• Toxicological Research
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• 제29권4호
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• pp.263-278
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• 2013

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent ${\alpha}$-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

• Toxicological Research
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• 제33권3호
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• pp.255-263
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• 2017

Chemotherapy is associated with male infertility. Cisplatin (cis-diamminedichloro-platinum (II) (CDDP) as a chemotherapy medication used to treat a number of cancers has been reported to most likely induce testicular toxicity. Administration of antioxidants, such as pentoxifylline (PTX) may reduce some Adverse Drug Reactions (ADRs) of CDDP. Therefore, this study investigated the potentially protective effects of PTX on CDDP-induced testicular toxicity in adult male rats. For this purpose, 42 male rats were randomly divided into 7 groups. The rats were orally pretreated with PTX at the 3 doses of 75, 150, and 300 mg/kg once a day for 14 successive days. On the $14^{th}$ day of the study, they were intraperitoneally (IP) administered with a single dose of CDDP (7 mg/kg). Finally, the sperm/testis parameters, serum levels of reproductive hormones, including testosterone, Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH) as the pivotal endocrine factors controlling testicular functions, and histopathological changes of testis tissue were examined. Pretreatment with the two doses of 75 and 150 mg/kg PTX indicated significant increases in the sperm count and motility induced by CDDP administration. The right and significantly left testis weights were decreased following the treatment with 300 mg/kg of PTX plus CDDP. However, 75 mg/kg of PTX plus CDDP showed the best near-to-normal histopathological features. The results demonstrated that PTX alone enhanced some parameters, such as the sperm count, while reducing other parameters, including sperm fast motility and germ layer thickness. Furthermore, despite testosterone or LH levels, the mean serum FSH level was significantly augmented by the doses of 75 and 150 mg/kg. It was concluded that PTX administration cannot reduce CDDP-induced testicular toxicity even at high doses (e.g., 300 mg/kg), while it seemed to partially intensify CDDP toxicity effects at a dose of 75 mg/kg. Thus, further research is required in this regard.

• Toxicological Research
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• 제33권3호
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• pp.239-253
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• 2017

Neodymium is a future-oriented material due to its unique properties, and its use is increasing in various industrial fields worldwide. However, the toxicity caused by repeated exposure to this metal has not been studied in detail thus far. The present study was carried out to investigate the potential inhalation toxicity of nano-sized neodymium oxide ($Nd_2O_3$) following a 28-day repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed to nano-sized $Nd_2O_3-containing$ aerosols via a nose-only inhalation system at doses of $0mg/m^3$, $0.5mg/m^3$, $2.5mg/m^3$, and $10mg/m^3$ for 6 hr/day, 5 days/week over a 28-day period, followed by a 28-day recovery period. During the experimental period, clinical signs, body weight, hematologic parameters, serum biochemical parameters, necropsy findings, organ weight, and histopathological findings were examined; neodymium distribution in the major organs and blood, bronchoalveolar lavage fluid (BALF), and oxidative stress in lung tissues were analyzed. Most of the neodymium was found to be deposited in lung tissues, showing a dose-dependent relationship. Infiltration of inflammatory cells and pulmonary alveolar proteinosis (PAP) were the main observations of lung histopathology. Infiltration of inflammatory cells was observed in the $2.5mg/m^3$ and higher dose treatment groups. PAP was observed in all treatment groups accompanied by an increase in lung weight, but was observed to a lesser extent in the $0.5mg/m^3$ treatment group. In BALF analysis, total cell counts, including macrophages and neutrophils, lactate dehydrogenase, albumin, interleukin-6, and tumor necrosis factor-alpha, increased significantly in all treatment groups. After a 4-week recovery period, these changes were generally reversed in the $0.5mg/m^3$ group, but were exacerbated in the $10mg/m^3$ group. The lowest-observed-adverse-effect concentration of nano-sized $Nd_2O_3$ was determined to be $0.5mg/m^3$, and the target organ was determined to be the lung, under the present experimental conditions in male rats.

• Toxicological Research
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• 제33권3호
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• pp.225-231
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• 2017

National reference standards (NRSs) for biologics are established through potency estimation by a multi-center joint study of standard materials used in the approval process for national lot release and quality control of vaccines, blood products, and other biologics. In this study, a stability evaluation was conducted to determine whether the potency of NRSs for six blood products was being maintained at a consistent level in Korea. The present study conducted real-time stability tests via in-vivo/in-vitro bioassay on NRSs for blood coagulation factor VIII concentrate (2nd standard), antithrombin concentrate, prekallikrein activator, anti-hepatitis B immunoglobulin, blood coagulation factor IX concentrate, and anti-tetanus human immunoglobulin, as well as a trend analysis using cumulative annual results. The real-time stability test results showed that the mean potency of six NRSs was all within the control limit. In the trend analysis, the potency of NRS for blood coagulation factor VIII concentrate (2nd standard) showed a decreasing trend, while the potency of all other products had been stably maintained. The present study confirmed that the mean potency of NRSs for six blood products had been stably maintained in Korea. The findings of the present study establish a foundation that can ensure the quality of NRSs for biologics in Korea, and it is expected to make a major contribution to the supply of high-quality biologics.

