• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.239-245
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• 2022

Protein and peptide candidates are screened to apply therapeutic application as a drug. Ensuring that these candidates are delivered and maximized effectiveness is still challenging and a variety of studies are ongoing. As drug delivery system vehicles, cell-penetrating peptide (CPP) can deliver various kinds of cargo into the cell cytosol. In a previous study, we developed Ara27 CPP, which are a zinc knuckle family protein of Arabidopsis, and confirmed internalization in human dermal fibroblasts and human dental pulp stem cells at low concentration with short time treatment condition without any toxicity. Ara27, an amphipathic CPP, could be modified and utilized in the biomedical field excluding the risk of toxicity. Therefore, we would like to confirm the non-toxic induced penetrating ability of Ara27 in various cell lines. The purpose of this study was to screen the cell internalization ability of Ara27 in various cell lines and to confirm Ara27 as a promising core CPP structure. First, Ara27 was screened to confirm non-toxicity concentration. Then, fluorescence-labeled Ara27 was treated on human normal cell lines, cancer cell lines and animal cell lines to identify the cellular internalization of Ara27. Ara27 was well intracellular localized in all cell lines and the intensity of fluorescence was remarkably increased in time pass manner. These results indicate that Ara27 has the potential as a core structure for applications in various drug delivery systems.

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

• Environmental Analysis Health and Toxicology
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• v.24 no.1
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• pp.9-16
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• 2009

Effects of salinity and standard toxic metals on fertilization and embryo development rates were investigated in the sea urchin, Hemicentrotus pulcherrimus. Spawning was induced by injecting $1{\sim}2$ mL of 0.5 M KCl into the coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. The fertilization rate was below 30% when salinity was 20 psu and lower, but was almost above 90% when salinity was 25 psu and higher. The embryo development rate was below 60% when salinity was 25 psu and lower, but was above 80% when salinity was between 30 and 35 psu. The fertilization and embryo development rates in the control condition(not including Cu and Cd) were greater than 90%, but decreased a high negative correlation with the increasing of Cu(r=-0.80, r=-0.78) and Cd(r=-0.90, r=-0.82) concentrations, respectively. The fertilization and embryo development rates were significantly inhibited in the addition of Cu($EC_{50}$=17.30 ppb, $EC_{50}$=10.32 ppb) and Cd($EC_{50}$=364.57 ppb, $EC_{50}$=244.04 ppb), respectively. These results suggest that salinity concentrations for successful fertilization and normal embryogenesis of H. pulcherrimus are above 25 psu and 30 psu, respectively, and the biological assays of fertilization and embryo development rates using H. pulcherrimus are useful methods for the ecological toxicity test of marine pollution elements.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.63-70
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• 1994

Thirty ewes received typical trauma to their oviducts and uterine horns from surgical embryo collection procedures. Ten percent Dexamethasone was used as an irrigant on the exposed abdominal tissue prior to closing the incision. The treatment group received 17mg colchicine Om! lewe) and the control group was administered a 1.0ml placebo(PSS). Fifteen ewes that were initially treated with 17mg /im colchicine showed acute colchicine toxicity within 2-5 days after initial treatment and were removed from the study. Due to acute colchicine toxicity at 17mg, the colchicine level was lowered to 8, 4 and 2mg(4 ewes/group). Treatments consisted of daily injections of colchicine. One ewe in the 8mg group developed toxicity on day 5. Therefore, ewes were then administered colchicine every other day from day 6 to day 14 postsurgeryat 4 and 2 mg. the second laparotomy was performed 9 weeks after first treatment. Following second laparotomy, the treatment group(n=5) received 4 mg colchicine every day for 14 days and there was no clinical symptoms of colchicine toxicity. The third laparotomy was performed by the same operators 5 weeks after final treatment and the adhesions scored. Adhesion grading was based on a scale of 0-4, with 4 being the most severe. The results of adhesion grading(> 3) at second laparotomy were not significantly different(P>0.05)between the two groups. Adhesion formation observed at third laparotomy showed a reduced, but not significant reduction (P>0.05) in the colchicine-treated ewes when compared with the controls. Ten ewes(5 control and 5 treatment)were examined cytogenetically by bone marrow analysis five days post-treatment. There was no difference(P>0.05)in the incidence of numerical or structural aberrations between the two groups.

• Toxicological Research
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• v.23 no.2
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• pp.151-158
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• 2007

tert-Butyl acetate is an organic solvent used for coatings, industrial cleaning, and surface treatment applications. This study investigated the potential adverse effects of tert-butyl acetate on pregnant dams and embryo-fetal development after maternal exposure on gestational days 6 through 19 in rats. The test chemical was administered to pregnant rats by gavage at dose levels of 0, 500, 1,000, 1,500, and 2,000 mg/kg/day. All dams were subjected to a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 2,000 mg/kg, treatment-related clinical signs, including piloerection, abnormal gait, decreased locomotor activity, loss of fur, reddish tear, anorexia, nasal discharge, vocalization and coma, were observed in a dose-dependent manner. All dams died between the 2nd day and 5th day of treatment due to a severe systemic toxicity. At 1,500 mg/kg, minimal maternal toxicity including an increase in the incidence of decreased locomotor activity and loss of fur, and an increase in the weights of adrenal glands and liver was observed. On the contrary, no significant adverse effect on the embryo-fetal development was detected. There were no adverse effects on either pregnant dams or embryo-fetal development at <1,000 mg/kg. These results show that a 14-day repeated oral dose of tert-butyl acetate in rats caused a minimal maternal toxicity including increases in the incidence of clinical signs and the weights of adrenal glands and liver, but no embryotoxicity and teratogenicity at 1,500 mg/kg/day. Under these experimental conditions, the no-observed-adverse-effect level (NOAEL) of tert-butyl acetate is estimated to be 1,000 mg/kg per day for dams and 1,500 mg/kg per day for embryo-fetal development.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.23-32
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• 2013

