Fundamental Toxicological Sciences
Online ISSN : 2189-115X
ISSN-L : 2189-115X
Volume 8, Issue 4
Displaying 1-4 of 4 articles from this issue
  • Taiki Kobayashi, Takasumi Shimomoto, Junichi Namekawa, Masanobu Kanou, ...
    2021 Volume 8 Issue 4 Pages 97-101
    Published: 2021
    Released on J-STAGE: August 03, 2021

    In previous studies, we suggested that hypoglycemia induced by antidiabetic drugs causes testicular toxicity. In this study, we evaluated whether spontaneously hyperglycemic and diabetic rats (Goto-Kakizaki rats) treated with an antidiabetic drug showed testicular histopathological changes. TMG-123, a glucokinase activator, was given to the rats for 4 weeks at 12.5, 25 and 50 mg/kg. The exposures of TMG-123 at 50 mg/kg were similar to those that caused hypoglycemia and testicular toxicity in SD rats, and the decrease in blood glucose levels on day 28 of dosing was similar to that in SD rats, which showed that the pharmacological action of TMG-123 was similar in both SD and Goto-Kakizaki rats. However, blood glucose levels in Goto-Kakizaki rats were originally much higher than those in SD rats, and hypoglycemia was not induced in the Goto-Kakizaki rats. The histopathological evaluation showed no testicular changes. These results corroborate our hypothesis.

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Original Article
  • Mariko Matsumoto, Sakiko Fujii, Nozomu Hirose, Takako Iso, Yoshiyuki S ...
    2021 Volume 8 Issue 4 Pages 103-116
    Published: 2021
    Released on J-STAGE: August 27, 2021

    The Japanese government requires risk assessment of chemicals under the Chemical Substances Control Law (CSCL). Toxicity data for polyoxymethylene (paraformaldehyde; CAS No.: 30525-89-4) for human health are insufficient though the chemical needs a screening assessment under the CSCL. Thus, polyoxymethylene was selected by the Safety Examination of Existing Chemicals and Safety Programmes of the Ministry of Health, Labour and Welfare (MHLW) to assess repeated-dose and reproductive/developmental toxicity. A combined toxicity screening was conducted following the OECD TG422. Male and female rats were administered the test chemical once daily by gavage at doses of 0 (control), 20, 60, or 200 mg/kg bw from 14 days before mating for a total of 28 to 61 days. The 200 mg/kg bw/day dose caused a significant decrease in food consumption. Histopathological examination found ulcers in the forestomach and glandular stomach, and erosion and inflammatory cell infiltration in the submucosa of the glandular stomach at the end of dosing in both sexes. Inflammatory cell infiltration in the submucosa of the glandular stomach was also observed in both sexes after the recovery period. No reproductive and developmental toxicity was observed even at the highest dose. A no-observed-adverse-effect level (NOAEL) for repeated-dose toxicity was 60 mg/kg bw/day, and a NOAEL for reproductive and developmental toxicity was 200 mg/kg bw/day, the highest dose tested.

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Original Article
  • Quang Phan Dinh, Sylvester Addai-Arhin, Randy Novirsa, Huiho Jeong, Wi ...
    2021 Volume 8 Issue 4 Pages 117-122
    Published: 2021
    Released on J-STAGE: September 08, 2021

    The Hg, Cd, and Pb concentrations in marketed cigarettes from South Korea, Vietnam, Japan, Indonesia, Taiwan, Thailand, United Kingdom (UK), Belgium, Italy, Finland, and France were investigated. The average Hg concentration in cigarettes marketed in Vietnam and Thailand had the highest trend. Meanwhile, there was more Cd found in cigarettes from Thailand, UK, and Belgium. The Pb concentrations in cigarettes from Belgium, UK, and Korea were higher than in others. In the health risk assessment in this study, the significant non-carcinogenic health risk (HI) values of Hg, Cd, and Pb were investigated. The results showed that the HI of Hg, Cd, and Pb were 4.12 × 10−2, 4.07 × 101, and 9.78 × 100, respectively. It indicated that only Cd and Pb had a significant HI. When the incremental lifetime cancer risk (ILCR) was estimated, the ILCRs for both Cd (7.32 × 10−4) and Pb (0.88 × 10−5) in cigarettes were higher than the acceptable limit. The acceptable and significant cancer risks for Pb and Cd, respectively were evaluated in cigarettes used in this study.

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Original Article
  • Hisae Aoshima, Takunori Matsumoto, Rinta Ibuki, Hirokazu Kawagishi
    2021 Volume 8 Issue 4 Pages 123-133
    Published: 2021
    Released on J-STAGE: September 10, 2021

    2-Azahypoxanthine (AHX) is a compound isolated from the agaricomycete Lepista sordida that forms fairy rings and 2-aza-8-oxohypoxanthine (AOH) is a metabolite of AHX in plants. In the present study, we assessed the safety of AOH for cosmetic applications via in vitro skin sensitization tests and human skin sensitization, phototoxicity, and photosensitization assays. In the tests, AOH did not induce skin sensitization in both human cell line activation test (h-CLAT) and KeratinoSensTM methods. AOH also did not induce human dermal phototoxicity or photosensitivity. Moreover, in repeat insult patch tests, the compound did not induce any human skin reaction. Hence, we conclude that AOH is safe as a cosmetic ingredient. To the best of our knowledge, this investigation is the first to evaluate the safety of AOH on human skin.

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