면역독성평가 대체시험법 개발을 위한 참조 시험물질 선정 방안

김창열 ( Changyul Kim ),허용 ( Yong Heo ) 한국동물실험대체법학회 2021 동물실험대체법학회지 Vol.15 No.1

Alternative test method for screening immunotoxic substances has not been actively challenged and no test guideline has been officialized internationally. Preparation of master list on reference chemicals is a critical process for decision on positive or negative immunotoxicity of test substances through alternative test method. The reference master list is recommended to include various scopes of immuntoxic xenobiotics including medicinal products, cosmetic ingredients, and industrial or environmental agents. Data bases or research results on human or animal immunotoxicity of chemicals were collected and analyzed for preparing the list of reference chemicals. Twenty eight chemicals were selected as non-immunotoxicants, which could be used as negative controls for immunotoxicity and 10 immunosuppressive drugs were chosen for classifying immunosuppressive toxicity of test substances. Considering chemicals used as positive controls for immunotoxicity, 38 substances with aberrant immune regulatory capacity were listed, which are categorized into 23 industrial or environmental agents, 12 medicinal products, and 3 agrochemicals. The list of reference test substances could contribute to development of in vitro alternative assay method for immunotoxicity evaluation.

폴리에틸렌 미세플라스틱의 임신 마우스 위내 투여 및 기도 점적에 따른 신생자 간독성 평가

김근우(GeunWoo Kim),김창열(ChangYul Kim) 한국환경보건학회 2022 한국환경보건학회지 Vol.48 No.2

Background: Current research suggests that humans are exposed to microplastics through consumption of foods and beverages, the airway route, and a variety of other means. Objectives: We evaluated oxidative stress and inflammation from polyethylene microplastics (PE-MPs) in the neonatal liver through intragastric administration or intratracheal instillation in pregnant mice. Methods: PE-MPs were administered from gestational day 9 to postnatal day 7. The intragastric administration group (0.01 mg/mouse/day or 0.1 mg/mouse/day) and intratracheal instillation group (6 μg/mouse/day or 60 μg/mouse/day) of PE-MPs were administered. After sacrifice, the oxidative stress and inflammation of the neonatal livers were measured. Results: As a result of the oxidative stress caused by PE-MPs in the neonatal livers, glutathione peroxidase decreased in a concentration-dependent manner in the intragastric administration group compared to the control group and intratracheal instillation decreased in high concentration PE-MPs. The catalase level increased at high concentrations of intragastric administration and intratracheal instillation. To confirm the level of inflammation caused by PE-MPs, monocyte chemoattractant protein-1 and tumor necrosis factor- alpha were increased compared to the control group except for intratracheal intilation-high concentration PE- MPs. The C-reactive protein level was decreased by intragastric administration compared to the control group and intratracheal instillation was increased compared to the control group. Conclusions: Despite the difficulty in comparing the toxic intensity between intragastric administration and intratracheal instillation of PE-MPs, our study revealed that oxidative stress and inflammation were induced in the neonatal liver. However, it is necessary to evaluate the toxic effects of microplastics on various organs as well. Overall, the present study indicates that the evaluation of toxic effects of long-term microplastic exposure, potential of microplastic toxicity on next-generation offspring and toxicity mechanism in human should be considered for further investigations.

폴리에틸렌 미세플라스틱과 납의 복합노출에 따른 실험동물의 세포면역기능 조절 장애 평가

이경우(Gyoungwoo Lee),김창열(Changyul Kim) 한국환경보건학회 2023 한국환경보건학회지 Vol.49 No.1

Background: The existing research results on the combined toxicity of these pollutants using mammals, such as rodents, are insufficient, especially in relation to changes in the immune system. Objectives: This study aims at evaluating the cellular immune response to PE-MPs solely or when combined with Pb, which possess excellent adsorption capacity with PE-MPs and is commonly co-exposed in our daily lives. Methods: The study investigated the cellular immune function of 9-week ICR mice with 28 days exposure to PE-MPs (2 mg/mouse/day) and Pb (0.1 mM in distilled water) individually and in combination. PE-MPs were administered via gastric intubation while the lead intake was conducted via the oral drinking water route. Cellular immunity was evaluated by analyzing the production for TH1 cytokines namely, TNF-α and IFN-γ and TH2 cytokines, IL-4 and IL-6 in culture supernatants from polyclonally activated splenic mononuclear cells ex vivo. Results: Both the PE-MPs only and the PE-MPs+Pb exposure group revealed an increased TH1 response with elevated TNF-α and IFN-γ levels and downregulated TH2 response with low IL-4, and IL-6 production levels compared to the control group. Furthermore, an increased IFN-γ/IL-4 ratio was found in the PE-MPs only and PE-MPs+Pb exposure groups, which indicated the skewedness to TH1 response. Meanwhile, reduced blood hemoglobin levels and increased levels of IL-4, the dominant TH2 cytokine in the Pb-only exposure group, were observed. Conclusions: Our current findings on the predominance of TH1 immune response in the PE-MPs and PE-MPs+Pb groups suggest that PE-MPs could be responsible for the predominant induction of the cellular immune changes. This finding could be used as an important landmark in research related to TH1 predominance, such as autoimmune diseases. It suggests that additional research on immune modulation using longer exposure durations or the same exposure route is required to elucidate stronger findings.

