Herbal Medicine: Expanded Commission E
Oat straw
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Latin Name: Avena sativa
Pharmacopeial Name: Avenae stramentum
Other Names: green oats, green tops, oats
Overview
Oat straw is the aboveground part of a plant more often associated with the commercial product milled from its seed. The cultivation of oatmeal dates back to at least 2000 B.C.E. Oats are native to warm Mediterranean regions of the world. In Europe, the oat plant is used for much more than its yield of grain. Extracts and tinctures prepared from the oat straw and the plant's immature, milky seed are readily available. These formulas are used as a nervous system restorative, to assist convalescence, and to strengthen a weakened constitution. Neurasthenia, shingles, herpes zoster, and herpes simplex are also treated with oat straw. It is sometimes recommended by European alternative practitioners as a phytomedicine for multiple sclerosis patients (Mills, 1988), but the efficacy of this application is not well documented. Commission E limits its approval to topical applications, allowing the administration of oat straw through baths to reduce inflammation and pruritis. In the 1970s, much research was conducted to determine if oat straw extracts helped cigarette smokers to quit. The results of these tests were negative, but led to research on oat straw's potential influence on reproductive hormones (Connor et al., 1975; Schmidt and Geckeler, 1976). In an experimental study, oat straw stimulated the release of luteinizing hormone from the adenohypophysis (a gland in the brain) of rats (Fukushima et al., 1976).
Description
Oat straw consists of the dried, threshed leaf and stem of Avena sativa L. [Fam. Poaceae] and its preparations in effective dosage. The preparation contains silicic acid.
Chemistry and Pharmacology
Two percent silicon dioxide occurs in the leaves and in the straw in soluble form as esters of silicic acid with polyphenols and monosaccharides and oligosaccharides. Oat straw contains a high content of iron (39 mg/kg dry weight), manganese (8.5 mg), and zinc (19.2 mg) (Wichtl and Bisset, 1994). The leaves contain triterpenoid saponins of the furostanol type (avenacosides) with strong in vitro fungicidal activity (Wichtl and Bisset, 1994). In vitro and in vivo, beta-glucan from oats has been shown to stimulate immune functions (Estrada et al., 1997).
Uses
The Commission E approved the topical use of oat straw in baths for inflammatory and seborrheic skin diseases, especially those with itching.
Contraindications
None known.
Side Effects
None known.
Use During Pregnancy and Lactation
No restrictions known.
Interactions with Other Drugs
None known.
Dosage and Administration
Unless otherwise prescribed: 100 g of cut herb for one full bath; equivalent preparations.
References
Connor, J., T. Connor, P.B. Marshall, A. Reid, M.J. Turnbull. 1975. The pharmacology of Avena sativa.J Pharm Pharmacol 27(2):9298. Estrada, A. et al. 1997. Immunomodulatory activities of oat beta-glucan in vitro and in vivo.Microbiol Immunol 41(12):991998. Fukushima, M., S. Watanabe, K. Kushima. 1976. Extraction and purification of a substance with luteinizing hormone releasing activity from the leaves of Avena sativa.Tohoku J Exp Med 119(2):115122. Mills, S.Y. 1988. The Dictionary of Modern Herbalism. New York: MJF Books. Schmidt, K. and K. Geckeler. 1976. Pharmacotherapy with Avena sativaa double blind study. Int J Clin Pharmacol Biopharm 14(3):214216. Wichtl, M. and N.G. Bisset (eds.). 1994. Herbal Drugs and Phytopharmaceuticals. Stuttgart: Medpharm Scientific Publishers.
Additional Resources
Anand, C.L. 1971. Effect of Avena sativa on cigarette smoking. Nature 233(5320):496. Grieve, M. 1979. A Modern Herbal. New York: Dover Publications, Inc. This material was adapted from The Complete German Commission E MonographsTherapeutic Guide to Herbal Medicines. M. Blumenthal, W.R. Busse, A. Goldberg, J. Gruenwald, T. Hall, C.W. Riggins, R.S. Rister (eds.) S. Klein and R.S. Rister (trans.). 1998. Austin: American Botanical Council; Boston: Integrative Medicine Communications.
1) The Overview section is new information. 2) Description, Chemistry and Pharmacology, Uses, Contraindications, Side Effects, Interactions with Other Drugs, and Dosage sections have been drawn from the original work. Additional information has been added in some or all of these sections, as noted with references. 3) The dosage for equivalent preparations (tea infusion, fluidextract, and tincture) have been provided based on the following example: - Unless otherwise prescribed: 2 g per day of [powdered, crushed, cut or whole] [plant part]
- Infusion: 2 g in 150 ml of water
- Fluidextract 1:1 (g/ml): 2 ml
- Tincture 1:5 (g/ml): 10 ml
4) The References and Additional Resources sections are new sections. Additional Resources are not cited in the monograph but are included for research purposes. This monograph, published by the Commission E in 1994, was modified based on new scientific research. It contains more extensive pharmacological and therapeutic information taken directly from the Commission E.
Excerpt from Herbal Medicine: Expanded Commission E Monographs
Copyright 2000 American Botanical Council
Published by Integrative Medicine Communications
Available from the American Botanical Council.
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