Studies Reveal How Plants Protect Us from
Disease By Marcia Wood April
Everyday foods, beverages, and spices contain healthful compounds that
help us fight harmful inflammation. And, in doing that, these
phytochemicalsthe resveratrol in red wine or the catechins in green,
white and black teas, for instancemay also reduce our risk of diseases
associated with chronic inflammation, including cancer and diabetes.
At the Agricultural Research
Human Nutrition Research Center in Davis, Calif., research molecular
H. Hwang conducts studies to solve the complex puzzle of precisely how
phytochemicals fight inflammation. His investigations with cells cultured in
his laboratory have uncovered probable modes of action used by phytochemicals
from red wine, green tea, garlic, curcumin and cinnamon.
Hwang's team has found, for example, that phytochemicals can interfere
with the normal flow of certain chemical signals or messages sent to and from
cells involved in chronic inflammation. The messages these cells send are in
the form of proteins. In particular, his group is closely examining proteins
known as TLRs (short for "Toll-Like Receptors") and NODs (an abbreviation for
the tongue-twisting "nucleotide binding oligomerization domain containing
Their experiments show that certain phytochemicals can interfere with
messages that, if unimpeded, could travel from TLRs and NODs, reaching and
activating genes that can trigger an inflammatory response.
The studies suggest that different phytochemicals have different ways
of interfering with these messages. For example, curcumin can undermine certain
TLRs when a specific part of curcumin's chemical structure reacts with what are
known as "sulfhydryl groups" in TLRs.
But resveratrol, found in red grapes, has a different set of targets.
Hwang's experiments suggest that resveratrol interferes with molecules called
"TBK1" and "RIP1." If unimpeded, these molecules would help convey signals to
and from TLRs.
about the research in the April 2009 issue of Agricultural Research
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture.