• Environmental Mutagens and Carcinogens
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• v.7 no.2
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• pp.59-64
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• 1987

Cytotoxic and genotoxic potential of monosodium glutamate (MSG) were evaluated in primary cultures of rat hepatocytes. When exposed to liver cell culture continuously for 24 hr, MSG did not show any cytotoxic effects up to 0.5% (w/v) level as determined by Tryphan Blue exclusion and lactic dehydrogenase release test. MSG also did not induce unscheduled DNA synthesis or DNA single-strand breaks in hepatocyte cultures up to 1% level. No synergistic effects of MSG were observed on aflatoxin B$_1$-induced DNA damage when 1% MSG was treated to liver cell culture along with aflatoxin B$_1$.

• Toxicological Research
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• v.14 no.4
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• pp.577-585
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• 1998

Cadmium is an important industrial and environmental pollutant and has adverse effects on cell growth and metabolism, although the mechanisms of its cellular toxicity are still unclear. This study was performed to elucidate the cytotoxic mechanism of cadmium in the viewpoint of oxidative stress and cytoskeleton alterations in WB-F344 rat liver epithelial cells. 200 $\mu\textrm{M}$ $CdCl_2$ caused a severe disassembling of microtubule and micro filament and an apparent cell retraction under an observation with fluorescence micoscope. (equation omitted)-tubulin and F-actin protein were highly thiolated at 20 min and then disappeared from 1 hour after the treatment of 200 $\mu$M CdCl$_2$in the immunoblot analysis. Intracellular GSH was decreased from 1hr to 24 hrs by 66.6 or 200 $\mu\textrm{M}$ of $CdCl_2$. Intracellular protein thiol was also decreased by 22.2, 66.6 and 200 $\mu\textrm{M}$ of $CdCl_2$ at 1 hour after its treatment. The product of lipid peroxidation (malondialdehyde) was increased from 4 hrs by 66.6 and 200$\mu\textrm{M}$ of $CdCl_2$. These data indicate that cadmium induces oxidative stress involving disassembling of microtubule and micro filament, thiolation of (equation omitted)-tubulin and actin protein, depletion of GSH and protein thiol, and increase of lipid peroxidation.

• Journal of Society of Preventive Korean Medicine
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• v.1 no.1
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• pp.48-54
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• 1997

Scutellariae radix, has been used as a natural drug for fever, inflammation, cataract, and liver disease in traditional medicine. This study was performed in order to investigate the antioxidative effects of Scutellariae radix aqua-acupuncture solution (SRAS) on lipid peroxidation by free radicals. Lipid peroxidation levels were determined by TBA method during the autoxidation of linoleic acid. In this linoleic acid autoxidation system, SRAS markedly exhibited antioxidant activity, which inhibited 89% of linoleic acid peroxidation. SRAS showed scavenging effects on ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) radical, inhibited superoxide generation in xanthine-xathine oxidase system, and also inhibited lipid peroxidation of rat liver tissue by hydroxyl radical derived from $H_2O_2-FE^{+2}$ system. These effects were similar to those of $dl-{\alpha}-tocopherol$, BHA and BHT. In addition, SRAS protected the cell death induced by ter-butyl hydroperoxide (t-BHP) and significantly increased cell viability in the normal rat liver cell (Ac2F). On the basis of these results, it is suggested that SRAS might play a protective role in lipid peroxidation by free radicals.

• Environmental Mutagens and Carcinogens
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• v.19 no.2
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• pp.89-94
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• 1999

Cell proliferation and c-Jun expression pattern in liver exposed by nongenotoxic carcinogens phenobarbital (PB) and clofibrate, and genotoxic carcinogen 2-amino-3-methylimidazo [4,5-f] quinoline (IQ) were investigated to see whether differential effects of genotoxic and non-genotoxic carcinogens on the development of neoplastic foci may be related to differential effect on cell proliferation. Male F344 rats were initially given a single intraperitioneal injection of diethylnitrosamine (200 mg/kg body weight), and 2 weeks later, animals were fed diets containing 0.03% IQ or 0.5% CE or 0.05% PB or basal diet as a control for 6 weeks. All rats were subjected to the two-thirds partial hepatectomy (PH) at week 3. Sequential sacrifice of rats was performed until 8 weeks. Cell proliferation was examined by immunohistochemical staining of bromodeoxyuridine and c-Jun expression was determined by northern blotting. The increase of cell proliferation rate after PH was significant in the rats fed 0.05% IQ and continued until 8 weeks, while the increase was not significant in the rats fed phenobarbital and clofibrate compared to that in the rats fed control diet. mRNA level of c-Jun in the liver treated with IQ was about 7 fold higher than that of control and peak at 5 hours after rH. In the liver treated with CE, mRNA level of c-Jun was 3-4 fold higher than that of control and the highest level of mRNA of c-Jun was seen at 24 hours after PH. These results show that differential effects of genotoxic and non-genotoxic carcinogens on the development of neoplastic foci may be related to differential effect on cell proliferation pattern.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.169-176
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• 1999

