• Journal of Wetlands Research
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• v.9 no.1
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• pp.79-89
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• 2007

This paper provides a comprehensive overview of the present status of several environmental problems caused by emerging toxic substances such as persistent organic pollutants (POPs), endocrine disrupting chemicals (EDCs), and arsenic in various environmental media in Vietnam. Monitoring data reported during the 1990s demonstrated elevated contamination of DDTs in most of these compartments in Vietnam. Studies in frame of the Asia-Pacific Mussel Watch Program revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. The estimated dietary intakes of PCBs and DDTs for Vietnamese were relatively high among Asian developing countries, suggesting potential risk for humans posed by thesechemicals. Widespread contamination of some endocrine active compounds such as alkylphenols and phthalates was observed at various sites along the coasts of northern and middle Vietnam. The presence of significant source of bisphenol-A along Red River estuary was revealed with the concentrations comparable to those reported for developed nations. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and middle Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and coastal environment. From ecotoxicological perspectives, concentrations of bis-phenol A and di(2-ethylhexyl)phthalates [DEHP] in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Widespread and elevated arsenic contamination was discovered inour recent surveys in groundwater in a large area of suburban areas of Hanoi city, the capital of Vietnam. The most recent investigation in 4 villages showed about more than 50 % of groundwater samples contained As concentrations exceeding 50 g/L (the WHO and Vietnamese standard). In particular, in Son Dong villages, 58 % of samples analyzed contained As concentrations higher than 200 g/L. Good correlations were found in As concentrations in water and hair and urine of peoples in corresponding families, suggesting the chronic exposure to As by people living in As-contaminated ground water areas. In Son Dong village, As levels in hair (mean: 1.7 mg/kg dry wt) and urine (g/g creatinine) exceeding the reference values recommended by WHO, suggesting potential for human risk posed by long term accumulation of As in human body. Future studies should be focused on the time trends of POPs and EDCs in biota in Vietnam in order to predict future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms. The issues of arsenic contamination in groundwater and their chronic toxic implications on human health should be systematically investigated in the future.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.306-316
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• 2017

The purpose of this study was to evaluate the effects of exposure to various children's drinks on the color stability of anterior primary teeth and different esthetic restorative materials clinically used in pediatric dentistry. Exfoliated maxillary primary central incisors that had been unaffected by caries were chosen as control group. Maxillary primary central incisor-shaped specimens made of strip crown and Nu-smile zirconia crowns were chosen as test groups. Polished strip resin crowns were additionally prepared to compare with unpolished strip resin crown. Each specimen and teeth were divided into 4 groups in which the test samples (n=5 each) were immersed in 4 different drinks (distilled water, cola, grape juice, jelly juice) for 6 days. In all 4 drink groups, all specimens generally showed increasing ${\Delta}E^*$ value (color difference) with time. Polished resin strip crown had higher ${\Delta}E^*$ value than the unpolished in cola, grape juice and jelly juice groups. ${\Delta}E^*$ value of zirconia crown in cola, grape juice and jelly juice groups were significantly different (p < 0.05). In conclusion, dietary control of children's drinks is required for preventing discoloration of restorative materials.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.54-58
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• 2014

The liver is vulnerable to alcohol-related injury because it is the primary site of alcohol metabolism. Additionally, a number of potentially dangerous by-products are generated as alcohol is broken down in the liver. However, dietary supplements may prevent or relieve some of alcohol's deleterious effects. Therefore, this study was conducted to evaluate the prophylactic effect of aqueous extract of Sesamum indicum (SI) on ethanol induced toxicity in rats. Male Wistar albino rats were divided into control, ethanol, pre-treatment, simultaneous and post-treatment groups. In the prophylactic experiment, Sesamum indicum, (200 mg/kg body weight) was administered by oral gavage for 28 days; two hours before, simultaneously with or two hours after ethanol exposure. Toxicity was induced by administering 45% ethanol (4.8 g/kg bw) by oral gavage. Lipid peroxidation (TBARS) and reduced glutathione (GSH) levels and catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and gluthathione-S-transferase (GST) activities were then determined in the liver, serum triglyceride (TG) levels, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were monitored and histological examination was carried out. The results revealed that ethanol administration led to significant elevation of TBARS level while depleting in the level of GSH as well as CAT, GPx, SOD and GST activities. Similarly, TG level and ALT and AST activities were elevated. The SI pre-treated group significantly inhibited TBARS, restored GSH level, enhanced CAT, GPx, SOD and GST activities and significantly decreased the elevated level of serum TG, ALT and AST activities. SI treatment (simultaneously with ethanol) exhibited similar effects to those of the SI pre-treated groups, while the SI post-treated group did not show the same protection as the Pre-treated group. S. indicum possesses antioxidant and hepatoprotective properties, that eliminate the deleterious effects of toxic metabolites of ethanol.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.306-320
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• 2015

