• Toxicological Research
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• 제21권4호
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• pp.325-332
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• 2005

The developmental toxicity of water extract of licorice (Glycyrrhiza glabra) was evaluated in rats. Licorice extract (500, 1,000 or 2,000 mg/kg) was dissolved in drinking water and orally administered to male rats from 9 weeks before mating to the day of copulation, and to females from 2 weeks before mating to gestational day 19. On gestational day 20, the animals were sacrificed for Cesarian section, and maternal and fetal abnormalities were examined. Licorice extract neither induce clinical signs, nor affect the body weight gain, feed and water intake, estrous cycle, copulation and fertility rates, blood $17\beta-estradiol$ level and organ weights of dams. Also, the implantation and development including body weights, absorption and death of embryos and fetuses were not influenced by in utero exposure to licorice. In addition, there were no increases in external, visceral and skeletal abnormalities of fetuses. Taken together, it is suggested that no observed adverse effect level of licorice extract is higher than 2,000 mg/kg, and that long-term in utero exposure to licorice might not cause developmental toxicities of embryos and fetuses.

• 한국식품위생안전성학회지
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• 제22권1호
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• pp.1-14
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• 2007

The term, "food safety", has traditionally been viewed as a practical science aimed at assuring the prevention acute illnesses caused by biological microorganisms, and only to a minor extent, chronic diseases cause by chronic low level exposures to natural and synthetic chemicals or pollutants. "food safety" meant to prevent microbiological agents/toxins in/on foods, due to contamination any where from "farm to Fork", from causing acute health effects, especially to the young, immune-compromised, genetically-predisposed and elderly. However, today a broader view must also include the fact that diet, perse (nutrients, vitamins/minerals, calories), as well as low level toxins and pollutant or supplemented synthetic chemicals, can alter gene expressions of stem/progenitor/terminally-differentiated cells, leading to chronic inflammation and other mal-functions that could lead to diseases such as cancer, diabetes, atherogenesis and possibly reproductive and neurological disorders. Understanding of the mechanisms by which natural or synthetic chemical toxins/toxicants, in/on food, interact with the pathogenesis of acute and chronic diseases, should lead to a "systems" approach to "food safety". Clearly, the interactions of diet/food with the genetic background, gender, and developmental state of the individual, together with (a) interactions of other endogenous/exogenous chemicals/drugs; (b) the specific biology of the cells being affected; (c) the mechanisms by which the presence or absence of toxins/toxicants and nutrients work to cause toxicities; and (d) how those mechanisms affect the pathogenesis of acute and/or chronic diseases, must be integrated into a "system" approach. Mechanisms of how toxins/toxicants cause cellular toxicities, such as mutagenesis; cytotoxicity and altered gene expression, must take into account (a) irreversible or reversal changes caused by these toxins or toxicants; (b)concepts of thresholds or no-thresholds of action; and (c) concepts of differential effects on stem cells, progenitor cells and terminally differentiated cells in different organs. This brief Commentary tries to illustrate this complex interaction between what is on/in foods with one disease, namely cancer. Since the understanding of cancer, while still incomplete, can shed light on the multiple ways that toxins/toxicants, as well as dietary modulation of nutrients/vitamins/metals/ calories, can either enhance or reduce the risk to cancer. In particular, diets that alter the embryo-fetal micro-environment might dramatically alter disease formation later in life. In effect "food safety" can not be assessed without understanding how food could be 'toxic', or how that mechanism of toxicity interacts with the pathogenesis of any disease.

• Toxicological Research
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• 제11권1호
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• pp.81-89
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• 1995

A teratogenicity study of KTC-1, a new semisynthetic rifamycin antituberculous drug, was conducted in Sprague-Dawley rats. Dosages of KTC-1 0, 7, 21, and 63 mg/kg/day were administered to darns orally gayage from day 7 to day 17 of gestation. Two-third of dams per group were subjected to cesarean section on day 21 of pregnancy for examination of their fetuses, and the remaining one-third of darns per group were allowed to deliver naturally for postnatal examination of their offspring. At 21 mg/kg/day, an increase in the skeletal variations of F1 fetuses and a decrease in the body weight of F1 offspring were seen. At 63 mg/kg/day, a loss in body weight was observed in darns. An increase in fetal death rate, a decrease in litter size and body weight, and an increase in the incidence of visceral malforrnations and skeletal variations were found in F1 fetuses. In particular, lumar rib occurred at an incidence of 31%. In addition, an increase in the dead newborns at birth and neonatal deaths during the lactation period, a loss in body weight, and a decrease in spleen weight were observed in F1 offspring. There were no signs of maternal toxicity or embryotoxicity at 7 mg/kg/day. The results suggest that the no-effect dose level(NOEL)for dams is 21 mg/kg/day, and NOELs for F1 fetuses and offspring are 7 mg/kg/day.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.82-93
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• 1994

