Abstract
Influences of various kind of antitumor agents on the host-mediated antitumor effect of schizophyllan (SPG) were examined. Mice were treated with an antitumor agent before or after the subcutaneous inoculation of sarcoma 180 cells. The treatment with SPG was carried out after the inoculation of tumor cells.
1. Influence of pretreatment with antitumor agent
(1) Except for adriamycin and 6-mercaptopurine, most agents showed no antitumor activity against sarcoma 180 in the case of pretreatment alone.
(2) Except for chromomycin A3, the pretreatment with the agent did not suppress the antitumor effect of SPG.
2. Influence of posttreatment with antitumor agent
(1) Actinomycin D, chromomycin A3, cyclophosphamide, methotrexate and prednisolone were ineffective on sarcoma 180 in the case of posttreatment alone. However, they did not suppress the antitumor activity of SPG. Cyclophosphamide showed the tendency to exhibit the combined effect with SPG.
(2) Mitomycin C, bleomycin, adriamycin, cytosine arabinoside, azathioprine, futraful, 6-mercaptopurine, dexamethasone, picibanil and krestin were effective on sarcoma 180 by the posttreatment alone. Among them, bleomycin, futraful and dexamethasone showed the combined effect with SPG.
Even if the antitumor agents gave the immunosuppressive effect on the host, it appeared to be recovered by the immunopotentiating activity of SPG.