This survey was carried out in 2014 to estimate the pesticide residue levels in commercial environment-friendly agricultural products in Seoul metropolitan area. Pesticide residues in 27 commodities were examined and analyzed using LC-MS/MS, which can simultaneously detect up to 85 pesticides. A total of 441 samples were collected and analyzed. Among the detected samples, the residue levels in 1.2% of organic agricultural products and 2.2% of pesticide-free agricultural products exceeded the maximum residue limits (MRLs); hence, 1.8% of the total samples exceeded the MRLs. The safety of the detected pesticides was assessed by monitoring the acceptable daily intake level (ADI) and acceptable dietary exposure (ADE) to the pesticides via consumption of the commodities. ADI and ADE are found to be 0.07728-9.46530% and 0.00141-0.17210%, respectively, which means that the residual pesticides in the environmental-friendly agricultural products in Korea are below the safe limit and therefore, pose no potential public health risks.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.559-592
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• 1999

It has been known that Ki(氣) energy is very effective on many adult diseases. Oriental Medicine has acknowledged Ki as an existing reality and investigated its effects on the body. However, the existence of Ki has not been fully explained. In order to find a conclusive evidence on the existence of Ki, this experiment was done to study the mutual relationship of Ki with a magnetic field and BEP (biological energy projector). The BEP apparatus was irradiated under the magnetic field on rats in the hyperlipidemic induced state. Following criterias were measured in this experiment: weight change, weight of the visceral organs, serum, hepatic lipid peroxide, bleeding time, tissue factor, and etc. The following results were obtained in this study: 1. The weight of rat significantly decreased in the magnetic field treated group and radically reduced in the group treated with both magnetic field and BEP. 2. The weight of liver, heart, and kidney increased in both the magnetic field treated group and magnetic field+BEP group compared to the normal group, but decreased in comparison to the control group. No changes were witnessed in the weight of spleen. 3. Serum and hepatic total cholesterol, total lipid, and lipid peroxide level significantly decreased in both magnetic field treated group and magnetic field+BEP treated group, while lipase activity has increased noticeably. 4. Serum HDL showed a significant increase in both magnetic field treated group and magnetic field+BEP treated group compared to the control group, while LDL and VLDL level decreased significantly. 5. A bleeding time significantly increased in both magnetic field treated group and magnetic field+BEP treated group compared to the control group. A tissue factor value of the lung decreased in the magnetic field treated group and magnetic field+BEP treated groups while increased in the control group. 6. Serum and hepatic lipid peroxide and glutathione level were significantly decreased in the magnetic field treated group and magnetic field+BEP treated group, while hepatic glutathione level was significantly increased compared to the control group. 7. A significant increase was found in the serum hydroxyl radical and SOD activity in the dietary hyperlipidemic rats, and significant decrease was found in the serum lipid peroxide content and superoxidase activity. 8. Hepatic cytosolic enzyme xanthine oxidase and aldehyde oxidase showed a significant decrease in the magnetic field treated group and magnetic field+BEP treated group. Through the above experimental results, one can suggest that the magnetic field with BEP can suppress hyperlipidemia and boost lipid metabolism and restructuring a lipid in liver, which increases the function of liver. To conclude, BEP is considered to show more potent effects under the exposure of magnetic field because magnetic field seems to increase the flow of Ki in the body.

