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 hypertension This 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.
You are taking chemotherapeutic agents (Pine bark extract has potent antioxidant effect and may interfere with the action of anthracyclines, platinum compounds, and alkylating agents)
You are taking immunosuppressants (Pine bark extract has immunostimulant effect and may antagonize the effects of immunosuppressants, such as cyclosporine and tacrolimus).
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 find pine bark extract has antioxidant, anti-inflammatory properties (6) and exhibits immunostimulant effect (1). Pine bark extract may 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 suggest it reduces menopausal symptoms in peri-menopausal women (8), and improves osteoarthritis symptoms (9)(10). It is also used to treat skin disorders such as hyperpigmentation (11) and 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 may improve symptoms of erectile dysfunction (18). Pycnogenol supplementation enhances memory in elderly participants (7). Studied for attention deficit hyperactivity disorder in adults and in children yielded mixed results (3)(4). An animal study finds Pycnogenol exhibits a protective effect against cardiotoxicity caused by doxorubicin without antagonizing its cytotoxic activity (20). However, this has not been confirmed in humans.
Adverse effects may include irritability and decreased energy especially when used for ADHD. Pine bark extract may interact with certain chemotherapeutic 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).
Chemotherapeutic Agents: Pine bark extract has potent antioxidant effect and may interfere with the action of anthracyclines, platinum compounds, and alkylating agents.
Immunosuppressants: Pine bark extract has immunostimulant effect and may antagonize the effects of immunosuppressants, such as cyclosporine and tacrolimus.
Tenenbaum, S et al. An experimental comparison of Pycnogenol and methylphenidate in adults with Attention-Deficit Hyperactivity Disorder (ADHD). JAD 2002;6(2):49-60. This double-blind, placebo-controlled, randomized crossover study was done to evaluate the effects of pycnogenol versus methylphenidate (Ritalin®) in patients with attention-deficit hyperactivity disorder. Twenty-four adults with ADHD were administered pycnogenol, Ritalin®, or a placebo for a 3-week period. After a 1-week washout period, patients were switched to another treatment for 3 more weeks. Researchers found no difference between the treatments and concluded that neither pycnogenol nor methylphenidate was effective in comparison to placebo in treating ADHD.
Arcangeli, P. Pycnogenol in chronic venous insufficiency. Fitoterapia 2000;71:236-44. In this double-blind study, 40 patients with chronic venous insufficiency (CVI) were randomly assigned to receive 300 mg pycnogenol or placebo daily for 2 months. Pain and heaviness of legs, and subcutaneous edema that are characteristic of CVI were assessed after 30 and 60 days. Patients who received pycnogenol reported significant reduction of edema and pain in the legs compared to those on placebo. Researchers concluded that pycnogenol can effectively relieve symptoms in CVI patients.
Liu, X et al. Pycnogenol, French maritime pine bark extract, improves endothelial function of hypertensive patients. Life Sciences 2004;74(7):855-62. Fifty eight patients with hypertension participated in this placebo-controlled, double-blind, parallel group study. Patients were given a combination of 5mg nifedipine and placebo or 5mg nifedipine and 100mg pycnogenol daily for 12 weeks. All patients received 20mg of nifedipine before the study began. Heart rate and blood pressure were determined at the beginning of the study and after every two weeks thereafter. The dose of nifedipine was adjusted (increased or decreased by 5mg) according to the measured blood pressure values at 2 week intervals. Researchers found that most patients had normal blood pressures after the 12 week period with 10mg nifedipine and pycnogenol, while only 4 patients had normal blood pressures in the placebo group. Therefore, researchers concluded that pycnogenol is effective in treating mild hypertension.
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.
