level of hepatic glutathione, Daesihotang increased the amount of glutathione significantly. And in the activity of glutathione-s-transferase, Daesihotang has decreasing effect but has no significancy. These result suggest that Daesihotang has strong effect on diabetes and it is useful to prevent diabetes, but has less effect on peroxidative damage by free radical.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.311-318
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• 2005

Oxidative stress has been reported to elevate ceramide level during cell death. The purpose of the present study was to modulate cell death in relation to cellular glutathione (GSH) level and GST (glutathione S-transferase) expression by regulating the sphingolipid metabolism. LLC­PK1 cells were treated with H$_2$O$_2$ in the absence of serum to induce cell death. Subsequent to exposure to H$_2$O$_2$, LLC-PK1 cells were treated with desipramine, sphingomyelinase inhibitor, and N-acetylcysteine (NAC), GSH substrate. Based on comparative visual observation with H202-treated control cells, it was observed that 0.5 $\mu$M of desipramine and 25 $\mu$M of NAC exhibited about 90 and $95\%$ of cytoprotection, respectively, against H$_2$O$_2$-induced cell death. Desipramine and NAC lowered the release of LDH activity by 36 and $3\%$ respectively, when compared to $71\%$ in H$_2$O$_2$-exposed cells. Cellular glutathione level in 500 $\mu$M H202-treated cells was reduced to 890 pmol as compared to control level of 1198 pmol per mg protein. GST P1-1 expression was decreased in H$_2$O$_2$-treated cells compared to healthy normal cells. In conclusion, it has been inferred that H$_2$O$_2$-induced cell death is closely related to cellular GSH level and GST P1-1 expression in LLC-PK1 cells and occurs via ceramide elevation by sphingomyelinase activation.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.139-145
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• 2008

We located a group of healthy young males (aged $20{\sim}30$) who had been taking a high dose (more than 5 g) of vitamin C daily for more than one year. We observed that this vitamin C group had plasma levels of vitamin C that were more than three times that of the control group. The control group had not taken any additional vitamin C except for that included in their diets. But the vitamin C group showed significantly lower amounts of Cu/ZnSOD, catalase and glutathione-s-transferase and lower activities of glutathione peroxidase and glutathione reductase in erythrocyte lysates than the control group. However, there was no difference in the plasma levels of lipid peroxides between the two groups. These results suggest that vitamin C offsets its own contribution to anti-oxidant activity by repressing the expression of anti-oxidant enzymes and also excludes the possibility that vitamin C acts as a pro-oxidant in vivo.