Assume that we are dealing with T. diffusa and not T. umifolia which is a small but significant adulterant in commerce. The constituent profile for these closely related plants is very distinct (Schäffer, Gröger, Pütz, & Zimmermann, 2013). Let’s also assume a holistic perspective as opposed to a reductionist one (i.e. Galen vs Paracelsus) and grant a-priori that extracting a full constituent profile of the whole plant is the optimal extraction goal for therapeutic use within the modality of modern Western Herbal Medicine (WHM).
Obviously, the easiest way to get the whole plant is by consuming fresh powdered leaf.
For many people who seek the therapeutic benefits of damiana this is an impractical method. Ethanolic extractions can extend the life of a product to bring it to a wider market out of season.
Damiana is not in E.S.C.O.P’s monographs or Hoffman’s “Medical Herbalism”, In Bone’s “Guide to Blending Liquid Herbs” no discussion of constituents occurs. In the Commission E monographs it is listed as an “Unapproved Herb.” It is listed in the 1983 “British Herbal Pharmacopoeia” which states that T. diffusa has 0.5-1% or green volatile oil (which is mirrored in Grieve’s “Modern Herbal”) , 5-7% of a bitter substance, “damianin”, and 3-4% if a mixture of resins, tannins, starch, gum and fixed oils (British Herbal Medicine Association, 1983). The constituents listed for Damiana in “Herbs and Natural Supplements 4th Edition) are: Alkaloids, flavonoids, arbutin (glycosated hydroquinone), essential oils containing caryophylline, delta-cadinene, beta-elemene and 1,8-cineole, 0.26% tertraphylin and possibly caffine (Braun & Cohen, 2015). Skinderi corroborates the above, but lists the volitale oil as containing: 1,8-cineole, pinenes, thymol, o-cadinene (Skenderi, 2003). Potter’s description of the constituent profile is similar (Williamson, 2003).
So a polity of authoritative texts list the constituents of damiana as follows with parts per million (ppm) as referenced from Jim Duke’s ethnobotanical database (Duke, 2016):
- arbutin – 7000ppm
- tannins – 75,000 ppm
- Glycosides (cyanogenic)
- tertraphylin B (barterin)
- Bitter substance
- damianin – 70,000ppm
- resins (note: resins are composed of more than just terpenes) – 65,000 ppm
- volatile oil
- 1,8-cineole – 1100ppm
- alpha pinine – 100ppm
- beta pinine – 100ppm
- mucilage (actually an exopolysaccharide)
- gum 150,000 ppm
- albuminoids 150,000 ppm
The main concern with extraction is ensure that the polarity of the solution is effective to fully extract the constituents. The because of the presence of oils and resins, a supercritical C02 (SCE) extraction stands a chance of getting a fuller constituent profile of these constituents (Ganora, 2009). An ethanolic concentration of 20% is considered the lowest for shelf stability (Ganora, 2009). The polysaccharides are typically water soluble. The glycosides are soluble in water or ethanol, ideally hot. The terpenes will require a high percentage ethanol solution. The flavinoids are all over the map but glycerin is a useful method for preventing the tannins from precipitating (Ganora, 2009).
With damiana, as with many plants, any single extraction method is going to come with some compromises. Lisa Ganora recommends using a medium ethanolic extraction method of 55-65% ethanol (Ganora, 2009). The BHP calls for 60% ethanol.
Based on my research and a full constituent assessment, an extraction of 30:10:60 (H20, Glycerite, Ethanol) will create a high polarity solution without being high enough to cause the tannins to precipitate out and take other important constituents with them. This may provide a fuller extraction even if many of the constituents facilitated by the addition of glycerin are not “active”.
So in conclusion: Whole plant, hot tea, SCE, or a combination of ethanol/glycerin are effective ways of extracting damiana.
Bone, K. (1996). Clinical applications of Ayurvedic and Chinese herbs: monographs for the Western herbal practitioner. Warwick, Qld.: Phytotherapy Press.
Bone, K. (2003). A clinical guide to blending liquid herbs: herbal formulations for the individual patient. St. Louis, Mo: Churchill Livingstone.
Braun, L., & Cohen, M. (2010). Herbs & natural supplements: an evidence-based guide (3rd ed.). Sydney; New York.: Elsevier Australia.
Braun, L., & Cohen, M. (2015). Herbs and natural supplements an evidence-based guide. (4th ed., Vol. 1). Edinburgh: Churchill Livingstone.
British Herbal Medicine Association (Ed.). (1983). British Herbal Pharmacopoeia. Bournemouth: British Herbal Medicine Association.
Duke, J. A. (2016). Dr. Duke’s Phytochemical and Ethnobotanical Databases. Ag Data Commons. Retrieved from https://doi.org/10.15482/USDA.ADC/1239279
European Scientific Cooperative on Phytotherapy (Ed.). (2003). ESCOP monographs. [Hauptbd.]: […] (2. ed., completely rev. and expanded). Exeter: ESCOP [u.a.].
Ganora, L. (2009). Herbal constituents: foundations of phytochemistry : a holistic approach for students and practitioners of botanical medicine. Louisville, Colo.: Herbalchem Press.
Hoffmann, D. (2003). Medical herbalism: the science and practice of herbal medicine. Rochester, Vt: Healing Arts Press.
Schäffer, M., Gröger, T., Pütz, M., & Zimmermann, R. (2013). Assessment of the presence of damiana in herbal blends of forensic interest based on comprehensive two-dimensional gas chromatography. Forensic Toxicology, 31(2), 251–262. https://doi.org/10.1007/s11419-013-0186-5
Skenderi, G. (2003). Herbal vade mecum: 800 herbs, spices, essential oils, lipids, etc., constituents, properties, uses, and caution. Rutherford, N.J: Herbacy Press.
Williamson, E. M. (2003). Potter’s herbal cyclopedia: the most modern and practical book for all those interested in the scientific as well as the traditional use of herbs in medicine. Saffron Walden: C.W. Daniel.