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C H A P T E R
17
Medical implications of
molecular parasitology
Richard D. Pearson 1 , Erik L. Hewlett 2 and William A. Petri, Jr. 3
1 Department of Medicine and Department of Pathology,
University of Virginia School of Medicine, Charlottesville, VA, USA;
2 Department of Medicine and Department of Pharmacology,
University of Virginia School of Medicine, Charlottesville, VA, USA; and
3 Department of Medicine and Department of Microbiology,
University of Virginia School of Medicine, Charlottesville, VA, USA
BACKGROUND
The history of anti-parasitic therapy dates to
antiquity. Healers have for millennia known of
the therapeutic efficacy of various leaves, roots
and bark. Effective therapy for malaria, for
example, was identified long before the etiology
and life cycle of Plasmodium spp. were defined.
While the Greeks were attributing intermittent
fevers to bad air, native South Americans were
successfully administering extracts of the bark
of the cinchona tree to treat malaria.
As the science of chemistry advanced in the
nineteenth and twentieth centuries, biologically
active molecules such as quinine from the
cinchona tree were isolated and characterized.
In other instances organic compounds were
found empirically to have therapeutic activity.
Congeners were subsequently synthesized and
screened. Those with the greatest efficacy and
least toxicity were adopted for therapy, usually
without an understanding of the mechanism
of action. Governments seeking to protect military
or colonial personnel often supported these
efforts. Many of the anti-parasitic drugs that are
currently in use were identified in this manner
(Table 17.1).
One of the most interesting examples began
with the observation by Paul Ehrlich, the father
of modern medicinal chemistry, and his colleagues
in 1891 that methylene blue dye was
effective in the treatment of malaria. Two
decades later, difficulty in acquiring quinine
during WWI led German scientists to synthesize
Molecular Medical Parasitology
ISBN 0–12–473346–8
433
Copyright © 2003 Elsevier Science Ltd.
All rights of reproduction in any form reserved.