Willow Bark: Pain Relief and More

Willow bark, known scientifically as Salix spp., has been used for centuries in traditional medicine for its various health benefits. Here's a comprehensive overview of its characteristics, traditional uses, health benefits, and relevant scientific research.

What is Willow?

Willow trees (Salix spp.) are deciduous shrubs or trees with elongated leaves that are typically narrow and lance-shaped. They produce catkins (flowers) in the spring, and their bark is often smooth and grayish-brown in color.

Willows are found in various habitats worldwide, including wetlands, riverbanks, and forests. They thrive in moist soil and are commonly found in temperate regions.

Typically, the bark of the Willow tree is used for its medicinal benefits. However, the leaves and stems of Willow also maintain many of the medicinal properties contained in the bark.

Primary Compounds of Willow

Salicin: The most well-known compound in willow bark, salicin, is converted to salicylic acid in the body, which has analgesic and anti-inflammatory effects similar to aspirin.

Flavonoids: Willow bark contains flavonoids such as quercetin and catechins, which contribute to its antioxidant and anti-inflammatory properties.

Willow contains hundreds of compounds, including ellagitannins, anthocianidins, miricetin, kaempferol, quercetin, gallic acid, macrocyclic tannins such as oenothein B, saponins, minerals, vitamins, volatile oils and essential amino acids.

Traditional Uses

Ancient civilizations, including the Egyptians, Greeks, and Native Americans, used willow bark to alleviate pain, fever, and inflammation.

In addition, Willow bark has been used in traditional Chinese medicine to treat pain, fever, and inflammatory conditions for thousands of years.

Health Benefits of Willow

1. Pain Relief: Willow bark contains salicin, a compound similar to aspirin, which has analgesic (pain-relieving) and anti-inflammatory properties. It is commonly used to alleviate pain associated with conditions such as headaches, backaches, and arthritis.

2. Anti-inflammatory Effects: Salicin and other compounds in willow bark have been found to inhibit the production of inflammatory substances in the body, making it effective in reducing inflammation and swelling.

3. Fever Reduction: Willow bark has traditionally been used to lower fever due to its antipyretic properties. It may help reduce fever by inhibiting the production of prostaglandins, which are involved in the body's inflammatory response.

4. Skin Health: Topical preparations containing willow bark extract are used to treat skin conditions such as acne, eczema, and psoriasis, thanks to its anti-inflammatory and antimicrobial properties.

Willow vs. Aspirin

Acetylsalicylic acid or aspirin is a synthetic molecule designed to mimic the effects of salicin, originally derived from willow bark and meadowsweet herb. For thousands of years, herbalists and ancient healers used both willow bark and meadowsweet for the relief of pain, inflammation, the relief of gastrointestinal upset, nausea, heart issues, rheumatism and many other disorders. With these sorts of effects there is no surprise some of its constituents might be anti-carcinogenic.

Willow bark has a long history of clinical use. It has been used by traditional physicians for over five thousand years for pain, rheumatism and inflammation. Sumerian Clay tablets some 4,000 years ago documented using willow leaves to treat fever and rheumatism. 

The 2500-3000 B.C. Ebers-Edwin Smith Surgical Papyrus—translated by James Breasted in the 1920s—documented the use of willow by the “Father of Medicine,” Imhotep. Imhotep used willow for healing wounds and inflammation.

The ancient Chinese also used willow to treat pain, wounds, goiter, hemorrhaging, and rheumatic fever. The ancient Greek physicians also used willow. 

Hippocrates, Celsius, Pliny the Elder, and Galen all recommended willow for pain and inflammation. Early western European physician and herbalist Dioscoridies also documented its use for pain and inflammation.

In 1828, salicin was isolated from the bark of the willow tree by Joseph Buchner. Two years later, salicin was isolated from the flower of the meadowsweet plant by Johann Pagenstecher. 

In 1838, a method of isolating salicylic acid from willow extract was discovered by the Italian Raffaele Piria. Meanwhile, German chemist Karl Jacob Lowig extracted the same salicylic acid from meadowsweet extract. 

In 1874, salicylic acid began to be produced for commercial use. Twenty-three years later, in 1897, Charles Garhardt, a chemist at the Friedrich Bayer & Company, synthesized a similar derivative by adding an acetyl group (OCOOH), to produce the more stable acetylsalicylic acid. The Bayer company proceeded to call it aspirin and began large-scale production.

