Using Properties and Flavors in Chinese Herbal Medicine

Properties of each herb refer to its temperature characteristics. They are cold, hot, warm, cool, and neutral. These properties are derived from observing the therapeutic effects of a medical substance. For example, a hot disease must be cooled by substances of a cold or cool property. Cold diseases must be warmed with substances with a hot or warm property. A substance with a cold property is different from one with a cool property only in degree, and so is the substance with a warm property and with a hot property. The cold and cool substances may have the function of clearing Heat, purging Fire, removing toxicity or nourishing Yin. They are used for Heat syndromes. The hot and warm substances may have the function of dispersing Cold syndromes, warming the interior or supporting Yang. Substances with a neutral property, neither hot nor cold in property, are used for either hot or cold syndromes.

FIVE FLAVORS

Five flavors refers to sour, bitter, sweet, pungent, and salty flavors of the herbs. Some substances may have a sixth, bland, flavor as well. Different flavors represent different functions. Substances with the same flavor may have similar functions. Functions of the substances represented by the five flavors are briefly summarized as follows.

Sour Substances of sour flavor have the function of astringing and arresting discharge. Most of them are used to treat deficiency syndromes or diarrhea. For example, Fructus Schisandrae (Wu Wei Zi) has the function of stopping seminal emission and sweating. Galla Chinensis (Wu Bei Zi) acts as an astringent in the intestine to stop diarrhea. Most sour substances may taste astringent as well. The function of the astringent flavor is somewhat similar to that of sour flavor. Thus, the astringent flavor is usually not considered as a separate entity in substance flavors.

Bitter Substances of bitter flavor have draining and drying functions. They are used for clearing Heat, purging Fire, treating constipation, resolving dampness, or lowering the rebelling Qi. Some bitter substances have the function of preserving Yin. For example, Rhizoma Anemarrhenae (Zhi Mu) and Cortex Phellodendri (Huang Bai) are used to treat atrophy syndromes due to Kidney Yin Deficiency.

Sweet Most of the substances of sweet flavor are tonics or herbs with the function of regulating middle Jiao (Heater) or relieving spasms. They are commonly used to treat deficiency symptoms [such as treating Qi deficiency with Radix Codonopsis (Dang Shen) and Yin deficiency with Radix Rehmanniae Preparata (Shu Di Huang )]; or to coordinate the function of other substances, such as Radix Glycyrrhizae (Gan Cao). Most substances with sweet flavor are good at removing moisture.

Pungent Substances of pungent flavor have the function of dispersing, and promoting Qi and Blood circulation. These substances, such as Herba Ephedrae (Ma Huang) and Herba Menthae (Bo He), are commonly used to treat exterior symptoms. Others such as Flos Carthami (Hong Hua) and Radix Aucklandiae (Mu Xiang) are used to treat symptoms due to Qi and Blood Stagnation.

Salty Substances of salty flavor have functions of softening hardness and soothing sore throats and relieving constipation by purging. Most of them are used to treat scrofula, hard masses, and constipation, such as Concha Arcae (Wu Leng Zi) and Natrii Sulfas (Mang Xiao).

Bland Substances with bland flavor function as diuretics and help to eliminate dampness. These herbs, such as Polyporus (Zhu Ling ) and Poria (Fu Ling), are used to treat edema and difficult urination.

In Chinese herbal theory, the property and flavor are integrative concepts. They work together to define the function of each herb. Clinically, however, flavor alone is not sufficient to represent the function of the herb. For example, both Rhizoma Coptidis (Huang Lian) and Radix Rehmanniae (Sheng Di Huang) are cold in property, but Rhizoma Coptidis (Huang Lian) is bitter and used for Damp-Heat syndromes while Radix Rehmanniae (Sheng Di Huang) is sweet and used for Yin Deficiency. Both Herba Ephedrae (Ma Huang) and Herba Menthae (Bo He) have the pungent flavor, but Herba Ephedrae (Ma Huang) is warm in property and used for dispersing Wind-Cold while Herba Menthae (Bo He) is cold in property and used for dispersing Wind-Heat.

Bibliography:

-Pharmacology and Application of Chinese Herbal Medicines (Zhong Yao Yao Li Yu Ying Yong) Yu Sheng Wang, et al. Beijing: People's Hygiene Publishing House, 1983.

-The Use of Chinese Herbal Combinations (Zhong Yao De Pei Wu Yun Yong) Guang Di Ding. Beijing: People's Medical Publishing House, 1982.