• Journal of Marine Life Science
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• v.6 no.2
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• pp.80-87
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• 2021

In this study, the toxic effects of PFOA and PFOS potassium salt on Mesocentrotus nudus using 10 min-fertilization rate and 48 h-normal embryogenesis were confirmed through the calculation of toxicity values such as Non-observed effective concentration, Low-observed effective concentration, and 50% of effective concentration. The case of 10 min-fertilization rate and 48 h-normal embryogenesis showed the concentration-dependent reduction pattern when exposed to PFOA and PFOS potassium salt, in tested concentration, respectively. The EC50 values of 10 min-fertilization rates for PFOA and PFOS potassium salt were 1346.43 mg/l and 536.18 mg/l, respectively, and the EC50 values of 48 h-normal embryogenesis were 42.67 mg/l and 17.81 mg/l, respectively. Both toxicity test methods showed high toxicity sensitivity to PFOS potassium salt. Recent studies have shown that the concentration of PFOA and PFOS in the marine environment has continuously decreased, and it is not enough to show acute toxicity to sea urchin. However, PFOA and PFOS have a very long half-life and can accumulate throughout the life of marine life, so it is still observed at a high concentration in shellfish. Therefore, a study on chronic toxicity through the whole-life cycle of marine organisms in coastal environments should be needed.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.45-52
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• 2015

Acute toxicity tests for 5 organic solvents were conducted using Euglena agilis carter (E. agilis), a Korean domestic organism. Organic solvents decreased the growth rate of E. agilis in a dose dependent manner. The toxicity to E. agilis was increased in the order of chloroform>acetone${\geq}$ethanol${\geq}$methanol>DMSO based on $EC_{50}$ values from growth test. Organic solvents also induced cell motility and morphological changes of E. agilis. Especially significant effects on the cell swimming velocity, motility, and compactness were observed for chloroform at the concentration of $EC_{50}$ calculated from 96 hr growth test. Overall, toxic responses of E. agilis to test substances are comparable to or more sensitive than D. magna, M. macrocopa and V. fischeri. Our study demonstrates that E. agilis can be a putative ecotoxicity test model organism to assess domestic water quality. Results obtained from this study can be applied to establish the standard test guidelines for ecotoxicity test using E. agilis.

• Journal of Life Science
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• v.26 no.2
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• pp.181-189
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• 2016

The aim of this study was to identify the effects of dithiopyr (DTP), a herbicide, on behavior in zebrafish. The toxicity of DTP has rarely been investigated in fish. In the present study, zebrafish were exposed to different concentrations of DTP in the range of 10-20 μM for 48 h in a test container, in order to measure the value of median lethal concentrations (LC₅₀). Behavioral experiments were performed, including the novel tank test (NTT) and the open field test (OFT), to assess stress responses or locomotion. After exposure to the DTP solution at a sublethal concentration of 2.5–10 μM for 6 min, the behavior of the zebrafish was observed for 6 min. In the acute toxicity test, the LC₅₀ value of DTP showed as 14.49 μM in the zebrafish. The NTT showed that the duration of immobility and the velocity were significantly increased by exposure at a concentration of 5 μM of DTP, compared with a control group (p<0.05). However, compared with the control group, DTP significantly decreased the distance moved and the frequency at the top of the tank, and significantly increased the turn angle and duration at the bottom, in a concentration-dependent manner (p<0.05). In addition, in the OFT, exposure to DTP significantly decreased the distance moved and velocity compared with the control group (p<0.05). Exposure to DTP also significantly increased the duration of immobility, the turn angle, and the meandering movement, in a concentration-dependent manner (p<0.05). Further, exposure to DTP at a low concentration elevated whole-body cortisol levels in the zebrafish. The results of this study thus suggest that DTP induces a toxic response and negative effects on behavior and the endocrine system in zebrafish.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.249-256
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• 2017