The purpose of this study is to evaluate the effects of oil dispersant and ultraviolet (UV) radiation on the toxicity of crude oil. The toxicity of water-accommodated fraction (WAF) and chemically enhanced water-accommodated fraction (CEWAF) of Hebei Spirit crude oil was investigated in the embryo of the Manila clam, Ruditapes philippinarum with- and without ultraviolet radiation. The WAF and CEWAF with- and without UV radiation affected significantly the embryonic development of R. philippinarum. The EC50s of WAF without UV, WAF with UV, CEWAF without UV, and CEWAF with UV were 2.82, 0.79, 1.60, and 0.45 g/L, respectively. CEWAF was 1.6 times more toxic than WAF. UV radiation increased crude oil toxicity to 3.6 times for both WAF and CEWAF. The oil dispersant and UV radiation did not affect the acute toxicity to the embryo but retarded the period of embryonic development up to 26%. R. philippinarum proved to be a sensitive species to reflect the toxic effects of oil spill combined with oil dispersant and UV radiation. It is suggested that the chemical analyses on the WAF and CEWAF is important for the identification and quantitative explanation of the phototoxic compounds in crude oil.

• Toxicological Research
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• v.17 no.4
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• pp.279-286
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• 2001

Recently, there is an increasing nationwide concern in Korea that exposure to electric and magnetic fields in the home environment may not be safe in humans. To identify possible effects of horizontally polarized magnetic fields (MF) exposure on embryo-fetal development, timed-mated female Sprague-Dawley rats (24/group) received continuous exposure to 60 Hz MF at field strengths of 0 Gauss (sham control), 50mG,833 mG, or 5000 mG. Dams received MF of sham exposures for 22hr/day on gestation days 6 through 20. Experimentally generated MF were monitored continuously througout the study. There was no evidence of maternal toxicity of developmental toxicity in any MF-exposed groups. Mean maternal body weight, organ weights, and gross findings in groups exposed to MF did not differ from those in sham control. No significant differences in fetal deaths, fetal body weight, and placental weight were observed between MF-exposed groups and sham control. External, visceral, and skeletal examination of fetuses demonstrated no significant differences in the incidence of fetal malformations between MF-exposed and sham control groups. In conclusion, exposure of pregnant Sprague-Dawley rats to 60 Hz at MF strengths up to 5000 mG during gestation day 6-20 did not produce any biologically significant effect in either dams of fetuses.

• Journal of Environmental Science International
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• v.17 no.7
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• pp.775-781
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• 2008

Effects of salinity and standard toxic metals on fertilization and embryo development rates were investigated in the sea urchin, Strongylocentrotus nudus. Spawning was induced by injecting 1ml of 0.5 M KCl into the coelomic cavity. The fertilization and embryo development rates were below 20% when salinity was 25 psu or lower, but were above 90% when salinity was between 30 and 35 psu. The fertilization and embryo development rates in the control condition (not including Cu and Cd) were greater than 90%, but decreased with a high negative correlation (r) of 0.89 and 0.91 with the increasing of Cu and Cd concentrations, respectively. These results suggest that salinity concentrations for successful fertilization and normal embryogenesis of S. nudus are between 30 and 35 psu, and the biological assays of fertilization and embryo development rates using S. nudus are useful methods for the ecological toxicity test of marine pollution elements.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.392-396
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• 2007

Aquatic ecotoxicity of bisphenol A, a well-known endocrine disrupter in mammals, was studied using laboratory-reared Daphnia magna as a test organism. The static acute 48 h $EC_{50}$ of bisphenol A for daphnid neonates(<24 hold) was 12.9 mg/l and 110 h $LC_{50}$ values of bisphenol A for daphnid embryos of different ages after deposition into the brood chamber increase with ages in the range of 1.55 mg/l-8.91 mg/l. Also, 48 h $EC_{50}s$ generally increase with daphnid's ages in the range of 12.9 mg/l-19.8 mg/l. In the acute toxicity tests using mature daphnids, the lethal response and immobility all showed good concentration-response relationship with exposure concentration and exposure time, showing little difference between lethality and immobility. These results clarify that acute toxicity tests, using daphnid and its embryo, could also be useful tools easily available for the assessment of ecotoxicity of various harmful chemicals.

• Toxicological Research
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• v.35 no.4
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• pp.343-351
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• 2019

Many in vitro developmental toxicity assays have been proposed over several decades. Since the late 1980s, we have made intermittent attempts to introduce in vitro assays as screening tests for developmental toxicity of inhouse candidate products. Two cell-based assays which were developed two decades apart were intensively studied. One was an assay of inhibitory effects on mouse ascites tumor cell attachment to a concanavalin A-coated plastic sheet surface (MOT assay), which we studied in the early days of assay development. The other was an assay of inhibitory effects on the differentiation of mouse embryonic stem cell to beating heart cells (EST assay), which we assessed more recently. We evaluated the suitability of the assays for screening in-house candidates. The concordance rates with in vivo developmental toxicity were at the 60% level. The EST assay classified chemicals that inhibited cell proliferation as embryo-toxic. Both assays had a significant false positive rate. The assays were generally considered unsuitable for screening the developmental toxicity of our candidate compounds. Recent test systems adopt advanced technologies. Despite such evolution of materials and methods, the concordance rates of the EST and MOT systems were similar. This may suggest that the fundamental predictivity of in vitro developmental toxicity assays has remained basically unchanged for decades. To improve their predictivity, in vitro developmental toxicity assays should be strictly based on elucidated pathogenetic mechanisms of developmental toxicity.