Highly purified preparations of pine bark extract taken from the Scotch pine (Pinus sylvestris) were found to have potent anti-inflammatory effects, according to study leader Kalevi Pihlaja from the University of Turku in Finland.

“The extracts probably have some similarities to Pycnogenol as they come from the same family of trees although we have not done any tests to compare them,” Pihlaga told NutraIngredients.com.

Pine bark extracts are thought to reduce inflammation through their antioxidant activity. Recent research on Pycnogenol shows that it has the potential to relieve high blood pressure, platelet aggregation, LDL (bad)-cholesterol and enhance circulation, making it a useful supplement for heart health.

Sales of supplements targeted at joint health and arthritis sufferers are growing strongly in Europe - many at over 10 per cent - owing to the rising numbers of elderly suffering from these conditions.

As part of a larger search for plant compounds for new functional food products or nutraceuticals, Pihlaja's team studied identified up to 28 compounds from the Scotch pine, some of which showed high biological activity.

The researchers then tested the various extracts against mouse inflammatory cells (macrophages) for their ability to produce nitric oxide and prostaglandin E2 (PGE2), chemicals which are known to help trigger inflammation when they are produced in excess amounts, as during disease or injury.

The results were then compared to the chemical responses of inflammatory cells that were not exposed to pine bark extracts.

The most highly purified extract tested (at 50 µg/mL concentration level) had the most potent anti-inflammatory activity. It inhibited nitric oxide production, an excess of which has been linked to arthritis and circulatory problems, by up to 63 per cent, the researchers will report in the 29 December issue of the Journal of Agricultural and Food Chemistry.

They also found that the same extract concentration inhibited prostaglandin production, an excess of which has been linked to arthritis and pain, by up to 77 per cent.

The extract inhibited prostaglandin E2 production probably by blocking COX-2 enzyme activity, which is normally enhanced during inflammatory responses, according to the scientists. Blocking this enzyme is the basis for some widely used arthritis medications.

It is not known how the compounds in the extract compare to anti-inflammatory agents that are already on the market. Some of the phenolic compounds identified in the extract are already familiar to scientists as potent disease-fighting antioxidants, but there are other compounds present in the extract that have not yet been characterized, the researchers say.

The extract did not appear to show any signs of cell toxicity in the current study however further studies on animals and humans will be needed to ensure the safety of its components, the researchers warned.

The paper was initially published on 10 November on the journal's website.