Macrophage Stimulator beta-(1-->3)-D-carboxymethylglucan improves the efficiency of chemotherapy of Lewis lung carcinoma

Regulation of activity of cathepsins B, L, and D in murine lymphosarcoma model at a combined treatment with cyclophosphamide and yeast polysaccharide

Changes in the activity of cysteine (cathepsins B and L) and aspartyl (cathepsin D) proteases were investigated at the development of susceptible and resistant variants of murine lymphosarcoma (LS). It has been demonstrated that the variant resistant to the cyclophosphamide treatment is characterized by a lower activity of all three cathepsins in the tumor tissue. Application of a higher dose of cyclophosphamide led to a more pronounced increase of the studied enzymatic activity in mice with a resistant variant of LS, than in those with a susceptible one. Administration of a yeast polysaccharide derivative - sulfoethyl glucan - enhanced therapeutic effect of cyclophosphamide in mice with both variants of LS, while the most efficient dose was found to be that of 10mg/kg body mass. In the intact mice, usage of both cyclophosphamide and sulfoethyl glucan led to a similar increase of the cathepsins activity in liver and spleen.

The effect of (1-->3)-beta-D-glucans, carboxymethylglucan and schizophyllan on human leukocytes in vitro

(1-->3)-beta-D-glucans are known as potent inductors of humoral and cell-mediated immunity in humans and animals. (1-->3)-beta-D-glucans isolated from various sources differ in their chemical structure and physical parameters and consequently in their immunomodulatory potential. In this study the immunomodulatory activity of two (1-->3)-beta-D-glucans schizophyllan (SPG) and carboxymethylglucan (CMG) was determined and compared on human blood leukocytes in vitro. Both SPG and CMG activated blood phagocytes and lymphocytes as demonstrated by increased whole blood production of reactive oxygen species, by increased production of pro-inflammatory cytokines IL-6, IL-8, and TNF-alpha, by increased surface expression of CD69 on lymphocytes, and by altered expression of CD11b and CD62L on polymorphonuclear leukocytes and monocytes. SPG demonstrated a significantly higher potential to stimulate blood phagocytes and production of selected pro-inflammatory cytokines than CMG. The higher potency of SPG to stimulate human blood phagocytes in vitro could be caused by factors such as higher branching frequencies or neutral polymer charge of SPG or different conformation in solution if compared with CMG.