• Toxicological Research
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• 제34권3호
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• pp.231-239
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• 2018

Bisphenol A, an everywhere chemical, is applied as a plasticizer in polycarbonate plastics, which often used in our everyday products and in epoxy resins as protective coatings and linings for food and beverage cans for decades. Human exposure to BPA may lead to adverse effects by interfering with oestrogen receptors. Our present study was conducted to investigate the protective effects of selenium (Se) and vitamin E (Vit E) on BPA-induced damage in the liver of male rats. Animals were randomly divided into four groups: the first group received olive oil and served as control. The second group received both (Se + Vit E) (0.5 mg/kg diet; 100 mg/kg of diet). The third one treated orally by (10 mg/kg b.w.) of BPA. The last group received (Se + Vit E) (0.5 mg/kg diet; 100 mg/kg of diet) concomitantly with (10 mg/kg b.w.) BPA. Exposure to BPA for three weeks engendered a hepatic disorder. An increased AST and ALT enzymatic activity was noticed in BPA-treated group as compared to other groups. Furthermore, a change in glucose, cholesterol, LDL-C, HDL-C, albumin, and bilirubin level was remarkable. Moreover, exposure to BPA increased malondialdehyde levels while reduced gluthatione content was decreased in the liver homogenate. A decrease in glutathione peroxidase, glutathione s-transferase and catalase activities was observed in the same group. Administration of selenium and vitamin E through the diet in BPA treated rats ameliorated the biochemical parameters cited above. In addition, an improvement in activities of liver enzymes was recorded. The histological findings confirmed the biochemical results. The model of this study that we employed characterized the relationships between BPA-induced hepatotoxicity and its alleviation by natural antioxidants like selenium and vitamin E.

• Toxicological Research
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• 제34권3호
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• pp.191-197
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• 2018

In 2015, a candidate for the second national reference standard (NRS) of Gloydius snake venom was produced to replace the first NRS of Gloydius snake venom. In the present study, the potencies of the candidate were determined by a collaborative study, and the qualification of the candidate was estimated. The potencies of the candidate were determined by measuring the murine lethal titers and lapine hemorrhagic titers of venom against the regional working reference standard (RWRS) for antivenom using the methods described in the previous report for the first NRS of Gloydius snake venom. Three Korean facilities contributed data from a total of 30 independent assays. Subsequently, two foreign national control research laboratories contributed to this collaborative study. The results were calculated using the Reed-Muench method for lethality and determined using a mixed-effects model for hemorrhage. The general common potencies of the lethal and hemorrhagic titers were obtained from the results of the 30 tests performed at three Korean facilities. The results are expressed in micrograms for 1 test dose (TD) with a 95% confidence interval as follows: a lethal titer of $90.13{\mu}g/TD$ (95% confidence interval = $87.39{\sim}92.86{\mu}g$) and a hemorrhagic titer of $10.80{\mu}g/TD$ (95% confidence interval = $10.46{\sim}11.14{\mu}g$). In addition, the candidate preparation showed good quality evaluation according to the results of the quality estimation of the candidate and is judged to be suitable to serve as the Korean NRS for snake venom. In conclusion, the second NRS of Gloydius snake venom was established in this study and will be used for national quality control, including a national lot release test of Korean antivenom products.

• Toxicological Research
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• 제34권3호
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• pp.221-229
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• 2018

Tenofovir nanoparticles are novel therapeutic intervention in human immunodeficiency virus (HIV) infection reaching the virus in their sanctuary sites. However, there has been no systemic toxicity testing of this formulation despite global concerns on the safety of nano drugs. Therefore, this study was designed to investigate the toxicity of Tenofovir nanoparticle (NTDF) on the liver and kidney using an animal model. Fifteen adult male Sprague-Dawley (SD) rats maintained at the animal house of the biomedical resources unit of the University of KwaZulu-Natal were weighed and divided into three groups. Control animals (A) were administered with normal saline (NS). The therapeutic doses of Tenofovir (TDF) and nanoparticles of Tenofovir (NTDF) were administered to group B and C and observed for signs of stress for four weeks after which animals were weighed and sacrificed. Liver and kidney were removed and fixed in formal saline, processed and stained using H/E, PAS and MT stains for light microscopy. Serum was obtained for renal function test (RFT) and liver function test (LFT). Cellular measurements and capturing were done using ImageJ and Leica software 2.0. Data were analysed using graph pad 6, p values < 0.05 were significant. We observed no signs of behavioural toxicity and no mortality during this study, however, in the kidneys, we reported mild morphological perturbations widening of Bowman's space, and vacuolations in glomerulus and tubules of TDF and NTDF animals. Also, there was a significant elevation of glycogen deposition in NTDF and TDF animals when compared with control. In the liver, there were mild histological changes with widening of sinusoidal spaces, vacuolations in hepatocytes and elevation of glycogen deposition in TDF and NTDF administered animals. In addition to this, there were no significant differences in stereological measurements and cell count, LFT, RFT, weight changes and organo-somatic index between treatment groups and control. In conclusion, NTDF and TDF in therapeutic doses can lead to mild hepatic and renal histological damage. Further studies are needed to understand the precise genetic mechanism.