DA-125, a new anthracycline antitumor antibiotic, was at dose levels of 0, 0.1, 0.3 and 1.0 mg/kg/day administered intravenously to pregnant Sprague-Dawley rats during the organogenetic period. Two-third of dams per group were subjected to caesarean section on day 20 of pregnancy and the remaining 10 dams per group were allowed to deliver. Effects of test substance on dams, embryonal development of Fl fetuses, as well as growth, behaviour and mating performance of Fl offspring were examined. 1. At 1 mg/kg, one out of the 10 dams showed difficult delivery. A decrease in food consumption, a loss in body weight and a decrease of spleen weight were found in this dose level group. At 0.3 mg/kg, difficult deliverys were observed in two out of the 10 dams. 2. At 1 mg/kg, an increased resorption rate and a decreased fetal weight were found. In addition, various types of external, visceral and skeletal malformations occurred at an incidence of 11.9, 41.8 and 14.5%, respectively. 3. At 1 mg/kg, body weight reduction, small eyeball, hydrocephalus and atrophy of sexual organs were observed in Fl offspring. One male pup receiving 0.3 mg/kg died on day 2 of lactation. The results show that the no-effect dose levels (NOELs) for dams and Fl offspring are 0.1 mg/kg/day and NOEL for Fl fetuses is 0.3 mg/kg/day.

• Journal of Yeungnam Medical Science
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• 제35권2호
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• pp.156-164
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• 2018

Environmental contaminants are one of the important causal factors for development of various human diseases. In particular, the perinatal period is highly vulnerable to environmental toxicants and resultant dysregulation of fetal development can cause detrimental health outcomes potentially affecting life-long health. Perfluoroalkyl compounds (PFCs), emerging environmental pollutants, are man-made organic molecules, which are widely used in diverse industries and consumer products. PFCs are non-degradable and bioaccumulate in the environment. Importantly, PFCs can be found in cord blood and breast milk as well as in the general population. Due to their physicochemical properties and potential toxicity, many studies have evaluated the health effects of PFCs. This review summarizes the epidemiological and experimental studies addressing the association of PFCs with neurotoxicity and immunotoxicity. While the relationships between PFC levels and changes in neural and immune health are not yet conclusive, accumulative studies provide evidence for positive associations between PFC levels and the incidence of attention deficit hyperactivity disorder and reduced immune response to vaccination both in children and adults. In conclusion, PFCs have the potential to affect human health linked with neurological disorders and immunosuppressive responses. However, our understanding of the molecular mechanism of the effects of PFCs on human health is still in its infancy. Therefore, along with efforts to develop methods to reduce exposure to PFCs, studies on the mode of action of these chemicals are required in the near future.

• Applied Microscopy
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• 제30권3호
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• pp.285-293
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• 2000

임신중에 투여된 불소가 흰쥐태아의 법랑질형성에 미치는 영향을 알아보고자 어미흰쥐에게 불소를 음용 시킨 후, 생후 11일이 경과된 어린 흰쥐를 희생하였다. 이후, 하악절치를 발치한 후, 법랑단백질의 종류 및 양적 변화와 법랑질 표면의 형태학적 변화를 관찰하였다. 분비법랑질과 성숙법랑질에서 추출한 법랑단백질을 전기 영동한 결과, 분비법량질에서는 분자량 $22\sim24kDa$의 amelogenin이 확인되었는데, 대조군에서보다 불소투여 농도가 높아질수록 양이 감소하였다. 성숙법랑질에서는 분자량이 68kDa의 enamelin이 확인되었으며, 대조군에 비해 불소투여 농도가 높을수록 양적인 증가가 확인되었다. 그리고 주사전자현미경을 사용하여 법랑질 표면을 관찰한 결과, 대조군에서는 평탄하고 매끄러운 표면인 반면에 불소투여군은 거친 표면과 균열이 심하게 나타났고, 불규칙한 소공이 관찰되었다. 그리고 일부에서는 균열과 함께 주머니 같은 결절과 법랑질 형성부전을 확인하였다. 따라서 본 연구결과, 태아발생과정 중 투여된 불소가 법랑질형성에 관여하는 법랑모세포에 영향을 줌으로써 단백질의 형성과 분비가 지연 또는 억제되며, 수분과 단백질 제거에 관여하는 법랑모세포의 기능을 저하시키는 것으로 사료된다. 이러한 단백질의 비정상적인 형성과 분비는 법랑질 형성부전 등의 법랑질형성에 전반적으로 영향을 미치는 것으로 확인되었다.