Aspirin’s mechanism of action in the body continued to be mysterious, however. Finally, in 1971, Sir John Vane determined that acetylsalicylic acid inhibited prostaglandin synthetase (later identified as cyclooxygenase), producing its anti-inflammatory and anti-thrombosis effects. Sir John Vane received the Nobel Prize for Medicine in 1982 for this hypothesis.

Like willow and meadowsweet, aspirin has an immediate effect to reduce pain. Aspirin and natural salicin bind to cylooxygenase-2 within the cells. This blocks the pain and inflammation cascade. Cylooxygenase-2 produces prostaglandins that in turn send messages to the brain that a particular part of the body is injured. When cylooxygenase-2 is blocked, the process of converting arachidonic acid to prostaglandins is halted.

Cylooxygenase-2 also stimulates the production of thromboxanes. These stimulate the process of blood clotting within the platelets—called platelet aggregation. This is again part of the healing process, because if a blood vessel were to be pierced, our blood would leak out, causing immediate death unless the vessel was sealed somehow. In other words, thromboxanes stimulate clotting, preventing our bodies from bleeding to death.

Side effects of Aspirin

This later effect also produces the side effect that aspirin is also known for—as a blood thinner. Because many heart attacks, strokes and other cardiovascular problems are caused by blood clots, low-dose aspirin is used to keep the blood thinner than normal for those with unhealthy artery health.

Aspirin’s blood-thinning effects have their benefit, but they can also create internal bleeding from a variety of internal injuries. The dangerous part of this is that the person may be bleeding internally without knowing it.

The problem with acetylsalicylic acid, because of its isolated and synthetic nature, is that its positive effects come with a price of several other adverse effects. Aspirin is notorious for damaging the lining of the stomach, and causing a variety of digestive issues, including acid reflux, ulcers, nausea and gastritis. Aspirin has also been known to produce some liver toxicity, Reye’s Syndrome (especially in children), and tinnitus—ringing of the ears.

The reason for some of aspirin’s benefits is that it is based upon a natural molecule with natural health benefits. The reason for aspirin’s unhealthy and sometimes dangerous side effects is because the salicylic molecule has been separated from the natural buffering molecules present in willow, meadowsweet and similar herbs. 

Willow has hundreds of constituents, other than salicin. Studies have indeed shown that natural salicin from these herbs has every bit of pain-relieving ability as aspirin and other COX-inhibitors. 

Willow herb also contains compounds that buffer the negative side effects of salicin - something that aspirin (salicylic acid) doesn't have. In other words, willow does not have these negative side effects because of the various buffering agents provided by nature.

Now let's take a look at some of the scientific research on the effects of Willow.

Willow and arthritis

Willow bark extract has been used in studies for the treatment of osteoarthritis and rheumatoid arthritis. Most have found that willow decreased inflammation and pain among the patients.

In a 2004 study from Germany's Eberhard Karls-University, researchers tested 127 outpatients with hip or knee osteoarthritis and 26 outpatients with active rheumatoid arthritis.

After six weeks of treatment with willow, diclofenac or a placebo, the researchers found that pain scores significantly decreased similarly in the willow bark group and in the diclofenac group compared with the placebo group.

A 2001 study from another German university tested 78 osteoarthritis patients for two weeks. After the test period, pain scores in the Willow group were significantly less than the patients given the placebo.

Anti-inflammatory

A number of studies have shown that Willow has a significant anti-inflammatory effect. In a 2010 study from Germany's Marburg University, researchers tested Willow's anti-inflammatory abilities and confirmed that Willow inhibited inflammation.

A 2013 study from Germany's University College Dublin found that Willow inhibited proinflammatory biomarkers.

Willow is also anti-inflammatory and analgesic. Willow and other Epilobium species such as E. rosmarinifolium have been shown to reduce inflammation and reduce acute pain.

Low Back Pain

Several studies have investigated whether Willow Bark can reduce low back pain. 

In a 2000 study, researchers from Isael's Rambam Medical Center tested 210 chronic low-back pain patients. They all reported current pain between 5 and 10 on a scale of 10. They were given either Willow bark extract at two dose levels or a placebo. Of those given the higher-dose Willow bark, 39 percent were pain-free after four weeks, and 21 percent were pain-free in the lower-dose group.

Both willow groups had significantly fewer patients needing rescue pain medication at the end of the treatment period.  

Willow fights Cancer

Research from the University Hospital Zurich tested willow bark extracts against human colon and cancer cells in a 2007 study. They found that willow and various fractions of willow bark inhibited the growth of human colon and lung cancer cells.

