Herbal Medicine: Expanded Commission E
Oak bark
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Latin Name: Quercus robur and/or Q. petraea, Q. alba
Pharmacopeial Name: Quercus cortex
Other Names: white oak bark (Q. alba)
Overview
The name quercus comes from the Celtic words quer (fine) and cuez (tree) (Grieve, 1979). Oak was so respected that a branch of the tree was stamped onto British coins for centuries. Oaks, being both pliable and extremely strong, were used for British ship building, and also for train cars and knife handles. Historically, oak bark decoctions or tinctures have been used for lung, throat, and gastrointestinal disorders, particularly in England, although the Greeks and Romans were also well acquainted with oak's astringent actions (Grieve, 1979). It has been used to treat hemorrhaging, intermittent fevers, chronic diarrhea, and dysentery. As a gargle, oak bark has been used to relieve chronic sore throats; it has also been prepared as a vaginal wash to treat leucorrhea (Hutchins, 1991). Quercus alba was listed in the United States Pharmacopoeia from 1820 until 1910 (Boyle, 1991). Future uses for oak bark require examination. Oak bark may also prove to be useful in the treatment of ureteral and kidney lithiasis. One study found that a proprietary medicine inhibited not only the formation of stones, but also the growth of bacteria surrounding them. Litiax was also shown to be diuretic and significantly reduced inflammation and pain (Mandana-Rodriguez and Gausa-Rull, 1980). Oak bark may also be useful in treating patients with pyoinflammatory skin diseases. A water alcohol glycerol extract has shown antistaphylococcal activity (Molochko et al., 1990).
Description
Oak bark consists of the dried bark of young branches and saplings of Quercus robur L. and Q. petraea (Mattuschka) Lieblein [Fam. Fagaceae], harvested in the spring, and their preparations in effective dosage. The preparation contains tannins.
Chemistry and Pharmacology
Constituents include about 10% saponins, 1015% tannins, calcium oxalate, starch, and a mixture of different triterpene glycosides with quillaic acid as the main sapogenin (Wichtl and Bisset, 1994). Other constituents include tannic acid, oak-red, resin, pectin, levulin, and quercitol (Stecher, 1968). The Commission E reported astringent and virustatic activity. Recent animal experiments have found that through oral administration, the saponins of the bark are able to reduce serum cholesterol levels. This activity is thought to be due to a reaction between the saponins and the bile acids, resulting in micelle formation and leading to inhibition of cholesterol uptake. The saponins are also thought to raise antibody production in the mouse; the experiments found that the immune response after viral infections was accelerated (Wichtl and Bisset, 1994).
Uses
The Commission E approved the internal use of oak bark for nonspecific, acute diarrhea, and local treatment of mild inflammation of the oral cavity and pharyngeal region, and genital and anal area. It was also approved externally for inflammatory skin diseases. The bark's saponin content is thought to possess expectorant activity in respiratory complaints (Wichtl and Bisset, 1994). Oak bark can be used topically for its astringent properties in cases of dermatitis without risk of irritation (Weiss, 1988).
Contraindications
Internal: None known. External: Skin damage over a large area. Baths: Full baths should not be taken.
Side Effects
None known.
Use During Pregnancy and Lactation
No restrictions known.
Interactions with Other Drugs
External: None known. Internal: The absorption of alkaloids and other alkaline drugs may be reduced or inhibited.
Dosage and Administration
Unless otherwise prescribed: 3 g per day of cut herb. Infusion: 3 g of herb in 150 ml water. Fluidextract 1:1 (g/ml): 3 ml. Tincture 1:5 (g/ml): 15 ml. For rinses, compresses and gargles: 20 g preparation per 1 liter of water; equivalent preparations. For full and partial baths: 5 g preparation per 1 liter of water; equivalent preparations. If diarrhea persists longer than three to four days, consult a physician. Other areas of application: Not more than two to three weeks.
References
Boyle, W. 1991. Official Herbs: Botanical Substances in the United States Pharmacopoeias 18201990. East Palestine, OH: Buckeye Naturopathic Press. Grieve, M. 1979. A Modern Herbal. New York: Dover Publications, Inc. Hutchins, A. 1991. Indian Herbology of North America. Boston: Shambala. Mandana-Rodriguez, A. and P. Gausa-Rull. 1980. [Therapeutic effects of Quercus extract in urolithiasis] [In Spanish]. Arch Esp Urol 33(2):205226. Molochko, V.A., T.M. Lastochkina, I.A. Krylov, K.A. Brangulis. 1990. [The antistaphylococcal properties of plant extracts in relation to their prospective use as therapeutic and prophylactic formulations for the skin] [In Russian]. Vestn Dermatol Venerol (8):5456. Stecher, P.G. (ed.). 1968. The Merck Index: An Encyclopedia of Chemicals and Drugs, 8th ed. Rahway, N.J.: Merck & Co., Inc. Weiss, R.F. 1988. Herbal Medicine. Beaconsfield, England: Beaconsfield Publishers. Wichtl, M. and N.G. Bisset (eds.). 1994. Herbal Drugs and Phytopharmaceuticals. Stuttgart: Medpharm Scientific Publishers.
Additional Resources
Deutscher Arzneimittel-Codex (DAC). 1986. Stuttgart: Deutscher Apotheker Verlag. Maharaj, I., K.J. Froh, J.B. Campbell. 1986. Immune responses of mice to inactivated rabies vaccine administered orally: potentiation by Quillaja saponin. Can J Microbiol 32(5):414420. McGuffin, M., C. Hobbs, R. Upton, A. Goldberg. 1997. American Herbal Product Association's Botanical Safety Handbook. Boca Raton: CRC Press. Oakenfull, D. 1986. Aggregation of saponins and bile acids in aqueous solution. Aust J Chem 39(10):16711683. sterreichisches Arzneibuch, Vols. 12, 1st suppl. ( AB). 19811983. Wien: Verlag der sterreichischen Staatsdruckerei. Pharmacopoeia Helvetica, 7th ed. Vol. 14.(Ph.Helv.VII). 1987. Bern: Office Central Fdral des Imprims et du Matriel. Rao, A.V. and C.W. Kendall. 1986. Dietary saponins and serum lipids. Food Chem Toxicol 24(5):441. Scott, M.T., M. Goss-Sampson, R. Bomford. 1985. Adjuvant activity of saponin: antigen localization studies. Int Arch Allergy Appl Immunol 77(4):409412. Sidhu, G.S. and D.G. Oakenfull. 1986. A mechanism for the hypocholesterolemic activity of saponins. Br J Nutr 55(3):643649. Tyler, V.E. 1994. Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York: Pharmaceutical Products Press. 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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