• The Journal of Korean Medicine
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• v.35 no.2
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• pp.28-33
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• 2014

Background: Samul-tang (Si-Wu-Tang, SMT) is a traditional herbal formula, which has been widely used to treat various diseases such as menstrual irregularity, bleeding and leucorrhea. Although many studies have investigated the pharmacological properties of SMT, its toxicity information has not yet been fully elucidated. Methods: Five Sprague Dawley (SD) rats of each sex were given a single dose (5000 mg/kg) of SMT by gavage; control rats received the vehicle only. After the single administration, mortality, clinical signs, body weight changes and gross findings were monitored for 15 days in accordance with Good Laboratory Practice (GLP) principles. Results: In a single oral dose toxicity study, there was no adverse effect on mortality, clinical sign, body weight change or gross finding in any treatment group. Conclusions: The results indicate that SMT did not induce toxic effects at a dose level up to 5000 mg/kg in rats and its median lethal dose ($LD_{50}$) was considered to be over 5000 mg/kg/day body weight for both genders.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.211-217
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• 2016

We examined damages from gamma-irradiaion and determined the optimal gamma-ray dose for mutation breeding in lentil (Lens culinaris L.) bean. Four individual lines (L-C, L-2, L-8 and L-9), that have remarkable adaptability in South Korea were gamma-irradiated at doses of 50, 70, 100, 200, 300, 400, and 500 Gy. The germination rate of seed decreased as the dose increased over 50 Gy in all lines. However, $LD_{50}$ and $RD_{50}$ were different among lines. The median lethal doses($LD_{50}$) were approximately 127 (L-C), 74 (L-2), 95 (L-8), and 144 (L-9) Gy. The median reduction doses($RD_{50}$) for plant height, number of leaves, root length, and flash weight were 156, 176, 150, and 180 Gy for L-C, 253, 198, 127, and 142 Gy for L-2, 188, 175, 200, and 190 Gy for L-8, and 162, 210, 224, and 184 for L-9, respectively. The growth characteristics of the $M_1$ generation decreased as the dose increased over 70 Gy. The optimal doses of gamma irradiation for mutation breeding of lentil were determined to be 70 Gy (L-2, L-8) and 100 Gy (L-C, L-9). We performed the comet assay to observe nuclear DNA damage induced by gamma-irradiation. In comet assay, a clear difference was identified over 100 Gy treatments. With increasing doses of gamma-ray in the range of 50 to 500 Gy, the rate of head DNA was decreased significantly from 97.5% to 81.6%. Tail length was consecutively increased from $1.9{\mu}m$ to $17.4{\mu}m$. Our result provides basic information for construction of mutant pools in lentils.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.36-39
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• 1978

With the current advances in insect toxicant bioassay, the need for easy methods of estimating the dosage-mortality regression equation has become vital. The Probit analysis seems to be not convenient for estimating the dosage-mortality regression equation and median lethal dose(LD50) because of its complexity in calculation. This study presents a comparision between Probit and Losit transformation for the estimation from bioassay results. Validation of the two methods is presented for the pathogenecity of nuclear polyhedrosis virus to the larva of fall web worm, Hyphantria cunea D.

• The Journal of Korean Obstetrics and Gynecology
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• v.26 no.1
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• pp.59-68
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• 2013

Objectives: This study was conducted to investigate the acute toxicity of Pyungwi-san(Pingwei-san in Chinese) in ICR mice, according to KFDA and OECD guideline. Methods: In the present study, 15 male and female ICR mice administrated singly by gavage at dose levels of 0 and 2000 mg/kg of Pyungwi-san. During the experimental period, no treatment-related death was observed. There were no adverse effects on clinical signs, body weight, and gross findings at all treatment groups. Results: These results showed that the single oral adminstration of Pyungwi-san (Pingwei-san) did not cause any toxic effect at the dose levels of 2000 mg/kg in rats. Conclusions: Taken together, the median lethal dose($LD_{50}$) of Pyungwi-san (Pingwei-san) was considered to be over 2000 mg/kg body for both sexes.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.13-23
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• 2024

Vespa velutina nigrithorax du Buysson, 1905 is the invaded species in Korea since 2003. Since its importance as the honey bee pest, beekeepers use insecticides to kill the adult and immature hornets. However, its legality and effectiveness has not been confirmed. This study investigated the susceptibility of insecticides commonly used to control hornets by beekeepers in Korea. Eight insecticides were tested on adult worker and larvae by topical or oral treatment. Adults showed more than 70% mortalities from Clothianidin, Dinotefuran, and Carbosulfan treatment within 30 minutes. Bifenthrin and Cartap hydrochloride showed relatively low toxicity. The median lethal dose (LD₅₀) for Clothianidin, Dinotefuran, and Carbosulfan was 0.29, 0.65, and 2.21 ㎍/bee, respectively. In larval feeding test where 5^th instar larvae were fed 3 times every 24 hours, the mortality began after second treatments. After 3rd treatments (72 h), all insecticides showed mortality more than 70%. The LD₅₀ values of Clothianidin, Dinotefuran, and Carbosulfan to V. velutina were approximately 10 to 100 times higher than those to honey bee, Apis mellifera. This study provides the basic information of those chemical toxicities to Vespa hornet and honey bees.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.45-57
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• 2015

