Yerba Santa

Scientific Name(s): Eriodictyon californicum (Hook. & Arn.) Torrey. Family: Hydrophyllaceae

Common Name(s): Yerba santa , eriodictyon , tarweed , consumptive's weed , bear's weed , mountain balm , gum plant 1

Uses

Historical evidence documents that yerba santa has been used in tea and medicinally for the management of bruises and rheumatic pain. The plant also has been used as an expectorant and in the treatment of respiratory diseases. There are no clinical studies to evaluate these effects.

Dosing

There is no recent clinical evidence to support dose recommendations for yerba santa. Classical use of the leaf as an expectorant was at 1 g doses.

Contraindications

Contraindications have not yet been determined.

Pregnancy/Lactation

Avoid use during pregnancy and lactation because of the lack of clinical studies.

Interactions

None well documented.

Adverse Reactions

Review of the scientific literature reveals little to no evidence evaluating the toxicity of yerba santa in humans or animals.

Toxicology

Review of the scientific literature reveals no evidence evaluating the toxicity of yerba santa in humans or animals.

Botany

The yerba santa plant is an evergreen aromatic shrub with woody rhizomes. It is indigenous to the hills and mountains of California, Oregon, and northern Mexico and is often cultivated as an ornamental shrub. The plant grows to 2.5 meters in height at elevations exceeding 1219 meters. The hairy, lance-shaped leaves are glutinous, and its flowers are white to lavender in color. 2 , 3 , 4 Also known as E. glutinosum Benth. and Wigandia californicum Hook. & Arn.

History

The name yerba santa (“holy weed”) was given by the Spanish priests who learned of the medicinal value of the shrub from the American Indians. 3 The plant has a long tradition of use in the United States. The thick sticky leaves, used either fresh or dried, were boiled to make a tea or taken as treatment for coughs, colds, asthma, and tuberculosis. The leaves have been powdered and used as a stimulating expectorant. 5 A liniment was applied topically to reduce fever. A poultice of fresh leaves was used to treat bruises, and young leaves were applied to relieve rheumatism. 6 , 7 The plant is contained in a number of otc herbal preparations. Yerba santa has been used as a pharmaceutical flavoring, particularly to mask the flavor of bitter drugs. 8 The fluid extract is used in foods and beverages.

Chemistry

Yerba santa contains a volatile oil, up to 6% eriodictyonine, about 0.5% eriodictyol (the aglycone of eriodictin), and several related alcoholic compounds, ericolin, and a resin. 2

Spectroscopic analysis and alkaline hydrolysis resulted in the isolation of 12 flavonoids. Eight active flavanones were identified as 3′-methyl-4′-isobutyryleriodictoyol, eriodictyol, homoeriodictyol, 5,4′-dihydroxy-6,7-dimethoxyflavanone, pinocembrin, sakuranetin, 5,7,4′-trihydroxy-6,3′-dimethoxyflavanone, and naringenin 4′-methyl ether. 9

Four active flavones were also isolated: cirsimaritin, chrysoeriol, hispidulin, and chrysin. 9

Uses and Pharmacology

Review of the scientific literature reveals no evidence evaluating the effectiveness of yerba santa in humans or animals. Tertiary resources report that eriodictyol exerts an expectorant action. 1 The plant also has been investigated for treating xerostomia, as a substitute for tobacco use, to reduce skin or mucosal irritation, and as a moisturizer. 4 , 10 , 11

Cirsimaritin and chrysoeriol may warrant further investigation in vivo as potential chemopreventive agents. 9

Animal/Clinical data

Research reveals no clinical data regarding the use of yerba santa for any condition.

Dosage

There is no recent clinical evidence to support dose of recommendations for yerba santa. Classical use of the leaf as an expectorant was at 1 g doses.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactations is lacking. Avoid use.

Interactions

None well documented.

Adverse Reactions

There are no reports of significant toxicity associated with the topical or systemic use of yerba santa.

Toxicology

There are no reports of significant toxicity associated with the topical or systemic use of yerba santa.

Bibliography

1. Windholz M, et al, eds. The Merck Index . 10th ed. Rahway, NJ: Merck & Co.; 1983.
2. Leung AY. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics . New York, NY: J. Wiley and Sons; 1980.
3. Chevallier A. The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing Inc.; 1996.
4. Parnell FW. Method and composition for treating xerostomia. US patent 4 938 963. 1990.
5. Lewis WH, Elvin-Lewis MPF. Medical Botany . New York, NY: J. Wiley and Sons; 1977.
6. Balls EK. Early Uses of California Plants . Berkeley, CA: University of California Press; 1962.
7. Sweet M. Common Edible and Useful Plants of the West . Healdsburg, CA: Naturegraph Publishers; 1976.
8. Morton JF. Major Medicinal Plants . Springfield, IL: C.C. Thomas; 1977.
9. Liu YL, Ho DK, Cassady JM, Cook VM, Baird WM. Isolation of potential cancer chemopreventive agents from Eriodictyon californicum . J Nat Prod . 1992;55:357-363.
10. Parnell FW. Drug delivery systems containing Eriodictyon fluid extract as an excipient, and methods, and compositions associated therewith. US patent 5 248 501. 1993.
11. Coy-Herbert P. Herbal composition as a substitute for tobacco. US patent 6 497 234. 2002.

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