Preventive medicine can be called the counterpart for treatment medicine, when dividing medical science into three parts such as fundamental medicine, clinical medicine and preventive medicine. Mainly focusing on prevention of disease, preventive medicine belongs to hygienics in western medicine. It is a field of medical science with very wide ranges that covers from prevention, early treatment to rehabilitation. At prevention stage before incidence of disease, what contemporary medicine mostly emphasizes is the strengthening of human body immunocompetence.
Immunity is the phenomenon that human body environment defenses against antigen from outside. In western medical respect, it is a process of immune system – WBC (macrophagocyte, lymphocyte), killer T cell, and so on – resists pathogenic organism.
Concept of immunity has also existed in Korean medicine in name of healthy qi(正氣) that maintains the balance of yin, yang, qi, and blood against external stimulus. Healthy qi, which is core concept in Korean medicine pathogenic theory, protects our body from external pathogen(邪氣). Pathogen, a relative concept from healthy qi, is similar to agent that causes disease when it penetrates into body.
Korean medicine considers the process of immunity as struggle between healthy qi in our body and external pathogen. Therefore if our healthy qi is strong enough, our body will be well-protected, but if not, it will become vulnerable. As a method of preventing disease, Korean medicine emphasizes life-nurturings, among which raising healthy qi to ward off pathogen is considered the most important one.
Immune process by healthy qi and defense qi
Healthy qi is the energy that protects body from pathogen. It is similar to level of immunity. We can call the state when body loses healthy qi and becomes weak 'Huh', which means deficiency. There are various states of Huh; qi deficiency, blood deficiency, yin deficiency, yang deficiency and so on.
If we loses healthy qi, we get easily infected. Defense qi circulating the body surface shows how healthy qi affects body. Defense qi is a sort of healthy qi that blocks external pathogen invasion into body. Defense qi is circulated through skin and flesh, and it protests against external pathogen. Defense qi flowing on skin prevents pathogen from getting into body and if pathogen comes into the body, defense qi sieges and blocks it. It is called 'struggle between the healthy qi and pathogenic qi', which is when pathogen is blocked by defense qi outside the body and fight with healthy qi inside body. This process can be compared with mononuclear phagocyte or macrophage process. It is like present immunity process.
≪Huangdi's Internal Classic(黃帝內徑)≫ which is one of Traditional Chinese Medicine classic books explains that heat or crassi can be made during this process. If healthy qi is defeated by pathogen, tumor, stomachache or headache appear and illness occurs.
Medicinal for strengthening the body
Generally speaking, traditional medicinal for strengthening one’s body system is called ‘tonifying and replenishing medicinal.’ The preventive meaning of this kind of medicinal is not restricted in the sense of protecting the body and filling up on healthy qi. Healthy qi indeed acts as a preventive system by holding up against external pathogen, but simultaneously fights off the external pathogen that already invaded the body. Thus tonifying medicinal can be prescribed before the occurrence of disease to help prevent it by replenishing the healthy qi, or after the outbreak to supplement the deficient state of the body and encourage the healthy qi to fight pathogens.
Tonifying and replenishing medicinal can be seen as formulas that acts to tonify yin, tonify yang, tonify qi, or tonify blood. Each type of tonifying medicinal is applied to pathological deficiency of body’s yin, yang, qi, and blood. Qi deficiency is a general term for decreased visceral and overall body function, and is often seen on patients with leucopenia, bronchial asthma, myasthenia gravis, and some types of rashes. Blood deficiency is the state in which blood flow motility is weak, and is related to symptoms such as anemia and hives. Yin deficiency is an expression for the lack of fluid, and is often matched with dryness of skin, tidal fever, and chronic rheumatism. Yang deficiency mostly refers to the insufficiency of kidney yang, and is often seen on allergic rhinitis, and chronic nephritis patients.
When one’s level of immunity is weak or hyperactive, one’s immune system is more or less malfunctioning. This not only leads the body to be easily effected to diseases, but also may trigger symptoms from self tissue damage. Many of these disease patterns correspond to deficiency symptoms from Trditional Korean medicine. So if tonifying medicinal is appropriately applied to immune system under-function, the medicinal will help treat the symptoms by immune regulatory effect.
