Researchers from Kingston University, London, in conjunction with Neal’s Yard Remedies, were ‘blown away’ by results that illustrated white tea’s ability to inhibit enzymes that attack collagen and elastase, and mimic the action of one of the body’s own antioxidant enzymes.
The study, published in the BioMed Central journal of Complementary and Alternative Medicine, tested 23 extracts from 21 plants, all provided by Neal’s Yard Remedies, and found white tea to be the star amongst the pack.
Extracts were tested for their anti-collagenase and anti-elastase activity, two enzymes that contribute to skin ageing by breaking down collagen and elastin, as well as their phenolic content and their antioxidant activity.
Testing for SOD ability
In addition, the team, led by Professor Declan Naughton from Kingston University, tested the extracts ability to mimic superoxide dismutase (SOD) which is a naturally occurring enzyme that breaks down the dangerous reactive oxygen species into oxygen and hydrogen peroxide.
White tea showed the highest inhibitory activity against collagenase at 87 per cent, compared to green tea (47.17 per cent) and rose tincture (40.96 per cent). Similarly, the extract’s anti-elastase effect was over 89 per cent, the highest of all those tested.
Furthermore, according Professor Naughton the concentrations used in these experiments were significantly lower than those you would find in a cup of tea.
“The levels are much smaller than you would have in a cup of tea. With the white tea we just had to keep diluting it, it was so strong,” he told CosmeticsDesign.
White tea has vastly superior inhibiting activity
Looking at the combined action of the extract on elastase and collagenase, white tea has a inhibiting activity of over 180 per cent. The next best of the extracts tested came in at 80 percent, explained Naughton.
“We were pretty blown away by the results,” he said.
In addition, white tea had the highest phenolic content as tested by the Foli-Ciocalteu assay, and high antioxidant capacity.
Five of the extracts showed good SOD mimetic activity (over 70 per cent), of which white tea was the highest coming in at 87.92 per cent and followed in second place by green tea at 86.41 per cent.
Although from the same plant, green, black and white tea appear to have very different health giving properties.
White tea comes the newest buds of the plant, so called because the new leaf buds are often covered in fine white hairs, whereas black tea is picked later and some of the components will have oxidised decreasing its health giving properties, explained Naughton.
These results are from in vitro tests and obviously need to be embellished by animal and human studies. But, for Naughton the scope for the potential benefits of the extract is large including many diseases that include inflammation as a feature of the disease, such as heart disease, arthritis and cancer.
“I would very much like to see other researchers and scientists continuing this work and looking at in vivo studies,” he said.
Source: BioMed Central journal of Complementary and Alternative Medicine
2009, Issue 9, volume 27
Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21 plants
Tamsyn SA Thring, Pauline Hili, Declan P Naughton