• Biomedical Science Letters
• /
• v.9 no.2
• /
• pp.75-84
• /
• 2003

To evaluate the influence of hepatic oxygen free radical systems on liver injury by topical p-phenylenediamine (PPD) application on rat skin, PPD (25 mg/16.5 $\textrm{cm}^2$) was topically applied to the abdominal region 5 times every other day and sacrificed. By PPD treatment, increasing rate of liver weight/body weight (%), serum activities of alanine aminotransferase and aspartate aminotransferase and decreasing rate of microsomal glucose-6-phosphatase activity were higher in the rats fed tungstate supplemented diet than those fed a standard diet. These findings indicate that group fed tungstate supplemented diet have more severe liver injury compared with group fed standard diet on topical PPD application. However, the activities of oxygen free radical generating enzymes such as xanthine oxidase (XO) and cytochrome P450 dependent aniline hydroxylase and those of oxygen free radical scavenging enzymes were not found to be different between these two animal groups. In the present study, a novel monitoring method to detect the generating of oxygen free radicals in liver extract was devised. Throughout this method, the oxidized PPD produced by oxygen free radicals was determined colorimetrically. The increasing rate of PPD oxidation by liver homogenate was higher in tungstate fed animals than in standard diet fed ones. Among the fractionations of liver extract, the mitochondrial and postmitochondrial fractions in the liver extract of tungstate fed animals led to a higher availability of PPD oxidation by PPD treatment compared with standard diet fed ones. In conclusion, these results suggest that an enhanced liver injury in tungstate fed animals treated with PPD may be due to oxygen free radicals produced in other systems except oxygen free radicals generating from cytosolic XO system. Especially, oxidative availability by PPD can be used for oxygen free radical detection in some tissue.

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

• Biomedical Science Letters
• /
• v.12 no.1
• /
• pp.49-52
• /
• 2006

To elucidate the effect of antioxidant complex containing $\beta-carotene$, vitamin E, vitamin C, Ginkgo Biloba leaf extract and selenium on oxygen :tree radical production and detoxification system, rats were fed normal diet and normal diet with antioxidant complex 0.1%, 0.3% and 0.5% for 3 weeks. Feed efficiency ratio, changes in body weight, weight gain and amounts of feces of rat are similar in four groups. Liver weight per body weight and hepatic lipid peroxide weight increased in 0.5% group. However, hepatic glutathione contents in all antioxidant complex added groups were significantly increased compare with normal control group. On the other hand, the activity of xanthine oxidase was a little increased due to the amounts of antioxidant complex. Superoxide dismutase and gutathione peroxidase activity of 0.1% antioxidant complex added group were increased about $10{\sim}20%$ in comparison to normal control group. These results suggest that the supplementation of antioxidant complex 0.1% to basal diet may reduce the hepatic damage caused by free radicals.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.3
• /
• pp.500-505
• /
• 2002

Many studies have shown that hyperglycemia leads to an increase of lipid peroxidation in diabetic patients and animals, reflecting a rise reactive oxygen species production. It is increasingly recognized that brain is another site of diabetic organ damage. Accordingly, this study was to investigate the effect of dandelion on oxygen free radical generating and scavenging system of brain in streptozotocin (STZ)-induced diabetic rats. Male Wistar rats were divided into diabetic (control) and diabetic-dandelion supplemented groups. Dandelion was supplemented for 4 weeks with dandelion leaf and root powder (DLP, DRP) or dandelion leaf and root water extract (DLW, DRW) based on 11.4 g of raw dandelion/kg diet. Diabetes was induced by single injection STZ (55 mg/kg B.W., i.p.)in a citrate buffer. Oxygen free radical generating enzymes, cytochrome P-450, amino-pyrine N-demethylase, aniline hydroxylase and xanthine oxidase, were lowered in dandelion supplemented-groups compared to the control group. Superoxide dismutase, catalase and gluthathione peroxidase activities of brain were also lower in dandelion leaf and root supplemented-group than in the control group, whereas glutathione S-transferase activity and gluthathione content were increased in dandelion supplemented-groups compared to the control group. With regard to the lipid peroxidation products, the malondialdehyde content of brain was lower in dandelion supplemented groups. Therefore, it could be suggested that powder and water extract of dandelion leaf or root are beneficial in preventing diabetic complication from lipid peroxidation and free radical in brain of diabetic rat brain.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.409-411
• /
• 2002

