Willow bark extracts

K. Wuthold, I. Germann, G. Roos, O. Kelber, D. Weiser, H. Heinle and K.-A. Kovar, Thin-layer chromatography and multivariate data analysis of willow bark extracts../. Chromatogr. Sci. 42 (2004) 306-309. 

The pharmacological actions of salicylates in humans are well documented and are applicable to willow. In recent clinical studies, willow bark extract had moderate analgesic effects in osteoarthritis and low back pain (93-96). 

In contrast, oral administration of a willow bark extract showed a low bioavailability of salicin (98). After ingestion of commercial sugar-coated tablets containing willow bark extract corresponding to a total amount of 54.9mg (0.192mmol) salicin, the serum of 12 volunteers showed a peak concentration of only 0.13 pg/mL salicylic acid this is only 5% of the serum... 

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 109 9-14. 

Chrubasik S, Kunzel O, Model A, Conradt C, Black A. Treatment of low back pain with a herbal or synthetic anti-rheumatic a randomized controlled study. Willow bark extract for low back pain. Rheumatology 2001 40 1388-1393. 

Chrubasik S, Kunzel O, Black A, Conradt C, Kerschbaumer E. Potential economic impact of using a proprietary willow bark extract in outpatient treatment of low back pain an open non-randomized study. Phytomedicine 2001 8 241-251. 

Schmid B, Ludtke R, Selbmann HK, et al. Effectiveness and tolerance of standardized willow bark extract in arthrosis patients. Randomized, placebo controlled double-blind study. Z Rheumatol 2000 59 314-320. 

Schmid B, Koetter I, Heide L. Pharmacokinetics of salicin after oral administration of a standardised willow bark extract. J Clin Pharmacol 2001 57 387-391. 

For many decades the pain relieving properties of willow bark extracts have been used in folk medicine (Fig. 1). Glycoside cleavage and oxidation is necessary for the biosynthesis of salicylic acid from the plant precursor p-D-glucopyranoside, the so-called saligenins. 

Kammerer B, Kahlich R, Biegert C, Gleiter CH, Heide L. HPLC-MS/MS analysis of willow bark extracts contained in pharmaceutical preparations. Phytochem Anal 2005 16(6) 470-8. 

Following up on Stone s research, German chemists isolated a tiny amount of the active ingredient of the willow-bark extract, which they called salicin, from Salix, the botanical name for the willow genus. Researchers in France further purified salicin and converted it to salicylic acid, which proved to be a potent pain-reliever. This product was later marketed as the salt sodium salicylate. Though an effective painkiller, sodium salicylate has the unfortunate side effect of causing nausea and, sometimes, stomach ulcers. 

A clinical trial of white willow bark extract (240 mg daily salicin) for 4 weeks resulted in a mild inhibition of platelet aggregation, as compared to control and 100 mg daily acetylsalicylate (Krivoy et al. 2001). A review of salicin-con-taining plants indicated that salicin does not elicit the same irreversible inhibition of platelet aggregation that acetylsalicylic acid in aspirin does (Meier and Liebi 1990). 

Marz, R.W., and F. Kemper. 2002. Willow bark extract—Effects and effectiveness. Status of current knowledge regarding pharmacology, toxicology and clinical aspects. Wien Med. Wexhenschr. 152(15-16) 354-359. 

NAB Willow Bark Extract See Willow (Salix alba) bark extract... 

Wild yam extract. See Wild yam (Dioscorea villosa) extract Wilkinite. See Bentonite Willinite. See Aluminum silicate Willow bark extract. See Willow (Salix alba) bark extract... 

Trade Name Synonyms NAB Willow Bark Extract [Arch Personal Care Prods. http //www. archchemicals, com]... 

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