Immunorestoration and augmentation of mitogen lymphocyte response in Graffi tumor bearing hamsters by purified saponin mixture from Astragalus corniculatus.

Investigations on the effect of purified saponin mixture (PSM) obtained from the aerial parts of Astragalus corniculatus Bieb. (Fabaceae) on mitogen response of the spleen cells in Graffi tumor bearing (GTBH) and healthy hamsters were reported. The saponin mixture in a doses of 50mg/kg b.w. was injected i.p. 4 times starting simultaneously with implantation of tumor cells. Stimulation indices to phytohemagglutinine (PHA) and lipopolysaccharide (LPS) of lymphocytes in spleens of tumor bearing hamsters (TBH) were significantly decreased during the whole period of the observation. It was established that PSM stimulated the functions of spleen cells in Graffi-TBH, resulting in increased mitogen response to PHA and LPS. The stimulation was better expressed in healthy PSM-treated hamsters. The proliferation response of spleen lymphocytes to PSM was also found. PSM did not change the in vitro proliferation ability of Graffi tumor cells. The results obtained proved the immunostimulating and immunorestorating activity of PSM on the T- and B-spleen cells in healthy and GTBH hamsters, as well as the proliferative response of it to PSM.

Influence of purified saponin mixture from Astragalus corniculatus Bieb. on phagocytic cells in Graffi-tumor bearing hamsters.

A purified saponin mixture (PSM) from Astragalus corniculatus Bieb. protected significantly hamsters against the experimental Graffi myeloid tumor. The application of PSM increased the survival rates, prolonged mean survival time and the tumor growth was markedly reduced. A purified saponin mixture (PSM) of Astragalus corniculatus Bieb. was evaluated for its immunostimulating potentials on the phagocytic cells in Graffi-tumor bearing hamsters. The number, migration and phagocytic indexes of peritoneal macrophages (pMøs) and of blood polymorphonuclear leukocytes (PMNs) were evaluated in healthy and Graffi-tumor bearing hamsters (G-TBH) treated with PSM. It was established that the Graffi myeloid tumor induced suppression of the phagocytic abilities of pMøs and PMNs. The number and migration of pMøs was significantly decreased during the whole period of observation. All tested parameters-number, migration and phagocytic activities of pMøs, as well as phagocytic ability of PMNs increased significantly in healthy and G-TBH after i.p. application of the 50 mg/kg body weight PSM. The PMS extracts from Astragalus corniculatus Bieb. are isolated and examined and their immunostimulating and immunorestorating impact on phagocitic cells was proven for the first time. This effect could be due to their high content of purified saponins.

Protective effect of Astragalus corniculatus saponins against myeloid graffi tumour in hamsters.

A purified mixture containing mostly saponins (PMS) from Astragalus corniculatus Bieb. was used in an in vivo model to demonstrate its protective effect against myeloid Graffi tumour in hamsters. Survivability, tumour growth and tumour transplantability were followed. Comparative studies revealed that the intraperitoneal administration of PMS: (i) decreased the tumour transplantability; (ii) inhibited tumour growth in the early stages of tumour progression; (iii) increased the mean survival time; (iv) reduced the percentage mortality. These results suggest that appropriate use of PMS could outline a promising strategy for the treatment of myeloid Graffi tumour.

Superoxide production by phagocytes in myeloid Graffi tumor-bearing hamsters.

A progressive suppression of the phagocytic ability of peritoneal macrophages and polymorphonuclears (PMNs) in hamsters with transplanted myeloid tumors was previously established. The i.p. application of Cu/Zn SOD, isolated from the fungal strain Humicola lutea (HLSOD) (2 injections before and 5 injections after tumor transplantation) induced the mean survival time of the animals as well as a temporally stimulating action on the macrophage and PMNs phagocyting indices. In the present work, the superoxide production of peritoneal macrophages and PMNs during 30 days of tumor progression was followed. Effects of the application of HLSOD in an optimal protective dose on the superoxide production in peritoneal macrophages and blood PMNs were examined. The spontaneous and phorbol-myristate acetate (PMA)-inducible O2- production in both types of phagocytes was 4-5-fold increased in tumor-bearing hamsters (TBH), as compared to the controls, at day 14 after tumor transplantation (the day of tumor appearance in transplanted animals). Furthermore, O2- production was also similar to the control values for the following days of observation. HLSOD treatment of TBH induced a normalization of superoxide production in macrophages and PMNs. Therefore, the established decrease of superoxide anions in phagocyting cells of TBH indicates possible effects of HLSOD on the host antioxidant defense.

Monoclonal antibodies to a tumour-associated antigen isolated from circulating immune complexes of bovine leukemia virus-infected cattle.

From circulating immune complexes (ICs) of BLV-infected cattle, an antigen preparation was produced that contained some virus-specific proteins and a tumour-associated antigen. Eleven hybridoma clones were produced that secreted monoclonal antibodies (MoAbs) to this tumour-associated antigen, and two of them, MoAbs 1B4 and 1E9, were used in further studies. Most antibodies were of IgG1 subclass and showed no cytotoxic activity towards lymphocytes of BLV-positive cattle or to certain tumour cells. The MoAbs 1B4 and 1E9 recognized an antigen of about 75 kD on the cell surface of bovine lymphosarcoma cells and circulating lymphocytes from BLV-infected cattle with persistent lymphocytosis. The results presented indicate that the circulating immune complexes from BLV-positive cattle contain a tumour-associated antigen that is expressed on tumour cells and on lymphocytes from cattle with persistent lymphocytosis.