In Oriental Medicine, the word ‘Immunity’ was first shown in an 18th century medical book in which the word means restraint from injuries caused by disease. Broadly speaking, if immunity is considered as a prevention and treatment of all the diseases, its concept originates from ≪Huangdi's Internal Classic(黃帝內徑)≫. In
Because Yang(陽) means protecting the body, the meaning of Yang-tonics accords with the concept of Immunology. The action of Yang qi is needed for the circulation of blood, fluid and humor(津液) and the formation and distribution of essence flavors(正味) of five grains(五穀). The evaporation of Yang Qi is needed for mental activity and function of intestinal organs. Thus, it is thought that Yang-tonifying medicinals have an effect on increasing the level of immunity in human organisms, and they have recently been applied to many diseases.
Most of Yang-tonifying Medicinals are assigned to the kidey meridian, acting as Kidney-tonifying medicine. As an innate source, the Kidney(腎) is the base of the body's defensive power. That is, a resistance against the intrusion of exopathogens can be connected to immunology's act of defending infection. Also, the Kidney was recognized as a bone marrow producing organ, which is related to the hematogenous functions of bone-marrow and the production of immune cells.
Interestingly, many herbal medicines tonifying the kidney are known to increase immune cells. This action reinforces the function of the pituitary gland-interrenal system and strengthens the immune function.
Yang-tonifying Herbs includes Epimedii Herba, Cuscutae Semen, Cistanches Herba, Psoraleae Fructus, Cynomorii Herba, Cortex Cinnamomi, Morinda officinalis, etc.
Cervus Nippon and Psoralia Corylifolia have clinical effects on leukopenia treatment. Also, Cuscufa Chinensis, Psoralia Corylifolia and Epimedium Brevicornum activate the phagocytosis of macrophagocyte and the conversion of T cells to relieve symptoms.
Because the spleen is an acquired source and an origin of vitality, most Qi-tonifying Herbs effect the spleen-stomach meridian. In immunity, several studies showed the spleen to be a basis of acquired constitution(後天的 體質). In Oriental Medicine, severely non-nutritious patients are diagnosised with a spleen deficiency. Their number of immunity and antibody cells are decreased and the whole immune system often shows to be lowered. Also, a patient with a spleen deficiency(脾虛) can easily get infection in the intestine or skin tissue. From this point of view, we can see that the spleen has an important effect in sustaining the body's immune system. It appeared that most of the components of Qi-tonifying medicinals have adjusted immune function.
Qi-tonifying medicines commonly contain polysaccharides a lot and it's considered that through their action, B cells and T cells can be activated, the secretion of cytokine can be increased, the capacity of macrophage can be enhanced and the productions of antibodies can be increased by them as to tonify the immunocompetence. Qi-tonifying medicines have boosting effects on lung and stomach as to strengthen our immune system. The most typical medicines contain Ginseng Radix, Pilose Asia-bell, Astragali Radix, Astractylodes Rhizoma alba and Dioscoreae Rhizoma. Especially, Water-extracted Ginseng Radix is regarded as having preventive effects on influenza and boosting our body's immune system as to enhance the effect of the vaccine against influenza.
Treatment of the disorder of the immune system.
It's hard to prevent our body from flu as the virus type is infinite and their infection process could be variable. Therefore, it's necessary to boost and maintain our immunocompetence to prevent it. 'Flu' is considered as 'Cold' in the West, similar to the fact that it is considered as 'Cold Pathogen' in the East. We can assume that flu has been considered in relation to the temperature. Epidemiological research reports that In temperate climate regions, the breaking out of flu increases in autumn and get to the highest point in winter and decreases in the spring. In tropical regions, however, it breaks out mostly at rainy season in the low temperature.
The most common virus causing cold is rhinovirus. As rhino means the nose, it is associated with runny nose which is a common symptom of cold. But this virus is very sensitive to the temperature as it can grow best when the body temperature is lower than 33 degrees celsius and the higher the temperature gets, the lower the growth of the virus. If the temperature is at 39 degrees, the growth rate is 400 times less than when it's at 33 degrees. As the result of experiments on animals, it seems that viruses causing influenza also spreads better at the lower temperature condition. In conclusion, Herbal medicines can enhance our immunocompetence for flu as they generally help the metabolism in our body as to have positive effects on the regulation of the body temperature.