• 생명과학회지
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• 제18권6호
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• pp.884-890
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• 2008

본 연구에서는 대두의 대표적인 생리활성 물질인 genistein의 처리에 따른 암세포의 증식억제에서 telomerase 및 COX-2 활성의 변화 연관성을 조사하였다. 이를 위하여 4가지 종류의 암세포주를 사용하였으며, genistein 처리에 의하여 암세포들의 증식억제에서 백혈병 세포인 U937 세포의 감수성이 감장 높게 나타났으며, genistein 처리에 따라 telomere 조절인자들의 발현이 대부분 억제되었으며, telomerase의 활성도 매우 유의적으로 감소되었다. 또한 genistein처리 농도가 증가함에 따라 COX-2의 발현이 전사 및 번역 수준에서 모두 감소되었으며 이에 따른 $PGE_2$의 생성 역시 현저하게 감소되었으나, COX-1의 발현에는 큰 변화가 없었다. 이러한 결과들은 genistein의 항암 활성을 이해하는 귀중한 자료로서 활용될 것으로 생각된다.

• Toxicological Research
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• 제31권2호
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• pp.157-163
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• 2015

Nanotechnology has advanced at an extremely rapid pace over the past several years in numerous fields of research. However, the uptake of nanoparticles (NPs) into the body after administration through various routes may pose a risk to human health. In this study, we investigated the potential ocular toxicity of 20-nm, negatively- charged zinc oxide (ZnO) NPs in rats using micro-computed tomography (micro-CT) and histopathological assessment. Animals were divided into four groups as control group, ZnO NPs treatment group (500 mg/kg/day), control recovery group, and ZnO NPs treatment and recovery group. Ocular samples were prepared from animals treated for 90 days (10 males and 10 females, respectively) and from recovery animals (5 males and 5 females, respectively) sacrificed at 14 days after final treatment and were compared to age-matched control animals. Micro-CT analyses represented the deposition and distribution of foreign materials in the eyes of rats treated with ZnO NPs, whereas control animals showed no such findings. X-ray fluorescence spectrometry and energy dispersive spectrometry showed the intraocular foreign materials as zinc in treated rats, whereas control animals showed no zinc signal. Histopathological examination revealed the retinopathy in the eyes of rats treated with ZnO NPs. Neuronal nuclei expression was decreased in neurons of the ganglion cell layer of animals treated with ZnO NPs compared to the control group. Taken together, treatment with 20-nm, negatively-charged ZnO NPs increased retinopathy, associated with local distribution of them in ocular lesions.

• Toxicological Research
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• 제32권1호
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• pp.81-87
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• 2016

Aflatoxin B1 (AFB1) is produced by Aspergillus flavus growing in feedstuffs. Early detection of maize contamination by aflatoxigenic fungi is advantageous since aflatoxins exert adverse health effects. In this study, we report the development of an optimized conventional PCR for AFB1 detection and a rapid, sensitive and simple screening Real-time PCR (qPCR) with SYBR Green and two pairs of primers targeting the aflR genes which involved aflatoxin biosynthesis. AFB1 contaminated maize samples were divided into three groups by the toxin concentration. Genomic DNA was extracted from those samples. The target genes for A. flavus were tested by conventional PCR and the PCR products were analyzed by electrophoresis. A conventional PCR was carried out as nested PCR to verify the gene amplicon sizes. PCR-RFLP patterns, obtained with Hinc II and Pvu II enzyme analysis showed the differences to distinguish aflatoxin-producing fungi. However, they are not quantitative and need a separation of the products on gel and their visualization under UV light. On the other hand, qPCR facilitates the monitoring of the reaction as it progresses. It does not require post-PCR handling, which reduces the risk of cross-contamination and handling errors. It results in a much faster throughout. We found that the optimal primer annealing temperature was $65^{\circ}C$. The optimized template and primer concentration were $1.5{\mu}L\;(50ng/{\mu}L)$ and $3{\mu}L\;(10{\mu}M/{\mu}L)$ respectively. SYBR Green qPCR of four genes demonstrated amplification curves and melting peaks for tub1, afIM, afIR, and afID genes are at $88.0^{\circ}C$, $87.5^{\circ}C$, $83.5^{\circ}C$, and $89.5^{\circ}C$ respectively. Consequently, it was found that the four primers had elevated annealing temperatures, nevertheless it is desirable since it enhances the DNA binding specificity of the dye. New qPCR protocol could be employed for the determination of aflatoxin content in feedstuff samples.