• 대한수의학회지
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• 제34권1호
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• pp.69-75
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• 1994

수은에 의한 기형발생은 이미 밝혀졌으나 이에 대한 치료가능 약제들의 효과에 대하여는 아직 밝혀진바 없다. 임신한 CD-1마우스에 20ppm의 수은(methylmercuic chloride)을 음수를 통해 임신 6일째 부터 15일 사이에 투여하고 이와 동시에 투여계획에 따라 기존 치료제 BAL과 티아민(thiamin)을 피하로 투여한 후 임신 18일째에 제왕절개술을 실시하였다. 티아민(200mg/체중 kg)과 BAL(5.0mg/체중 kg) 그리고 티아민과 BAL의 병용치료군의 태아는 체중과 두부-둔부 길이 그리고 태반의 무게가 수은 단독 투여군에 비하여 유의성 있게 무겁거나 길어 대조군에서 보인 수치에 가까왔다. 죽은 태아/재흡수율과 기형인 태아 발생율은 티아민과 BAL 치료군에서 감소되었으며 투여용량이 높을수록 발생율이 낮았다. 또한 높은 농도의 티아민과 BAL은 어미 마우스의 사료 및 음수섭취량을 증가시켰으며 간의 상대적 무게도 증가 시켰다. 이 연구 결과는 티아민을 단독 또는 키레이트제재와 병용투여할 경우 수은에 의한 기형발생을 감소시키거나 방지 할 수 있는 효과가 있음을 보여주고 있다.

• Clinical and Experimental Reproductive Medicine
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• 제20권2호
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• pp.165-176
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• 1993

These studies were carried out to investigate the optimal freezing protocol for 2 cell mouse embryos and to find the probability of quality control with 2-cell embryos frozen. The embryos showed the best survival by the protocol composed of a freezing solution with the cryoprotectants(1.5M propanediol + 0.1M sucrose), and a 2-steop thawing method(room temperature, 20 sec-37$^{\circ}C$, 20 sec). The developmental ability of frozen-thaw 2-cell embryos did not differ from that of fresh 2-cell embryos in m-KRB medium with 0.4% bovine serum albumin. But development of frozen-thaw embryos was depended on the supplements of the medium. In the albumin-free medium, the developmental rate(rate of blastocysts) was significantly reduced, compared with that in the medium with 0.4% BSA. Also, when frozen-thaw embryos were cultured in the meduim with human fetal cord serum(HCS), the developmental rate of frozen-thaw embryos was sligtly reduced, compared with that of fresh 2-cell embryos. Finally, frozen-thaw 2-cell mouse embryos were more sensitive to the toxic agent of disposable-plastic syringe. Therefore, toxicity of medium could be effectively detected by frozen-thaw 2-cell mouse embryos.

• Toxicological Research
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• 제24권2호
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• pp.137-150
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• 2008

Sexually mature male and female rats were orally intubated with the organophosphorus insecticide, Pestban at a daily dosage of 7.45 or 3.72 mg/kg bwt, equivalent to 1/20 and 1/40 $LD_{50}$, respectively. Male rats were exposed for 70 days, while the female rats were exposed for 14 days, premating, during mating and throughout the whole length of gestation and lactation periods till weaning. The results showed depressed acetylcholinesterase(AChE) activity in the brain of parents, fetuses and their placentae in a dose-dependent manner. The fertility was significantly reduced with increasing the dose in both treated groups, with more pronounced suppressive effects in the male treated group. The number of implantation sites and viable fetuses were significantly reduced in pregnant females of both treated groups. However, the number of resorptions, dead fetuses, and pre-and postimplantation losses were significantly increased. The incidence of resorptions was more pronounced in treated female compared to male group and was dose dependant. The behavioral responses as well as fetal survival and viability indices were altered in both treated groups during the lactation period. The incidence of these effects was more pronounced in the treated female group and occurred in a dose-related manner. The recorded morphological, visceral, and skeletal anomalies were significantly increased with increasing the dose in fetuses of both treated groups, with more pronounced effects on fetuses of treated females. In conclusion, the exposure of adult male and female rats to Pestban would cause adverse effects on fertility and reproduction.

• 농업과학연구
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• 제47권3호
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• pp.657-665
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• 2020

The objective of this study was to investigate whether supplementation of pentoxifylline (PTX; phosphodiesterase inhibitor) to thawed boar semen improves the post-thaw motility of sperm and affects the efficiency of artificial insemination (AI) and further development. To determine the concentration of PTX for AI, frozen-thawed semen was incubated with 0, 5, 10, and 20 mM PTX in an extender freezing medium, respectively, after thawing. Kinematic properties of sperm were examined with a computer-assisted semen analysis (CASA) system. In addition, viability and mitochondrial activity were also tested by LIVE/DEAD and a MitoTracker kit. There were no significant differences in the kinetic parameters of thawed sperm between control and treatment groups, but overall assessment parameters such as motility and rapid progressive were higher in the 10 mM PTX group. In the viability and mitochondrial assay, there were no significant differences observed in the PTX treatment, compared to the control. For further analysis, artificial inseminations were performed using frozen semen and 10 mM PTX treated cryopreserved semen, respectively. There were no differences in pregnancy rates and fetus weights among the groups until 30 and 40 days, but litter size was reduced and relatively low-birth weight was observed in the PTX group. In summary, our findings suggest that enhancement of in vitro sperm quality or non-toxicity supplemented by PTX may have detrimental effects on fetus development.