Protection against metastasis of radiation-induced thymic lymphosarcoma and weight loss in C57Bl/6NCr1BR mice by an autoclave-resistant factor present in soybeans.
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.
Evans
S M
SM
Department of Radiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104.
Van Winkle
T
T
Szuhaj
B
B
Michel
K E
KE
Kennedy
A R
AR
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009381:Neoplasms, Radiation-Induced / Q000188:drug therapy / Q000473:pathology*; D010936:Plant Extracts / Q000627:therapeutic use; D013025:Glycine max; D013953:Thymus Neoplasms / Q000188:drug therapy / Q000473:pathology*; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000627:therapeutic use*; D015431:Weight Loss
D000970:Antineoplastic Agents; D010936:Plant Extracts; D014358:Trypsin Inhibitor, Bowman-Birk Soybean