Before reviewing relevant medicinal herbs, it seems useful to take a quick look at how the immune system functions. There are basically two parts to our immune system: the innate (nonspecific) and the adaptive (specific) immune responses.
The innate immune response
The innate (nonspecific) part of immune system recognizes the difference between “self” and “non-self.” It includes entire organs and certain white blood cells:
* Skin prevents entry of microbes
* Mucous traps microbes and dust particles that enter the respiratory tract
* Cilia line the respiratory tract, continuously sweeping mucous and trapped debris away from the lungs and out through the mouth and nose
* Reflexive actions such as coughing and sneezing expel invaders
* Chemical barriers, such as stomach acid in the stomach or lysozyme in tears, create hostile environments or contain antibacterial enzymes lethal to many invaders.
* Fever reduces iron in the blood, slowing and stopping reproduction of bacteria and fungi, and also stimulates phagocytes
* Inflammation prevents local infection from spreading, increases the local temperature to stimulate phagocytes, and attracts white cells to the site of infection
* Lymphocytes release interferon, peptides that bind to uninfected cells and stimulate them to produce proteins that will block many viruses from reproducing
* A chemical compound circulating in the blood and lymph system called properdin stimulates a group of proteins called “complement,” which work together to make pathogens more susceptible to phagocytosis, attract phagocytic cells, chemically burn through pathogen cell membranes, change the molecular structure of viruses, and produces other effects to help stop infections.
* Phagocytes called macrophages engulf and “digest” microbes, parasites, and other invaders
* While digesting an invader, macrophages (and other immune system cells) save a piece of the invader’s cell surface (with antigen) to present to T-lymphocytes so they can “learn” to recognize that invader. Which brings us to the adaptive immune system.
The adaptive (specific) immune response
The adaptive (specific) part of the immune system provides resistance to specific pathogens that it recognizes and remembers from prior exposure. T- and B-lymphocytes each carry a particular antigen-receptor cell. They are then able to recognize and respond to specific pathogens that carry that antigen.
T-lymphocytes recognize and attach to the surfaces of foreign cells and interact directly with them. They also produce:
* Cytokines (interferon, interleukins, etc.) that enhance cellular response to antigens, activate more t cells, and stimulate the product of b-lymphocytes
* Toxins that kill foreign cells
* Memory t-cells don’t respond to initial invasions. Instead, on subsequent exposures to the pathogen, they immediately divide into cytotoxic t-cells that attack the pathogen. Memory t-cells may live for years.
B-lymphocytes produce antibodies (Immunoglobulins or IgGs) that recognize specific antigens.
* Often they bind to the pathogens’ antigen and cause pathogen cells to clump together, making it easier for phagocytes to recognize and engulf them.
* They may also bind to toxic portions of a pathogen’s cell surface and neutralize the cell.
* IgG-G and IgG-M also activate the set of proteins called “complement”
* B-lymphocyte memory cells may live for years.
Please note that I am not a medical professional and this article is for informational purposes only. This is not intended to substitute for medical advice. Many medicinal herbs can be toxic in specific circumstances and can interact with prescribed pharmaceuticals. Therefore, before taking herbs for medicinal purposes, please consult with your doctor if you are already on prescription drugs, if you are pregnant, or if you develop symptoms of the flu or some other ailment.
Reference:
David Shier, Jackie Butler, Ricki Lewis. Hole’s Essentials of Human Anatomy and Physiology. New York, NY. 2006. McGraw-Hill Higher Education.
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