Objectives: This study aims to compare the physicochemical characteristics, toxicological data with Occupational Exposure Limits (OELs) of chemicals under the Occupational Safety and Health Act(OSHA) regulated by the Ministry of Employment and Labor of Korea. Methods: Information on chemicals which have OELs on physicochemical characteristics and toxicological data was collected using Material Safety Data Sheet(MSDS) from Korea Occupational Safety and Health Agency(KOSHA) and the Korea Information System for Chemical Safety Management(KISChem) in 2014. Statistical analyses including correlation and simple regression were performed to compare the OELs with chemical characteristics including molecular weight, boiling point, odor threshold, vapor pressure, vapor density, solubility and octanol-water partition coefficient(OWPC) and toxicological data such as median lethal dose($LD_{50}$) and median lethal concentration($LC_{50}$). Results: A total of 656 chemicals have OELs under OSHA in Korea. The numbers of chemicals which have eight-hour time weighted average(TWA) and short term exposure limits(STEL) are 618 and 190, respectively. TWA was significantly correlated with boiling point and STEL was only correlated with vapor pressure among physicochemical characteristics. Solubility and OWPC between "skin" and "no skin" substances which indicate skin penetration were not significantly different. Both $LD_{50}$ and $LC_{50}$ were correlated with TWA, while the $LC_{50}$ was not with STEL. As health indicators, health rating and Emergency Response Planning Guidelines(ERPG) rating as recommended by the National Fire Protection Association(NFPA) and American Industrial Hygiene Association(AIHA) were associated with OELs and reflect the chemical hazards. Conclusions: We found relationships between OEL and chemical information including physicochemical characteristics and toxicological data. The study has an important meaning for understanding present regulatory OELs.

• Nutrition Research and Practice
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• v.11 no.6
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• pp.452-460
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• 2017

BACKGROUD/OBJECTIVES: Turanose, ${\alpha}$-D-glucosyl-($1{\rightarrow}3$)-${\alpha}$-D-fructose, is a sucrose isomer which naturally exists in honey. To evaluate toxicity of turanose, acute and subchronic oral toxicity studies were conducted with ICR mice. MATERIALS AND METHODS: For the acute oral toxicity study, turanose was administered as a single oral dose [10 g/kg body weight (b.w.)]. In the subchronic toxicity study, ICR mice were administered 0, 1.75, 3.5, and 7 g/kg b.w. doses of turanose daily for 13 weeks. RESULTS: No signs of acute toxicity, including abnormal behavior, adverse effect, or mortality, were observed over the 14-day study period. In addition, no changes in body weight or food consumption were observed and the median lethal dose (LD50) for oral intake of turanose was determined to be greater than 10 g/kg b.w. General clinical behavior, changes in body weight and food consumption, absolute and relative organ weights, and mortality were not affected in any of the treatment group for 13 weeks. These doses also did not affect the macroscopic pathology, histology, hematology, and blood biochemical analysis of the mice examined. CONCLUSION: No toxicity was observed in the acute and 13-week subchronic oral toxicology studies that were conducted with ICR mice. Furthermore, the no-observed-adverse-effect level is greater than 7 g/kg/day for both male and female ICR mice.

• The Journal of Korean Medicine
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• v.32 no.3
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• pp.18-24
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• 2011

Objective: Leejung-tang (Rechu-to in Japanese) is a traditional Korean herbal formula used for treatment of gastrointestinal disorders such as vomiting, stomach pain, chronic gastritis and gastrointestinal ulceration. The present study was carried out to investigate the potential acute toxicity of Leejung-tang water extract (LJT) by a single oral dose in Crl:CD (SD) rats in compliance with current guidelines. Methods: In the preliminary study, there were no adverse effects such as death, clinical signs, and body weight changes at dose levels of 500, 1000, and 2000 mg/kg/day body weight. Based on the results, a dose of 2000 mg/kg was selected as the toxicological limited dose. LJT was administered once by gavage to male and female rats at dose levels of 0 and 2000 mg/kg bodyweight. During the study period, mortalities, clinical findings, and body weight changes were observed for 14 days following the administration. On day 14 after the treatment, the animals were sacrificed by carbon dioxide overdose and complete gross postmortem examinations were performed. Results: In present study, no treatment-related deaths were observed. There were no adverse effects on clinical signs and body weight changes. In addition, there were no observed gross findings in all groups except for a kidney cyst in the 2000 mg/kg/day female group. Conclusion: The results indicated that LJT did not induce toxic effects at a dose level up to 2000 mg/kg in rats and its median lethal dose ($LD_{50}$) was considered to be over 2000 mg/kg/day body weight for both genders.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.58-71
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• 2015