In this study, we evaluated the potential of 70% ethanol extract from Persicaria nepalensis (PNE) as a cosmetic ingredient by primary skin irritation, ocular irritation, and maximization tests for delayed hypersensitivity in New Zealand white rabbits and Hartley guinea pig. Skin safety study was performed to evaluate the potential toxicity of PNE using the primary irritation test. In the primary irritation test, 50% PNE was applied to the skin, and no adverse reactions such as erythema and edema were observed at the intact skin sites. Therefore, PNE was classified as a practically non-irritating material based on a primary irritation index of "0.0.". In the ocular irritation test, the 50% PNE applied did not show any adverse reactions in the different parts of rabbit eyes, including the cornea, iris, and conjunctiva. Thus, PNE was classified as a practically non-irritating material based on an acute ocular irritation index of "0.0.". Skin sensitization was tested by the Guinea Pig Maximization Test (GPMT) and Freund's Complete Adjuvant (FCA) using an intradermal injection of 10% PNE. Edema and erythema were not observed 24 and 48 h after the topical application of PNE in skin sensitization test, which exhibited a sensitization score of "0.0.". Therefore, it can be suggested that P. nepalensis could be used as potential candidates for cosmoceutical ingredients, without any major side effects.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.142-148
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• 2009

Anxiety disorders are one of the serious problems which need proper therapy devoid of side effects of presently available medicines. The present study evaluates the anxiolytic and sedative activity of leaf galls of Piper nigrum Linn. in Swiss Albino mice. The pet. ether, chloroform, ethyl acetate and ethanol extracts of leaf galls of Piper nigrum Linn were obtained by continuous soxhlet extraction. The prepared extracts were found to be safe up to 2000 mg/kg body weight of mice in the acute toxicity study. Each extract was assessed for anxiolytic activity in Swiss Albino mice by elevated plus Maze, open field test, rota rod test and phenobarbitone induced sleeping time test. In the Elevated Plus Maze test, the pet.ether extract and chloroform extract at a dose of 50 mg/kg b.w. orally, significantly (P < 0.01) increased the number of entries and time spent in open arm comparable with standard diazepam at the dose of 10 mg/kg. b.w. p.o. In the open field test, pet. ether extract (50 mg/kg b.w. p.o.) showed significant increase (P < 0.01) in ambulation and activity in the center. Chloroform extract (50 mg/kg b.w p.o.) was significant (P < 0.05) for both ambulation and center activity. Pet. ether extract (50 mg/kg b.w. p.o) also showed significant activity (P < 0.01) in rota rod test. All the results are comparable with standard diazepam at the dose of 1 mg /kg b.w, p.o. Moreover all the extracts showed significant (P < 0.01) increase in the phenobarbitone induced sleeping time among which pet.ether showed more prominent activity (36%) comparable with control. The results revealed that, the active pet.ether extract and chloroform extract of leaf galls of Piper nigrum Linn is worthwhile to develop the bioactive principle for anxiolytic activity.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.141-147
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• 2008

Globally Harmonized System (GHS) for classification and labelling will provide an internationally agreed hazard classification system of chemical products and for communication of those hazards. This study aimed for establishment of the oral acute toxic class (ATC) method and application of GHS on pesticides. The ATC method was developed for determining $LD_{50}$ estimates of chemical substances with significantly fewer animals than needed when applying conventional $LD_{50}$ tests. We carried out $LD_{50}$ test and ATC test on 13 pesticides, Although methidathion EC and parathion-ethyl EC showed significantly different in $LD_{50}$ values between $LD_{50}$ test and ATC method, there are no difference in toxicity class by GHS. Both tests on the other pesticides showed almost equal results and toxicity class by GHS. Therefore, this study indicated high possibility of application of ATC method and GHS on pesticides.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.165-170
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• 2013

In this study, physico-chemical properties and environmental fate were investigated and ecotoxicity tests using fish, daphnia and algae were conducted for an initial ecological risk assessment of 1,2-Benzisothiazol-3-one. Due to low volatility of the test substance under environmental conditions, it is likely to distributed in soil and water environment. The compound has low adsorption in the soil, with low bioconcentration potential. Acute toxicity results showed that 96 h-$LC_{50}$ for Oryzias laties was 4.7 mg/L (measured) and 48h-$EC_{50}$ for Daphnia magna was 3.3 mg/L (measured). In a growth inhibition test with Pseudokirchneriella subcapitata, 72 h-$EC_{50}$ was 0.456 mg/L (growth rate, nominal) and 0.262 mg/L (yield, nominal). Using the acute toxicity value of algae, predicted no-effect concentration (PNEC) in the aquatic environment was determined to be 2.62 ${\mu}g/L$ using an factor of 100. According to globally harmonized system (GHS), the compound was categorized as aquatic acute 1 for algae, while it was categorized as aquatic acute 2 for fish and daphnia. This screening assessment suggests that the test substance may pose ecological risks in the aquatic environment.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.103-110
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• 2014

