Cytokine and antibody production during the course of resolution in Plasmodium yoelii 17XL-infected BALB/c mice treated with febrifugine and isofebrifugine mixture from leaves of Hydrangea macrophylla var. Otaksa.

Cytokine and antibody production was investigated during the course of resolution of primary infection in Plasmodium yoelii 17XL-infected BALB/c mice treated with a mixture of febrifugine and isofebrifugine. The infected mice in an untreated control group showed a progressively increasing parasitemia, leading to mouse death. In contrast, infected mice given the mixture orally showed low parasitemia levels during administration. Following a transient increase in parasitemia in the bloodstream of the treated mice, no parasites could be detected by microscopic examination. Analysis of cytokines in plasma showed that the plasma IFN-gamma levels elevated significantly within the first week of infection in both groups. Furthermore, on day 20 the plasma IFN-gamma and IL-4 levels elevated significantly in the treated mice and the production of both cytokines was sustained until at least day 40. The production of both cytokines in the treated mice was coincident with a decrease in parasitemia. The production of parasite-specific antibodies in the course of P. yoelii 17XL infection was also monitored. In the drug-treated mice, the titers of parasite-specific IgG1, IgG2a, IgG2b and IgG3 elevated significantly from day 20; and the production of parasite-specific antibodies was coincident with a decrease in parasite numbers in the bloodstream.