
French Marine Pine Bark Extract, Pine Bark, Procyanidin Oligomers, Procyanodolic Oligomers, PCO, PCOs
Pycnogenol®
Obtained from the bark of the French maritime pine tree, Pinus maritima, pine bark extract consists of proanthocyanidins and is marketed under the tradename Pycnogenol®. In vitro and animal studies indicate that pine bark extract has antioxidant, anti-inflammatory (6), immunostimulant (1), and neuroprotective (31) effects. Pine bark extract may also have antiviral and antimicrobial activities. It inhibits HIV attachment and replication (15), suppresses encephalomyocarditis virus (EMV) replication (16), and represses Helicobacter pylori growth and adherence to gastric cells (17).
Pine bark extract has been studied in humans for various conditions. Preliminary research suggests that it reduces menopausal symptoms in peri-menopausal women (8), relieves symptoms of dysmenorrhea (27), and improves osteoarthritic symptoms (9) (10). It is also used to treat skin disorders such as hyperpigmentation (11), erythema (12), endometriosis (13), and systemic lupus erythematosus (14). Pine bark extract can improve endothelial dysfunction (2) and chronic venous insufficiency (5). Chewing gum containing pine bark extract may reduce gingival bleeding and plaque accumulation (19). When used in conjunction with L-arginine, Pycnogenol is effective in improving symptoms of erectile dysfunction (18) (29). Pycnogenol supplementation also enhanced memory in elderly participants (7). Studies of attention deficit hyperactivity disorder in adults and in children yielded mixed results (3) (4).
In vitro studies show antimetastatic effects of pine bark extract (32). Pycnogenol may also protect against cardiotoxicity caused by doxorubicin without antagonizing its cytotoxic activity (20). Preliminary findings from a study involving cancer patients suggest usefulness of pycnogenol is reducing adverse effects associated with radiotherapy and chemotherapy (30). Further research is needed.
Adverse effects may include irritability and decreased energy especially when used for ADHD.
Pine bark extract may interact with certain chemotherapeutic drugs, anticoagulant/antiplatelet drugs, and immunosuppressants.
Pine bark extract acts as an antioxidant by scavenging reactive oxygen and nitrogen species and suppressing production of peroxides (21). It increases the activities of antioxidant enzymes by increasing the intracellular glutathione levels (22). In addition to increasing NO production which induces vasodilation (2), pine bark extract also blocks the NF-kB activation stimulated by tumor necrosis factor-alpha (TNF-alpha) and inhibits production of adhesion proteins that cause inflammation and atherosclerosis (22). An in vitro study suggests that Pycnogenol induces apoptosis in human breast cancer cells and not in normal breast cells although the mechanism is not clear (23). Other in vitro studies have also shown that it reduces neuronal apoptosis, an important feature of Alzheimer's disease, by decreasing free radical generation (24). In animal studies, pine bark extract exhibits a protective effect on cardiotoxicity caused by antitumor drugs, such as doxorubicin, due to its ability to act as a free-radical scavenger (20).
Many pine bark extracts on the market are not standardized and the concentration of active components and bioactivities are hard to determine. Since pycnogenol is a complex mixture of different compounds, the bioavailability and metabolic pathways that most of them follow are still unknown. However, one of the components in pycnogenol, ferulic acid, was shown to be excreted in the urine as glucuronide and sulfate within 18-24 hours after oral administration (25).
Pine bark extract has potent antioxidant effects. It may interfere with the action of certain chemotherapeutic drugs and radiation therapy.
Yang HM, Liao MF, Zhu SY, Liao MN, Rohdewald P. A randomised, double-blind, placebo-controlled trial on the effect of Pycnogenol on the climacteric syndrome in peri-menopausal women. Acta Obstet Gynecol Scand. 2007;86(8):978-985.
