Variations in C-reactive protein, plasma free radicals and fibrinogen values in patients with osteoarthritis treated with Pycnogenol®

In a previous, double-blind, placebo-controlled study we evaluated the efficacy of a 3-month treatment with Pycnogenol® for 156 patients with osteoarthritis of the knee. Pycnogenol® significantly decreased joint pain and improved joint function as evaluated using the WOMAC score and walking performance of patients on a treadmill. In this study, we further investigated the anti-inflammatory and antioxidant activity of Pycnogenol® in a subset of the osteoarthritis patients presenting with elevated C-reactive protein (CRP) and plasma-free radicals. Elevated CRP levels have been suggested to be associated with disease progression in osteoarthritis. In our study, 29 subjects of the Pycnogenol® group and 26 patients in the placebo group showed CRP levels higher than 3 mg/l at baseline. Comparison of blood specimens drawn at baseline and after 3-month treatment showed that Pycnogenol® significantly decreased plasma free radicals to 70.1% of baseline values. Plasma CRP levels decreased from baseline 3.9 mg/l to 1.1 mg/l in the Pycnogenol® group whereas the control group had initial values of 3.9 mg/l which decreased to 3.6 mg/l. The CRP decrease in the Pycnogenol® was statistical significant as compared to the control group (P < 0.05). Fibrinogen levels were found to be lowered to 62.8% of initial values (P < 0.05) in response to Pycnogenol®. No significant changes for plasma free radicals, CRP and fibrinogen were found in the placebo-treated group. The decrease of systemic inflammatory markers suggests that Pycnogenol® may exert anti-inflammatory activity in osteoarthritic joints and patients did not present with other ailments or infections. The nature of the anti-inflammatory effects of Pycnogenol® with regard to CRP warrants further investigation. © 2008 w. S. Maney and Son Ltd.