Protection against metastasis of radiation-induced thymic lymphosarcoma and weight loss in C57Bl/6NCr1BR mice by an autoclave-resistant factor present in soybeans

Radiat Res. 1992 Nov;132(2):259-62.


We have investigated the ability of Bowman-Birk inhibitor, a protease (trypsin and chymotrypsin) inhibitor, to protect against radiation-induced thymic lymphosarcoma in C57Bl/6NCr1BR mice. Fifty-five 7-week-old male mice were randomized into 11 groups and gavaged 5 days per week with purified Bowman-Birk inhibitor, Bowman-Birk inhibitor concentrate, and autoclaved Bowman-Birk inhibitor concentrate. Following 7 days of gavage, those mice undergoing total-body or sham total-body irradiation received 1.7 Gy weekly for 4 weeks. At 6 months following the radiation exposure, all mice were sacrificed and examined histopathologically. Samples of Bowman-Birk inhibitor concentrate, purified Bowman-Birk inhibitor, and autoclaved Bowman-Birk inhibitor concentrate were evaluated with thin-layer chromatography. The mice treated with total-body irradiation and autoclaved Bowman-Birk inhibitor had significantly (P < 0.05) fewer deaths, lower average grade of lymphosarcoma, and larger fat stores compared to those treated with total-body irradiation and water gavage. The results for the total-body-irradiated mice receiving Bowman-Birk inhibitor concentrate suggested an effect midway between these two groups. Thin-layer chromatography analysis indicated that sterols and the phospholipids varied in the three different samples in a way that approximately corresponded with the observed effects. We have observed that an autoclave-resistant factor in soybeans is capable of reducing metastasis of radiation-induced lymphosarcoma and weight loss in C57Bl/6NCr1BR mice, presumably by preventing the extension and metastasis of cancer cells. Thus, in addition to the anticarcinogenic Bowman-Birk inhibitor, there appears to be another anticarcinogenic agent in soybeans which is capable of inhibiting the later stages of cancer cell development.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use*
  • Lymphoma, Non-Hodgkin / drug therapy
  • Lymphoma, Non-Hodgkin / pathology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neoplasm Metastasis / prevention & control*
  • Neoplasms, Radiation-Induced / drug therapy
  • Neoplasms, Radiation-Induced / pathology*
  • Plant Extracts / therapeutic use
  • Soybeans
  • Thymus Neoplasms / drug therapy
  • Thymus Neoplasms / pathology*
  • Trypsin Inhibitor, Bowman-Birk Soybean / therapeutic use*
  • Weight Loss


  • Antineoplastic Agents
  • Plant Extracts
  • Trypsin Inhibitor, Bowman-Birk Soybean