Coumarin-containing Herbs

Summary

Coumarin-containing Herbs

introduction:
Coumarins are naturally occurring benzopyrene derivatives. Coumarins are found in many families particularly Fabiaceae and Umbelliferae, and in some Solanaceae (scopoletin). The fermentation product of coumarin is dicoumarol which is a potent anticoagulant. However natural coumarins are rendered inactive in the human gastrointestinal tract, and on oral administration of therapeutic doses these herbs are not considered to be anticoagulant.

There is a persistent view, although not among herbalists, that sustained excessive doses of coumarin herbs are best avoided in concurrent anticoagulant therapy. In herbal therapeutics, the primary use of coumarin-containing plants is anti-edema and tonifying venous circulation, not anticoagulation. Similar considerations apply to salicylate containing plants which appear to lack the anticoagulant effects of aspirin.
(Mills SY. 1991, 287.)

See Herb Group: Immunological: Salicylate-containing Herbs

herbs theoretically affecting drug toxicity: Heparin and Warfarin.

• Evidence for coumarin containing plants affecting anticoagulant drugs is lacking.




Herbs

Common herbs containing significant coumarin constituents:
• Aesculus hippocastanum (Horse chestnut seed)
• Ammi visnaga (Visnaga)
• Asperula odorata (Sweet Woodruff)
• Galium odoratum (Bedstraw)
• Melilotus spp. (Sweet Clover)
• Trifolium pratense (Red clover)

Restricted or unusual herbs containing significant coumarin constituents:
• Dipteryx odorata (Tonka bean seeds)
• Pilosella officinarum (Mouse-ear Hawkweed)




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The information presented in Interactions is for informational and educational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, case reports, and/or traditional usage with sources as cited in each topic. The results reported may not necessarily occur in all individuals and different individuals with the same medical conditions with the same symptoms will often require differing treatments. For many of the conditions discussed, treatment with conventional medical therapies, including prescription drugs or over-the-counter medications, is also available. Consult your physician, an appropriately trained healthcare practitioner, and/or pharmacist for any health concern or medical problem before using any herbal products or nutritional supplements or before making any changes in prescribed medications and/or before attempting to independently treat a medical condition using supplements, herbs, remedies, or other forms of self-care.



References

Hoult JR, Paya M. Pharmacological and biochemical actions of simple coumarins: natural products with therapeutic potential. Gen Pharmacol 1996 Jun;27(4):713-722. (Review)
Abstract: More than 300 coumarins have been identified from natural sources, especially green plants. The pharmacological and biochemical properties and therapeutic applications of simple coumarins depend upon the pattern of substitution. More complex related compounds based on the coumarin nucleus include the dicoumarol/warfarin anticoagulants, aflatoxins and the psoralens (photosensitizing agents). 2. Coumarin itself (1,2-benzopyrone) has long-established efficacy in slow-onset long-term reduction of lymphoedema in man, as confirmed in recent double-blind trials against elephantiasis and postmastectomy swelling of the arm. The mechanism of action is uncertain, but may involve macrophage-induced proteolysis of oedema protein. However, coumarin has low absolute bioavailability in man (< 5%), due to extensive first-pass hepatic conversion to 7-hydroxycoumarin followed by glucuronidation. It may, therefore, be a prodrug. 3. Scoparone (6,7-dimethoxycoumarin) has been purified from the hypolipidaemic Chinese herb Artemisia scoparia and shown to reduce the proliferative responses of human peripheral mononuclear cells, to relax smooth muscle, to reduce total cholesterol and triglycerides and to retard the characteristic pathomorphological changes in hypercholesterolaemic diabetic rabbits. Various properties of scoparone were suggested to account for these findings, including ability to scavenge reactive oxygen species, inhibition of tyrosine kinases and potentiation of prostaglandin generation. 4. Osthole (7-methoxy-8-[3-methylpent-2-enyl]coumarin) from Angelica pubescens, used also in Chinese medicine, causes hypotension in vivo, and inhibits platelet aggregation and smooth muscle contraction in vitro. It may interfere with calcium influx and with cyclic nucleotide phosphodiesterases. 5. Cloricromene, a synthetic coumarin derivative, also possesses antithrombotic antiplatelet actions, inhibits PMN neutrophil function and causes vasodilatation. Some of these properties of cloricromene have been ascribed to inhibition of arachidonate release from membrane phospholipids. 6. Simple coumarins possessing ortho-dihydroxy functions, such as fraxetin and 4-methyldaphnetin, are potent inhibitors (low micromolar) of lipid peroxidation and scavengers of superoxide anion radicals and of aqueous alkylperoxyl radicals, but may be pro-oxidant (enhancing generation of hydroxyl radicals) in the presence of free iron ions. These coumarins also inhibit the proinflammatory 5-lipoxygenase enzyme at micromolar concentrations. Another related coumarin, 5,7-dihydroxy-4-methylcoumarin, is of special interest as it inhibits lipid peroxidation, and scavenges alkylperoxyl and superoxide radicals. Unlike most other simple coumarins studied, 5,7-dihydroxy-4-methylcoumarin also scavenges hypochlorous acid, and is a potent inhibitor of cyclo-oxygenase, but is not pro-oxidant. 7. 5,7- and 6,7-dihydroxy-4-methylcoumarin both reduced the duration of ventricular fibrillation in postischaemic reperfused isolated perfused rat hearts (in which oxygen-derived free radicals are implicated), showing that these antioxidant coumarins possess beneficial properties in this pathophysiological model. 8. In view of the established low toxicity, relative cheapness, presence in the diet and occurrence in various herbal remedies of coumarins, it appears prudent to evaluate their properties and applications further.

Mills SY. The Essential Book of Herbal Medicine. London, UK: Arkana, 1991.