Moringa oleifera Treatment Induces T Cell Activation in Plasmodium chabaudi Infection

Abstract

Abstract Malaria is a chronic infection that induces the generation of effector T cells and pro-inflammatory cytokines but never results in sterile immunity. Anti-malaria drugs can alleviate the life-threatening symptoms associated with primary infection, but many of these life-saving drugs are becoming obsolete due to growing resistance. This calls for the development of new strategies to control the disease, and the herbal plant Moringa oleifera is a promising candidate. Studies have shown that Moringa oleifera possesses potent suppressive and curative antimalarial properties, but these studies have mostly been restricted to assessment of parasitemia. Therefore, we sought to investigate the effect of Moringa on malaria immunity in vivo using the rodent parasite strain P. chabaudi. We observed that Moringa treatment slightly reduced parasite burden compared to the untreated controls. Looking at the immune response, mice treated with high dose Moringa (60 mg/mouse) for a short time (7 days) or low dose Moringa (30 mg/mouse) for a longer time (3 weeks), exhibited increased numbers of Teff cells accompanied by an increase in Tbet expression. To further investigate this, we treated mice with Moringa after infection (curatively) or before infection (prophylactically), and observed that mice that were treated with Moringa after infection exhibited increased Teff numbers, IFNγ and TNFα secretion. Interestingly, the mice that were treated before infection had significantly higher Tbet expression. These data suggest that Moringa treatment leads to CD4 T cell activation and production of pro-inflammatory cytokines after malaria infection. Future studies will investigate the mechanism by which Moringa treatment modulates CD4 T cell functions.