PROCESSING CHINESE HERBS

Basic Principles And Its Therapeutic Importance

Dr. Michael Tierra L.Ac., O.M.D.

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Ever wonder why the apparent right Chinese formula based on the most careful pattern diagnosis, does not yield the results expected. Perhaps one reason is that the herbs are not properly processed based on traditional indications. Furthermore, many books fail to describe whether an herb in any given formula is intended to be processed or not.

    Processing herbs to alter their properties is an ancient method used in TCM that is actually able to alter or enhance one or a number of specific biochemical constituents.

            The term “Pao chih” refers to herbal processing. One useful book currently published on this topic entitled “Pao Zhi” by Philippe Sionneau is published by Blue Poppy Press. To demonstrate the importance of herbal processing the traditional TCM formula called “Bu Zhong Yi Qi Tang is given with non-prepared and prepared ingredients and shows how the same formula using either prepared or non-prepared ingredients can have dramatically different and even opposing properties. This is often not sufficiently pointed out in herb books and formularies and I am sure it is one of the reasons that occasionally intended effects are not achieved clinically.

    Even many practitioners, in attempt to implement clinical shortcuts, have come to believe that the differences between a processed and unprocessed herb is so slight that it is not necessary. Certainly when we are dealing with potentially lethal herbs this represents a dangerous point of view. 

 

A comparison of both versions as presented in Pao Zhi is presented below as applied to Bu Zhong Yi Qi Tang (Ginseng and Astragalus Combination). This is the primary tonic formula developed by Li Dong Yuan who developed the principle of treatment according to the Spleen Stomach School (see other article on this site). It is also regarded as one of the major spleen tonic formulas this despite the fact that it has two constituents, bupleurum and cimicifuga, that are traditionally used for dispersing stagnant qi and detoxification. By comparing the two versions, the non-prepared and the prepared version we see how by using specially processed ingredients as intended by Li Dong, the formula is significantly different in its action to the same version with non-prepared ingredients.

 

Bu Zhong Yi Qi Tang: Non-prepared ingredients

Uncooked astragalus – secures the exterior (counteracts abnormal perspiration), diuretic, disperses swelling

Uncooked codonopsis supplements qi and engenders fluids.

Uncooked atractylodis secures the exterior, is diuretic, tonifies the spleen and dries dampness

Uncooked licorice clears heat, detoxifies

Uncooked angelica sinensis (Dang Quai) lubricates the intestines (laxative) and frees the stools.

Uncooked citrus (chen pi) dried dampness and transforms phlegm

Uncooked cimicifuga and uncooked bupleurum, resolves the exterior, detoxifies

 

The overall effect of this formula is to antiperspirant, diuretic, laxative, detoxifying, astringent

 

Bu Zhong Yi Qi Tang: Prepared ingredients 

 

Honey-fried astragalus tonifies the center (stomach and spleen) raises the qi

Honey fried codonopsis tonifies spleen and stomach and tonifies qi

Stir fried atractylodis tonifies the spleen, dries dampness and promotes metabolism of food

Mix-fried licorice tonifies the center and harmonizes the stomach

Wine stir fried angelica sinensis (dang quai) tonifies blood, harmonizes the constructive qi

Stir-fried citrus peel regulates qi, aids digestion

Honey mix-fried cimicifuga and stir-fried bupleurum raise the qi

 

The overall effect is to tonify the center (spleen-stomach), tonify qi, and raise qi.

 

It is in the prepared form that the classical indications for Bu Zhong Yi Qi Tang that the indications given in formularies exist but alas, this is not often stated (my apologies because it is not even stated in my writings).

 

There are a few general considerations that are considered. For instance heating any ingredient makes it warmer, adding honey makes it more qi tonifying and phlegm relieving, adding vinegar brings it to the liver, carbonizing helps it to inhibit bleeding, soaking or adding alcohol makes it warmer and more dispersing, adding salt to a formula helps direct it to the kidneys.

 

Examples of carbonizing herbs to stop bleeding are carbonized cattail pollen, carbonized human hair, carbonized agrimony and carbonized wormwood or mugwort.

 

Part of an ingredient tend to emphasize specific properties and actions. For instance dang gui (angelica sinensis) has four parts. 1. The upper portion of the root (dang gui tou) is more blood dispersing and hemostatic especially when it is carbonized. 2. The body or main part of the root (dang gui shen) is more blood nourishing. 3. The secondary roots of the lower extremity (dang qui wei) is often prepared with rice wine and is more blood moving. 4. The smaller rootlets (dang gui xu) is usually prepared in rice wine and is more blood moving especially to the capillaries.

