http://nyti.ms/1Jvrfs4
Ground-up artemisia plants, from which the anti-malaria drug artemisinin
is derived, appear to work much better than the refined drug does by
itself, according to research at the University of Massachusetts.
Artemisinin, discovered by Chinese scientists
in a project started by Mao Zedong to help the North Vietnamese, has
become the newest malaria miracle cure. But parasites resistant to it have emerged.
Scientists
infected mice with two strains of rodent malaria — one that is already
artemisinin-resistant and one that is not, but is biologically similar
to Plasmodium falciparum, the deadliest strain of human malaria. They
then fed the mice pure artemisinin or dried artemisia annua plants bred
for high drug content at Worcester Polytechnic Institute.
The study was published this month by the Proceedings of the National Academy of Sciences.
The
whole plant cured mice with artemisinin-resistant malaria. In mice with
the dangerous strain, parasites resistant to the plant failed to emerge
even after 49 successive infections — three times as many as it took
for parasites resistant to artemisinin alone to evolve.
“We
don’t know what the precise mechanism is,” said Stephen M. Rich, a
University of Massachusetts microbiologist and the paper’s lead author,
but the plant contains dozens of toxic chemicals that repel or kill
fungi, bacteria, insects and even rival plants. Some may protect the
artemisinin from being broken down by the liver. Also, he said, malaria
parasites share an ancestor with plants and contain vestigial versions
of the chlorophyll-producing organelles. The natural herbicides some
plants use to kill rivals may also work on them, he said.
