• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.19.1-19.7
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• 2016

A laboratory experiment was conducted to determine hexavalent chromium ($Cr^{6+}$) accumulation in the mullet and investigate $Cr^{6+}$ toxicity using a panel of biomarkers including metallothioneins (MTs), glutathione (GSH), glutathione S-transferase (GST), and superoxide dismutases (SODs) for 4 weeks. $Cr^{6+}$ bioaccumulation in all tissues, except muscle, was consistently time- and dose-dependent. The accumulation of $Cr^{6+}$ for 4-week exposures was in the following order: $kidney{\approx}liver$ > $intestine{\approx}gill$ > spleen > muscle. Compared with the control, $Cr^{6+}$ bioaccumulation was increased in ${\geq}200{\mu}g\;L^{-1}$ groups (P < 0.05). An independent relation was observed between accumulation factors (AFs) and exposure concentration. But AFs increased with exposure time. In the liver and gill, GST and SOD differed from the control at a high $Cr^{6+}$ concentration at 2 and 4 weeks (P < 0.05). This study indicated that the gills were as sensitive as the liver to $Cr^{6+}$ toxicity. However, the latter appeared to influence largely on the organism's adaptive response to $Cr^{6+}$, since $Cr^{6+}$ may elevate GSH and MT levels by enhancing the hepatic uptake of metal in the mullet.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.199-205
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• 2010

The crystallization speed (v) of amorphous (InTe)$_x$(GeTe) (x = 0.1, 0.3 and 0.5) films and their thermal, optical and electrical behaviors have been investigated using nano-pulse scanner (wavelength = 658 nm, laser beam diameter < 2 ${\mu}m$), X-ray diffraction (XRD), 4-point probe and UV-vis-IR spectrophotometer. These results were compared with those of $Ge_2Sb_2Te_5$ (GST) film, comprehensively utilized for phase-change random access memory (PRAM). Both v-value and thermal stability of (InTe)$_{0.1}$(GeTe) and (InTe)$_{0.3}$(GeTe) films could be enhanced in comparison with those of the GST. Contrarily, the v-value in the (InTe)$_{0.5}$(GeTe) film was so drastically deteriorated that we could not quantitatively evaluate it. This deterioration is thought because amorphous (InTe)$_{0.5}$(GeTe) film has relatively high reflectance, resulting in too low absorption to cause the crystallization. Conclusively, it could be thought that a proper compositional (InTe)$_x$(GeTe) films (e.g., x < 0.3) may be good candidates with both high crystallization speed and thermal stability for PRAM application.

• Journal of Life Science
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• v.20 no.2
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• pp.161-168
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• 2010

White-skinned sweet potato (Ipomoea batatas L.) has been traditionally used for diabetes treatment and management in many countries. In this experiment, methanol extract of white-skinned sweet potato (WSPMe) at a dose of 100 or 200 mg/kg body weight was tested to evaluate its effect on renal damage in streptozotocin (STZ)-induced diabetic rats. Its efficacy was compared with that of insulin secretogogue, glimepiride ($50\;{\mu}g/kg$ body weight). Experimental diabetes was induced by a single dose of STZ (45 mg/kg, i.p.) injection. The WSPMe and glimepiride were administered orally for 14 days and the effects on glucose, renal markers including blood urea nitrogen (BUN), creatinine and lactate dehydrogenase (LDH), lipid peroxide (LPO) level, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathion-S-transferase (GST) activities in kidney were studied. An increase in BUN, creatinine, LDH, glucose, LPO levels and decrease in SOD, CAT, GPx and GST features were observed in diabetic control rats. Administration of WSPMe at a dose of 200 mg/kg body weight caused a significant improvement in blood glucose, LPO level, renal markers, lipid peroxidation markers and increased antioxidant levels in diabetic kidney. In conclusion, the WSPMe was found to be effective in reducing oxidative stress, thus confirming the ethnopharmacological use of I. batatas L. in protecting diabetes and its complications.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.107-113
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• 2011

Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pre-treatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.782-787
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• 2002