• Journal of fish pathology
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• v.23 no.2
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• pp.189-198
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• 2010

Experiments were carried out to determine the hematological changes in olive flounder, Paralichthys olivaceus, after sub-chronic dietary pentachlorophenol (PCP) concentrations (0, 0.1, 0.5 and 1.0 mg/kg) exposure 6 weeks. The RBC count, Ht and Hb were significantly decreased in PCP 0.5 mg/kg exposed flounder compared to control group. The flounder exposed to PCP concentration 0.5 mg/kg started to increase significantly in serum magnesium concentrations after 4 weeks. The low concentration of serum calcium concentration was observed at 6 weeks of the experiment in PCP concentration 0.5 mg/kg. Although serum total protein concentrations was significantly reduced compared to the control group at PCP concentration 0.5 mg/kg, serum glucose concentration was found to be significantly increased over the control group. A significant increment of GOT, GPT and LDH activities in the flounder serum was noticed after 4 weeks at PCP concentrations over 0.5 mg/kg without typical changes of Al-P. These results indicate that flounder can be affected by PCP in terms of inorganic matter, organic matter and enzyme activity in serum when they were exposed to the PCP concentrations 0.5 mg/kg or higher.

• Nutritional Sciences
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• v.9 no.1
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• pp.20-28
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• 2006

Aryl sulfotransferase (AST) IV is a liver enzyme involved in detoxication and has been shown to be susceptible to down regulation by a number of hepatotoxic xenobiotics. Studies presented here to investigate the ability of biological and non-biological divalent metal cations on AST IV activity showed that AST IV was strongly inhibited following in vitro or in vivo exposure to. Zn ( II ), Co ( II ) or Cd ( II ). It was found that $0.025\sim$2.5 uM of these metal ions were sufficient to cause $50\%$ of inhibition in vitro in purified AST IV and $0.25\sim$25 uM of these metal ions in liver cytosolic fractions. For the in vivo study, 1,000 mg Cu ( II )/kg, 2,000 mg Zn ( II )/kg or 250 mg Cd( II )/kg was added to individual diets and administered to three (3) group; of mts over a 7 week period The Co ( II )-supplemented diet produced no apparent change in rat growth rate and resulted in 30-fold increase in liver cytotolic Cu ( II ) levels, suggesting that elevated levels of Cu ( II ) ion in the liver were responsible for the loss of AST IV activity. In contrast, the Zn ( II )-supplemented diet caused a decrease in rat growth rates and resulted in zero increase in liver Zn ( II ) levels, which suggested an indirect inhibition mechanism was caused by Zn ( II ) in the liver. Rats were fed the Cd-supplemented diet also displayed a decrease in growth rate with little or no change in liver Cu ( II ) or Zn ( II ) levels. When the liver cytosols of mts from the metal ion diets were immunochemically analyzed for the AST IV and albumin contents, no significant changes were observed in albumin levels. However, AST IV contents in the cytosols of mts fed the Zn ( II )-supplemented diets showed a slight decrease in amount These results showed that AST IV activity in vitro and in vivo can be inhibited by Co ( II ), Zn ( II ), and Cd ( II ) by apparently different mechanisms. The immediate response to a Zn injection showed a decrease in AST IV activity but not in the AST IV content in liver cytosol. These mechanisms appeared to involve direct actions of the metal ion on AST IV activity and indirect actions affecting AST IV amount.

• Development and Reproduction
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• v.23 no.3
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• pp.223-229
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• 2019