폴리에틸렌 미세플라스틱의 임신 마우스 위내투여에 따른 모체 및 신생자 독성평가

송영민(YoungMin Song),김창열(ChangYul Kim) 한국환경보건학회 2021 한국환경보건학회지 Vol.47 No.5

Background: Plastic particles less than 5 mm in diameter (microplastics) are well-known for causing various toxicities such as lung inflammation, oxidative stress, genotoxicity, and reproductive toxicity. As microplastics become smaller, they can move across cell membranes, the placenta, and the blood-brain barrier. Objectives: We evaluated the toxicities of polyethylene microplastics (PE-PMs) in dams and neonates through intragastric intubation of pregnant ICR mice. Methods: Low concentrations (0.01 mg/mouse/day) and high concentrations (0.1 mg/mouse/day) of polyethylene microplastics were administered from the ninth day of pregnancy to postnatal day seven. The control group was administered with distilled water. On the day of sacrifice, the weight of dams and neonates and the organ weight of neonates was measured. Further, acetylcholinesterase levels and glutathione peroxidase levels were evaluated by using a blood sample obtained on the sacrifice day. Results: No significant difference in the number of neonates was found, but the body weight gain of dams was seen to be lower in the low-dose group. On the other hand, we observed a consecutively declining trend in the weight gain and organ weight of neonates among the high-, control, and low-dose groups. Meanwhile, the serum acetylcholinesterase and glutathione peroxidase level were higher in the low-dose group compared to the control group. Further, the dose-dependent accumulation of microplastics in the organs of neonates revealed the transport of plastic particles from dams to their offspring. Conclusions: Although the exact mechanism of toxicity caused by microplastics could not be confirmed, it was validated that exposure to microplastics during pregnancy and lactation causes its migration between generations and accumulation throughout the body. Hence, it is necessary to evaluate the systemic toxicity of microplastics and assessment of co-morbidities such as second-generation toxicity, neurotoxicity, and depression following long-term exposure.

실험동물 랫드를 이용한 미세먼지 기도노출에 따른 호흡기계 독성에 대한 마늘의 예방효과 탐색

이윤범(YoonBum Lee),김근우(GeunWoo Kim),송영민(YoungMin Song),한영훈(YoungHoon Han),하창수(ChangSu Ha),이지선(JiSun Lee),김민희(MinHee Kim),손혜영(HyeYoung Son),이기용(GiYong Lee),허 용(Yong Heo),김창열(ChangYul Kim) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.6

Objectives: Exposure to fine dust (PM10) could contribute to the occurrence of cardiovascular disease or respiratory abnormalities. Since garlic is known to possess an anti-oxidative stress effect, the present study was performed to evaluate the effect of garlic intake on fine dust-mediated pulmonary toxicity. Methods: Rats were intratracheally instilled with fine dust at 15 mg/kg body weight (BW)/day for five days following five-day intragastric intubation of garlic at 0.7 or 1.4 g/kgBW/day, or 13.1 mg/kgBW/day S-allyl-cysteine (SAC) as a reference component in garlic. Blood and bronchoalveolar lavage fluid (BALF) were collected. Results: Deposit of fine dust was visually and histopathologically observed in the lungs. Body weight gain during the instillation period was significantly lowered in all the groups instilled with fine dust. Neutrophil numbers in blood were significantly elevated in the fine dust alone group, but this alteration was diminished in the groups administered with garlic. Levels of serum glutathione were lower in the rats instilled with fine dust alone, and this decrease in the glutathione level seems dose-dependently compensated among the groups administered with garlic. Similar findings were observed in the BALF with statistical significance. Typical pulmonary histopathological observation related with inflammation was demonstrated in the lungs of the rats exposed to fine dust alone, whereas such histopathologic findings were not improved in the groups administered with garlic. Conclusion: The present study suggests that garlic intake could alleviate fine dust-mediated pulmonary or systemic toxicities. Further investigation is necessary to delineate the mechanism of garlic-mediated effects on pulmonary function.