• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(환경)
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• pp.412-415
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• 1994

The fundamental assumption that thresholds exist for noncarcinogenic toxic effects of chemicals is reviewed; this assumption forms the basis for the no-observed-effect level/ safety-factor (NOEL/SF) approach to risk assessment for such effects. The origin and evolution of the NOEL/SF approach are traced, and its limitations are discussed. The recently proposed use of dose-response modeling to estimate a benchmark dose as a replacement for the NOEL is explained. The possibility of expanding dose-response modeling of non carcinogenic effects to include the estimation of assumed thresholds is discussed. A new method for conversion of quantitative toxic responses to a probability scale for risk assessment via dose-response modeling is outlined.

• Toxicological Research
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• 제19권1호
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• pp.73-82
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• 2003

To evaluate influence of Saposhnikovia divaricata (Turcz.) Schischk extract on rat, Saposhnikovia divaricata (Turcz.) Schischk extract was diluted with 0.9% saline (100 mg/ml/kg, 10 mg/ml/kg, and 1 mg/ml/kg, respectively), and each of diluted test material extract was daily treated subcutaneously for 4 weeks and single-treated subcutaneously for 2 weeks. There were no significances in body weight analysis, urinary analysis, and ophthalmological test. However, in serum biochemical analysis and hematological analysis, we found some significances in high and middle dose group compared with control group. These significances in serum biochemical analysis and hematological analysis may be not induced by test material, because it was not found to be significant from control group in histopathological examination. Therefore, it was concluded that NOEL (No Observed Effect Level) of test material extract may be higher than all treatment doses used in this study, and Saposhnikovia divaricata (Turcz.) Schischk extract may be a non-toxic material.

• Toxicological Research
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• 제19권1호
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• pp.51-66
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• 2003

This study was performed to evaluate single and repeated-dose toxicities of Bee Venom Extracts (F1, F3) in Spraque-Dawley. F1 was injected subcutaneously to rat at dose levels of 0, 0.0002, 0.002, 0.02 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. F3 was injected subcutaneously to rat at dose level of 0, 0.003, 0.03, 0.3 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. In both studies, there were no dose related changes in mortality, clinical sign, body weight change, food and water consumption, opthalmoscopy, organ weights, urine analysis, biochemical examination, and hematological findings of all animals treated with Bee Venom (F1, F3). Gross and histopathological findings revealed no evidence of specific toxicity related to Bee Venom (F1, F3). These results suggest that the subcutaneous NOEL (No Observed Effect Level) of Bee Venom (F1, F3) may be over F1 -0.02 mg/kg, F3-0.3 mg/kg.

• 한국자원식물학회지
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• 제28권4호
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• pp.371-381
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• 2015

The object of this study was to obtain single oral dose toxicity of Arisaema Rhizome (Arisaema amurense f. serratum (Nakai) Kitag) aqueous extracts. Arisaema Rhizome (Chunnamsong in Korean) is one of the most important folk remedy plants used in Asia. In the study, a 28-day rat oral gavage study has been conducted with the extracts from Arisaema Rhizome at dose of 1,250, 2,500 and 5,000 ㎎/㎏/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000 ㎎/㎏/day of the water-extracts from Arisaema Rhizome.

• 약학회지
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• 제58권1호
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• pp.62-70
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• 2014

A 28-day repeated-dose oral toxicity test was performed to determine the no-observed-effect level (NOEL) and establish an optimum dose of the highly toxic Aconiti Ciliare Tuber (ACT) used as a folk remedy. Repeated oral doses of 1,250, 2,500, and 5,000 mg/kg/day of the hot water extract of ACT were administered to five male and five female Sprague-Dawley rats in each group for 4 weeks. The indicators for toxicity included results of examination of common symptoms and changes in weight and feed intake, eye test, urinalysis, hematological and serum biochemical analyses, and post-mortem weight measurement of organs, and visual inspections. All animals survived at the end of the experiment; in addition, we observed no specific test substance-mediated symptoms. We observed no test substance-mediated changes in body weight and feed intake. We observed statistically significant changes in male OB and pH levels (p<0.05). Further, the biochemical test showed statistically significant changes in the IP value of male rats and $CL^-$valueoffemalerats (p<0.05). However, all changes were within historical data. The post-mortem examinations showed no test substance-mediated changes. Moreover, statistically significant changes under the test conditions were confirmed to have been caused by factors other than the test substance. Thus, the maximum NOEL of ACT extract in rats was estimated to be 5,000 mg/kg/day.

• 생명과학회지
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• 제26권10호
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• pp.1153-1162
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• 2016

계종버섯(Thermitomyces albuminosus)의 안정성을 입증하기 위하여 사료에 계종버섯의 분말을 5%, 2.5%, 1.25%, 0%를 혼합하여 90일 동안 랫드에 자유 급이 시켜 실험동물의 일반증상, 체중변화, 혈액학적 검사, 부검소견, 임상병리, 조직병리학적 검사의 결과를 토대로 독성을 평가하였다. 독성판정기준은 독성의 정도와 양상에 따라 weight-based classification (독성 강도에 따른 분류)로 분류 하였는데 비시험물질-유래 변화인 NOEL, 시험물질-유래 경미한 변화는 NOAEL, 시험물질-유래 중요한 변화는 LOAEL을 기준으로 나누었다. 시험결과, 수컷 좌, 우측 신장 중량이 용량의존적으로 증가하여 고용량군에서는 12%, 8% 증가 하였다. 하지만 임상, 조직병리학적 결과 독성으로 판단되는 소견이 관찰되지 않아 시험물질-유래 경미한 변화로 판단으로 분류하였다. 따라서 판정기준에 따라 수컷은 NOAEL 암컷은 NOEL이 식이함량 5%로 추정되지만 식약처고시에 따라 암수 모두 NOAEL이 식이함량의 5%로 추정할 수 있다. 따라서 계종버섯은 식품 또는 기능성식품으로의 개발에 문제가 없을 것으로 사료된다.