BACKGROUND: Azadirachta indica has been widely used as environment-friendly organic materials because of its insecticidal properties. This study was carried out to investigate the acute toxicity and the subacute toxicity of Azadirachta indica extract(AIE) in rats. METHODS AND RESULTS: For the oral acute toxicity test, Sprague-Dawley rats were gavaged with 2.0 g/Kg bw of AIE. The $LD_{50}$ value was greater than 2.0 g/Kg bw for both male and female rats. For the subacute toxicity study, rats were treated with AIE at doses of 0.5, 1.0, 2.0 mg/Kg bw once a day for 4 weeks(n=10 animals per each group). There were no significant changes in body weight, food intake and water consumption observed during the experimental duration. In addition, no difference of relative kidney weight was observed among all treated groups. Serum creatinine level in the AIE 2.0 g/Kg group increased significantly compared with that of control group in male rats, but serum blood urea nitrogen was significantly decreased in a dose-dependent manner (p<0.05). Significant increase of serum cholesterol levels were observed in all AIE groups, compared with the control group, in the female rats (p<0.05). However, histopathological examination of the kidney did not reveal any significant lesions in all groups. CONCLUSION: On the basis of results, it could be concluded that oral administration AIE didn't cause any toxic response in kidney, except the increased serum cholesterol.

• Microbiology and Biotechnology Letters
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• v.9 no.3
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• pp.117-121
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• 1981

Safety of yellow pigment produced by Monascus sp. CS-2 was evaluated. Acute oral toxicity, pyrogen test, and histamine test, as well as antimicrobial activity were determined. The results obtained were; LD oral in mice was 132.5 mg/20 g, pyrogen test in rabbit was 5 mg/kg, and histamine test in cat was 10 mg/kg. Also the pigment was particularly sensitive to Bacillus subtilis (ATCC 6633), Sarcina lutea (ATCC 9341) and Staphylococcus aureus (ATCC 6538 P), whereas not sensitive to Pseudomonas pyosyanea (ACTC 10490), Bacillus var. mycoides (ATCC 11778), Bordetella bronchiseptica (ATCC 4617) and Staphylococcus epidermidis(ATCC 12228).

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.650-657
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• 2011

The object of this study was to obtain acute information (single oral dose toxicity) of Taraxaci Herba (Dried total parts of Taraxacum platycarpum. H.Dahlstedt (Compositae)), has been traditionally used in Korean medicine for treating various inflammatory diseases. In order to observe the 50% lethal dose (LD 50), approximate lethal dosage (ALD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2,000, 1,000, 500 mg/kg according to the recommendation of Korea Food and Drug Administration Guidelines. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after single oral treatment of Taraxaci Herba aqueous extracts according to KFDA Guidelines with organ weights and histopathological observations of 12 types of principle organs. After single oral treatment of Taraxaci Herba aqueous extracts, we could not find any mortality and toxicological evidences up to 2,000 mg/kg treated group, the limited dosages in rodents at body and organ weights, clinical signs, gross and histopathological observations. Except for slight soft feces, which were detected in male mice treated with 2,000 mg/kg of Taraxaci Herba aqueous extracts at 1 day after end of treatment. The results obtained in this study suggest that the LD 50 and ALD of Taraxaci Herba aqueous extracts in both female and male mice after single oral treatment were considered as over 2,000 mg/kg because no mortalities were detected up to 2000 mg/kg that was the highest dose recommended by KFDA and OECD. However, it also observed that the possibility of digestive disorders, like diarrhea when administered over 2,000 mg/kg of Taraxaci Herba aqueous extracts in the present study, but these possibilities of digestive disorders can be disregard in clinical use because they ate transient in the highest dosages male only.