Plant Profiler

Yerba santa (Eriodictyon californicum)

Yerba santa (Eriodictyon californicum) Image
Synonyms / Common Names / Related Terms
Consumptive's weed, bear's weed, eriodictyol, Eriodictyon californicum, Eriodictyon glutinosum, gum bush, holy herb, mountain balm, sacred herb, tarweed, Wigandia californicum.

Brand name products: American Indian Baby Smudge Bundles Clarity (Yerba Santa) from Ancient Aromas, Flower Essence FES North American Flower Essences Yerba Santa ¼ Oz from FES Quintessentials, HerbPharm Yerba Santa 1 Oz from HerbPharm, Mouth Kote from Parnell Pharmaceuticals, Turtle Island Yerba Santa Leaf from Turtle Island, Yerba Santa 1 Oz from Nature's Apothecary, Yerba Santa Botanical from Viable Herbal Solutions, Yerba Santa liquid Extract from Eclectic Institute.

Note: Not to be confused with other herbs which share the same common name(s). For example, the common name "mountain balm" is also used for Ceanothus velutinus, Satureja chandleri, and Calamintha nepeta. The common name "consumptive's weed" is associated with three different Eriodictyon species. The common name "gum bush" is also associated with several different Eriodictyon species. The common name "bear's weed" is also used for Arctostaphylos uva-ursi. The common name "tarweed" is associated with many species of Hemizonia and Madia. The common name "holy herb" is used for marijuana (Cannabis sativa), hyssop (Sorghum vulgare), basil (Ocimum basilicum), verbena (Verbena officinalis) and aloe (Aloe barbadensis). The common name "sacred herb" is used for marijuana and tobacco (Nicotiana tabacum).

Mechanism of Action


  • Constituents: The leaf surfaces of Eriodictyon californicum are coated with flavanoids, particularly the flavanones homoeriodictyol, eriodictyol, and methyl flavanones. The constituent flavanones and flavones include (in order of abundance): homoeriodictyol, cirsimaritin, chrysoeriol, hispidulin, eriodictyol, 5,7,4'-trihydroxy-6,3'-dimethoxyflavanone, 5,4'-dihydroxy-6,7-dimethoxyflavanone, sakuranetin, 3'-methyl-4'-isobutyryleriodictyol, naringenin 4'-methyl ether, pinocembrin and chrysin.1,8,9,10,11,12,13,14,15,16 Also present are chrysoeriol, luteolin, apigenin, nepetin, jaceosidin, kaempferol 3-O-glucoside, quercitin 3-O-glucoside, and several methyl derivatives of eriodictyol, such as eriodictyol 7-methyl ether and eriodictyol 4'-methyl ether.12
  • Anti-oxidant properties: Flavanones in Eriodictyon californicum are potent free radical scavengers.14,15,16,17 Eriodictyol has been reported as being a more potent free radical scavenger that vitamin E, although the clinical implications of this assertion are not known.18
  • Anti-parasitic: Flavanones, such as eriodictyol, have been reported as being active against malaria and trypanosomes in pre-clinical studies.7,19,20
  • Cancer: There has been research interest in several flavonoids in Eriodictyon species as potential anticancer agents1, with pre-clinical reports of cytotoxicity to cancer cell lines1,2 but not normal cells3. Proposed mechanisms include inhibition of ATP-dependent calcium uptake4, inhibition of glutathione S-transferase5, or induction of apoptosis by cytochrome c release and caspase-3 activation.6 Flavanones may inhibit the activation of carcinogens such as benzo(a)pyrene.1


  • Absorption: The pharmacokinetics of Eriodictyon flavanones are not well reported. The pharmacokinetics of a minor component, apigenin (a flavone), is known and is typical of flavonoids.21 Following oral administration, absorption and elimination are slow with possible accumulation in the body.
  • Metabolism: The major flavanone homoeriodictyol is a metabolite of eriodictyol, and is formed through methylation of eriodictyol.22 Metabolism likely involves colonic oxidation by intestinal microbes.23 Cleavage of the C ring leads to phloroglucinol and dihydrocaffeic acid as metabolites of both eriodictyol and homoeriodictyol.16,23 Demethylation is required to produce dihydrocaffeic acid as a metabolite of homoeriodictyol. Early studies reported that homoeriodictyol is broken down in the same way eriodictyol is broken down in the rodent body.22 Metabolism of apigenin, a minor flavone component, may occur in the gut and liver.21 About 50% of the dose appears in the urine and 12% in the feces. Glucuronide and sulfate conjugates appear in the urine. The half life is 91.8 hours. The clearance is 1.95 mL/hour.
  • Elimination: Dehydroxylation of dihydrocaffeic acid produces the major urinary metabolite 3-(3-hydroxyphenyl)-propionic acid.22,23 Unidentified glucuronide conjugates also appear in the urine.22


