A mushroom derived 'carbohydrate-fraction' reinstates host-immunity and protects from Leishmania donovani infection

The anti-leishmanial effect of the 'carbohydrate-fraction', isolated from an edible mushroom Astraeus hygrometricus, was evaluated against Leishmania donovani infection both in vitro and in vivo. Ah(f-Car) induced the expression of inducible nitric oxide synthase 2 (iNOS2) and pro-inflammatory cytokines like TNF-alpha and IL-12, with subsequent downregulation of the anti-inflammatory cytokines as TGF-beta and IL-10, in vitro and in vivo along with a remarkable increase in the expressions of IL-6, IL-1 beta, IFN-gamma and IRFs, IRF-7 and IRF-8 in vivo. Ah(f-Car) also reduced the parasite burden in the spleen and liver dose-dependently with a simultaneous proliferation of Ly6C(+) cells in the bone marrow of Leishmania-infected experimental animals. It also increased the monocyte population dose-dependently and the expression of the myeloid transcription factor PU.1, in vivo, which presumably signifies the expansion of protective macrophages. Thus, Ah(f-Car) might be a potent anti-leishmanial lead with unique and effective adjuvant capacity.