 

In general the leafy and flower parts of a plant are more detoxifying and dispersing while the heavier roots are more tonifying.

 

The objectives of processing are as follows:

1. To diminish toxicity, moderate drastic actions, diminish side effects.

I do not recommend students doing this with raw aconite since if it is not done properly the the original extreme poisonous nature of the herb may be not be neutralized to render it safe enough for use. Generally speaking raw aconite is called wu tou or sheng fu zi and must be carefully used. Prepared fu zi is subjected to salt to begin the process of neutralizing some of its deadly alkaloids (aconitine) to change it to the safer acetyl (more acidic) form called benzoylaconine or aconine. In fact baking or cooking for a long time in pressurized hot water can help to neutralize the toxic aconitum in raw aconite. The final tests have shown that in various samples of prepared aconite (fu zi) the aconine and benzoyl aconine were 1/2000 or 1/250 that of aconitine respectively. Traditionally it is usually prepared first with salt and then cooked with licorice and black beans. Nevertheless since quality of preparation is important to achieve maximum neutralization of aconitine, all aconite when used should be subjected to at least one hour of boiling before adding other herbs to be sure that the poisonous aconitine is sufficiently neutralized. The importance of this cannot be over emphasized as there have been instances of aconite toxicity because patients were not sufficiently advised in how to prepare their aconite formulas.

 

            Another herb that is important to process to neutralize toxicity is pinellia ternata (Ban xia). Unprocessed it is acrid, warm and toxic and is strictly reserved for external use. It softens hard nodules (lymphatic swellings), reduces swelling, stops pain and is useful for a wide variety of external affections including swollen glands, skin inflammations, abscesses, mastitis, goiter, and injuries. Externally it is very safe to use but poisonous when taken internally.

Prepared pinellia, the one customarily used to dry and warm the center, stop vomiting, clear phlegm, lower qi, stop coughing and is only slightly toxic. It is usually prepared by slicing and frying it over a medium flame in ginger juice made from grated and pressed whole ginger root. It is sometimes also prepared with both ginger and alum. Again, as with other potentially serious toxic herbs, students are cautioned to not try this method unless specifically trained by someone experienced in processing methods.

 

Zizyphus seeds are used to calm the spirit and for the treatment of insomnia. The raw seeds however are somewhat more toxic and stimulating than the dry roasted seeds. Both are useful for insomnia but the dry seeds are therefore better.

 

2. Modifying the energetic properties (flavor, nature and action) of and ingredient.

These methods are relatively simple and safe and can be easily performed by a practitioner and student especially because it is not expected to counteract toxic properties. The purpose is to make change the flavor -- which will influence what organs or systems an herb will effect; alter its heating or cooling properties – which influences the basic stimulating, cooling or sedating effect of an herb; or its action – basically whether it is diuretic, laxative, diaphoretic, etc.

For example uncooked ginger is more surface dispersing while dried ginger is more internally warming. Fresh ginger containes a large quantity of gingerol and a small amount of shogaol but no zingerone, while dried ginger contains more shogaol, less gingerol and only a trace amount of zingerone.

Uncooked rehmannia is colder and more detoxifying and has the properties of reducing fever, relieving thirst, promoting fluids. There are many ways of preparing rehmannia but the most common cooked in rice wine. This makes it more of a yin, blood and essence tonic, and kidney yin tonic. The method is to cook the dried root in rice wine steam. This is then dried and traditionally repeated 9 times.

 

Polygonum multiflorum (He shou Wu) is another herb whose action, nature and properties are drastically different dependent upon whether it is used in its unprocessed or processed form.

Uncooked (sheng) he shou wu is not unsimilar to the western yellow dock root to which it is related. It is bitter, sweet, astringent and neutral energy. It lubricates the intestines, is laxative, detoxifying and relieves swollen and inflamed lymph nodes. It is used for constipation caused by dryness, for skin inflammation caused by damp heat (like yellow dock (Rumex cripus) and for scrofula (swollen glands). By cooking it in the steam of black soy beans and yellow rice wine its nature changes to warm and tonic. It is used to tonify the liver and kidneys, and for blood and essence deficiency.

