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T. Hongyo

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    P1.05 - Poster Session 1 - Preclinical Models of Therapeutics/Imaging (ID 156)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P1.05-017 - Ascorbic acid and AHCC suppress lung fibrosis and cancer caused by irradiation (ID 2650)

      09:30 - 16:30  |  Author(s): T. Hongyo

      • Abstract

      Lung fibrosis can be caused by irradiation in radiotherapy or bone marrow transplantation, and many reports have documented an association between diffuse pulmonary fibrosis and lung cancer. Although a large number of compounds showed good radioprotection in in vitro studies, most of them failed in vivo due to acute toxicity and side effects. We tried to induce lung fibrosis in mice by irradiation, and at the same time, examined some compounds which are clinically used and thought to work as radioprotectors.

      C57BL/6J mice,4-6weeks old were exposed to X-ray radiation, dose rate 0.88Gy/min, in the following conditions; (1) local fractionate irradiation (limited to the thorax); 2Gy/day x 10 or 20 days. (2) local single doze irradiation; 10, 15, 20 Gy. (3) total body single doze irradiation; 4Gy. At the same time, we administrated to each mouse by subcutaneous or intraperitoneal injection prior to irradiation sterile saline or 11 compounds which are clinically used and consist of antioxidants, sulfhydryl compounds, immunomodulators and so on. We examined the lung tissue of each mouse 5-8 months after irradiation, by checking microscopic change with Masson trichrome staining, and measured the Sircol assay level of the lung.

      By Masson trichrome staining, lung fibrosis were seen in the tissues irradiated with 40Gy in 20 equal fraction and 15 and 20Gy single dose more than 7 months after irradiation. The Sircol assay level of the lung rose as the radiation dose increased except for 4Gy total body irradiation, suggesting lung fibrotic change. Among the 11 compounds, administration of ascorbic acid and AHCC (Active Hexose Correlated Compound) showed no fibrotic change by Masson trichrome staining and they suppressed all the Sircol level of the lung.

      Lung fibrosis after irradiation was suppressed by ascorbic acid and AHCC. We might be able to prevent lung tissue impairment after irradiation by using ascorbic acid and/or AHCC, and find other compounds which can be safe radioprotectors by this method.