The purposes of this study were to set up the method of the natural killer(NK) cell activity assay using the flow cytometer and to examine the characteristics and distribution of the NK cell during rat hepatocarcinogenesis. Forty five male 6 week-old specific pathogen free(SPF) Sprague-Dawley rats were randomly divided into three groups. Group I was the non-treated control and given normal diet and water. Group II was treated with diethylnitrosamine(DEN, 200mg/kg, i.p.) and partial hepatectomy. Group III was treated with DEN, partial hepatectomy and 0.05% phenobarbital sodium in water from 3 to 16 weeks. All animals were examined the morphology of the large granular lymphocyte(LGL), the LGL percent of the total lymphocytes and the LGL conjugation rate with YAC-1 cell in peripheral blood, spleen and liver. Moreover, activity of the LGL isolated from peripheral blood lymphocytes was determined using the flow cytometer. As results, LGL were observed in the peripheral blood, spleen and liver. LGL were observed the relatively faintly staining basophilic cytoplasm with granules, and eccentric, often kidney-shaped nuclei in Giemsa stain. Its size was $11{\sim}13{\mu}m$. LGL percentage of the isolated lymphocytes in peripheral blood, spleen and liver were 1.8~2.3%, 1.3~1.4% and 0.87~0.99%, respectively. LGL conjugation rate with YAC-1 cell was shown to be peripheral blood(9.3~10.3 %) > spleen(7.7~8.7%) > liver(5.6~7.0%). The activity of the LGL isolated from peripheral blood lymphocytes in Group I, II and III was 33.7%, 30.5% and 35.4%, respectively. However, all values were not significantly between groups.

• Journal of Life Science
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• v.19 no.9
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• pp.1321-1327
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• 2009

The present study examined the comparative effects of various amino acids on the alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities of yeast Saccharomyces cereviciae and rat liver homogenate in vitro. Methionine showed the highest activity in yeast ADH among the amino acids used in this study, but this was not higher than that of the hangover product, Condition-Power (CP) used as positive control. Methionine was also found to be the best amino acid in terms of the ALDH activity in rat liver homogenate among the treatment amino acids, which was comparatively higher than that of positive control CP. It was chosen for further experiments and yeast ADH activity increased in parallel with increased methionine concentration, but not rat liver ALDH activity, and it was comparatively higher than those of the positive control. Arginine showed the highest values in yeast ALDH and rat liver ADH activities among amino acids, and it was chosen for further experiments. Yeast ALDH activity increased in parallel with increased arginine concentration, which was higher than that of positive control CP, and rat liver ADH activity was also comparatively higher in all treatment concentrations of arginine than that of positive control CP. The native electrophoresis of ADH and ALDH from cell-free extracts of yeast Saccharomyces cerevisiae cultured in the growth medium containing various arginine concentrations by $0{\sim}0.1%$ showed two active bands upon zymogram staining analysis, and the straining intensity of ADH and ALDH active bands in arginine treatment yeast was stronger than that of non-yeast or low treatment yeast. These results indicate that alcohol metabolizing enzyme activities can be enhanced by arginine and methionine, suggesting that arginine and methionine have potent ethanol-metabolizing activities.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.229-238
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• 2012

Cyclooxygenase(COX-2) is an inducible enzyme that catalyzes the synthesis of prostaglandins (PGs) from arachidonic acid. Over-expression of COX-2 has been reported to be associated with progressive hepatic fibrosis in chronic hepatic C infection and rat liver fibrosis induced by carbon tetrachloride($CCl_4$). Recently, it is well known that mast cell products can stimulate the proliferation of hepatic stellate cells and key players in liver fibrosis. But little is known regarding their role in $CCl_4$-induced liver fibrosis in rat. Our aim was to investigate the relation between COX-2 expression and mast cells during liver fibrosis after $CCl_4$ treatment. Thirty Wistar rats were divided into five groups (non-treated 0, 2, 4, 6 and 8-week after $CCl_4$-treatment). Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to assess the expression of ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), collagen-1 and COX-2 in liver tissue from $CCl_4$-treated rats. The density of collagen and mast cells were determined using a computerized image analysis system in liver sections stained with picrosirius red and toluidine blue, respectively. The expression levels of ${\alpha}$-SMA, collagen-1 and COX-2 mRNA were significantly higher at 2 wk in $CCl_4$-treated groups than non-treated group. The number of mast cells in liver tissues increased gradually from 2 wk to 6 wk depending on the fibrosis severity but decreased abruptly at 8 wk. The significant increase of collagen-1 and ${\alpha}$-SMA mRNA expression in $CCl_4$-treated rats was continued until 6 wk while the COX-2 mRNA was significantly decreased at 8 wk. These results suggest that increased mast cells are closely associated with COX-2 over-expression during hepatic fibrogenesis of $CCl_4$-treated rats.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.417-428
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• 1996

