The antitumor effects of polysacchrides Spirulina Platensis (PSP) were studied in vivo and vitro.In vitro tests,the highest
inhibited rates on B 37 mamma carcinoma cells and K 562 leukemic cells were 68.0% and 46.0%
respectively when the concentration was 0.3～1.5g·L 1 .In vivo tests,when the dosage were 300,150,and 75mg·kg 1 p.o,the inhibited rates were 55.2%,44.6% and 33.8%;47.1%,36.4% and 31.0% and 56.9%,44.7% and 22.8% respectively on the transplanted tumor cells of Sarcinoma 180,
H 22 Hepatic tumor and EAC tumor cells in mice.PSP is biological activated substance which has widely immune effect.It had the effects of increasing the weight of spleen and thymus and of increasing proliferation of activated NK cell activity and TNF α levels from 34×10 3 to 75×10 3 IU·L 1 and of having function of activated splenocyte to produce interleukin 2(rIL 2) in tumor bearing mice.It is suggested that PSP has the ability to inhibit tumor and mechanism is partly to enhance immunity in tumor bearing imce.In addition,enhancing or recovering the number of WBC which reduced by CTX is also important function in treatment of tumor.