Proflamin, a new antitumor agent: preparation, physicochemical properties and antitumor activity

Proflamin is a new biological response-modifying antitumor agent. It was isolated from the culture mycelium of Flammulina velutipes (Curt. ex Fr.) Sing. by means of ion exchange column chromatography and molecular sieving. It is a weakly acidic glycoprotein containing more than 90% protein and less than 10% carbohydrate, and its molecular weight is 13,000 +/- 4,000. The antitumor effect of proflamin was studied with murine tumors. It was markedly effective against the syngeneic tumors, B-16 melanoma (B-16) and adenocarcinoma 755 (Ca-755). At a dose of 10 mg/kg po, the increases in median survival time of mice with B-16 and Ca-755 were 86 and 84%, respectively. Proflamin exhibited no cytocidal effect against the cultured cell lines in vitro. Oral administration of proflamin produced no lethal or any other apparent adverse effect in mice.