Effect of Salicis Cortex Extract on Human Platelet Aggregation

Abstract

The bark of Salix species contains several prodrugs of salicylate, mainly salicin. The aim of this study was to investigate if during pain treatment with Salicis cortex extract platelet aggregation was affected. A total of 51 patients were enrolled in the study. Thirty-five patients suffering from acute exacerbations of chronic low back pain received randomly and double-blind either Salicis cortex extract with 240 mg salicin/day (n = 19) or placebo (n = 16). Further sixteen patients with stable chronic ischemic heart disease were given 100 mg acetylsalicylate per day. Platelet aggregation was studied using an aggregometer. As aggregating agents, arachidonic acid (500 μg/ml), adenosine di-phosphate (2 × 10^-5 M) and collagen (0.18 μg/ml) were used. The mean maximal arachidonic acid induced platelet aggregation was 61 %, 78 % and 13 % in the Salicis cortex extract, placebo and acetylsalicylate groups. Acetylsalicylate had a significant inhibitory effect on platelet aggregation compared to Salicis cortex extract (p = 0.001) and placebo (p = 0.001). There was also a significant difference between the placebo and the willow bark-treated groups in the maximal platelet aggregation induced by arachidonic acid (p = 0.04) and ADP (p = 0.01). No statistical difference was found between the groups when collagen was applied to the human platelets. Daily consumption of Salicis cortex extract with 240 mg salicin per day affects platelet aggregation to a far lesser extent than acetylsalicylate. Further investigation needs to clarify if this finding is of clinical relevance in patients with impaired thrombocyte function.

Key words

Salicis cortex extract - Salix daphnoides - Salix purpurea - Salicaceae - placebo - acetylsalicylate - thrombocycte aggregation - clinical study

References

• 1 Chrubasik S, Eisenberg E. Treatment of rheumatic pain with herbal medicine in Europe.  Pain Digest. 1998;  8 231-6
• 2 European Scientific Cooperative on Phytotherapy Monographs (ESCOP). Salicis Cortex Fascicule 4, ISBN 1-901964-00-0. The Netherlands; 1997
• 3 Mills S Y, Jakoby R K, Chacksfield M, Wiloughby M. Effect of a proprietary herbal medicine on the relief of chronic arthritic pain: a double-blind study.  British Journal of Rheumatology. 1996;  35 874-8
• 4 Schaffner W. Weidenrinde - Ein Antirheumatikum der modernen Phytotherapie?. In: Chrubasik S, Wink M, Eds Rheumatherapie mit Phytopharmaka. Stuttgart; Hippokrates-Verlag 1997: 125-7
• 5 Schmid B M. Behandlung von Cox- und Gonarthrosen mit einem Trockenextrakt aus Salix purpurea und daphnoides . University of Tübingen; PhD-thesis 1998
• 6 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.  American Journal of Medicine. 2000;  109 9-14
• 7 Steinegger V E, Hovel H. Analytische und biologische Untersuchungen an Salicaceen-Wirkstoffen, insbesondere an Salicin.  Pharmaceutica Acta Helvetiae (Zürich). 1972;  47 222-34
• 8 Born G UR. Aggregation of blood platelet by adenoside diphosphate and its reversal.  Nature (London). 1962;  194 927-9
• 9 Aviram M, Fuhrman B, Keidar S, Maor I, Rosenblatt M, Daukner G, Brook G. Platelet-modified low density lipoproteins induce macrophage cholesterol accumulation and platelet activation.  Journal of Clinical Chemistry and Clinical Biochemistry (Berlin). 1989;  27 3-12
• 10 Weitz J I, Hirsch J. New antithrombotic agents.  Chest. 1998;  114 715S-727S
• 11 Patrono C. Aspirin as an antiplatelet drug.  New England Journal of Medicine. 1994;  330 1287-94
• 12 Clarke R J, Mayo G, Price P, Fitzgerald G A. Suppression of thromboxane A2 but not of systemic prostacyclin by controlled aspirin.  New England Journal of Medicine. 1991;  325 1137-41
• 13 Noble J M, Thomas T H, Ford G A. Effect of age on plasma membrane asymmetry and membrane fluidity in human leukocytes and platelets.  The Journals of Gerontology Series A, Biological Sciences and Medical Science. 1999;  54 M601-6
• 14 Bock M, DE Haan J, Beck K H, Gutensohn K, Hertfelder H J, Kager R, Hein M U, Beeser H, Weber D, Kretschmer V. Standardization of the PFA-100(R) platelet function test in 105 mmol/l buffered citrate: effect of gender, smoking and oral contraceptives.  British Journal of Haematology. 1999;  106 898-904
• 15 Rosenkranz B, Fischer C, Meese O, Frohlich C. Effects of salicylate and acetylsalicylic acid alone and in combination on platelet aggregation and prostanoid synthesis in man.  British Journal of Clinical Pharmacology. 1986;  21 309-17
• 16 Roncaglioni M C, Ulrich M MW, Muller A D, Soute B AM, De Boear-van den Berg  AG, Vermeer C. The vitamin-antagonism of salicylate and warfarin.  Thrombosis Research. 1986;  42 727-36