Intensification of antitumor-immunity by protein-bound polysaccharide, EA6, derived from Flammulina velutipes (Curt. ex Fr.) Sing. combined with murine leukemia L1210 vaccine in animal experiments.

The antitumor effect of protein-bound polysaccharide, EA6, derived from fruit bodies of Flammulina velutipes (Curt. ex Fr.) Sing., when combined with a vaccine treatment was studied by the challenge test in BDF1 mice and L1210 murine leukemia system. Intensification of the antitumor effect of EA6 was dependent on doses, timing, and frequency of intraperitoneal administration of the material to the immunization by concanavalin A and/or glutaraldehyde treated L1210 vaccine. Administration of EA6 prior to the injection of the vaccine, or repeated injection of more than 4 times did not increase the life span of the animals. But when EA6 was given (40 mg/kg) after the injection of the vaccine, marked prolongation of the life span (ILS of 223%) was observed against challenging of 1 x 10(2) cells of L1210. Combined treatment of EA6 with vaccine exhibited prolonged ILS in the mice challenged with 1 x 10(3) cells of L1210. The specific immunity for L1210 induced by the vaccine was not affected by EA6.

Intensification of host's immunity by squalene in sarcoma 180 bearing ICR mice.

Effect of highly purified squalene (HP-SQ) obtained from liver of a shark, Centrophorus atromarginative Garman, on antitumor activity and host's immune response was studied in sarcoma 180 bearing female ICR mice. HP-SQ was administered intraperitoneally (i.p.) to solid tumor-bearing or healthy mice at the dose of 0.1 ml/mouse/d for consecutive 10 d. The administration of HP-SQ exerted the host's resistance against challenging 5 x 10(4) cells of ascites sarcoma 180, and it resulted in marked prolongation of survival of the mice (ILS; 110%). Function of the reticuloendothelial system estimated by a carbon clearance test was enhanced by i.p. administration of HP-SQ in both the healthy and the tumor-bearing mice. Number of IgM antibody forming cells against sheep red blood cells (SRBC) in the spleen was counted 4 d after intravenous injection of 2 x 10(7) cells of SRBC. The number of the IgM antibody forming cell increased by HP-SQ administration in the tumor-bearing and the healthy mice. Delayed hypersensitivity reaction against SRBC measuring swelling of the foot pads of mice was also stimulated by the i.p. administration of the material.

Augmentation of antitumor activity by combined cryo-destruction of sarcoma 180 and protein-bound polysaccharide, EA6, isolated from Flammulina velutipes (Curt. ex Fr.) Sing. in ICR mice.

Augmentation of antitumor activity by combined in situ freeze-destruction of tumor (cryosurgery) and administration of antitumor active substances isolated from a hot water extract of an edible mushroom, Flammulina velutipes (Curt. ex Fr.) SING., was investigated in sarcoma 180 bearing ICR mice. Antitumor active substances of the mushroom included beta-(1,3)-glucan (EA3) and protein-bound polysaccharide (EA6). Antitumor activity was evaluated by the growth rate of the solid tumor rechallenged subcutaneously (s.c.) or by cumulative mortalities of the mice rechallenged intraperitoneally (i.p.) with the ascites tumor, on day 7 after cryosurgery. Weak antitumor effect induced by cryosurgery against challenged solid tumor of sarcoma 180 was markedly augmented by i.p. administration of EA6 (10 mg/kg). Cryosurgery of the solid sarcoma 180 apparently did not induce any antitumor effect against challenged ascites sarcoma 180. However, when cryosurgery was combined with oral administration of the polysaccharides (50 mg/kg), prolonged survival of the mice challenged with ascites sarcoma 180 i.p. was recognized by EA6, but not by EA3. Timing of the administration of EA6 (i.p.) with cryosurgery was best in pre- and post-cryosurgery. Immunological activity of EA6 to the host was discussed.