In order to prevent side reactions due to free radical formation occurring in the reactions of singlet oxygen generated in solution phse, it was required that singlet oxygen is generated in gas phase from an apparatus of a solid-gas system. We have accomplished to construct an apparatus generating singlet oxygen in solid-gas system, which is composed of a flexible optical fibre tube connected by a dye-sensitizer probe containing rose bengal dye on polymer or inorganic material. Through the optical fibre tube visible light from a laser and an oxygen stream are passed into the sensitizer probe where singlet oxygen is generated. The determination of singlet oxygen was carried out by two methods. One involves the detection of the luminescence of singlet oxygen at 1268 mn and the other involves the chemiluminescence reaction of a dihydroisobenzofuran with singlet oxygen emitting luminescence at 456 nm.

• Journal of Korean Physical Therapy Science
• /
• v.8 no.1
• /
• pp.923-934
• /
• 2001

In order to investigate a pathogenesis of liver damage induced by skin burn, thermal injury was induced by scald burn on entirely dorsal surface in rats (total body surface area 30%) except for inhalated injury. At 5 and 24 h after scald bum, biochemical assay and morphological changes in skin tissue, serum and liver tissue were examined. The effects of bum injury on the levels of glutathione, lipid peroxide and on the activities of oxygen free radical generating and scavenging enzymes have been determined in association with observing of histologic and ultrastructural changes, measuring the protein concentration in plasma, and counting the number of intravascular polymorphonuclear leukocytes. The activity of xanthine oxidase, an enzyme of oxygen free radical generating system. was elevated (p<0.01) in serum, but not in skin and in liver tissue. Futhermore, thermal injury decreased not only the protein concentration in plasma but also the number of leukocytes, that indicates induction of edema formation with protein exudation and inflammation by neutrophil infiltration into the internal organs. These data suggest that acute dermal scald burn injury leads to liver damage, that is related to elevation of xanthine oxidase activity in serum. Xanthine oxidase may be a key role in the pathogenesis of liver damage induced by skin burn.

• Toxicological Research
• /
• v.22 no.1
• /
• pp.39-45
• /
• 2006

As the antioxidant and free radical scavenger, glutathione (GSH) participates in the preservation of cellular redox status and defense against reactive oxygen species and xenobiotics. Glutamate-cysteine ligase (GCL; also known as ${\gamma}$-glutamylcysteine synthetase, EC 6.3.2.2) is the rate limiting enzyme in GSH synthesis. In the present study, the accurate method for determination of GCL activity in crude liver extracts was developed by measuring both ${\gamma}$-glutamylcysteine and GSH from cysteine in the presence of glutamate, glycine and an ATP-generating system. We added glycine to promote the conversion of ${\gamma}$-glutamylcysteine to GSH, and to minimize the possibility of ${\gamma}$-glutamylcysteine metabolism to cysteine and oxoproline by ${\gamma}$-glutamylcyclotransferase. We established optimal conditions and substrate concentrations for the enzyme assay, and verified that inhibition of GCL by GSH did not interfere with this assay. Therefore, this assay of hepatic GCL under optimal conditions could provide a more accurate measurement of this enzyme activity in the crude liver extracts.

