United States Pharmacopeia Safety Review of Willow Bark

Wiener medizinische Wochenschrift (1946), 2007

The efficacy of willow bark extract in the treatment of painful mobility disorders, such as back pain and arthritis, has been attributed to the content of salicin and its derivatives as pro-drugs of salicylates. However, based on clinical experience and the evidence of experimental pharmacological studies, the fraction of total salicin cannot satisfactorily explain the clinical efficacy of willow bark. In addition, salicins and their metabolites lack the acetylating potential of ASA and must therefore possess a different mechanism of action. A detailed pharmacological screening of the aqueous willow bark extract STW 33-I addressed the question of the identification of fractions contributing to the overall effect. All in vivo and in vitro models studied pointed to relevant contributions of the fraction of polyphenols and flavonoids. The single compounds or their combinations responsible for the effect remain to be elucidated.

Journal of Toxicology and Environmental Health, Part A, 2019

Salix alba (SA), commonly known as white willow, is a plant used in folk medicine for the treatment of chronic and acute inflammation, infection, pain, and fever. The phytochemical characterization of the bark extract of this plant indicated that its main component is salicin, a precursor of the anti-inflammatory agent acetylsalicylic acid. Considering the lack of studies evaluating the genetic toxicity and cytotoxic action of SA bark extract on human cells, as well as the chemical characterization of its major phenolic compounds, the present study was designed to (1) investigate the cytotoxic and genotoxic potential of SA bark extract on human peripheral leukocyte cells and human hepatoma cell line HepG2, and (2) characterize its major phenolic constituents. The phenolic compounds found were salicylic acid, salicin, salidroside, saligenin, tremulodin, salicoylsalicin, salicortin, and tremulacin. The results using trypan blue staining test showed viability decreases (viability less than 70%) for concentrations of SA extract equal and higher to 200 µg/ml. Low genotoxic activity (comet assay) was exhibited for 50 and 100 µg/ml SA extract in human leukocytes. SA did not exert a marked clastogenic/aneugenic effect on leukocytes and HepG2 human cells. Data suggest that the genotoxic effects of SA bark extract occur when it is not metabolized by liver enzymes.

International Journal of Molecular Sciences

Salix cortex-containing medicine is used against pain conditions, fever, headaches, and inflammation, which are partly mediated via arachidonic acid-derived prostaglandins (PGs). We used an activity-guided fractionation strategy, followed by structure elucidation experiments using LC-MS/MS, CD-spectroscopy, and 1D/2D NMR techniques, to identify the compounds relevant for the inhibition of PGE2 release from activated human peripheral blood mononuclear cells. Subsequent compound purification by means of preparative and semipreparative HPLC revealed 2′-O-acetylsalicortin (1), 3′-O-acetylsalicortin (2), 2′-O-acetylsalicin (3), 2′,6′-O-diacetylsalicortin (4), lasiandrin (5), tremulacin (6), and cinnamrutinose A (7). In contrast to 3 and 7, compounds 1, 2, 4, 5, and 6 showed inhibitory activity against PGE2 release with different potencies. Polyphenols were not relevant for the bioactivity of the Salix extract but salicylates, which degrade to, e.g., catechol, salicylic acid, salicin, and...

Industrial Crops and Products, 2009

Willow based herbal products containing salicin and its derivatives can be used to alleviate aches and fevers. To guarantee the high quality of the willow drugs and moderate low

The Willows, belonging to the genus Salix, encompass a vast array of species and hybrids, totaling between 330 to 500 species along with approximately 200 hybrids. These plants are found across continents such as Africa, North America, Europe, and Asia, exhibiting diverse forms ranging from trees to shrubs and prostrate plants. Traditionally, Willows have been utilized in folk medicine due to their rich reservoir of biologically active compounds, with salicin being a notable example, serving as a prodrug for salicylic acid. The chemical composition of Willows is highly diverse, with 322 secondary metabolites identified thus far.

Aqueous extract of Salix tetrasperma Roxburgh (Family: Salicaceae) was investigated for diuretic and laxative activity in albino rats that was compared with standard drugs Furosemide (10mg/kg, p.o.) and Agar agar (300mg/kg, p.o.), respectively. The extract was found to produce significant diuretic as well as laxative activity in dose dependant manner. The activities may be contributed to the phytoconstituents present. INTRODUCTION The extracts of many plants used in traditional medicine contain curative agents that are used in many modern medicines. As part of the quest for potentially valuable plants of medicinal value. Salix tetrasperma Roxburgh (Family: Salicaceae), commonly called Indian Willow, It is a medium sized tree of wet and swampy places, shedding the leaves at the end of monsoon season. The bark is rough, with deep, vertical fissures and the young shoots leaves are silky 1-4. The dried leaves are reported to possess cardiotonic and neurotonic activity 5,6. The leaves and bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt 7 as a remedy for aches and fever 8. The decoction of both leaf and root is used for treating whooping cough in children 9. The paste of both leaf and root is applied externally in scorpion stings, bug bites, for sores and warts 10. The decoction of the dried root is taken orally for the treatment of hepatitis 10. The sap of the stem is used orally by females for treating dysmenorrhea 1. The hot water extract of the entire plant is used in vaginal cavity to induce abortion in pregnant females and administered rectally to treat local sores in the rectum 1. The aqueous extract of the stem bark has been reported to increase testosterone level in rats at 500.0 mg/kg, p.o. 11 and also accelerates semen coagulation in rats at a concentration of 2% w/v 12. A dose of 0.094 mg/kg of aerial parts shows hypothermic activity in mice 13. Aqueous extract of dried leaf reported to possess cardiotonic activity and the methanol extract of the dried leaf possess reverse transcriptase inhibition effect 14. Ethanolic extract of the aerial parts is reported to be inactive against Staphylococcus aureus, Bacillus subtilis, Salmonella typhosa, Escherichia coli, Candida albicans, Trichophyton mentagrophytes etc 15, 16. However, only a few phytochemical have been reported on this plant in the literature like various types of sapogenins such as quinovic acid, salicortin, saligenin, phenolic glycosides and pyrocatechol was isolated from the barks and leaves 17. The active extract of the bark, called salicin 18 was isolated to its crystalline form. The entire plant is reported contain tannins, triterpenes, viz. b-amyrin, lupeol 5 and chalcinasterol 4 , steroids viz. b-sitosterol and stigmasterol 19, 20. Whilst salicortin, saligenin and pyrocatechol can occur in quite large quantities in intact plant material 21, 22 free salicylaldehyde seems to occur only in very low concentrations 23. However, salicylaldehyde may be formed from saligenin 24, 25 by

