Pycnogenol, an extract from the bark of the French maritime pine, has been linked to preventing deep vein thrombosis and platelet aggregation in humans, and anti-inflammatory effects in animal studies.
The pine extract is produced exclusively by Horphag Research, which also sponsored this new research.
The researchers, from Bayerische Julius-Maximilians Univeristy, Germany, looked at inhibition of the cyclooxygenase, COX-1 and COX-2: enzymes that are well known to be responsible for inflammation and pain.
"We here provide the first report on active principles in human plasma after intake of Pycnogenol that statistically significantly inhibited the enzymatic activity of COX-1 and COX-2," wrote lead author Angelika Schäfer in Biomedicine and Pharmacotherapy (Vol. 60, pp. 5-9).
The small study followed pycnogenol supplementation (200 mg) of the diet of five people for five days. At the end of the test period, the mean inhibition of COX-1 and COX-2 was found to be 14 and 16.5 per cent, respectively.
This result is undermined by the fact that only three of the five volunteers showed COX-1 inhibition, and only two on the five showed COX-2 inhibition.
The researchers then recruited ten more volunteers and gave then 300 mg pine bark extract supplements to measure the bioavailability of Pycnogenol. Thirty minutes after taking the supplement, the mean inhibition of COX-1 and COX-2 was 22.5 and 15 per cent.
"This suggests a strikingly rapid bioavailability of bioeffective compounds after oral intake of the extract," said Schäfer.
The mechanism by which Pycnogenol inhibits the cyclooxygenase enzymes is unclear, and the picture is blurred further since the extract is a complex mixture of various components including catechin, epicatechin, polyphenolic monomers and cinnamic acids.
"The next challenge is to identify the responsible active principle(s) that are rapidly bioavailable in human serum samples," concluded Schäfer.
Approximately seven million people in the UK alone are reported to have long-term health problems associated with arthritis. Around 206 million working days were lost in the UK in 1999-2000, equal to £18 billion (€26 billion) of lost productivity.