Traditional antimalarial phytotherapy remedies used by the Kwale community of the Kenyan Coast

In Kenya, most people especially in rural areas use traditional medicine and medicinal plants to treat many diseases including malaria. Malaria is of national concern in Kenya, in view of development of resistant strains of Plasmodium falciparum to drugs especially chloroquine, which had been effective and affordable. There is need for alternative and affordable therapy. Many antimalarial drugs have been derived from medicinal plants and this is evident from the reported antiplasmodial activity. The aim of the study was to document medicinal plants traditionally used to treat malaria by the Digo community of Kwale district. Traditional health practitioners were interviewed with standardized questionnaires in order to obtain information on medicinal plants traditionally used for management of malaria. Twenty-five species in 21 genera and 16 families were encountered during the study. Celestraceae, Leguminosae and Rubiaceae families represented the species most commonly cited. Three plant species, namely; Maytenus putterlickioides, Warburgia stuhlmannii and Pentas bussei are documented for the first time for the treatment of malaria.     

In utero exposure to helminth and mycobacterial antigens generates cytokine responses similar to that observed in adults.

Neonates exposed to parasite antigens (Ags) in utero may develop altered fetal immunity that could affect subsequent responses to infection. We hypothesized that cord blood lymphocytes (CBL) from offspring of mothers residing in an area highly endemic for schistosomiasis, filariasis, and tuberculosis in Kenya would either fail to respond or generate a predominantly Th2-associated cytokine response to helminth and mycobacterial antigens (PPD) in vitro compared to maternal PBMC. Kenyan CBL generated helminth Ag-specific IL-5 (range 29-194 pg/ml), IL-10 (121-2,115 pg/ml), and/or IFN-gamma (78 pg/ml-10.6 ng/ml) in 26, 46, and 57% of neonates, respectively (n = 40). PPD induced IFN-gamma in 30% of Kenyan CBL (range 79-1,896 pg/ml), but little or no IL-4 or IL-5. No Ag-specific IL-4, IL-5, or IFN-gamma release was detected by CBL obtained in the United States (n = 11). Ag-driven cytokine production was primarily CD4-dependent. Cytokine responses to helminth and mycobacterial Ags by maternal PBMC mirrored that observed in neonates. CBL from helminth infected and/or PPD-sensitized mothers produced more Ag-specific cytokines compared to CBL from uninfected mothers (P < 0.05). These data demonstrate that the human fetus develops similar patterns of cytokine production observed in adults and indicates that prenatal exposure may not lead to tolerance or altered fetal immunity. .     

Extended long-term culture reveals a highly quiescent and primitive human hematopoietic progenitor population

Long-term culture-initiating cells (LTC-IC) are hematopoietic progenitors able to generate colony-forming unit-cells (CFU) after 5 to 8 weeks (35 to 60 days) of culture on bone marrow (BM) stroma and represent the most primitive progenitors currently detectable in vitro. We have recently reported that long-term cultures initiated with CD34+CD38- cells from BM or cord blood are able to continue generating CFU for at least 100 days, ie, beyond the standard LTC-IC period. In this report, single-cell cultures from cord blood and retroviral marking of cord blood and BM were used to study whether the subpopulation of CD34+CD38- cells able to generate CFU beyond 60 days ("extended long-term culture-initiating cells" or ELTC-IC) are functionally distinct from LTC-IC in terms of timing of initial clonal proliferation and generative capacity. All cord blood LTC-IC formed clones of greater than 50 cells by day 30. In contrast, cord blood ELTC- IC proliferated later in culture, 50% forming clones after day 30. Although efficient retroviral marking of LTC-IC was seen (25% to 45%), marking of ELTC-IC was inefficient (< 1%), consistent with a more quiescent progenitor population. There was a positive correlation between time of clonal proliferation and generative capacity. ELTC-IC generated threefold to fourfold more progeny than did LTC-IC (P < .002). These studies show that there is a functional hierarchy of progenitors in long-term culture which correlates with their level of quiescence. By extending the LTC-IC assay, a more primitive progenitor may be studied that may be functionally closer to the human long-term repopulation stem cell in vivo.