Secrets of ancient Chinese herb revealed
2012-12-24 09:02
Paris - Scientist in the United States on Sunday offered a
molecular-level explanation for how a Chinese herbal medicine used for more than
2 000 years tackles fever and eases malaria.
The herb is an extract of the root of a flowering plant
called blue evergreen hydrangea, known in Chinese as chang shan and in Latin as
Dichroa febrifuga Lour.
Chang shan's use dates back to the Han dynasty of 206 BC to
220 AD, according to ancient documents recording Chinese oral traditions.
In 2009, researchers made insights into its active
ingredient, febrifuginone, which can be pharmaceutically made as a molecule
called halofuginone.
They found that halofuginone prevented production of rogue
Th17 immune cells which attack healthy cells, causing inflammation that leads
to fever.
A study published in the journal Nature on Sunday found
halofuginone works by hampering production of proteins for making
"bad" Th17 cells, but not the "good" ones.
Specifically, it blocks molecules called transfer RNA
(tRNA), whose job is to assemble a protein bit by bit, in line with the DNA
code written in the gene.
As for malaria, halofuginone appears to interfere with the
same protein-assembly process that enables malaria parasites to live in the
blood, the study said.
"Our new results solved a mystery that has puzzled
people about the mechanism that has been used to treat fever from a malaria
infection going back probably 2 000 years or more," said Paul Schimmel,
who headed the team at the Scripps Research Institute in California.
Halofuginone has been tested in small-scale human trials to
treat cancer and muscular dystrophy. Drug engineers also eye it as a potential
tool for combating inflammatory bowel disease and rheumatoid arthritis, which
are also autoimmune diseases.