 

Licorice (glycyrrhiza species) also known as “gan zao” is most commonly processed in the clinic according to its use. Unprocessed licorice is sweet, neutral and detoxifying. It is better for heat or inflammatory conditions and to relieve cough. Honey-fried licorice is slightly warm, qi tonifying, calming and pain relieving. It is simply made by dry stir frying licorice root slices with a little honey until the slices are darker yellow. Ideally the amount of honey used is regulated so that the finished processed licorice is only slightly sticky. Researchers have found that licorice contains the antispasmodic constituent, isoliquiritigenen and its glycoside isoliquiritin; the detoxifying and diuretic constituent is glycyrrhizin, glycyrrhizic acid which when boiled in water produces glycyrrhetinic acid and glucuronic acid. The inner portion of the licorice root contains 2.5 times as much glycyrrhizic acid as the external bark bt only half as much isoliquiritigenin as the bark. By removing the bark the content of glycyrrhizic acid is increased in proportion to isoliquiritigenin and eliminates the bitter (detoxifying) ingredient found in the outer bark of the root. Licorice is char-fried to diminish the more detoxifying glycyrrhizin and glycyrrhizic acid while increasing the antispasmodic and probably more tonifying isoliquiritigenin. Stir frying an ingredient with honey is used to increase its sweetness and therefore its spleen and stomach qi tonic effects.

 

3. Reinforcing desired therapeutic effects of an ingredient.

The therapeutic properties of certain ingredients can be augmented through certain methods of preparation. For instance the pain relieving properties of corydalis (Yanhuosuo) is increased when the sliced and dried root is stir fried with rice vinegar (cu chao). This is done in a wok and sprinkling or spraying rice vinegar on the roots as they are dry fried. Similarly the liver qi dispersing effects of bupleurum are increased when it is stir-fried in vinegar (cu chao). Stir frying in vinegar is typically used whenever one wants to direct the properties of an herb more to the liver based on the principle that the sour taste belongs to the liver. 

 

4. Modifying the affected organ systems 

The organ and systems of the body that are affected by an ingredient can be modified or changed based on certain methods of preparation. When both bupleurum and cyperus are dry-fried with rice vinegar their ability to more effectively relieve liver qi stagnation is increased. The direction of influence of rhubarb can be changed from being a down bearing laxative of the unprocessed rhubarb to a more upbearing blood dispersing and upper burner dispersing effects when it is prepared in rice wine (jiu zhi). This is prepared by stir frying slices of dried rhubarb n yellow rice wine using a wok over a low flame until all the alcohol is absorbed and the roots are dry with or with only a slight alcohol odor. This method is typically applied whenever one wants to enhance blood circulating properties in an ingredient. `

 

Cortex Phellodendri (Huang bai) when unprepared is bitter, cold, drying and downbearing. It clears heat, eliminates dampness and resolves toxins. Stir fried with a 2 to 3 percent solution of salt water or by sprinkling salt water on it changes it to direct its heat clearing properties specifically to clear yin deficient heat. The herb, anemarrhenae Zhi mu) with which phellodendron is commonly combined for yin deficiency is similarly prepared with salt.

 

5. Dissipating disagreeable odors and flavors

This involves methods of preparation to assist patients in taking substances and ingredients that have a disagreeable odor or taste. Trogopterorus (wu ling zhi) is treated in vinegar, Bombyx batrycatus (jiang can) is treated with wheat bran, sargassum seaweed is treated in clear water. Any herb added for flavor or the addition of honey or sugar may also be included in this method.

 

6. Facilitating storage, pharmaceutical production and assimilation.

 

The way herbs are sliced or utilized are also considered in preparation. In general roots are sliced with a diagonal cut rather than a lateral cross section. This allows for more of the inner properties of the root to be available for extraction.

Also certain rocks and shells are calcined in order to facilitate their pulverization

 

7. Washing and eliminating foreign, non-medicinal substances

 

The fine hairs of locquat leaves can irritate the throat so these are brushed off. The center of the root of polygalae (yuan zhi) is removed. Sargassum and cistanchis (rou cong rong) are rinsed in clear water to clear their disagreeable odor.

 

The science and art of preparing medicinal ingredients is an involved and distinct branch of traditional Chinese Medicine and the above only constitutes an introduction to make students and practitioners more aware of the importance of this aspect of treatment. Too often we see practitioners and books ignoring this and I’m afraid, by so doing the desired therapeutic effects may be severely compromised. When using dried extracts of Chinese herbs, some of these are available in their unprocessed or processed form while others are not. This certainly makes a case for the use of whole herbs so that the practitioner can process the herbs that are given to the client. It also makes a case for referring patients to trusted Chinese herbal pharmacies to have their prescriptions filled.

 

Bibliography:

Pao Zhi: An introduction to eh Use of Processed Chinese Medicinals by Philippe Sionneau, published in 1995 by blue Poppy Press (303) 447-8372

 

Bulletin of the Oriental Healing Arts institute of the USA, volume 8, No. 5, July 1983 – A study of Chinese Herbal Processing.

