• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.3 no.3
• /
• pp.169-175
• /
• 1999

2,4-Dinitrophenol(DNP) is a metabolic uncoupler that prevents cells from creating energy for growth and it has been suggested that the availability of sodium ions may be important in mitigating the effects of uncouplers. Accordingly, the degradation of DNP was investigated using activated sludge which had been adapted to mineralize DNP. After the acclimation of the activated sludge, the effect of sodium ions on the toxicity of high concentrations(80 to 100mg/L) of DNP was investigated over a sodium ion concentration range of 9.3$\times$10-5 to 94mM. The concentration of sodium ions in the activated sludge mixed liquor seemed to have little effect on the DNP toxicity. However, a lack of sodium in the grwoth media resulted in a reduction of the DNP degradation rate by a bacterial isolate from the activated sludge culture identified as Nocardia asteroides.

• Biomolecules & Therapeutics
• /
• v.28 no.4
• /
• pp.302-310
• /
• 2020

Botulinum toxins are neurotoxic modular proteins composed of a heavy chain and a light chain connected by a disulfide bond and are produced by Clostridium botulinum. Although lethally toxic, botulinum toxin in low doses is clinically effective in numerous medical conditions, including muscle spasticity, strabismus, hyperactive urinary bladder, excessive sweating, and migraine. Globally, several companies are now producing products containing botulinum toxin for medical and cosmetic purposes, including the reduction of facial wrinkles. To test the efficacy and toxicity of botulinum toxin, animal tests have been solely and widely used, resulting in the inevitable sacrifice of hundreds of animals. Hence, alternative methods are urgently required to replace animals in botulinum toxin testing. Here, the various alternative methods developed to test the toxicity and efficacy of botulinum toxins have been briefly reviewed and future perspectives have been detailed.

• Genomics & Informatics
• /
• v.21 no.2
• /
• pp.25.1-25.12
• /
• 2023

Adaptation of infections and hosts has resulted in several metabolic mechanisms adopted by intracellular pathogens to combat the defense responses and the lack of fuel during infection. Human tuberculosis caused by Mycobacterium tuberculosis (MTB) is the world's first cause of mortality tied to a single disease. This study aims to characterize and anticipate potential antigen characteristics for promising vaccine candidates for the hypothetical protein of MTB through computational strategies. The protein is associated with the catalyzation of dithiol oxidation and/or disulfide reduction because of the protein's anticipated disulfide oxidoreductase properties. This investigation analyzed the protein's physicochemical characteristics, protein-protein interactions, subcellular locations, anticipated active sites, secondary and tertiary structures, allergenicity, antigenicity, and toxicity properties. The protein has significant active amino acid residues with no allergenicity, elevated antigenicity, and no toxicity.

• Journal of Oriental Neuropsychiatry
• /
• v.20 no.1
• /
• pp.21-42
• /
• 2009

Objectives : This Study was performed to assess the antioxidant and neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells and primary rat mesencephalic dopaminergic neurons. Methods : The anioxidant effect was investigated using the DPPH radical and ABTS cation scavenging assays and total polyphenol amout of Chunghyul-dan(Qingxuedan). The neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells was evaluated using MTT assay. The scavenging activity of Chunghyul-dan(Qingxuedan) on ROS production induced by 6-OHDA(6-hydroxydopamine) in PC12 cells was evaluated, as well as the attenuating effect on GSH reduction. Finally, we examined the neuroprotective effect of Chunghyul-dan(Qingxuedan) against 6-0HDA-induced toxicity in the primary culture of rat mesencephalic doperminergic neurons. Results : Chunghyul-dan(Qingxuedan) showed concentration-dependent scavenging activities in DPPH radical and ABTS cation scavenging assays and it was not cytotoxic to PC12 cells. In postand co-treatment, Chunghyul-dan(Qingxuedan) protected PC12 cells from the 6-OHDA induced toxicity at 50 and 100 ${\mu}$g/mL significantly. And Chunghyu!-dan(Qingxuedan) decreased the 6-OHDA induced ROS production at a dose dependent manner, while increaing the 6-OHDA induced GSH reduction at 50 and 100 ${\mu}$g/mL significantly. Finally, Chunghyul-dan(Qingxuedan) showed signicant protection of rat mescencephalic dopaminergic neurons from 6-OHDA at 1 ${\mu}$g/mL. Conclusions : These results demonstrate that Chunghyul-dan(Qingxuedan) has the antioxidant and neuroprotective effect against 6-0HDA induced cytotoxicity through decreasing ROS production and increasing GSH reduction.

