| ||Herbal Medicine: Herbal Therapy & the Adrenal Glands||
Alternative medicine abounds in ideas about and remedies for the adrenal glands. Unfortunately they are often just an expression of a fundamental lack of knowledge about the adrenals. The ideas couched in these terms are often valid and helpful, but invoking some adrenal tonic' effect must be based upon actual physiology and not pseudo-science.
The two adrenals sit astride each kidney, deep in the back part of the abdomen. However, it is vital to recognize that each of these glands has two parts, a cortex or outer part, and a medulla or central portion. These have markedly different functions. When therapy is directed towards these glands, it must be appropriate to the adrenal function the practitioner wants to address.
The adrenal medulla secretes the hormones adrenaline (epinephrine) and noradrenaline (norepinephrine), responsible for the rapid increases in nervous system and metabolic activity involved in the stress response. Summarizing the effects of these two hormones
- Acts on [alpha] and [beta] receptors.
- Increases contractility & excitability of heart muscle, thus increasing cardiac output.
- Facilitates blood flow to muscles, brain, and viscera.
- Enhances blood sugar levels by stimulating conversion of glycogen to glucose in liver.
- Inhibits smooth muscle contraction.
- Acts primarily on [alpha] receptors.
- Increases peripheral vascular resistance, leading to increased blood pressure.
For a discussion of the contribution that can made by herbs in support of the adrenal medulla when under stress, please refer to the section on Stress and the General Adaptation Syndrome. Adaptogens are the core of this support, with saponins such as the eleuthero sides directly impacting the medulla. Nervine tonic support of some kind is usually indicated as well, although this does not directly impact the medulla. The contribution from such nervines is a more generalized systemic support that eases the impact of tension and anxiety. Bitter tonics can be helpful as well. Examples might include
Adaptogens: Panax spp.(Ginseng ), Eleutherococcus senticosus (Siberian Ginseng)
Nervine Tonics: Scutellaria later if olia (Scullcap), Hypericum perforatum (St. John's Wort), Avena sativa (Oats)
The cortex is responsible for production of glucocorticoids, such as cortisol, which have a regulatory effects on metabolism, the immune system, certain aspects of behavior, and many other processes. The cortex also secretes aldosterone, fundamental to the homeostatic control of sodium and potassium secretion by the kidney. These hormones are synthesized from cholesterol.
Glucocorticoids (cortisone and hydrocortisone)
- Enhance protein catabolism and inhibit protein synthesis.
- Antagonize action of insulin.
- Increase synthesis of glucose by liver.
- Influence defense mechanism of body and its reaction to stress.
- Influence emotions.
Mineralocorticoids (aldosterone, desoxycorticosterone)
- Regulate re-absorption of sodium cation.
- Regulate excretion of potassium cation by renal tubules.
Adrenosterones (adrenal androgens)
Herbal medicines can impact the adrenal cortex in a variety of ways. Most important is the direct effect of plants rich in a specific variety of saponin such as Glycyrrhiza glabra (Liquorice). Borage (Borago offici nalis),
Whilst the cortex and medulla produce different hormones in response to differing stimuli, they share a complex role in some situations, for example the stress response. As has been described in the section on stress, the immediate response is controlled mainly, though not completely, by the adrenal gland's central medulla, while long-term response is handled by the surrounding cortex. The initial response-preparing the body for what has been called the fight-or-flight reaction-involves:
1. Increased nervous-system activity.
2. Release of adrenaline and/or noradrenalin into the blood stream by the adrenal medulla. These hormones support the nervous system through metabolic activity. The body's response to these chemicals includes:
If the stressful situation is very intense or continues over a period of time, the adrenal cortex becomes increasingly involved in the stress reaction. The activity of the cortex is largely controlled by blood levels of adrenocorticotrophichormone (ACTH), which is released by the anterior pituitary gland. When information about sustained stress has been processed by the central nervous system, a whole range of new bodily responses occurs, and it is these longer-term reactions that can adversely affect the quality of life.
- increase in heart rate and blood pressure.
- surface constriction of blood vessels, so that the blood leaves the skin to provide the muscles with more sugar and oxygen (which is why we go white with shock).
- mobilization of the liver's energy reserves through the release of stored glucose.
|Whilst working in conservation and lecturing in ecology and the eco-crisis for the University of Wales, David Hoffman became convinced that to heal the world, to embrace planetary wholeness and responsibility for it......more