 

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Following is a summary overview on the Preparation of Chinese herbs from a highly informative TCM website:  http://www.ontcm.com/index.htm.

What about the Preparation of Herbs

Herbs should be processed before using or making into various forms. Because most Chinese herbs are used unprepared, besides general handling, quite a few should be specifically processed to meet demands for their clinical use. Preparation, a traditional Chinese pharmaceutical technology, was formed in a long history of practice with its complete theoretical system and strict technique.

1. Aims of Preparation
High effects, low toxicity and convenience for use are the main aims of preparing Chinese herbs.

1.1. To enhance curative effects
For example: corydalis tuber can obviously strengthen its analgesic effect by stir-baking with vinegar; ephedra can strengthen the effects of alleviating cough, and relieving asthma by stir-baking with honey; and eucommia bark can strengthen the effects of calming the liver and reducing blood pressure by stir-baking with salt.

1.2. To reduce toxic effects
Some extremely toxic should not be used orally without preparation for reducing their toxicity. For example: defatted powder of croton seed, kansui root and knoxia root boiled with vinegar, Sichuan aconite root and wild aconite root boiled for a long time, and pinellia tuber and arisaema tuber decocted with ginger and alum can all reduce their toxic effects.

1.3. To change properties of herbs and expand their uses
Appropriate preparation can change cold or hot nature and augment effects of herbs. For example, dried rehmannia root, being cold in nature for removing heat from blood to stop bleeding, can be made into prepared rehmannia root for warming and tonifying essence and blood. Prepared arisaema being warm and dry in nature for resolving cold phlegm, expelling wind and alleviating spasm, can he made into biled arisaema with cool and moist nature for removing heat, resoling phlegm, expelling wind and arresting convulsion. Fleece-flower root with its main effects of treating malaria and loosing the bowels can be made into prepared fleece flower root with its special effects of tonifying the liver and kidney and nourishing essence and blood.

In addition, through preparation, herbs become easy to use and store. Also, the abnormal flavor and some un-beneficial ingredients are removed.

2. Methods for Preparation
Methods for preparation of Chinese herbs include purification, preparation with water, preparation with fire and preparation with both water and fire. Methods for preparation of Chinese herbs are closely related to their clinical usage;

2.1. Stir-baking
Herbs are put into a pot over a fire, continually stir-baked to a certain extent and taken out. According to extent of heating, herbs can be stir-baked yellow in color, stir-baked charred or stir-baked carbonized. To be stir-baked yellow or stir-baked charred can moderate herbs' properties or strengthen the effect of invigorating the spleen; and to be stir-baked carbonized can strengthen the effects of stopping bleeding and arresting diarrhea.

2.2. Stir-baking with auxiliary fluid
The common auxiliary fluid includes wine, vinegar, and honey, saline and ginger juice. Herbs stir-baked with auxiliary fluid can strengthen effects, reduce toxicity and remove abnormal flavor. For example: Chinese angelica root stir-baked with wine can strengthen the effects of promoting circulation of blood; corydalis tuber stir-baked with vinegar can strengthen its analgesic effect; and kansui root stir-baked with vinegar can reduce toxicity. In addition, herbs stir-baked with other auxiliary materials including sand and talc powder can make them crispy and en able their active ingredients to be easily decocted out, such as pangolin scales, stir-baked with sand and hedgehog skin stir-baked with talc powder.

2.3. Calcination
Herbs are directly or indirectly calcined over a fierce fire to make them crispy for easily crushing or carbonized. Most of the solid and hard mineral herbs or shells are directly calcined, such as dragon's bone and oyster shell. Carbonize6 palm and carbonized hair are made by means of calcination in a sealed refractory vessel.

2.4. Roasting
Wrapped in moistened paper or flour paste, herbs are heated in smoldering cinder or roasted in a oven until the coating becomes charred in order to remove oil from herbs or to moderate their properties, such as roasted aucklandia root roasted ginger and roasted nutmeg.

2.5. Steaming
Herbs are steamed solely or with auxiliary materials to change their proper ties, strengthen their potency and reduce their toxic effects.

2.6. Boiling
Herbs are boiled in water and auxiliary materials to reduce their toxicity, such as genkwa flower boiled with vinegar, and Sichuan aconite root boiled with bean curd.

2.7. Water-refining
Mineral herbs insoluble in water are crushed, put in a mortar, ground with water into fine powder in suspension, then poured into a vessel for precipitation and dried, such as wet-refined cinnabar then and water-refined talc.

In addition, there are fermentation, germination, frosting and many other methods for preparation, such as medicated leaven, germinated barley and defatted powder of croton seed.

Source: http://tcm.medboo.com/