• Journal of Environmental Health Sciences
• /
• v.33 no.2 s.95
• /
• pp.123-131
• /
• 2007

Many environmental contaminants including several metals, polycyclic aromatic hydrocarbons, and pharmaceuticals, have been identified to be phototoxic in the water environment. Concerns regarding photo-enhancement of toxicity of several environmental contaminants have been increasing because of the increased level of ultraviolet irradiation on the earth surface. However, there exist arguments that there might be certain defense mechanisms taking place in the aquatic ecosystem, which may include behavioral characteristics or genetic acclimation. This study was conducted to understand the potential responses of aquatic receptors to several phototoxic metals in the real environment, where long-term acclimation of such organisms to low dose UV-B may take place. For this purpose, water flea Daphnia magna was acclimated to environmentally relevant dose of UV-B (12 to $18uW/cm^2$) for >11 generations. The differences in developmental and life history characteristics, and toxicity responses were evaluated. Acclimation did not affect the daphnids' growth, longevity, and reproduction characteristics such as time to first brood, and brood size: After 21 d, survival of D. magna was not influenced by UV-B acclimation. When the number of young per female was compared. the daphnids acclimated for 11 generations tend to produce less number of neonates than the un-acclimated individuals but with no statistical significance (p>0.05). Four metals that were reported to be phototoxic elsewhere were employed in this evaluation, that include As, Cd. Cu, and Ni. UV-B level being applied in acclimation did increase the toxicity of Cd and Cu, significantly (p<0.05). However, the toxicities of As and Ni were not affected by irradiation of UV-B. Phototoxic responses were evaluated between the acclimated and the un-acclimated daphnids. For Cu, UV-B acclimation led to reduction of the photo-induced toxicity $(p\approx0.1)$ in daphnids. Non-acclimated Daphnia were affected by 50% at 4.18 ug/l Cu. but UV-B acclimated individuals exhibited $EC_{50}$ of 5.89 ug/l. With Cd, UV-B acclimation appeared to increase phototoxicity (p>0.05). With As and Ni, UV-B acclimation did not influence photo-induced toxicity. This observation may be in part explained by the type of reactive oxygen species that were generated by each metal. Similar to UV-B light, Cu is known to generate superoxide anion by acting as redox cycling toxicant. This is one of the first studies that employed_laboratory based UV-B acclimated test species for photoenhanced toxicity evaluation.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.11
• /
• pp.1087-1094
• /
• 2008

Diazinon is a phosphorothiate insecticide widely used in the world including Korea. This study investigates the feasibility of photolysis and photocatalysis processes for the degradation of diazinon in water. Both photolysis and photocatalysis reactiosn were effective in degrdading diazinon, however lower TOC removals were achieved. In case of photocatalysis, approximately 40% of nitrogen from diazinon was recovered as NO$_3^-$, and less than 5% of phosphorus as PO$_4{^{3-}}$. However, the sulfur in diazinon molecule was completely recovered to SO$_4{^{2-}}$ from photocatalysis reaction, and the recovery from photolysis was 50%, indicating that P=S bond easily breaks first during photolysis and photocatalysis. The poor recoveries of ionic byproducts and TOC from photolysis and photocatalysis indicate the presence of other organic intermediates during reactions. The formation of organic intermediates were identified during reactions using GC/MS and LC/MS/MS, and the main degradation products were diazoxon, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMP), respectively. Finally, the acute 48-hr toxicity test using Daphnia magna were employed to measure the toxicity reduction during photocatalysis of degradation. The results showed that the toxicity increased until 180 min of the photocatalysis reaction (from EC$_{50}$ (%) of 69.6 to 13.2%), however, acute toxicity completely disappeared (>100%) after 360 min. The toxicity results showed that the intermediates from photocatalysis such as diazoxon were more toxic than diazinon itself, however these intermediates can be degraded or mineralized with further reaction.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.222-228
• /
• 2008

Algal Growth-inhibition tests were conducted with 6 pesticides butachlor GR (5%), butachlor EW (33%), isoprothiolane GR (12%), isoprothiolane EC (40%), diazinon GR (3%) and diazinon EC (34%) to determine their comparative toxicity to three species of freshwater green algae Selenastrum capricornutum, Scenedesmus subspicatus, Chlorella vulgris and one species diatom Nitzschia palea. The test species were exposed to the test pesticide for 72 hours and the toxicity represented $EC_{50}$ value calculated by the reduction in growth rate at 72 hours. The toxicity of EC or EW formulation to green algae and diatom was higher than the toxicity of GR formulation at all test in this study. Also, the toxicity of EC formulation was higher than the toxicity technical pesticide. These results indicate that the types of pesticide formulation may affect on their toxicity on algae and the green alga, S. capricornutum and S. subspicatus were more sensitive than C. vulgris. Also, the sensitivity of the diatom, N. palea showed equal or lower than S. capricornutum, S. subspicatus but more sensitive than C. vulgris.

