title: Uncaria tomentosa extract increases the number of myeloid progenitor cells in the bone marrow of mice infected with Listeria monocytogenes.
abstract: In this study, we demonstrated that Uncaria tomentosa extract (UTE) protects mice from a lethal dose of Listeria monocytogenes when administered prophylactically at 50, 100, 150 and 200 mg/kg for 7 days, with survival rates up to 35%. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with L. monocytogenes, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow. Non-infected mice treated with 100 mg/kg UTE also presented higher numbers of CFU-GM in the bone marrow than the controls. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected mice pre-treated with UTE. Moreover, stimulation of myelopoiesis and CSA occurred in a dose-dependent manner, a plateaux being reached with the dose of 100 mg/kg. Further studies to investigate the levels of factors such as IL-1 and IL-6 were undertaken. We observed increases in the levels of IL-1 and IL-6 in mice infected with L. monocytogenes and treated with 100 mg/kg of UTE. White blood cells (WBC) and differential counting were also performed, and our results demonstrated no significant changes in these data, when infected mice were pre-treated with 100 mg/kg of UTE. All together, our results suggest that UTE indirectly modulates immune activity and probably disengages Listeria-induced supression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (CSFs, IL-1 and IL-6).
authors.affiliation: Departamento de Farmacologia/Hemocentro, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), C.P. 6111, CEP 13083-970, Campinas, SP, Brazil.
authors.forename: Samara
authors.initials: S
authors.lastname: Eberlin
authors.forename: Leonilda M B
authors.initials: LM
authors.lastname: dos Santos
authors.forename: Mary L S
authors.initials: ML
authors.lastname: Queiroz
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects*; D020948:Cat's Claw; D006410:Hematopoiesis / Q000187:drug effects; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008088:Listeriosis / Q000097:blood / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D023461:Myeloid Progenitor Cells / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*
chemical_list: D007375:Interleukin-1; D015850:Interleukin-6; D010936:Plant Extracts