Green Tea as possible treatment for psoriasis and dandruff

A team of researchers led by Dr Stephen Hsu, from the Medical College of Georgia, Augusta, USA, investigated the effect of topical application of green tea polyphenols on the skin of mice, finding that it significantly reduced flaky skin.

Although the exact pathogenesis of the conditions are not known, they are associated with the acceleration of the usual replacement processes of the skin leading to a proliferation of live skin cells that reach the surface before the dead cells have been shed.

According to the study the application of green tea appeared to slow down the over proliferation by acting on an enzyme called caspase 14 - an enzyme that seems to be involved in epithelial cell differentiation.

In psoriasis patients this enzyme is defective, perhaps leading to the proliferation of cells characteristic of the condition, however researchers say that more studies are needed to identify the exact biochemical pathway.

The report, published in this month's Experimental Dermatology, suggests that the green tea extract is beneficial, working to reducing histological abnormalities and promoting caspase 14 into the active form.

"Our results also suggest that green tea extract, a non toxic plant-derived extract, could be potentially useful in treating inflammatory skin conditions' the report states.

However, further research on humans will be needed to determine the compound's full effects and the possibility of using it as an alternative treatment.

Current treatments for psoriasis involve the topical applications of tar preparations that can stain and have strong odours, topical steroids, often with deleterious long term effects, and photo treatment with UVA and B, with its associated dangers.

Treatments for dandruff centre around the use of zinc pyrithione, that some have suggested could be damaging to the environment.

In addition increasing numbers of consumers are searching for natural alternatives to the chemical active ingredients often found in such treatments; suggesting that there will be significant interest in a possible green tea treatment.

Nevertheless, there is significant work to be done before such a treatment would be available for consumers.

Of particular importance is the fact that the active nature of the chemicals in green tea means that they oxidise too quickly when mixed with other ingredients; researchers need to find a stable formula.

Furthermore, Dr Hsu states that researchers need to find a fat soluble formula, which will be able to permeate human skin, unlike the current water soluble one, which cannot.

Source : Experimental Dermatology Volume 16, pages 678-684 "Green tea polyphenol induces caspase 14 in epidermal keratinocytes via MAPK pathways and reduces psoriasiform lesions in the flaky skin mouse model" Stephen Hsu, Douglas Dickinson, James Borke, Douglas S. Walsh, Joseph Wood, Haiyan Qin, Julia Winger, Henna Pearl, George Schuster and Wendy B. Bollag