Adaptogen

The word adaptogen, is used by herbalists to refer to a natural herb product that increases the body's resistance to stresses such as trauma, anxiety and bodily fatigue. In the past they have been called rejuvenating herbs, qi tonics, rasayanas, or restoratives.

Knowledge about adaptogens dates back thousands of years to ancient India and China, but serious scientific study did not begin until the late 1940s. In 1947, Dr. Nikolai Lazarev defined an adaptogen as an agent that allows the body to counter adverse physical, chemical, or biological stressors by raising nonspecific resistance toward such stress, thus allowing the organism to “adapt” to the stressful circumstances..

In 1968, Israel I. Brekhman, PhD, and Dr. I. V. Dardymov formally gave adaptogens a functional definition, as follows:


 * 1) An adaptogen is nontoxic to the recipient.
 * 2) An adaptogen produces a nonspecific response in the body—an increase in the power of resistance against multiple stressors including physical, chemical, or biological agents.
 * 3) An adaptogen has a normalizing influence on physiology, irrespective of the direction of change from physiological norms caused by the stressor.

Very simply, adaptogens are nontoxic in normal doses, produce a nonspecific defensive response to stress, and have a normalizing influence on the body. They normalize the hypothalamic-pituitary-adrenal axis (HPA axis). As defined, adaptogens constitute a new class of natural, homeostatic metabolic regulators. It is claimed that adaptogenic herbs are unique from other substances in their ability to balance endocrine hormones and the immune system, and they help the body to maintain optimal homeostasis. Adaptogens have a normalizing effect on the body and are capable of either toning down the activity of hyperfunctioning systems or strengthening the activity of hypofunctioning systems. However they are also functional at the level of allostasis which is a more dynamic reaction to long term stress, lacking the fixed reference points of homeostasis.

Adaptogenic Herbs
Most herbal adaptogens that have been identified are used in either Ayurveda or Traditional Chinese Medicine (TCM). Adaptogens with a significant level of scientific research confirming their use include: Ashwagandha (Withania somnifera), Cordyceps (Cordyceps sinensis), Dang Shen (Codonopsis pilosula), Eleuthero (Eleutherococcus senticosus), Holy Basil (Ocimum sanctum), Ginseng (Panax ginseng), Guduchi (Tinospora cordifolia), Jiaogulan (Gynostemma pentaphyllum), Licorice (Glycyrrhiza glabra), Maca (Lepidium meyenii), Reishi (Ganoderma lucidum), Rhaponticum (Rhaponticum carthamoides or Stemmacantha carthamoides), Rhodiola (Rhodiola rosea), Schisandra (Schisandra chinensis), Chaga mushroom (Inonotus obliquus) and Shilajit (Ashphaltum bitumen).

Possible adaptogens with less scientific research include: Amla (Emblica officinalis), Astragalus (Astragalus membranaceus), He Shou Wu (Polygonum multiflorum), Lycium (Lycium chinensis), Prince Seng (Pseudostellaria heterophylla), Shatavari (Asparagus racemosus) and Suma (Pfaffia paniculata).

Panax ginseng is an example of an adaptogen that has demonstrated an "overall normalizing effect." Among the active ingredients found in Panax Ginseng are substances called ginsenosides. The herb contains ginsenosides Rg1, which can stimulate the nervous system, and ginsenosides Rb1, which calms it. However ginsenosides alone do not determine the active strength of ginseng and some preparations with higher ginsenosides have lower activity, indicating that cofactors are necessary to potentiate the adaptogenic properties of ginseng.

Constituents Common to Adaptogens
It can be difficult to determine which constituents are active ingredients in plants with as diffuse an effect as adaptogens. According to adaptogen researcher Panossian and medical botanist and herbalist Robyn Klein, adaptogens tend to have the following consitituents:

Triterpenes (mevalonate pathway)
 * Triterpenoid saponins:      dammarane triterpene saponins, cucurbitacins
 * Phytosterols:     beta-sitosterol
 * Phytoecdysteroids:      20-ecdysone, turkesterone

Phenylpropanes (shikimate pathway)
 * Flavonoids:     glucopyranosides, prenylated flavonoids, flavan glycosides
 * Lignans:    schizandrin, sesamin, syringaresinol

Oxylipins (acetate pathway)
 * Hydroxylated fatty acids:     octadecadienoic acid

Triterpenoid saponins have been the focus of most studies of adaptogen constituents. Saponins include ginsenoside from Panax ginseng, gypenosides from Gynostemma and eleutherosides from Eleutherococcus. The lipophilic properties of ginsenosides, for instance, favor binding to intracellular steroid hormone receptors. Triterpenes also include phytosterols and phytoecdysteroids, both of which are thought to have adaptogenic roles in mammals. Phytosterols have been studied more in food science than phytotherapy but are known to have immune function. Phytoecdysteroids are in common use by athletes and weight lifters for the anabolic effects they produce. Rhaponticum carthamoides is notable for these compounds. Oxylipins are fatty acids that have been oxidized and display prostaglandin-like activity due to a shape similar to leukotrienes. Examples are the hydroxylated fatty acids in licorice, Glycyrrhiza glabra.