This study was done to investigate the effects of Korean mistletoe water extract and lectin on the apoptosis and preneoplastic lesion in chemically induced rat hepatocarcinogenesis. To attain the above objectives, weanling Sprague-Dawley male rats were fed modified AIN-76 diets containing 10% corn oil for 9 weeks. One week after feeding starts, rats were intraperitoneally injected twice with a dose of diethylnitrosamine (DEN, 50 mg/kg body weight (BW). Rats were provided with 0.05% phenobarbital (PB) in drinking water from one week after DEN treatment until the end of experiment. During the period of PB treatment, rats were injected with mistletoe extract (100 $\mu\textrm{g}$/kg BW) and lectin (10 $\mu\textrm{g}$/kg BW) twice a week. At the end of 9th week, rats were sacrificed and the formation of hepatic glutathione S-transferase placental form positive (GST-P$^{+}$) foci, apoptosis, DNA fragmentation and apoptosis related proteins were determined respectively. The formation of GST-P$^{+}$foci was significantly decreased by mistletoe extract or lectin treatment. Although there was no effect on apoptosis and DNA fragmentation in hepatic tissue by mistletoe extract or lectin treatment, caspase-9 and fas-L were increased. These results suggest that Korean mistletoe extract and lectin have a potential to inhibit hepatocarcinogenesis by increasing apoptosis.sis.

• Journal of Preventive Medicine and Public Health
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• v.31 no.2 s.61
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• pp.275-284
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• 1998

Activities of enzymes involved in the metabolism of various carcinogenic xenobiotics is one of the most important host factors for cancer occurrence. N-acetyltransferase (NAT) and glutathione S-transferases (GST) are enzymes which .educe the toxicity of activated carcinogenic metabolites. Slow N-acetylation and lack of GST mu (GSTMI) were reported as risk factors of bladder cancer. GST theta (GSTT1), which is another type of GST, was reported to be deleted at higher proportion among Koreans. Since cause of bladder cancer is not fully explained by single risk factor, many kinds of enzymes would be involved in the metabolism of carcinogens excreted in urine. This study was performed to investigate whether the polymorphisms of NAT2, GSTM1 and GSTT1 are risk factors of bladder cancer and to evaluate the effects of their interaction on bladder cancer development. Sixty-seven bladder cancer and 67 age- and sex-matched non-cancer patients hospitalized in Chungbuk National University Hospital from March to December 1996, are the subjects of this case-control study. Questionnaire interview was done and the genotypes of NAT2, GSTM1 and GSTT1 were identified using PCR methods with DNA extracted from venous blood. The effects of the polymorphism of NAT2 and GSTM1 and their interaction on bladder cancer were statistically tested after controlling the other risk factors. The frequencies of slow, intermediate, and rapid acetylators were 3.0%, 38.8%, and 58.2% to. the cases, and 7.6%, 40.9%, and 51.5% for the controls, respectively. The risk of bladder cancer was not associated with the increase of NAT2 activity($\chi^2_{trend}=1.18$, P-value>0.05). GSTM1 was deleted in 68.7% of the cases and 49.3% of the controls ($\chi^2=5.21$, P-value<0.05), and the odds ratio (95% CI) was 2.23 (1.12 - 4.56). GSTT1 deletion, the .ate of which were 26.9% for the bladder cancer patients and 43.3% for the controls, was a significant protective factor against bladder cancer. Smoking history turned out to be insignificant as a risk factor of bladder cancer (OR=1.85, 95% CI: 0.85 - 4.03), and occupation could not be tested because of the extremely small number of occupational history related to the increase of bladder cancer. In multiple logistic analysis controlling the effects of other risk factors, GSTM1 deletion was the only significant risk factor for bladder cancer (OR: 2.56, 95% CI: 1.22-5.36, P-value<0.05), but slow acetylation and GSTT1 deletion were not. These results suggest that GSTM1 deletion may be a significant risk factor of bladder cancer. Since there have been much debates on causal relationship between slow acetylation and GSTT1 deletion, and bladder cancer, further studies are needed.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.507-513
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• 2004

Aflatoxins are produced mainly by Aspergillus flavus and Aspergillus parasiticus that grow in improperly stored cereals. Aflatoxin B1 ($AFB_1$) is a potent hepatocarcinogen in a variety of experimental animals including human beings. In spite of a high attention to the hepatocarcinogenecity of $AFB_1$, the relative toxicity of aflatoxins ($AFB_2$ and $AFG_1$) is not fully clarified. Sprague-Dawley male rats were orally administered with $AFB_1$, $AFB_2$, and $AFG_1$ at the dose of 250 ${\mu}g/kg$ (additionally including a dose of $1250{\mu}g/kg $ for $AFB_1$) body weight. Animals were then killed at 12, 24 or 48 hrs following aflatoxin exposure. Subsequently the immunohistochemical examination of p53, cytochrome p450 1A1 (CYP450 1A1), and glutathione-S-transferase placental form (GST-P) were performed. The level of the 8-OxodG in the liver was determined. Expressions of CYP450 1A1 and p53 were high in the liver of rats through 48 hrs after treatment of $AFB_1$ at the single dose of $250{\mu}g/kg $. This pattern was more clear as increasing doses. The treatment of $AFB_2$ and $AFG_1$ did not affect the expression of CYP450 1A1 but it caused weak expression of p53. The activity of GST were not found in the liver of rats treated with aflatoxins. The formation of 8-OxodG by $AFB_1$ increased in a dose-dependent manner up to 24 hrs after a single treatment of $AFB_1$ thereafter decreased to the level of control. The treatment of $AFB_2$ and $AFG_1$ did not affect the levels of 8-OxodG in the liver of rats with increasing time. These results in the present study indicate that $AFB_1$ among aflatoxins with low comparable levels is the most toxic as determined by early biomarkers such as CYP450 1A1, p53, GST-P, and 8-OxodG.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.195-202
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• 2015

