OBJECTIVE: Few studies have investigated the effects produced by combinations of polysaccharides and chemotherapeutic drugs in cancer treatment.We hypothesized that a combinationo fpolysaccha rides(COP) from Lentinus edodes and Tricholoma matsutake would improve the efficacy of 5-fluorouracil(5-FU)-mediated inhibition of H22 cell growth.METHODS: Mice were injected H22 cells and then treated with either 5-FU, polysaccharides from Tricholoma matsutake(PTM), polysaccharides from Lentinus edodes(PL), PTM+PL, 5-FU+PTM, 5-FU+PL, or 5-FU+COP. The tumor weight and volume,and splenic CD4 + and CD8 + T cell frequencies,were determined. Additionally, splenic natural killer(NK) cell and cytotoxic Tlymphocyte (CTL) activities were assessed and the serum levels of tumor necrosis factor-α(TNF-α),Interleukin-2(IL-2),and Interferon-γ (IFN-γ) were measured. 5-FU, PL, PTM, PTM+PL, 5-FU+PL, and 5-FU+PTM groups, mice treated with 5-FU+COP showed:(a)significantly reduced tumor weight and volume(P