The research found that the various extracts of willow "showed anti-proliferative activity." They also concluded:

"We showed that willow bark extract BNO 1455 and its fractions inhibit the cell growth and promote apoptosis in human colon and lung cancer cell lines irrespective of their COX-selectivity."

Other research has shown that aspirin can help prevent cancers. The salicin content is the likely cause according to these studies. 

Willow is an Antibiotic

Bacteria that have learned to resist our many antibiotic medicines are killing more and more people every year. Currently, about 700,000 people die around the world each year from antibiotic-resistant infections. And 23,000 people die every year just in the U.S. from bacteria that are resistant to multiple antibiotics – called multi-drug-resistant bacteria or MDRs.

Furthermore, an analysis commissioned by the United Kingdom government, led by economist Jim O’Neill, found that deaths from MDRs may kill 10 million people a year by the year 2050.

A number of natural strategies that will combat antibiotic-resistant bacteria. These have included raw honeys, goldenseal, garlic, citrus peels, ginseng leaf and several herbal essential oils. Now we can add a new one to this list of natural antibiotics.

But until doctors begin employing such natural strategies, there is a standard modality of treatment for MDRs: Screen the bacteria for resistance and employ the antibiotic that it seems to not be resistant to.

Despite the resistance screen, the treatment result often ends up being less accurate: Dose the infected person with multiple antibiotics – one after another – until finding the antibiotic that works (if any). A newer conventional strategy is to alternate antibiotic pharmaceuticals.

Whatever the antibiotic strategy, these intensive pharmaceutical antibiotic courses have one common result outside of their effect upon the bacterial infection: They often wrack the patient’s body with exhaustion and side effects.

These side effects include liver damage, headaches, gastrointestinal issues – not to mention they kill off the gut’s probiotic populations.

As we’ve shown with other research, employing natural strategies is not necessarily mutually exclusive. In other words, many of these natural antibiotic strategies are not only effective against MDRs: They are also synergistic with pharmaceutical antibiotic strategies.

Even better – they can be taken simultaneously and reduce the dosing of pharmaceutical antibiotics.

Research comes from Bucharest’s National Institute for Chemical-Pharmaceutical Research and Development tested Willow as an antibiotic. In the 2016 study, the Great Willow herb (Epilobi hirsute) and its constituents against nine different strains of antibiotic resistant bacteria. These included strains of:

• Staphylococcus aureus (two strains)
• Enterococcus faecalis
• Staphylococcus epidermidis
• Pseudomonas aeruginosa
• Proteus mirabilis
• Escherichia coli (three strains)

The scientists utilized a method of measuring antibiotic activity by what is called Minimum Inhibitory Concentration or MIC. This assay means establishing the lowest concentration that prevents the growth of the bacteria overnight.

They tested a whole extract of the Willowherb leaf, and three extracts that selected for certain phenol constituents that are inside the Willowherb plant.

The researchers found that the whole extract and two of the selective extracts successfully fought off bacteria growth for five of the nine MDRs. MIC’s for these bacteria ranged from 50 micrograms GAE per milliliter. These included two of the S. aureus strains, S. epidermidis, P. mirabilis and P. aeruginosa bacteria. The activity against these bacteria, according to the researchers, was described as “good antimicrobial activity.”

Another one of the selective extracts showed good antibacterial activity against the S. epidermidis and on one of the S. aureus bacteria strains.

In other words, the Willow herb by itself proved to be an effective antibiotic against a majority of the antibiotic-resistant bacteria.

That speaks significantly to the fact that just because a bacteria strain has figured out how to evade pharmaceutical antibiotics, it won’t necessarily be able to evade nature’s antibiotics.

On top of this significant finding, the researchers also established that the Willow extracts could be combined with pharmaceutical antibiotics – with the result of greater antibiotic activity.

Yes, combining treatment of the bacteria with Willowherb with antibiotic medicines all proved to increase their antibacterial effectiveness. Antibiotics tested included Ampicillin (a Penicillin), Gentamicin (Aminoglycoside), Tetracycline, Sulfamethoxazole-Trimethoprim (Sulphonamide), Ciprofloxacin (Fluoroquinolone) and Cefoxitine (Cephalosporin).

The researchers found that Tetracycline and Ampicillin were the antibiotics most successful in inhibiting many of the MDRs studied. But to the surprise of the researchers, the Willowherb plant extracts increased the effects of these antibiotics by as much as 61 percent.

The increased effectiveness ranged from 16 percent to 61 percent among the different antibiotics. In other words, when those active antibiotics were combined with Willowherb, they were significantly more effective against those resistant bacteria.

