Yerba Santa
Scientific Name(s): Eriodictyon angustifolium Nutt., Eriodictyon californicum (Hook. and Arn.) Torrey
Common Name(s): Bear's weed, California yerba santa, Consumptive's weed, Eriodictyon, Gum plant, Mountain balm, Santa herba, Tarweed, Yerba santa
Medically reviewed by Drugs.com. Last updated on Apr 22, 2024.
Clinical Overview
Use
Yerba santa leaves have traditionally been boiled to make tea, taken as an expectorant for treatment of respiratory conditions, and used for management of bruises and rheumatic pain. Recent clinical studies have investigated yerba santa as a neuroprotective and antioxidative agent, as well as a possible aid in weight management. However, clinical studies are limited, and yerba santa cannot be recommended for any indication.
Dosing
Clinical data are lacking to provide dosing recommendations for yerba santa.
Contraindications
Contraindications have not been identified.
Pregnancy/Lactation
Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
There are no reports of significant adverse reactions associated with topical or systemic use of yerba santa.
Toxicology
No data.
Scientific Family
- Hydrophyllaceae (waterleaf)
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 m in height at elevations exceeding 1,219 m. The hairy, lance-shaped leaves are glutinous, and the flowers are white to lavender in color. Synonyms of E. californicum include Eriodictyon glutinosum Benth. and Wigandia californicum Hook. & Arn.(Chevalier 1996, Khan 2010, USDA 2022)
History
The name yerba santa ("holy weed") was given by Spanish priests who learned of the medicinal value of the shrub from American Indians.(Chevalier 1996) The plant has a long tradition of use in the United States. The thick, sticky leaves, used either fresh or dried, have been boiled to make tea or taken as a treatment for cough, colds, asthma, and tuberculosis; the leaves have been powdered and used as a stimulating expectorant.(Lewis 1977) A liniment has been applied topically to reduce fever. A poultice of fresh leaves has been used to treat bruises, and young leaves have been applied to relieve rheumatism.(Balls 1962, Sweet 1976) Yerba santa is contained in a number of herbal preparations and has been used as a pharmaceutical flavoring, particularly to mask the flavor of bitter drugs.(Khan 2010) The fluid extract is used in foods and beverages.(Duke 2002)
Related/similar drugs
turmeric, Ginkgo Biloba
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.(Duke 1992, Khan 2010)
Spectroscopic analysis and alkaline hydrolysis resulted in the isolation of 12 flavonoids. Identified pharmacologically active flavanones were 3′-methyl-4′-isobutyryleriodictoyol, eriodictyol, homoeriodictyol, 5,4′-dihydroxy-6,7-dimethoxyflavanone, pinocembrin, sakuranetin, 5,7,4′-trihydroxy-6,3′-dimethoxyflavanone, naringenin 4′-methyl ether, and 7-methoxy-3',4',5-trihydroxyflavanone (also known as sterubin).(Liu 1992, Maher 2020) The neuroprotective properties of extracts prepared from Eriodictyon taxa leaves correlated with the amount of sterubin, but not with eriodictyol or homoeriodictyol, indicating that sterubin is the major active compound across Eriodictyon species.(Maher 2020) Four active flavones were also isolated: cirsimaritin, chrysoeriol, hispidulin, and chrysin.(Liu 1992)
Uses and Pharmacology
Alzheimer disease
Animal and in vitro data
In vitro studies suggest that sterubin, found in E. californicum, is a potent neuroprotective and anti-inflammatory compound with possible benefits in Alzheimer disease.(Fischer 2019) The activity of sterubin was investigated for the first time in vivo using an Alzheimer disease mouse model. Sterubin had a positive impact on short- and long-term memory at low dosages.(Hofmann 2020)
Anti-inflammatory effects
In vitro data
Anti-inflammatory effects have been proposed for Eriodictyon extracts based on screening studies(Mazzio 2016, Walker 2016); it has been suggested that the chemical constituent eriodictyol can inhibit mast cell degranulation.(Yoo 2012)
Cancer
Animal data
In animal models, eriodictyol has been used as an effective chemopreventive agent against dimethylhydrazine-induced colon carcinogenesis.(Mariyappan 2017)
Hair pigmentation
In vitro data
Eriodictyon angustifolium extracts, but not E. californicum extracts, have been shown to reduce human hair graying. It has been proposed that an E. angustifolium extract, which is abundant in sterubin, may be suitable as a potential cosmetic and medical agent for the prevention and improvement of hair graying. It is unclear why E. californicum, which also contains sterubin, did not have a comparable effect, though the difference is possibly explained by the difference in quantity of the flavonoid.(Taguchi 2020)
Weight management
Animal and in vitro data
In a study evaluating in vitro and in vivo models (in an oxygen radical absorbance capacity assay and in Caenorhabditis elegans, respectively) to determine whether santa herba exerts caffeine-like energizing effects, an E. californicum extract was shown to bind to adenosine receptor A2A, stimulate C. elegans motility (+7.5%) and locomotion, and yield high antioxidative capacities.(Mӧdinger 2021)
Clinical data
In a study evaluating effects of santa herba extract on body weight and appetite-related parameters in women who were overweight (body mass index [BMI] 25 to less than 30 kg/m2) or obese (BMI 30 to 35 kg/m2) (N=50), participants received either 400 mg of an E. californicum extract containing at least 4% homoeriodictyol (n=25) or placebo capsules (n=25) twice daily for 12 weeks with main meals. While a nonsignificant trend toward body weight reduction was observed in the overall study population, E. californicum consumption resulted in significant reductions in body weight (P=0.042) and body fat (P=0.044), as well as a tendency toward reduced leptin levels (P=0.065), in women with obesity compared to placebo. The authors concluded that daily E. californicum consumption may aid in weight management, particularly in individuals with a BMI exceeding 30 kg/m2.(Mӧdinger 2021)
Other uses
Tertiary resources report that eriodictyol has an expectorant action.(Khan 2010) Yerba santa has also been investigated for treating xerostomia, as a substitute for tobacco use, for reducing skin or mucosal irritation, and as a moisturizer.(Coy-Herbert 2002, Lewis 1977, Parnell 1993)
Dosing
Clinical data are lacking to provide dosing recommendations for yerba santa. One small study in women with a BMI of at least 25 kg/m2 evaluated an E. californicum extract (at a dosage of 400 mg twice daily for 12 weeks) as a possible aid in weight management.(Mӧdinger 2021)
Pregnancy / Lactation
Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
There are no reports of significant adverse reactions associated with topical or systemic use of yerba santa.
Allergic contact dermatitis has been reported for the related species Eriodictyon parryi (poodle-dog bush).(Czaplicki 2013)
Toxicology
There are no reports of significant toxicity associated with topical or systemic use of yerba santa.
Index Terms
- Eriodictyon glutinosum Benth.
- Wigandia californicum Hook. & Arn.
References
Disclaimer
This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.
This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.
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