US researchers reported Tuesday that the properties of green tea
might offer a new treatment for skin disorders such as psoriasis
and dandruff.
In skin diseases like psoriasis, skin cells multiply out of
control, causing the skin to be thicker and to flake off. Immune
cells in the body are also activated, causing inflammation to set
in.
In a study published on the latest issue of Experimental
Dermatology, researchers from Medical College of Georgia studied an
animal model for inflammatory skin diseases, and those treated with
green tea showed slower growth of skin cells and the presence of a
gene that regulates the cells' life cycles.
Animal models treated with green tea also showed reduced levels
of proliferating cell nuclear antigen (PCNA), a gene expressed when
skin cells multiply. In psoriasis, the gene is over-expressed and
speeds production of skin cells.
Dr. Stephen Hsu, lead investigator on the study, said that the
traditional treatment of ultraviolet light and medication can
control the lesions of the skin, but may cause squamous cell
carcinoma -- the second most common form of skin cancer, after
long-term use.
Green tea, which is plant-derived, may be an alternative, he
says. But researchers must work to overcome some barriers with the
treatment and further study is needed to determine the full
effects.
The chemicals in green tea are so active that they are oxidized
too quickly when mixed with other ingredients. They also dissolve
in water, which cannot penetrate the skin's barrier.
Researchers are looking for a balanced formula that can dissolve
in fats, which can permeate the skin, Dr. Hsu said.
(Xinhua News Agency August 8, 2007)