Equipos de aireación

The origin and development of Chinese traditional medicine (CTM), attributed to Shen Lon, is based on the knowledge and experience gained over generations to ensure health and treat disease. It has a history spanning more than 2000 years. Similarly, in ancient Europe, materia medica have also been employed for centuries. The use of medicinal herbs is mentioned in ancient Egyptian medical papyri that were discovered by Ebers in 1862 and translated into English by Ebbell in 1937. More than 800 prescriptions in Eber's Papyrus emphasize that medicines were originally foods. Thus, different civilizations discovered the medicinal properties of some food substances in the same way. Herbal medicine usage in the 16th century increased with the introduction of novel Eastern remedies, such as nutmeg from the East Indies, purgative rhubarb from India, and camphor from Japan (Cheng, 2000;

Chan, 2005).

The Chinese still believe in the benefits of CTM, and herbal medications remain popular among Chinese societies around the world. One of the main reasons may be the relatively high incidence of side effects associated with Western medicine. This may be why it is used as a last resort, when Western medicine is too toxic or unable to provide the expected benefit.

CTM emphasizes the integrity of the human body and its relationship with the environment. The yin-yang theory and the five-element theory use ancient cosmology to explain nature, materialism, and dialectics in China. The five-element or phase theory named Wun Shing in Chinese, means "five matters." As shown in Table 5.1, the five-element theory can be applied to a wide range of aspects of humans and the environment, including organs and emotions. The colors in the five-element theory can be applied to symptoms when making a diagnosis. By this theory herbs were also classified depending on taste and sometimes colors. For example, a herb with a black color or salty taste would be assumed to affect the function of the kidney because it is classified under the same group of elements (see Table 5.1).

Similarly, a herb with a red color or bitter taste would be associated with the function of the heart.

Significant CTM theories include those developed by Zhang-Fu (regarding the pathophysiology of disease), Bian-Zheng (diagnosis), and Lun-Zhi (treatment). Herbal medication has been refined by skilled practitioners over the centuries, and one of its famous experts was Chang Chon- Zhing, who practiced during the Jin and Yuan dynasties (1271-1368).

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According to experts, several prescriptions were recorded in the ancient CTM books. Therapeutic principles were divided into eight categories, which included the diaphoretic method (Han Fah),

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the emetic method (Tu Fah), the purgative method (Xia Fah), the regulatory method (Tee Fah), the warming method (Wen Fah), the heat-purging method (ChingFah), the resolving method (Xiao Fah), and the tonic method (Bu Fah). Except for the emetic method, the other methods were widely used in CTM clinical practice. Sometimes two or more methods were employed together to achieve the desired results. Methods were applied flexibly, depending on individual cases (Cheng, 2000;

Chan, 2005).

The prescription of herbs, named Fang-Chi in Chinese, may comprise either one or many herbs. The prescription is sometimes named depending on the number of herbs used, such as "7- component prescription" (Chi-Fang) and "10-component prescription" (Shi-Jie). The "large" prescriptions refer to the use of several herbs to treat diseases due to virulent pathogens. However, experts in CTM can modify ancient prescriptions by the addition or deletion of herbs or modification of doses depending on the individual's disease. This is called Zhia-Gean Fang. In practice, the CTM experts revise classic prescriptions depending on the symptoms of the patients. Also, differences in the active principles of herbs owing to variation in season or location are also considered.

Herbs contained in the prescription are classified according to four properties depending on their presumed pharmacological activity. The major herb is termed the "chief' or the king (Zhing) in the prescription. Secondary herbs are called "adjuvants" or "ministers," named Chen in Chinese. Minor herbs are known as "assistants" and named Zhou, and additive herbs or "guiders" are called Shi. Most CTM prescriptions contain these four components. However, each property may not be represented by only one herb. In some cases, two or more herbs may function as the major component or Zhing.

Furthermore, in the "small" prescription or monoprescription, one herb may be both Zhing and Chen or even more components. Also, a herb may be Chen in one prescription but Shi in another. The properties of herbs are therefore relative but not absolute, and this is an important trait of CTM. This principle could be explained by the drug interactions in the use of herbs (Cheng, 2000; Chan, 2005).