Objectives: The aims of this study were to investigate the classification system of chemical substances in the Occupational Safety and Health Act(OSHA) and Chemical Substances Control Act(CSCA) and to compare several health indices (i.e., Time Weighted Average (TWA), Lethal Dose ($LD_{50}$), and Lethal Concentration ($LC_{50}$) of chemical substances by categories in each law. Methods: The chemicals regulated by each law were classified by the specific categories provided in the respective law; seven categories for OSHA (chemicals with OELs, chemicals prohibited from manufacturing, etc., chemicals requiring approval, chemicals kept below permissible limits, chemicals requiring workplace monitoring, chemicals requiring special management, and chemicals requiring special heath diagnosis) and five categories from the CSCA(poisonous substances, permitted substances, restricted substances, prohibited substances, and substances requiring preparation for accidents). Information on physicochemical properties, health indices including CMR characteristics, $LD_{50}$ and $LD_{50}$ were searched from the homepages of the Korean Occupational and Safety Agency and the National Institute of Environmental Research, etc. Statistical analysis was conducted for comparison between TWA and health index for each category. Results: The number of chemicals based on CAS numbers was different from the numbers of series of chemicals listed in each law because of repeat listings due to different names (e.g., glycol monoethylether vs. 2-ethoxy ethanol) and grouping of different chemicals under the same serial number(i.e., five different benzidine-related chemicals were categorized under one serial number(06-4-13) as prohibited substances under the CSCA). A total of 722 chemicals and 995 chemicals were listed at the OSHA and its sub-regulations and CSCA and its sub-regulations, respectively. Among these, 36.8% based on OSHA chemicals and 26.7% based on CSCA chemicals were regulated simultaneously through both laws. The correlation coefficients between TWA and $LC_{50}$ and between TWA and $LD_{50}$, were 0.641 and 0.506, respectively. The geometric mean values of TWA calculated by each category in both laws have no tendency according to category. The patterns of cumulative graph for TWA, $LD_{50}$, $LC_{50}$ were similar to the chemicals regulated by OHSA and CCSA, but their median values were lower for CCSA regulated chemicals than OSHA regulated chemicals. The GM of carcinogenic chemicals under the OSHA was significantly lower than non-CMR chemicals($2.21mg/m^3$ vs $5.69mg/m^3$, p=0.006), while there was no significant difference in CSCA chemicals($0.85mg/m^3$ vs $1.04mg/m^3$, p=0.448). $LC_{50}$ showed no significant difference between carcinogens, mutagens, reproductive toxic chemicals and non-CMR chemicals in both laws' regulated chemicals, while there was a difference between carcinogens and non-CMR chemicals in $LD_{50}$ of the CSCA. Conclusions: This study found that there was no specific tendency or significant difference in health indicessuch TWA, $LD_{50}$ and $LC_{50}$ in subcategories of chemicals as classified by the Ministry of Labor and Employment and the Ministry of Environment. Considering the background and the purpose of each law, collaboration for harmonization in chemical categorizing and regulation is necessary.

• The Korea Journal of Herbology
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• v.26 no.2
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• pp.39-43
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• 2011

Objectives : This study was conducted to evaluate the acute toxicity and safety of Ssanghwa-tang (Shuanhetang in Chinese, Sou-wa-to in Japanese) in Crl : CD Sprague-Dawley (SD) rat though the current regulatory guideline. Methods : In this study, 10 rats of each sex were randomly assigned to two groups of 5 rats each and were administrated singly by gavage at dose levels of 0 and 2000 mg/kg/day of ssanghwa-tang water extract (SHT). After single administration of SHT, mortalities, clinical signs, body weight changes, gross findings were observed for the 15-day period. Results : Acute toxicity tests revealed that a single oral administration of SHT at dose levels of 2000 mg/kg did not affect clinical signs, body weight, and gross findings, evaluating the safety of SHT. The SHT treatment did not result in any toxicologically significant changes in mortality, clinical signs, body weight changes. Conclusions : These results showed that the single oral administration of SHT did not cause any toxic effect at the dose levels of 2000 mg/kg/day in rats. In conclusion, the median lethal dose (LD50) of SHT was considered to be over 2000 mg/kg/day body for both sexes.