• 한방비만학회지
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• 제18권1호
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• pp.36-49
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• 2018

Objectives: The study is aimed at evaluating the possible toxicity in 90-day repeated oral administration of modified Samjung-hwan (mSJH) in Sprague-Dawley (SD) rats. This study was conducted to detect the no-observed adverse effect level (NOAEL). Methods: Modified SJH extract was administered orally in male and female SD rats at dose of 0, 1,000, 2,000, 4,000 mg/kg. Each group consisted of 10 rats of each gender. The modified SJH extract was given once a day for 90 days. We monitored the changes of mortalities, clinical signs, body weight changes, food consumption, ophthalmologic findings, urine analysis, hematology, serum biochemistry, necropsy findings, organ weights, histological markers of all animals treated with modified SJH extract during the study period. Results: There were no toxicologically significant changes in mortalities, clinical signs, body weight gains, food consumption, ophthalmologic findings, urine analysis, hematology, serum biochemistry, necropsy findings, organ weights, histological markers in any of rats tested. Conclusions: The NOAEL of the modified SJH extract in male rats and no observed effect level (NOEL) in female rats are considered 4,000 mg/kg.

• 한국식품위생안전성학회지
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• 제20권1호
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• pp.7-12
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• 2005

The purpose of this study was to examine the four week repeated toxicity in Sprague-Dawley rats orally administrated with Rhus-II (water fraction of Rhus Veniciflua). In acute toxicity test, three groups (40 rats of both sex) were administrated different dosages of Rhus-II, 2 g/kg (high dosage group), 1 g/kg, 0.5 g/kg and one group (10 rats of both sex) were received by orally only saline according to the Regulation on Korea Food and Drug Administration, respectively. There was no difference in body weight change, feed intake and water consumption among different dose groups. There was no alteration in relative organ weight by the administration of Rhus-II. No death of abnormal clinical signs was observed during the experimental period. Between the groups orally administered Rhus-II and the control group, there was no statistical significance in urinalysis, hematological test or serum biochemical values. There were no gross findings at final sacrifice. There was no evidence of histopathological alteration mediated by four week treatment with Rhus-II. These results suggest that no observable effect level(NOEL) of the test orally administration was considered to be more than 2g/kg in rats under the conditions employed in this study.

• 한국약용작물학회지
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• 제26권2호
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• pp.157-169
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• 2018

Background: Cassia tora L., an annual or perennial plant of the Fabaceae family, is traditional medicine with various biological activities, including anti-constipation and, anti-inflammation. Chemical compounds such as anthraquinone glycoside and naphthalene derivatives have been isolated from this plant. Cassia tora L. is a common contaminant of agricultural commodities, but is toxic to cattle and poultry. Methods and Results: To investigate the potential toxicity, Cassia tora L. aqueous extract (CO) was administered orally to rats for 26 weeks at 0 (control), 300, 1,500 and 3,000 mg/kg/day (n = 10 for male rats for each dose). The positive control comprised animals orally administered anthraquinone 100 mg/kg/day. There was no treatment-related mortality. An increase in the kidney weight was observed at 3,000 mg/kg/day of CO and anthraquinone 100 mg/kg/day. Macrophage infiltration in the colon was observed at CO 1,500 and 3,000 mg/kg/day and anthraquinone 100 mg/kg/day, but there were no significant toxicological changes in the incidence and severity of the finding. Conclusions: The oral no-observed-adverse-effect level (NOAEL) of CO was 3,000 mg/kg/day in male rats and no target organs were identified. In addition, 300 mg/kg was found to be the no-observed-effect level (NOEL) for systemic toxicity under the conditions of the study.

• Environmental Analysis Health and Toxicology
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• 제21권2호
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• pp.173-184
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• 2006

From the harmfulness expectation test conducted through a toxicity anticipation program, methylcyclohexane turned out to be harmful and simulative, but no carcinogenicity was anticipated. In a four-hour acute inhalation toxicity test, the result showed that lethal concentration ($LC_{50}$) was 3,750 ppm (15,054 mg/L), which was identified as a harmful substance on the basis of the harmful substance classification standard $2 of the Industrial safety and health law. methylcyclohexane fell under the category $4(2,500 substance from the GHS standard acute toxicity harmfulness classification. Also, from subchronic inhalation toxicity test that included 6 hours a day, five days a week, and for 13 weeks, we could observe weight, activity, long term weight, blood and blood biochemical influence from the exposure of test substance. No-observed effect level (NOEL) was determined below $100{\sim}400ppm$ inboth male and female. This material falls under the Category 2 ($50{\sim}250ppm/6hours/90days$) in the GHS (Globally Harmonized System) standard trace long-term whole body toxicity repeated exposure, and can be classified as a harmful substance in accordance with the Industrial Safety and Health Law harmful substance standard $NOEL{\leq}0.5mg/L/6hr/90day$ (rat).