The effects of waterborne arsenic (As) exposure on bioaccumulation and antioxidant defenses were examined in the liver and gills of tilapia, Oreochromis niloticus, under thermal stress. Tilapia were exposed to different As concentrations (0, 200, and $400{\mu}g\;L^{-1}$) at three water temperatures (20, 25, and $30^{\circ}C$) for 20 days. After As exposure, higher levels of As accumulation were observed in the gills compared with the liver in elevated water temperatures. In terms of the antioxidant response, glutathione (GSH) levels and the activities of glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST) significantly decreased in the liver and gills of tilapia exposed to As for 20 days, regardless of the As concentration (200 and $400{\mu}g\;L^{-1}$) or water temperature. These enzyme activities exhibited greater fluctuations in the liver and gills of tilapia after As exposure in water warmer than $20^{\circ}C$. The present findings suggest that the simultaneous stress of temperature change and As exposure can accelerate As accumulation and alter the antioxidant enzymes activities of tilapia.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.629-633
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• 1992

Caffeine이 랫드의 간조직에서 diethylnitrosamine(200mg/kg B.W., DEN)에 의해 유도되는 preneoplastic altered foci형성의 promotion단계에 미치는 효과를 관찰한 바 다음과 같은 결과를 얻었다. Altered foci의 지표로 사용되는 glutathione S-transferase(GST-P)-positive foci의 수는 caffeine 음수 $m{\ell}$당 2mg 병행투여군($3.10{\pm}2.74$) 및 1mg병행 투여군($5.86{\pm}2.83$) 모두에서 DEN 단독투여 대조군($11.55{\pm}5.82$)에 비하여 현저히 낮게 나타났으며 면적 또한 caffeine 2mg 병행투여군($0.13{\pm}0.11$), 1mg 병행투여군($0.21{\pm}0.12$)에서 DEN 단독투여 대조군($0.76{\pm}0.33$)에 비하여 유의성있는 낮은 수치가 관찰되었다. 간 세포배양에서 unscheduled DNA synthesis(UDS)는 DEN($250{\mu}g/m{\ell}$ of medium)단독처리군에 비하여 caffeine($200{\mu}g/m{\ell}$ of medium) 처리시 약 70% 감소하였다. 이러한 결과는 caffeine이 간암발생의 promotion단계에 작용하여 억제효과를 나타냄을 암시하며 이는 DNA회복의 억제와 관계됨을 알 수 있었다.

• Toxicological Research
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• v.27 no.1
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• pp.37-41
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• 2011

This study investigated the antioxidative action of Corni Fructus aqueous extract on kidneys of diabetic mice. The electron donating abilities of Corni Fructus aqueous extract and its antioxidant activities (XO, SOD, CAT, GST, eNOS) in kidneys of C57BL/6 or db/db mice were evaluated. For in vivo study, seven week-old male mice were divided into normal control group (NC, C57BL/6 mice), diabetic control group (DC, db/db mice) and Corni Fructus (500 mg/kg/day for 8 weeks) treated diabetic group (DCF, db/db mice). The electron donating abilities of Corni Fructus aqueous extract exhibited 7%, 24.4%, and 42.7% at concentrations of 100, 500, and $1000\;{\mu}g/ml$, respectively. The activity of XO in the DCF group was significantly lower than the DC group by 35% (p < 0.05). The SOD activity was significantly higher in the DCF group than the DC group by 26% (p < 0.05). The activities of CAT and GST were lowered in the DCF group than the DC group by 26% (p < 0.05) and 7.6%, respectively. The mRNA expression of eNOS in kidneys was lower in the DCF group than the DC group by 24%. These results indicate that Corni Fructus reduced oxidation stress as evidenced by the restoration of the enzymatic antioxidative defense system in renal tissues of db/db mice. It is suggested that these antioxidative actions of Corni Fructus on renal tissues in db/db mice could contribute to its renoprotective effects on diabetic nephropathy.