New hopes for medicinal use of cranberries and tea
Compounds extracted from cranberries and tea have potential uses in stroke and skin cancer, respectively, according to reports from the American Chemical Society meeting in New York this week.
Researchers from Massachusetts University, North Dartmouth, reported
that cranberry juice exerts neuroprotective effects under conditions
of stroke simulated in in vitro studies on rat neurons.
Neurons treated with cranberry extract suffered 43 per cent less necrosis
when deprived of oxygen compared with controls. The extract also protected
reperfusion damage, which can occur after stroke when oxygen resumes
flow to the brain, exposing cells to excess levels of highly reactive
oxygen species.
Researcher Dr Catherine Neto said that blueberries had demonstrated similar
effects. Her group aims to isolate the active compounds in the hope that
a stroke fighting drug or nutraceutical can be developed. Anthocyanins,
potent antioxidants common in both types of berries, are among early
candidates for further research.
The American Chemical Society also heard about development of an anti-cancer
cream based on tea polyphenols.
Dr Zigang Dong, Minnesota University, Austin, reported that topical exposure
to these compounds in mouse models of skin cancer reduced levels of the
JNK-2 enzyme. This enzyme appears to play a key role in the development
of non-melanoma tumours after sun exposure.
His team is working to optimise the efficacy of the tea compounds. A
cream, designed to be applied after excessive sun exposure or combined
with sunscreen, could help maximise cancer protection. Human testing
could begin in a few years although the team does not yet know whether
the tea chemicals inhibit development of melanoma.
Dr Dong said that drinking tea may help, but a large amount would be
needed to accumulate in the skin. “It is easier to concentrate
in a cream form and it’s probably more effective,” he added. |