• Toxicological Research
• /
• v.19 no.3
• /
• pp.227-234
• /
• 2003

2-Bromopropane (2-BP), a halogenated propane analogue, is a substitute for chlorofluorocarbones (CFCs) which have a great potential to destroy the ozone layer and to warm the earth's environment. The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 17 in ICR mice. The test chemical was administered subcutaneously to pregnant mice at dose levels of 0, 313, 625 or 1,250 mg/kg/day. All dams were subjected to caesarean section on GD 18 and their fetuses were examined for external, visceral and skeletal abnormalities. In the 1,250 mg/kg group, maternal toxicity included an increase in the incidence of abnormal clinical signs and a decrease in the maternal body weight, body weight gain, and corrected body weight. Developmental toxicity included a decrease in the fetal body weight, a reduction in the placental weight, an increase in the fetal skeletal variation and ossification delay. There were no adverse effects on either pregnant dams or embryo-fetal development in the 313 and 625 mg/kg groups. These results suggest that a 12-day subcutaneous dose of 2-BP is embryotoxic at a maternally toxic dose (i.e., 1,250 mg/kg/day) in ICR mice. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 625 mg/kg/day for dams and embryo-fetuses, respectively.

• Toxicological Research
• /
• v.14 no.2
• /
• pp.193-203
• /
• 1998

The toxicity of DA-125. a new anthracycline anticancer agent, on the male reproductive system was studied in Sprague-Dawley rats. Forty male rats were rando$m\ell$y assigned to Jour groups with ten rats in each group and given single intraveneous doses of DA-125 at dose levels of 0. 12.5. 25. and 50 mg/kg body weight. On day 56 after treatment the animals were allowed to mate. and their male reproductive Junctions and organs were examined in detail. Copulated females were sacrificed on day 20 of gestation for examination of embryo-fetal development. One out of ten rats in the 50 mg/kg group died on day 12 after treatment. Clinical signs such as emaciation. sedation, anorexia. swelling. dark material around eye. alopecia. and diarrhea were observed in the 25 and/or 50 mg/kg groups. Reduction in the body weight gain. decrease in the absolute weights of testes. epididymis and seminal vesicles. and/or decrease in the number of testicular sperm heads were also found. Although histopathological changes such as atrophy of seminiferous tubules. loss or decrease of spermatogenic cells. exfoliation of spermatogenic cells. vacuolization of Sertoli cells. decrease of sperm. and/or increase of necrotic spermatogenic cells in epididymal ducts were observed. no adverse effects on the motility and morphology of epididymal sperm. copulation index. fertility index. and embryo-fetal development were detected in the 25 and 50 mg/kg groups. There were no evidences of male reproductive toxicity in the 12.5 mg/kg group. These results show that single intravenouse doses of DA-125 produce significant dose-related testicular atrophy. histopathological changes. and oligozoospermia in rats and $LD_{10}$ for DA-125 appears to be 50 mg/kg body weight.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.9
• /
• pp.4393-4402
• /
• 2012

Colon cancer is the third most common malignant neoplasm in the world and it remains an important cause of death, especially in western countries. The toxic environmental pollutant, 1, 2-dimethylhydrazine (DMH), is also a colon-specific carcinogen. Tannic acid (TA) is reported to be effective against various types of chemically induced toxicity and also carcinogenesis. In the present study, we evaluated the chemopreventive efficacy of TA against DMH induced colon toxicity in a rat model. Efficacy of TA against the colon toxicity was evaluated in terms of biochemical estimation of antioxidant enzyme activities, lipid peroxidation, histopathological changes and expression of early molecular markers of inflammation and tumor promotion. DMH treatment induced oxidative stress enzymes (p<0.001) and an early inflammatory and tumor promotion response in the colons of Wistar rats. TA treatment prevented deteriorative effects induced by DMH through a protective mechanism that involved reduction of oxidative stress as well as COX-2, i-NOS, PCNA protein expression levels and TNF-${\alpha}$ (p<0.001) release. It could be concluded from our results that TA markedly protects against chemically induced colon toxicity and acts plausibly by virtue of its antioxidant, anti-inflammatory and antiproliferative activities.