In order to know the toxic effect and carcinogenic activity in rats and mice fed with juice of Korean native Petasites japonicus Maxim of its pellet(4% or 8%) which were dried, milled and mixed with basal diet, the investigations were carried out by macroscopy and histopathology. Macroscopically, although remarkable changes were not observed in the liver of mice, there were slight to moderate swelling of rat livers in the whole groups at 12 to 14 weeks after feeding and milky spots in rats fed with its juice and 8% pelleted Petasites japonicus Maxim diet and a normal diet for 1 week alternatively for 14 weeks. Moreover, moderate to severe swelling and milk spots were recognized in livers of all rats fed with its juice and 8% pellet or 8% pelleted Petasites japonicus Maxim for 16 weeks. But, in cases of rats fed with its juice and 4% pellet or 4% pelleted Petasites japonicus Maxim, only swelling of livers was recognized moderately or severely. Histopathologically, major lesions were found in livers of both rats and mice. There were congestion, hemorrhage, fatty change, focal necrosis, megalocytosis and hyperplasia of endothelial cell in livers of mice and rats, the additional lesions such as proliferation of bile duct and nodular regeneration with diffuse regenerating cells were seen in livers of rats. In addition, preneoplastic lesions, the areas of milky spots macroscopically, were observed in livers of rats fed with Petasites japonicus Maxim for 14 to 16 weeks. In a few cases, haemangioendothelial sarcoma in livers was detected in rats fed with Petasites japonicus Maxim for 16 weeks. Petasites japonicus maxim growing naturally in Korea seem to exhibit toxic effect especially in liver and it contained a causative agent of primary liver tumors.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.194-204
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• 2011

This study was carried out to compare the histopathological differences of liver lesions in carbon tetrachloride ($CCI_4$), dimethylnitrosamine (DMN), thioacetamide (TAA) and bile duct ligation (BDL)-induced rats. $CCl_4$, DMN and TAA were administered intraperitoneally and conducted bile duct ligation for 4 weeks to induce hepatic fibrosis. Indices of liver cell injury (steatosis, hydropic degeneration, bile duct hyperplasia, hemorrhage & hemosiderin deposition), the extent of liver fibrosis (fibrotic area) and the rate of regeneration (number of PCNA-positive cells) were investigated in each group. Liver tissues were stained with hematoxylin-eosin (HE), sirius red, prussian blue and immunostained with ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), proliferative cell nuclear antigen (PCNA), and quantified using a computerized image analysis system. Liver cell steatosis was significantly increased in $CCl_4$ and TAA groups, and hydropic degeneration and bile duct hyperplasia were significantly increased in TAA and BDL groups when compared with that in normal control, respectively. Fibrosis area was significantly increased in all four groups, especially in $CCl_4$ group. Correlation between ${\alpha}$-SMA and TGF-${\beta}1$ expressions in four groups was good. Hemorrhage area in liver parenchyma was significantly increased in DMN group only when compared with that in normal control, while hemosiderin deposition area was significantly increased in TAA and BDL groups as well as DMN group. The Number of PCNA-positive cells was significantly increased in all four groups, especially in TAA group. These results indicate that the duration and methods of hepatotoxic drug treatment are very important factors to make plans for animal experimentation on the induction of hepatic fibrogenesis in rats.

• Molecular & Cellular Toxicology
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• v.1 no.4
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• pp.256-261
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• 2005

The recent DNA microarray technology enables us to understand gene expression profiling in cell line and animal models. The technology has potential possibility to comprehend mechanism of multiple genes were related to compounds which have toxicity in biological system. So, microarray system has been used for the prediction of toxicity through gene expression induced by toxicants. It has been shown that compounds with similar toxic mechanisms produce similar changes in gene expression in vivo system. Here we focus on the use of toxicogenomics for the determination of gene expression analysis associated with hepatotoxicity in rat liver and cell line (WB-F344). Methotrexate (MTX) is a chemotherapy agent that has been used for many years in the treatment of cancer because it affects cells that are rapidly dividing. Also it has been known the toxicity of MTX, in a MTX abortion, it stops embryonic cells from dividing and multiplying and is a non-surgical method of ending pregnancy in its early stages. We have shown DNA microarray analyses to assess MTX-specific expression profiles in vivo and in vitro. Male Sprague-Dawely VAF+ albino rats of 5-6 weeks old and WB-F344 cell line have been treated with MTX. Total RNA was isolated from Rat liver and cell line that has treated with MTX. 4.8 K cDNA microarray in house has been used for gene expression profiling of MTX treatment. We have found quite distinct gene expression patterns induced by MTX in a cell line and in vivo system.