Groene thee mogelijk ook goed tegen
autoimmuunziektes.*
Uit een laboratoriumonderzoek blijkt dat de
stof in groene thee, EGCG niet alleen tegen ontstekingen maar ook effectief
blijkt te zijn om cellen te beschermen tegen aanvallen van auto-antigenen die
autoimmuunziektes veroorzaken.
Green Tea May
Protect Against Autoimmune Diseases
Tea
compound suppressed immune-cell activity in skin and salivary glands.
-- Green tea,
already lauded for its cancer-fighting ability,
may also protect against certain autoimmune diseases, new research suggests.
Green teas
inhibit the expression of antigens made by the body, substances that can trigger
an immune response, explained study author Stephen Hsu, an
associate professor in the School of Dentistry at the Medical College of Georgia
in Augusta. He is to report on the research Sunday at the Arthritis Foundation's Arthritis Research Conference
in Atlanta.
He focused on
EGCG, a substance found in green tea known to suppress inflammation, and its
effect on skin and salivary gland cells. In one autoimmune disorder, Sjogren's syndrome, the salivary glands are affected, causing
dry mouth. In another autoimmune disorder, lupus, the skin is affected.
Hsu's team
isolated 130 autoantigens from cells and exposed them to EGCG. Autoantigens are
molecules in the body with useful functions, according to Hsu, but changes in
either their amount or their location can result in an unwanted immune response.
Of the 130
autoantigens "most were inhibited or without changes" when exposed to
the EGCG, he said. "Among them, a group of key autoantigens were inhibited."
While the
research is very preliminary, he said, eventually green tea might help protect
cells from being attacked by the autoantigens. Besides applications for the dry
mouth that affects those with Sjogren's, Hsu said green tea might prove useful
for the skin found in lupus.
The Georgia
researcher speculated that EGCG modulates the presence of the autoantigens, in
addition to its ability to suppress inflammation.
According to Hsu,
other research with green tea in animal models has shown it can reduce arthritis.
The new study is
"a significant beginning," said Nihal Ahmad, an assistant professor of
dermatology at the University of Wisconsin at Madison, who was part of a team in
1999 that showed that polyphenols (of which EGCG is one) in green tea could
prevent induced arthritis in mice.
The Hsu research,
he said, "appears to have great potential," though it "needs more
work." However, "based on the cell culture study, we can only say that
we can be hopeful."
(Juli 2005)