• KSBB Journal
• /
• v.10 no.5
• /
• pp.561-567
• /
• 1995

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxygen toxicity induced by paraquat was studied. In aerobic culture condition, yeasts lacking MnSOD (milochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared with wild type were observed under anaerobic condition. When exposed to paraquat, the growth of yeasts lacking CuZnSOD was severely affected by higher than 0.01mM of paraquat in culture medium. By the analysis of several cellular components ivolved in free radical generating and scavenging system, it was found that, under aerobic condition, the content of lipid peroxides in cell membrane as well as cellular activity of glutathion peroxidase of CuZnSOD-deficient mutants was increased in the presence of paraquat, although significant decrease of catalase activity was observed in those stratns. In MnSOD-deficient yeast, however, increment in cellular activity of glutathion peroxldase and catalase by paraquat was observed without any deterioration of membrane lipid. It implies that the lack of mitochondrial SOD could be compensated by both of glutathion peroxldase and catalase, but that only glutathion peroxidase might act for CuZnSOD in cytoplasm. In contrast, all of SOD-deficient mutants showed a significant decrease in catalase activity, but slight increase in the activities of glutathion peroxidase, when cultivated anaerobically in the medium containing paraquat. Nevertheless, any significant changes of lipid peroxides in cell membranes were not observed during anaerobic cultivation of SOD-deficient mutants. It suggests that a little amount of free radicals generated by paraquat under anaerobic condition could be sufficiently overcome by glutathion peroxidase but not by catalase.

• Journal of Life Science
• /
• v.19 no.4
• /
• pp.429-435
• /
• 2009

Oxidative stress is a consequence of an imbalance of the defense system against cellular damage generated by reactive oxygen species (ROSs) such as superoxide anions (menadione; MD). Most organisms have evolved a variety of defense systems to protect cells from adverse conditions. In order to evaluate stress tolerance against oxidative stress generating MD, comparative analyses of antioxidant capacity, or free radical scavenger ability, were performed between S. cerevisiae KNU5377 (KNU5377) and three wild-type S. cerevisiae strains. In a medium containing 0.4 mM MD, the KNU5377 strain showed higher cell viability and antioxidant ability, and contained higher levels of trehalose, superoxide dismutase, thioredoxin system, glucose-6-phosphate dehydrogenase, and some heat shock proteins. The KNU5377 strain also produced a lower level of oxidative stress biomarker than the other three yeast strains. These results indicate that S. cerevisiae KNU5377 has a higher level of tolerance to oxidative stress due to the increased expression of cell rescue proteins and molecules, thus alleviating cellular damage more efficiently than other S. cerevisiae strains.

• Applied Microscopy
• /
• v.31 no.1
• /
• pp.37-47
• /
• 2001

In order to investigate a pathogenesis of liver damage induced by skin burn, thermal injury was induced by scald burn on entirely dorsal surface in rats (total burn surface area $20\sim25\%$) except for inhalated injury. At 5 and 24 h after scald burn, biochemical assay and morphological changes in serum and liver tissue were examined. Skin burn increased liver weight (% of body weight, p<0.05) and the activity of serum aniline amino-transferase (ALT, p<0.05), in addition, the activity of xanthine oxidase (XO), an enzyme of oxygen free radical generating system, was elevated (p<0.01) in serum, but not in skin and in liver. Postburn treatment of allopurinol intraperitoneally decreased liver weight, serum ALT activity and serum XO activity. Scald burn induced ultrastructurally swelling of endoplasmic reticulum, ribosome detachment, accumulation of lipid, dilatation of bile canaliculi and intercellular space, neutrophil infiltration, activation of Kupffer's cells and degeneration of hepatocytic microvilli. Futhermore , thermal injury decreased not only the protein concentration in plasma but also the number of intravascular leukocytes, that indicates induction of edema formation with protein exudation and inflammation by neutrophil infiltration into the internal organs. However allopurinol injection after burn inhibited post burn ultrastructural changes. These data suggest that acute dermal scald burn injury leads to liver damage, that is related to elevation of xanthine oxidase activity in serum. Xanthine oxidase may be a key role in the pathogenesis of liver damage induced by skin burn.