Chemists at Galway-Mayo Institute of Technology have been extracting and testing various compounds from the European hollybush - the common holly as most people know it - with the hope that it may eventually be put to more productive uses than making up a garland at Christmas.
The tests, which have been carried out over the past 18 months, are being conducted in an effort to pinpoint the characteristics of several potential medicinal chemicals.
Holly extracts have been used in traditional folk remedies for centuries, and chemists in China and Japan have tested their own variety of hollybush. In South America, it is used to make the high caffeine drink mate, taken as a pick-me-up, while Indians in the Amazon Basin use it in another drink often consumed at ceremonials. The properties of the European hollybush, ilex aquifolium, have been largely ignored by researchers, though it is still used in parts of Spain and Turkey to treat everything from dizziness and hypertension to cancer.
Traditionally, there are reports of holly compounds extracted from bark or root being used in the treatment of gout, warts, dropsy (oedema) and fever, or as a diuretic to remove excess water from the body. Other reports suggest they may be effective in the treatment of cancer in the intestine, liver and stomach.
Dr Myles Keogh told The Irish Times their research was prompted by the availability of significant quantities of holly locally. "So far, we have isolated several potential medicinal chemicals, which need to be tested further for potency and effectiveness."
His team have isolated three saponins from the bush's roots. These are similar to compounds found in the Foxglove flower, known as digitalis compounds, which are used in the treatment of heart disease.
They also have similarities with chemicals in soya beans and yams linked with resistance to cancer. Other related compounds have been used as "adjuvants" that strengthen the immunological impact of vaccines.
The holly saponins are somewhat unusual in that each has a pair of sugars which make them more permeable, so they might get into cells more easily, Dr Keogh told New Scientist magazine, which first published details of their work.
More recently, the team has isolated compounds called triterpenes from holly bark. These have also been extracted from birch bark in the USA, notably betulinic acid, which is being tested for use in treatment of melanoma skin cancer by the US Food and Drug Administration. As triterpenes make up about 20 per cent of the bark's weight, it means if they prove useful it will be possible to extract sufficient for commercial use.
The problem with many of these compounds, according to Dr Keogh, an organic chemist, is that many of them are very toxic. Their efficacy may be significant but there is the possibility of toxic effects, so they have to be carefully assessed and dosage levels meticulously determined.