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance (IR). T2DM is correlated with obesity and most T2DM medications have been developed for enhancing insulin sensitivity. Silk protein fibroin (SPF) from spiders has been suggested as an attractive biomaterial for medical purposes. We generated transgenic rice (TR) expressing SPF and fed it to diabetic $BKS.Cg-m+/+Lepr^{db}$ mice to monitor the changes in blood glucose levels and adipose tissue proteins associated with energy metabolism and insulin signaling. In the present study, the adipocyte size in abdominal fat in TR-SPF-fed mice was remarkably smaller than that of the control. Whereas the adenosine monophosphate-activated protein kinase (AMPK)-activated protein kinase and insulin receptor substrate 1 (IRS1) protein levels were increased in abdominal adipose tissues after TR-SPF feeding, levels of six-transmembrane protein of prostate 2 (STAMP2) proteins decreased. Phosphorylation of AMPK at threonine 172 and IRS1 at serine 307 and tyrosine 632 were both increased in adipose tissues from TR-SPF-fed mice. Increased expression and phosphorylation of IRS1 at both serine 307 and tyrosine 632 in adipose tissues indicated that adipocytes obtained from abdominal fat in TR-SPF-fed mice were more susceptible to insulin signaling than that of the control. STAMP2 protein levels decreased in adipose tissues from TR-SPF-fed mice, indicating that STAMP2 proteins were reducing adipocytes that were undergoing lipolysis. Taken together, this study showed that TR-SPF was effective in reducing blood glucose levels in diabetic mice and that concurrent lipolysis in abdominal adipocytes was associated with alterations of AMPK, IRS1, and STAMP2. Increased IRS1 expression and its phosphorylation by TR-SFP were considered to be particularly important in the induction of lipolysis in adipocytes, as well as in reducing blood glucose levels in this animal model.

• Journal of Ginseng Research
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• v.37 no.4
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• pp.425-434
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• 2013

UV irradiation is the main factor contributing to skin damages that are associated with an excessive production of matrix-degrading metalloproteinase (MMP)-1 and a deficient expression of collagens. To date, red ginseng has been revealed to possess many biomedical effects, such as anti-aging, anti-oxidation, and anti-inflammatory. In this study, we prepared the Korean Red Ginseng extracts treated with enzyme (KRGE) and investigated the effects of dietary KRGE on the formation of wrinkles generated by UVB irradiation in hairless mice. It was found that KRGE inhibited the UVB-induced formation of wrinkles, epidermal thickness, and skin dryness in hairless mice. Further results also showed that KRGE attenuated UVB-induced MMP-${\beta}$1 level, while accelerated procollagen type I, transforming growth factor-${\beta}$1 secretion. Interestingly, the expression of profilaggrin and filaggrin in both the epidermis and dermis were decreased due to UVB exposure and reversed by KRGE. The KRGE 0.06% was prior to KRGE 0.24%. In view of these results, which indicated that KRGE protected skin from UVB-induced photodamages, which may not only mediated by regulating of MMP-1 and procollagen type I, but also by increasing the production of profilaggrin and filaggrin. In conclusion, our results suggest that KRGE may be a promising agent for the treatment of skin photodamages. The challenge of KRGE will be expected as cosmeceuticals and nutraceuticals in order to intervene in aging-related degenerative skin changes.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.391-395
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• 2018

There is an increasing concern over arsenic (As) contamination of paddy soil and rice with regard to food safety. This study was conducted to investigate total and inorganic As concentration in one hundred husked and polished rice samples collected at the non-contaminated paddy soil in Korea. Arsenic species in rice samples were extracted using 1% nitric acid ($HNO_3$) with a microwave oven and were measured using high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. Mean concentrations of total As in husked rice and polished rice were 0.18 and $0.11mg\;kg^{-1}$, respectively. Also, average inorganic As concentrations in husked rice and polished rice were 0.11 and $0.07mg\;kg^{-1}$, respectively. These levels are lower than the standard guideline value 0.35 and $0.2mg\;kg^{-1}$ for inorganic As in husked and polished rice recommended by Codex Committee on Contaminants in Foods and Ministry of Food and Drug Safety, respectively. The mean of the inorganic As ratio for the total amount of As was 0.65 and 0.67 for husked rice and polished rice, respectively, and the range was from 0.08 to 1.0. For health risk assessment, the average value of cancer risk probability was $9.24{\times}10^{-5}$ and ranged from $2.30{\times}10^{-5}$ to $1.90{\times}10^{-5}$. Therefore, human exposure to As through dietary intake of surveyed rice samples might considered to be a low health risk.