In TKM, the flu is considered as 'affection by cold' or 'invasion of wind' and it's regarded that we get cold because the defensive energy called 'Defense qi' cannot protect the interstices tightly so that pathogenic wind invade in weakened part. Therefore, we have to boost the defensive energy and tighten the interstices to prevent the invasion of pathogenic energy and prevent our body from cold. Prescriptions containing medicines that tonifies lung-qi is commonly used because lung qi produces defense qi. Medicines like Okbyeongpungsan(玉屏風散) which mainly contains milk vetch root(黃芪) are commonly used. Dropping the solution of milk vetch root on the nose is considered as a good method for preventing cold. Milk vetch root increases the concentration of SlgA and lgG in mucous membranes of the surface of the nose and neutralizes the phagocytic activities of phagocytic cells. By the fact that the values of the SlgA and lgG in the serum have increased, these herbal medicines are proven to have the boosting effects on the immunocompetence.
2. Glomerular nephritis
Most cases of nephritis are caused by antigen substances in blood combining with specific antibody to form antigen-antibody compound. When this compound is excreted through glomerulus, it files up on basement membrane, activates alexin, and cause inflammatory response. Traditional Korean medicinals used in the early stages of nephritis are ‘heat-clearing and detoxicating medicinal’(淸熱解毒藥), and ‘wind-dispelling and dampness-draining medicinal’(擧風利濕藥), which restrain immune responses. By pattern identification in TKM, chronic nephritis can be traced back to malfunction of kidney-yin and kidney-yang. Based on this diagnosis, treatment should focus on tonifying kidney-yin and kidney yang to regulate immune system, and also control overactive immune response by ‘blood-activating and stasis-resolving medicinal’(活血化瘀藥) and are ‘heat-clearing and detoxicating medicinal’(淸熱解毒藥). Particularly, Tripterygium regelii Sprague, which is a medicinal material traditionally used to treat kidney related disorders, is known to have anti-inflammatory, pain-relieving, and fever-reducing effects, thus suppressing B-cell actions and inducing T-cell to repress immune responses.
Hyperthyroidism is often linked with mental predispositions which are generally expressed in terms such as ‘liver qi depression’(肝氣鬱滯), or ‘yin deficiency with yang hyperactivity’(陰虛陽亢). This pattern identification correspond to the modern diagnosis hat stress may cause hyperthyroidism. LATS, which is found among the blood serum of hyperthyroid patients, is a kind of immunoglobulin and is affiliated with IgG type antibody. Hyperthyroidism is often linked with mental predispositions which are generally expressed in terms such as ‘liver qi depression’(肝氣鬱滯), or ‘yin deficiency with yang hyperactivity’(陰虛陽亢). This pattern identification correspond to the modern diagnosis hat stress may cause hyperthyroidism. LATS, which is found among the blood serum of hyperthyroid patients, is a kind of immunoglobulin and is affiliated with IgG type antibody. Patients that are sorted into ‘yin deficiency with yang hyperactivity pattern’ are also often found with increased IgG/blood serum figure.
Clinically used medicinal are targeted to ‘enrich yin and tonify qi’(養陰益氣), ‘harmonize the stomach and liver’(和胃平肝), ‘dispel phlegm and resolve dampness’(祛痰化濕). Medicinal materials on such formula are Astragalus membranaceus, Codonopsis pilosula Nannfeldt, Angelica gigas Nakai, Paeonia lactiflora, and Leonurus sibiricus L. Especially in an experiment where hyperthyroidism-induced white mice were given the ‘enrich yin and tonify qi’ medicine ‘甲亢復方’(material: Astragalus membranaceus, Paeonia lactiflora, Leonurus sibiricus L, Coptis chinensis, Rehmannia glutinosa, Cyperus rotundus, tortoise shell), their increased blood serum cAMP content was reduced. Also, liver tissue oxygen level and water drinking amount were decreased, and abnormal changes in adrenal cortex functions were regulated. Also in studies with human subjects, patients with hyperthyroidism showed high level of cAMP in blood serum and low cGMP level. This shows that by regulating disorders in cAMP/cGMP system in hyperthyroid patients, immune malfunction can be prevented.