Alkaloids obtained from the plant Evanta have been shown to have dual effects in Leishmania infection; a direct leishmanicidal effect on the parasite and more importantly, the alkaloids affect both polyclonal and Leishmania-specific stimulation of T-cells. Dendritic cells (DCs) play a pivotal role in stimulation and polarization of naïve T cells towards a Th1, Th2, Th17 or regulatory phenotype. In leishmaniasis, the interactions between the parasites and DCs are complex and involve contradictory functions that can stimulate or suppress T cell responses, leading to the control of infection or progression of disease. In this study the effect of an alkaloid extract of Evanta (AEE) or the purified alkaloid 2-phenilquinoline (2Ph) on the activation of human DCs and their ability to stimulate allogeneic CD4+ T cells was analyzed. The expression of surface activation molecules was not affected on DCs stimulated in the presence of AEE or 2Ph nor did AEE-DCs or 2Ph-CDs affect the expression of activation surface molecules on allogeneic CD4+ T cells. In contrast, as compared with control, the secretion of IL-12p40, IL-23 and IL-6 was lower from AEE-DCs and 2Ph-CDs and allogeneic CD4+ T cells co-cultured with these DCs secreted lower levels of IFN-γ and IL-10 but the same levels of IL-17. These results demonstrate that AEE and 2Ph affect the stimulation of DCs and their ability to stimulate allogeneic CD4+ T cells by reducing the production of IFN-γ, IL-12 p40, IL-6 and IL-23. This suggests that AEE and 2Ph may take part in regulation of inflammation.
|Number of pages||6|
|Publication status||Published - May 2013|
Bibliographical noteFunding Information:
The authors wish to acknowledge Dr. Alberto Giménez for providing the extracts and to Consejo Indígena del Pueblo Tacana (CIPTA), Tumupasha and Rogelio Chuqui from the Tacana community of Santa Rosa de Maravilla, for collection of plant material. We are thankful to Swechha Mainali Pokharel for the technical support. This work was financially supported by the Swedish International Development Cooperation Agency (SIDA) .
- Dendritic cells
- Galipea longiflora Krause
- Natural products