A randomized, double-blind, placebo-controlled study of 200 peri-menopausal Taiwanese women analyzed the effect of pine bark extract (Pycnogenol®, 200 mg daily) on menopausal symptoms. After 6 months, the participants completed the Women's Health Questionnaire, which demonstrated the climacteric symptom-relieving characteristics of Pycnogenol as compared to the placebo group. The authors concluded that because Taiwanese women report differing peri-menopausal symptoms compared to European women, this study should be expanded to other populations of women.
Nishioka K, et al. Pycnogenol, French maritime pine bark extract, augments endothelium-dependent vasodilation in humans. Hypertens Res 2007;30(9):775-780.
The effect of Pycnogenol on forearm blood flow in response to endothelial-dependent (acetylcholine, Ach) and independent (sodium nitroprusside, SNP) vasodilators was assessed in this small, double-blind, randomized, placebo-controlled study of 16 healthy men. Participants either received placebo or Pycnogenol (180 mg daily) for 2 weeks before forearm blood flow was measured. Although Pycnogenol alone did not affect forearm blood flow, Ach-dependent forearm blood flow was increased in the Pycnogenol-treated group, an effect that was reversed upon administration of a NO synthase inhibitor. Pycnogenol did not influence vasodilation mediated by SNP, indicating that Pycnogenol influences endothelial-dependent vasodilation most likely through enhancing NO synthesis. Further studies with larger numbers of participants are required to determine if Pycnogenol is beneficial in subjects with oxidative stress-related diseases.
Ryan J, et al. An examination of the effects of the antioxidant Pycnogenol on cognitive performance, serum lipid profile, endocrinological and oxidative stress biomarkers in an elderly population. J Psychopharmacol 2008;22(5):553-562.
In a double-blind, placebo-controlled, matched-paired study, the effect of Pycnogenol on cognitive function and serum lipid profiles was assessed in 101 elderly participants. After 3 months, working memory was enhanced in the participants receiving Pycnogenol (150 mg/day) as compared to the placebo group. The authors surmise that this enhancement may be due to the anti-oxidant activity of Pycnogenol. Larger, long term studies are necessary to full determine the clinical benefits of Pycnogenol supplementation on memory.
Bottom Line: Pine bark extract has not been shown to treat or prevent cancer.
Pycnogenol is derived from the bark of the French maritime pine tree. Studies have shown that it is effective in treating many inflammatory conditions, skin disorders, and chronic venous insufficiency (poor blood circulation) because of its antioxidant and antiinflammatory properties. It was also shown to be effective in treating erectile dysfunction when used in combination with L-arginine. Animal studies indicate that pycnogenol exhibits protective effect against cardiac toxicity caused by doxorubicin (a chemo drug). But human data is lacking.
Treatment of attention deficit hyperactivity disorder (ADHD)In a recent clinical trial, 24 patients with ADHD were given pycnogenol, Ritalin or placebo for 3 weeks. After a 1-week no-treatment period, patients were switched to another treatment for 3 more weeks. Researchers found no difference between the treatments and researchers concluded that neither pycnogenol nor Ritalin was effective in comparison to placebo in treating ADHD.
Treatment of chronic venous insufficiency (CVI)
In a recent study, 40 patients with CVI were given either 360 mg of pycnogenol or 600 mg of Venostasin (horse chestnut seed extract) daily for 4 weeks. Researchers found that pycnogenol effectively improved the symptoms associated with CVI such as increased circumference of lower limbs, pain, and night-time swelling in comparison to Venostasin. It also lowered the low-density lipoprotein (LDL) cholesterol values.
Treatment of hypertensionThis clinical trial involved 58 patients with hypertension. Patients were given a combination of 5mg nifedipine and placebo or 5mg nifedipine and 100mg pyncogenol daily for 12 weeks. All patients were given 20mg of nifedipine before the study began. The dosage of nifedipine was adjusted (increased or lowered by 5 mg) according to measured blood pressure values every two weeks. Researchers found that most patients had normal blood pressure after the 12 week period with 10mg nifedipine and pycnogenol. They concluded that pycnogenol is effective in treating mild hypertension.
Many pine bark extracts on the market are not standardized and the concentration of active components and bioactivities are hard to determine.