  1. Liu, Y. L., Ho, D. K., Cassady, J. M., Cook, V. M., and Baird, W. M. Isolation of potential cancer chemopreventive agents from Eriodictyon californicum. J Nat Prod  1992;55(3):357-363. 1593282
  2. Mori A, Nishino C, Enoki N., and Tawata S. Cytotoxicity of plant flavonoids against HeLa cells. Phytochem 1988;27:1017-1020.
  3. Matsuo, M., Sasaki, N., Saga, K., and Kaneko, T. Cytotoxicity of flavonoids toward cultured normal human cells. Biol Pharm Bull  2005;28(2):253-259. 15684479
  4. Thiyagarajah, P., Kuttan, S. C., Lim, S. C., Teo, T. S., and Das, N. P. Effect of myricetin and other flavonoids on the liver plasma membrane Ca2+ pump. Kinetics and structure-function relationships. Biochem Pharmacol  3-1-1991;41(5):669-675. 1998524
  5. van Zanden, J. J., Geraets, L., Wortelboer, H. M., van Bladeren, P. J., Rietjens, I. M., and Cnubben, N. H. Structural requirements for the flavonoid-mediated modulation of glutathione S-transferase P1-1 and GS-X pump activity in MCF7 breast cancer cells. Biochem Pharmacol  4-15-2004;67(8):1607-1617. 15041478
  6. Way, TD, Kao, MC, and Lin, JK. Degradation of HER2/neu by apigenin induces apoptosis through cytochrome c release and caspase-3 activation in HER2/neu overexpressing breast cancer cells. FEBS Lett 2005;578:145-152.
  7. Aviado, D. M., Bacalzo, L. V., and Belej, M. A. Prevention of acute pulmonary insufficiency by eriodictyol. J Pharmacol Exp Ther  1974;189(1):157-166. 4207243
  8. Mossler, G. The chemical investigation of Eriodictyon glutinosum. Ann 1907;351:233-254.
  9. Geissman, TA. The isolation of eriodictyol and homoeriodictyol an improved procedure. J Am Chem Soc 1940;62:3258-3259.
  10. Bacon, JD, Hannan, GL, Fang, N, and Mabry, TJ. Chemosystematics of the Hydrophyllaceae: flavonoids of three species of Eriodictyon. Biochem System Ecol 1986;14:591-595.
  11. Bohm, BA and Constant, H. Leaf surface flavonoids of Eriodictyon trichocalyx. Biochem System Ecol 1990;18:491-492.
  12. Johnson, ND. Flavonoid aglycones from Eriodictyon californicum resin and their implications for herbivory and UV screening. Biochem System Ecol 1983;11:211-215.
  13. Johnson, ND and Brain, SA. The response of leaf resin to artificial herbivory in Eriodictyon californicum. Biochem System Ecol 1985;13:5-9.
  14. Huguet, A. I., Manez, S., and Alcaraz, M. J. Superoxide scavenging properties of flavonoids in a non-enzymic system. Z Naturforsch [C] 1990;45(1-2):19-24. 2158783
  15. Tsimogiannis, DI and Oreopoulou, V. Free radical scavenging and antioxidant activity of 5,7,3',4'-hydroxy substituted flavonoids. Inn Food Sci Emerg Tech 2004;5:523-528.
  16. Miyake, Y, Yamamoto, K, and Osawa, T. Metabolism of antioxidant in lemon fruit (Citrus limon Burm.f.) by human intestinal bacteria. J Agric Food Chem 1997;45:3738-3742.
  17. Matsuda, H, Wang, T, Managi, H, and Yoshikawa M. Structural requirements of flavonoids for inhibition of protein glycation and radical scavenging activities. Bioorg Med Chem 2003;11:5317-5323.
  18. Heim, KE, Tagliaferro, AR, and Bobily, DJ. Flavonoid antioxidants: chemistry, metabolism and stucture activity relationships. J Nutr Biochem 2002;13:572-584.
  19. Ahmed, M. S., Galal, A. M., Ross, S. A., Ferreira, D., ElSohly, M. A., Ibrahim, A. S., Mossa, J. S., and El Feraly, F. S. A weakly antimalarial biflavanone from Rhus retinorrhoea. Phytochemistry 2001;58(4):599-602. 11576606
  20. Grael, C. F., Vichnewski, W., Souza, G. E., Lopes, J. L., Albuquerque, S., and Cunha, W. R. A study of the trypanocidal and analgesic properties from Lychnophora granmongolense (Duarte) Semir & Leitao Filho. Phytother Res  2000;14(3):203-206. 10815016
  21. Gradolatto, A., Basly, JP, Berges, R., Teyssier, C., Chagnon, MC, Siess, MH, and Canivenc-Lavi, MC. Pharmacokinetics and metabolism of apigenin in female and male rats after a single oral administration. Drug Metab Dispos 2005;33:49-54.
  22. Booth, AN, Jones, FT, and DeEDS, F. Metabolic fate of hesperidin, eriodictyol, homoeridictyol, and diosmin. J Biol Chem  1958;230(2):661-668. 13525384
  23. Rechner, A. R., Smith, MA, Kuhnle, F, Gibson GR, Debnam, ES, Srai, SKS, Moore, KP, and Rice-Evans, CA. Colonic metabolism of dietary polyphenols: influence of structure on microbial fermentation products. Free Rad Biol Med 2004;36:212-225.

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