That means that less antibiotic would be needed to kill the same infection – when used alongside Willowherb.

This is a significant finding. The researchers stressed the importance of this finding:

“Together, these results demonstrate not only Epilobi hirsuti herba extracts own antimicrobial properties, but also the capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.”

This isn’t the first time scientists have recognized Willowherbs’ – along with other Epilobium species’ – ability to inhibit microbes.

A study from the University La Sapienza found that Willowherb and related species – Epilobium angustifolium, E. palustre, E. tetragonum and E. rosmarinifolium – could not only inhibit bacteria: They also inhibited numerous strains of yeasts and other fungi.

It's an Antioxidant too

A 2009 study from Hungary’s Semmelweis University found that Willow had significant antioxidant properties. These properties included significant free radical scavenging abilities.

All of these effects combine to form Willowherb’s effectiveness. 

But remember, it is nature’s synergy between these phytochemicals that produces those effects. It is a one-plus-one-equals-three scenario.

REFERENCES:

HM Government. Review on Antimicrobial Resistance: Tackling drug-resistant infections globally. http://amr-review.org/ Accessed June 14, 2016.

Lucia Pirvu, Isabela Nicorescu, Cristina Hlevca, Bujor Albu, Valentin Nicorescu. Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria. Open Chemistry. Volume 14, Issue 1, Pages 65–75, ISSN (Online) 2391-5420, DOI: 10.1515/chem-2016-0004, March 2016.

Battinelli L, Tita B, Evandri MG, Mazzanti G. Antimicrobial activity of Epilobium spp. extracts. Farmaco. 2001 May-Jul;56(5-7):345-8.

Hevesi Tóth B, Blazics B, Kéry A.Polyphenol composition and antioxidant capacity of Epilobium species. J Pharm Biomed Anal. 2009 Jan 15;49(1):26-31. doi: 10.1016/j.jpba.2008.09.047.

Chrubasik S, Eisenberg E, Balan E, Weinberger T, Luzzati R, Conradt C. Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study. Am J Med. 2000 Jul;109(1):9-14. doi: 10.1016/s0002-9343(00)00442-3.

Biegert C, Wagner I, Lüdtke R, Kötter I, Lohmüller C, Günaydin I, Taxis K, Heide L. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol. 2004 Nov;31(11):2121-30. PMID: 15517622.

Drummond EM, Harbourne N, Marete E, Martyn D, Jacquier J, O'Riordan D, Gibney ER. Inhibition of proinflammatory biomarkers in THP1 macrophages by polyphenols derived from chamomile, meadowsweet and willow bark. Phytother Res. 2013 Apr;27(4):588-94. doi: 10.1002/ptr.4753.

Clauson KA, Santamarina ML, Buettner CM, Cauffield JS. Evaluation of presence of aspirin-related warnings with willow bark. Ann Pharmacother. 2005 Jul-Aug;39(7-8):1234-7. doi: 10.1345/aph.1E650.

Hostanska K, Jürgenliemk G, Abel G, Nahrstedt A, Saller R. Willow bark extract (BNO1455) and its fractions suppress growth and induce apoptosis in human colon and lung cancer cells. Cancer Detect Prev. 2007;31(2):129-39. doi: 10.1016/j.cdp.2007.03.001.

Schmid B, Lüdtke R, Selbmann HK, Kötter I, Tschirdewahn B, Schaffner W, Heide L. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized placebo-controlled, double blind clinical trial. Phytother Res. 2001 Jun;15(4):344-50. doi: 10.1002/ptr.981.

Hassan C, Rex DK, Cooper GS, Zullo A, Launois R, Benamouzig R. Primary prevention of colorectal cancer with low-dose aspirin in combination with endoscopy: a cost-effectiveness analysis. Gut. 2011 Oct 13.

Chang ET, Frøslev T, Sørensen HT, Pedersen L. A nationwide study of aspirin, other non-steroidal anti-inflammatory drugs, and Hodgkin lymphoma risk inDenmark. Br J Cancer. 2011 Oct 25.

McCarty MF. Minimizing the cancer-promotional activity of cox-2 as a central strategy in cancer prevention. Med Hypotheses. 2011 Oct 14.

Cao L, Young N, Liu H, Silvestry S, Sun W, Zhao N, Diehl J, Sun J. Preoperative Aspirin Use and Outcomes in Cardiac Surgery Patients. Ann Surg. 2011 Oct 12.