2011

Salix caprea (Salicaceae) is one of the medicinal plants in Kashmir valley, commonly known as Goat willow. Plants are the natural industry for the production of secondary metabolites. Crude drugs are the natural sources for isolation of natural products which are used as medicines. So the current knowledge of their chemical composition is necessary for research work. In this short chemical review we have summarised the chemical composition or chemical constituents which were earlier isolated from various parts of the Salix caprea. This chemical review definitely stimulates the researchers and scientists for further work on Salix caprea.

PloS one, 2007

Many higher plants contain novel metabolites with antimicrobial, antifungal and antiviral properties. However, in the developed world almost all clinically used chemotherapeutics have been produced by in vitro chemical synthesis. Exceptions, like taxol and vincristine, were structurally complex metabolites that were difficult to synthesize in vitro. Many non-natural, synthetic drugs cause severe side effects that were not acceptable except as treatments of last resort for terminal diseases such as cancer. The metabolites discovered in medicinal plants may avoid the side effect of synthetic drugs, because they must accumulate within living cells. The aim here was to test an aqueous extract from the young developing leaves of willow (Salix safsaf, Salicaceae) trees for activity against human carcinoma cells in vivo and in vitro. In vivo Ehrlich Ascites Carcinoma Cells (EACC) were injected into the intraperitoneal cavity of mice. The willow extract was fed via stomach tube. The (EACC) ...

The American Journal of Medicine, 2000

Herbal medicines are widely used for the treatment of pain, although there is not much information on their effectiveness. This study was designed to evaluate the effectiveness of willow (Salix) bark extract, which is widely used in Europe, for the treatment of low back pain. SUBJECTS AND METHODS: We enrolled 210 patients with an exacerbation of chronic low back pain who reported current pain of 5 or more (out of 10) on a visual analog scale. They were randomly assigned to receive an oral willow bark extract with either 120 mg (low dose) or 240 mg (high dose) of salicin, or placebo, with tramadol as the sole rescue medication, in a 4-week blinded trial. The principal outcome measure was the proportion of patients who were pain-free without tramadol for at least 5 days during the final week of the study. RESULTS: The treatment and placebo groups were similar at baseline in 114 of 120 clinical features. A total of 191 patients completed the study. The numbers of pain-free patients in the last week of treatment were 27 (39%) of 65 in the group receiving high-dose extract, 15 (21%) of 67 in the group receiving low-dose extract, and 4 (6%) of 59 in the placebo group (P Ͻ0.001). The response in the high-dose group was evident after only 1 week of treatment. Significantly more patients in the placebo group required tramadol (P Ͻ0.001) during each week of the study. One patient suffered a severe allergic reaction, perhaps to the extract. CONCLUSION: Willow bark extract may be a useful and safe treatment for low back pain.

2007

Eight clones of dark-leaved willow (Salix myrsinifolia Salisb.) and two S. myrsinifolia x phylicifolia hybrids were cultivated for two years (2001-2003) in Kaavi and Punkaharju, Eastern Finland by different cultivation methods with the aim of comparing the effects of cultivation method and clone on plant growth, total salicylate yield and willow resistance for herbivores and plant pathogens. The cultivation methods included different combinations of soil management practices, black plastic mulch and fertilisation. Willow growth was measured in Kaavi and in Punkaharju six times during the growing seasons 2001-2002, and the above-ground biomass of the willows was measured at the end of the growing season 2002. The severity of Melampsora-rust was calculated from leaf samples collected at the end of the growing seasons 2001 and 2002. The feeding damage caused by insects was measured in the field during the growing seasons and winter browsing by voles was studied in the field and in the laboratory feeding experiment. Concentrations of salicylates and other phenolic glucosides and condensed tannins were analysed from the leaves and bark of the willows grown in Kaavi. The yield of total salicylates after twoyear cultivation was also measured. The use of plastic mulch doubled willow growth and total salicylate yield compared to the control treatment in unmulched soil. Rust severity and insect feeding seemed, however, to be more dependent on willow clone. Vole browsing in the field and in the laboratory was higher amongst the plants grown in unmulched soil compared to those grown in plastic mulch. Feeding was controlled by the diameter of the twig and the concentrations of salicylates and condensed tannins in the bark. Generally, willow chemistry was highly dependent on the clone, and the effects of cultivation methods on plant chemistry also differed amongst the clones. These results indicate that for reliable cultivation, it is important to match the cultivation method with the selected plant material.