Fucoidan Cures Infection with both Antimony-Susceptible and -Resistant Strains of Leishmania Donovani through Th1 Response and Macrophage-Derived Oxidants

Kar, Susanta and Sharma, Gunjan and Das, Pijush K (2011) Fucoidan Cures Infection with both Antimony-Susceptible and -Resistant Strains of Leishmania Donovani through Th1 Response and Macrophage-Derived Oxidants. Journal of Antimicrobial Chemotherapy, 66. pp. 618-625.

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    Abstract

    The aim of this study was to evaluate and characterize the antileishmanial efficacy of fucoidan, a polyanionic sulphated polysaccharide from brown algae, in experimental infections of BALB/c mice with antimony- susceptible (AG83) and -resistant (GE18ER) Leishmania donovani. The effect of fucoidan was assessed against intracellular parasites in cultured macrophages and in suppressing splenic and liver parasite burdens in a BALB/c mouse model of visceral leishmaniasis by microscopic evaluation of surviving intracellular amastigotes stained with Giemsa. To evaluate the type of immunological responses, real-time PCR and ELISA were performed for various Th1 and Th2 cytokines in both in vitro and in vivo infected conditions. To determine the effector mechanism, reactive oxygen species (ROS) and NO were measured in fucoidan-treated animals by H2DCFDA-based fluorometric analysis and Griess reaction, respectively. In addition to having appreciable inhibitory effect on amastigote multiplication within macrophages (.93% inhibition at 50 mg/mL), complete elimination of liver and spleen parasite burden was achieved by fucoidan at a dose of 200 mg/kg/day given orally, 3 times weekly, in a 6-week mouse model of both antimony-susceptible and -resistant strains. This curative effect is associated with switching of T cell differentiation from Th2 to Th1 mode. Further, splenocytes of fucoidan-treated infected (AG83 and GE18FR) mice generated significantly enhanced levels of superoxide and NO. Not only was this treatment curative when administered orally 15 days post-infection, but it also imparted resistance to reinfection. These results suggest the effectiveness of fucoidan as potent immunomodulator for controlling both antimony-susceptible and -resistant visceral leishmaniasis.

    Item Type: Article
    URI: http://www.eprints.iicb.res.in/id/eprint/109
    Subjects: Infectious Diseases and Immunology
    Divisions: Indian Institute of Chemical Biology
    Depositing User: Ms Sutapa Ganguly
    Date Deposited: 29 Sep 2011 11:52
    Last Modified: 01 Feb 2012 13:23
    Official URL: http://dx.doi.org/10.1093/jac/dkq502
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