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Classification of herbs in CTM is different from the modern pharmacological method. Based on their physical properties, either color or taste, each herb can be linked with the theory of five elements (Table 5.2), named Woo-Wei in Chinese. Also, the properties of herbs can be classified according to the four-chi principle (Su-Chi in Chinese). Four-chi refers to the four properties of

TABLE 5.2

Pharmacological Classification of Chinese Herbs Herbs for relieving exterior syndrome Herbs for eliminating heat Herbs for purgation (cathartics) Herbs for eliminating wind dampness Herbs for dispelling dampness Diuretics

TABLE 5.1

Five-Element Theory in Chinese Traditional Medicine

Indicator 1 2 3 4 5

Taste Sour Bitter Sweet Pungent Salty

Color Blue (dark) Red Yellow White Black

Evils Wind Heat Damp Dry Cold

Organs Liver Heart Spleen Lung Kidney

Emotions Anger J°y Worry Grief Fear

Senses Eyes Tongue Mouth Nose Ear

Expressions Shouting Laughing Singing Wailing Groaning

Orientations East South Middle West North

Elements Wood Fire Earth Gold Water

Note: Each element has a correlative connection. For example, impaired function of the liver may produce problems in the eyes;

excessive joy is harmful to the "heart," which includes the functions of the brain; and black, herbs would be likely to affect the function of the kidney.

5 4 Pharmacodynamic Basis of Herbal M edic ine

Herbs for activating blood circulation and removing blood stasis Expectorants, antitussives, and dyspnea-relieving herbs Sedatives Herbs for soothing the liver and suppressing wind

Herbs for promoting resuscitation Tonics

Astringents

Note: Limited toxicological data are available on medicinal plants.

However, there exists a considerable overlap between those herbs used for medicinal purposes and those used for cosmetic or culinary purposes, for which a significant body of information exists. There is no reason to doubt the safety of culinary herbs used in herbal remedies, providing the intended dose and route of administration are consistent with their food use. When intended for use in larger therapeutic doses, the safety of culinary herbs requires reevaluation.

herbs: cold, hot, warm, and cool. Depending on the yin-yang theory, a herb with a cold property is suitable to treat a "hot" symptom. For example, the herb Rhizoma zingiberis belongs to the "hot" group and is therefore used in the treatment of diarrhea, which is considered a "cold" disorder.

Two other principles used in CTM are more difficult to understand and reconcile with the practice of modern Western medicine. These are the attributive meridians (Qui Jing) and the direction of the herb's action. The direction of a herb is considered important in its application. Ascending (sheng), descending (jiang), floating (fu), and sinking (chen) are terms used to indicate the directions of herbs and aid practitioners in deciding the best way to combat pathogenic factors. Herbs having a descending property are appropriate to treat vomiting and hiccups that are caused by the "abnormal ascent of the stomach." Floating herbs can disperse pathogenic factors to treat disorders on the surface of the human body. The direction of herbs corresponds to the four-chi (Su- Chi) and the five-element (Woo-Wei) theories. Herbs combining acrid and sweet tastes and warm and hot properties are usually ascending and floating in action. Similarly, herbs that taste bitter, sour, and have cool and cold properties are mostly sinking and descending in action. The flowers and leaves of plants and the herbs that are light in weight are mostly ascending and floating, whereas heavy herbs such as seeds and minerals are mostly sinking and descending in action.

The attributive meridian principle (Qui Jing) relates to the theory of organs and meridians (Zhang-Fu). Meridians are considered to connect the interior and exterior parts of the human body. The most optimum result occurs when the herb meets with the right meridian. This does not necessarily mean that a disorder from a known meridian must be treated by a herb that can only enter this meridian.

In clinical application, herbs are classified into 18 groups, as shown in Table 5.2. Some of these are similar to the therapeutic groups used in Western medicine, such as digestives, anthelmintics, purgatives (cathartics), diuretics, expectorants, and antitussives, which are widely used in herbal medication. However, some groups have no equivalent in the Western system, such as herbs for relieving exterior syndrome, herbs for eliminating heat, herbs for eliminating wind dampness, herbs for dispelling dampness, herbs for warming the interior, and the herbs for regulation of Chi. Hemostatics, dyspnea-relieving herbs, and those used for activating blood circulation and removing blood stasis may have some similarity to Western drugs used to act on the cardiovascular system, but tonics and astringents are applied in a different manner. Although the terms used in the classification may be similar, the main principle is quite different from that of modern pharmacology.

The potential toxicity of herbs has long been emphasized in CTM. Du-Jing is the Chinese term used to denote the harmful effects of herbs. The degree of toxicity is generally defined as "very poisonous"

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and "slightly poisonous" to indicate caution in the handling of certain herbs. It is important that the practitioner obtain a full understanding of CTM, including the compatibility, indications, and contraindications of herbs (Cheng, 2000; Chan, 2005).