Written by Joyce Smith, BS. Salix extract significantly decreased dysmenorrhea in comparison to mefenamic acid, the standard treatment for dysmenorrhea.
Dysmenorrhea, painful menstruation, typically involving abdominal cramps, is a common gynecological problem that can begin 1-3 years after menarche 1 and affects 80-90% of women of reproductive age (18-28 years of age) 1. High levels of prostaglandins (PGs) have been attributed to the pain, nausea, diarrhea, headaches and vomiting, depression, and fatigue, which often accompany dysmenorrhea, yet factors such as genetics, stress, and different body types may also contribute to symptoms. While non-steroidal inflammatory drugs (NSAIDs) are commonly used for menstrual pain, their potential side-effects have spurred a worldwide interest in herbals such as lavender, ginger, aloe vera and salix that have also been used to treat dysmenorrhea 2. Salix, derived from willow bark, has a 3,500 year history of use, and was first used as a pain reliever and antipyretic in aspirin 3. It contains salicylic acid, and along with its derivative, salicin reduces pain and fever, inflammation, mild rheumatic pain and even headaches 4; however, studies documenting the effect of salix on dysmenorrhea is sparse, thus leading to the present study designed to evaluate its effect on dysmenorrhea and compare its effectiveness to mefenamic acid, a NSAID and a standard treatment for pain.
In a double-blind, randomized crossover clinical trial 5, 96 female university students with level two or three of primary dysmenorrhea were evenly divided into an intervention group receiving 400 mg of salix daily and a control group receiving 750 mg of mefenamic acid daily. Both groups experienced two consecutive menses before treatment during which time they recorded dysmenorrhea severity. Treatment and placebo received salix extract or mefenamic acid during the next two consecutive cycles, followed by a washout period of two consecutive menses and a final two-week cycle where salix and mefenamic acid treatments were crossed over. Primary outcomes were pain intensity, measured by the visual analog scale (VAS), amount of bleeding, and severity of dysmenorrhea symptoms.
Findings revealed that the mefenamic acid group of students had a significantly higher level of pain (based on VAS) than the salix group over time (1.61 ± 0.06, P < 0.001). Symptoms varied within the two groups. An average of 77.39% of the students in the salix group showed no symptoms while 22.18% of them experienced only mild symptoms. In the mefenamic acid group of students, an average of 44.58% had mild symptoms while 28.12% experienced moderate symptoms. The amount of bleeding in the salix and mefenamic acid groups was not significantly different (P=0.31).
Researchers attribute the effect of salix on dysmenorrhea reduction to its ability to inhibit the activity of (PGs) 4. Salix extract’s effect on pain relief is through its co-active compounds (flavonoids and polyphenols) that inhibit COX-2 and lipoxygenase activity 6. These compounds have significant anti-inflammatory activity 7 and inhibit PG production 4. Thus, it seems that salix decreases dysmenorrhea intensity similar to mefenamic acid with antiprostaglandin effects. It should be noted that although study participants reported no adverse effects from Salix extract, it does contain silicin and salicylic acid and should be administered cautiously or not at all with NSAIDs and glucocorticoids because of these compounds. According to Vlachojannis et al 2011, “The multi-component active principle of salix (willow bark) provides a broader mechanism of action than aspirin and is devoid of serious adverse events,” and in contrast to synthetic aspirin, it does not damage the gastrointestinal mucosa. In addition, a salix extract dose containing 240 mg salicin showed no major impact on blood clotting, and a final note, “In patients with known aspirin allergy willow bark products are contraindicated.” 8
Source: Dehkordi, Z. Raisi, M. Rafieian-Kopaei, and F. S. Hosseini-Baharanchi. “A double-blind controlled crossover study to investigate the efficacy of salix extract on primary dysmenorrhea.” Complementary therapies in medicine 44 (2019): 102-109.
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Posted March 23, 2020.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
- Nevatte T, O’Brien PMS, Bäckström T, et al. ISPMD consensus on the management of premenstrual disorders. Archives of women’s mental health. 2013;16(4):279-291.
- Saei Gharenaz M, Ozgoli G. Effect of medicinal plants in the treatment of primary dysmenorrhea in Iran: a review article. The Iranian Journal of Obstetrics, Gynecology and Infertility. 2015;18(160):14-31.
- Desborough MJ, Keeling DM. The aspirin story–from willow to wonder drug. British journal of haematology. 2017;177(5):674-683.
- Baumann J, Wurm G, Von Bruchhausen F. Prostaglandin synthetase inhibition by flavonoids and phenolic compounds in relation to their O2–scavenging properties (author’s transl). Archiv der Pharmazie. 1980;313(4):330.
- Dehkordi ZR, Rafieian-Kopaei M, Hosseini-Baharanchi F. A double-blind controlled crossover study to investigate the efficacy of salix extract on primary dysmenorrhea. Complementary therapies in medicine. 2019;44:102-109.
- Laughton MJ, Evans PJ, Moroney MA, Hoult J, Halliwell B. Inhibition of mammalian 5-lipoxygenase and cyclo-oxygenase by flavonoids and phenolic dietary additives: relationship to antioxidant activity and to iron ion-reducing ability. Biochemical pharmacology. 1991;42(9):1673-1681.
- González R, Ballester I, López-Posadas R, et al. Effects of flavonoids and other polyphenols on inflammation. Critical reviews in food science and nutrition. 2011;51(4):331-362.
- Vlachojannis J, Magora F, Chrubasik S. Willow species and aspirin: different mechanism of actions. Phytotherapy Research. 2011;25(7):1102-1104.
