RESUMO
The importance of both granulocytes and macrophages in the response to Listeria monocytogenes infection make this infection a suitable choice to investigate the effects of Pluchea quitoc on hematopoiesis. A significant depletion of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) was observed at 48 and 72 h after intraperitoneal infection of mice with 1 x 10(4) L. monocytogenes. However, the treatment of infected animals with P. quitoc ethanolic extract (250, 500 or 1000 mg/kg) given orally for 3 consecutive days prior to infection produced a stimulatory effect on myelopoiesis, restoring the number of CFU-GM to normal. This same dose-schedule also increased colony formation in normal mice as compared to controls. In addition, P. quitoc significantly enhanced survival of infected mice. Thus, it is probable that the ability of P. quitoc to induce a higher reserve of granulocyte-macrophage precursors in the bone marrow is of major significance in determining early resistance to infection.
Assuntos
Hematopoese/efeitos dos fármacos , Listeriose/tratamento farmacológico , Listeriose/imunologia , Extratos Vegetais/farmacologia , Animais , Ensaio de Unidades Formadoras de Colônias , Granulócitos/efeitos dos fármacos , Granulócitos/imunologia , Granulócitos/patologia , Listeriose/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Plantas MedicinaisRESUMO
Two dichromenoxanthones [1,6-dihydroxy-6',6'-dimethylpyrano(2',3':3,4)-6'',6''-dimethylpyrano(2'',3'':7,8)xanthone (brasilixanthone A) and 1,6-dihydroxy-6',6'-dimethylpyrano(2',3':2,3)-6'',6''-dimethylpyrano(2'',3'':7,8)xanthone (brasilixanthone B)], along with betulinic acid, friedelin, sitosterol and stigmasterol were isolated from the roots and stems of Tovomita brasiliensis. Their structures were characterized on the basis of 1H and 13C NMR spectral data, including 2D NMR experiments.