Curcumin-arteether combination therapy of Plasmodium berghei-infected mice prevents recrudescence through immunomodulation

PLoS One. 2012;7(1):e29442. doi: 10.1371/journal.pone.0029442. Epub 2012 Jan 20.

Abstract

Earlier studies in this laboratory have shown the potential of artemisinin-curcumin combination therapy in experimental malaria. In a parasite recrudescence model in mice infected with Plasmodium berghei (ANKA), a single dose of alpha,beta-arteether (ART) with three oral doses of curcumin prevented recrudescence, providing almost 95% protection. The parasites were completely cleared in blood with ART-alone (AE) or ART+curcumin (AC) treatments in the short-term, although the clearance was faster in the latter case involving increased ROS generation. But, parasites in liver and spleen were not cleared in AE or AC treatments, perhaps, serving as a reservoir for recrudescence. Parasitemia in blood reached up to 60% in AE-treated mice during the recrudescence phase, leading to death of animals. A transient increase of up to 2-3% parasitemia was observed in AC-treatment, leading to protection and reversal of splenomegaly. A striking increase in spleen mRNA levels for TLR2, IL-10 and IgG-subclass antibodies but a decrease in those for INFγ and IL-12 was observed in AC-treatment. There was a striking increase in IL-10 and IgG subclass antibody levels but a decrease in INFγ levels in sera leading to protection against recrudescence. AC-treatment failed to protect against recrudescence in TLR2(-/-) and IL-10(-/-) animals. IL-10 injection to AE-treated wild type mice and AC-treated TLR2(-/-) mice was able to prolong survival. Blood from the recrudescence phase in AE-treatment, but not from AC-treatment, was able to reinfect and kill naïve animals. Sera from the recrudescence phase of AC-treated animals reacted with several parasite proteins compared to that from AE-treated animals. It is proposed that activation of TLR2-mediated innate immune response leading to enhanced IL-10 production and generation of anti-parasite antibodies contribute to protective immunity in AC-treated mice. These results indicate a potential for curcumin-based combination therapy to be tested for prevention of recrudescence in falciparum and relapse in vivax malaria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimalarials / therapeutic use*
  • Artemisinins / therapeutic use*
  • Curcumin / therapeutic use*
  • Drug Therapy, Combination
  • Immunomodulation / drug effects*
  • Interferon-gamma / metabolism
  • Interleukin-10 / metabolism
  • Interleukin-12 / metabolism
  • Malaria / drug therapy*
  • Malaria / immunology*
  • Malaria / metabolism
  • Mice
  • Mice, Mutant Strains
  • Plasmodium berghei / drug effects*
  • Plasmodium berghei / pathogenicity*
  • Spleen / drug effects
  • Spleen / metabolism
  • Toll-Like Receptor 2 / metabolism

Substances

  • Antimalarials
  • Artemisinins
  • Tlr2 protein, mouse
  • Toll-Like Receptor 2
  • Interleukin-10
  • Interleukin-12
  • Interferon-gamma
  • Curcumin
  • artemotil