Effect of Plantago major on cell proliferation in vitro.

Plantago major (Plantaginaceae) is popularly used to treat tumors, infections and as a blood purifier. Aqueous, methanol, chloroform and hexane extracts of the aerial parts (leaves and seeds) were added to CD(1) mice bone marrow and spleen cultures incubated at 37 degrees C for 72h, and also added to Escherichia coli, Bacillus subtilis and Candida albicans cultures, while methanol extract dilutions were added to HTC-15, OVCAR, UISO and KB cell line cultures. Doses of 0.4 and 0.2 mg/mL of aqueous and methanol extracts increased the bone marrow cell concentration by 2.70- and 3.15-fold, respectively, and increased the spleen cell concentration by 3.38- and 6.39-fold, respectively (p < 0.001). Aqueous extract inhibited Bacillus subtilis growth from 78 to 21%; hexane extract inhibited the growth of Escherichia coli, and methanol and chloroform extracts weakly inhibited the growth of Bacillus subtilis and Escherichia coli, respectively. Methanol extract (1 microg/mL) decreased the UISO and OVCAR cell concentrations to 59 and 82%, respectively. Data demonstrate for the first time that Plantago major has hematopoietic activity in vitro.

A model for the induction of aplastic anemia by subcutaneous administration of benzene in mice.

Long-term exposure to benzene vapors is associated with hematological diseases such as leukemia, lymphoma and aplastic anemia. CD(1) male mice were randomly assigned to six groups: 1B(10), 1B(15), 1B(20), 2B(10), 2B(15), and 2B(20.) 1B mice were administered 2 ml/kg (1940 mg/kg) subcutaneous injection (in the dorsal region) of benzene 5 days a week, and 2B mice were exposed 3 days a week (Monday, Wednesday and Friday) until a total of 10, 15 and 20 doses were completed. About 48 h after treatment completion, leukocyte, erythrocyte, and bone marrow cells were counted, and spleen histopathology was analyzed. 1B(15) and 1B(20) mice showed lethargy and irritability, 80% body and 42% spleen weight loss (P<0.001), while body and spleen weight loss were less severe in 2B mice (12 and 48%, respectively). After exposure to 20 benzene doses, 1B(20) and 2B(20) mice showed decreased hemoglobin concentrations, and erythrocyte, leukocyte and bone marrow cell counts (37, 34, 80 and 50%, respectively in group 1B(20); P<0.001; and 12, 48, 62 and 62%, respectively in group 2B(20)). Thrombocytopenia occurred only in group 2B. Both benzene-treatment schemes caused aplastic anemia, however, the disease was masked by spleen toxicity in group 1B. Scheme 2 allowed mice survival and caused less non-hematological effects. We establish here a reproducible and inexpensive experimental model to induce aplastic anemia in mice by subcutaneous injection of 2 ml/kg benzene, using two short-term treatment schemes.

[Hematologic changes associated with infection of mice by Cryptococcus neoformans]. / Cambios hematológicos asociados a la infección de ratones con Cryptococcus neoformans.

The pathogenicity of the L, P and E strains of C. neoformans was studied in 3-5 weeks old CD1 male mice. Cell suspensions containing the most (L), and the least (E) pathogenic strains were inoculated intracerebrally (IC), and intraperitoneally (IP). After 14 days total and differential counts were made for erythrocytes, leukocytes and platelets, yeasts from infected organs were recovered in Sabouraud Dextrose Agar (SDA). The capsular material from C. neoformans was used to stimulate in vivo and in vitro platelet production. Mice inoculated with the L strain, showed increase of neutrophils and platelets, decrease of lymphocytes, the yeast was recovered from spleen, liver and lungs and from brain of mice injected by the IC route. In contrast, strain E produced an increase of neutrophils, reduction of lymphocytes, and was only isolated from the brain of mice inoculated IC. The capsular material stimulated the production and maturation of megakaryocytes only in vitro. The development of the infection and the yeast dissemination were associated with increases in the number of platelets, probably as a result of the stimulant effect of the capsular material on the maturation of megakaryocytes.