A PHARMACIST’S PERSPECTIVE ON THE FUNDAMENTALS OF CHINESE HERBAL MEDICINE
Speaker: Mr. TN Ma B. Pharm. (Hons), Degree of TCM 5th August 2007 Commonwealth Pharmaceutical Association
Conference 2007
Why Herbal Medicine?
Unsatisfactory of the effect of modern medicine e.g.
side effects from NSAIDs; only relieve symptoms. Theory of “Complicated disease can not be treated by a single or few chemical entities”. Herb has polyphytochemicals. Herbal medicine is more compatible and well tolerated. Herbal medicine has tonic & beneficial properties which could nourish our body, strengthen our immune system and detoxify from harmful substances e.g. Ginseng but not the modern medicine.
Examples of Modern Drugs derived from Plants or Nature
Artemisinin Digoxin Morphine Quinine Taxol Vinblastine Vincristine Ephedrine Insulin Anti-malarial Cardiac Glycoside Analgesic Anti-Malarial Anti-Neoplastic Anti-Neoplastic Bronchodilator Hormone Qing Hao (Artemisia annua) Foxglove / Digitals Purpurea Opium Cinchona Rubiaceae Taxus Brevifolia / Yew Vinca Rosea (Catharanthus roseus) Ephedra sinica Yeast
Antibiotics
-
Fungi
Natural vs. Synthetic/ Artificial
All livings are organic and may evolve from
the same ancient i.e. single cell. Herbs are natural. They are organic livings and only produce specific stereoisomers i.e D- or L-enantiomer e.g L-ascorbic acid whereas synthetic chemicals are racemic (before stereo-separation/ enantioconvergent synthesis). Enantiomers have identical chemical and physical properties except the affinity to bind with specific receptor.
Natural vs. Synthetic/ Artificial
Thalidomide is an example of a racemic drug,
in which one enantiomer produces a desirable antiemetic effect, whereas the other is toxic and produces a teratogenic side-effect. Medicines contain single enantiomer: 5 mg levocetirizine (Xyzal) vs.10 mg cetirizine Desloratadine (Aerius) vs. Loratadine(Clarityne) Esomeprazole(Nexium) vs. Omeprazole(Losec) Are we more advance than the natural creature?
Stereochemistry
Structure of Vinblastine Vinblastine has more than 10 chiral carbons.
Chinese Herbal Medicine 中药
Chinese Herbal Medicine is part of the
ancient system of Traditional Chinese Medicine (TCM), which has been practiced more than 5000 years in China. TCM diagnostic techniques determine the cause of ill health and “patterns of disharmony” in the body, and herbs are prescribed to restore harmony to the mind, body and emotions.
Chinese Herbal Medicine
To understand Chinese Herbal Medicine we
need a basic understanding of the concepts and philosophy of Yin and Yang, 5 Elements, Qi or Energy, Properties & Flavours of Herbs, Herbal Processing etc. TCM Uses old fashioned language and expressions such as evil wind penetrating the body (common cold or flu) or fire burning the heart (myocarditis) has never evolved a modern terminology. To have a better understanding is not easy.
Yin and Yang 阴阳
Yin and Yang are the 2 fundamental
principles or forces in the universe. Everything in the natural world contains the 2 opposite components. Yin and Yang not only oppose but also contain each other, without the other, neither can exist. This relationship of coexistence is known as interdependence.
Yin and Yang 阴阳
Yin represents cold, water, moisture, passive,
water retention, low activity, pale complexion, anemia, pale colour tongue, weak pulse, cold hands & feet, aversion to cold, lack of energy, lethargy etc. Yang represents hot, dry, expansive, overactive, flushes, red face, dry skin, red colour tongue, strong & fast pulse, hot & sweaty hands, fond of cold drinks, thirst, hot temper etc
Yin and Yang 阴阳
Ancient Chinese philosophers believed that the human
body is controlled by 2 forces: negative or Yin and positive or Yang. The ideal state of health is when the 2 forces are in a harmonious balance. Many factors can disturb this balance, e.g. changes in weather, food, air and emotional factors. Within certain limits, the body adjusts the relative imbalance of YinYang automatically. When imbalances reach critical levels, illness sets in. In human body, sympathetic nervous system represents Yang while parasympathetic nervous system represents Yin.
Application of Yin Yang Theory
When a person suffers from diabetes, one of
the most obvious symptoms is thirst. Diabetics are usually Yin deficient (water deficient) resulting in excessive Yang manifestations. In the case of diabetes, the saliva and mucus secretion dry up under the influence of Yang forces. Yin herbs are given.
The 5 Elements 五行
The ancient Chinese Philosophers thought
that the relationship of all form of activities, material, abstract objects, weather, colours, tastes and body organs can be symbolized under the 5 elements: Wood, Fire, Earth, Metal and Water. Each of these elements represents a force or Qi which can boost, generate or suppress, subjugate the activities of other elements.
The 5 Elements
Generative Cycle
The cycle proceed as follows: Wood burns to generate Fire; Fire produces ashes which generate Earth; Earth generates Metal; Metal when melted turns into liquid like Water; Water promotes growth of plants whereby generating Wood. The generative cycle may explain the positive feed back mechanism in our body.
The 5 Elements
Subjugating Cycle
The cycle works in the following manner: Wood (trees and grasses) holds the Earth (soil) together; Earth holds Water and keeps it in ponds, lakes and rivers; Water controls Fire by extinguishing it; Fire subjugates Metal by melting it; Metal subjugates Wood by cutting it. Subjugating cycle may explain the negative feed back mechanism in our body.
The 5 Elements
Each of our body’s vital organs is
represented by an element:
Wood represents liver & gall bladder Fire represents heart & small intestine Earth represents spleen & stomach Metal represents lung & large intestine Water represents kidney & urinary bladder
The 5 Elements
Metal
金
Water 水 Generates
Metal
Fire 火
金 Subjugates
Earth 土
生
Fire 火
Wood 木
克
Earth 土 Water 水
From the relationships of 5 elements, a Chinese Doctor is guided
(partly) by these when prescribing herbal remedies or acupuncture treatment.
The Characters & Functions of Chinese Herbal Medicine
Every herbs has its own specific characters.
In TCM, the different characters of herbs are
used to treat diseases, rectify the hyperactivity or hypo-activity of Yin & Yang, and help the body restore its normal physiological functions and thus health.
Properties and Flavours 四气五味
Every herbs and drugs are grouped into The
4 Properties & 5 Flavours. 4 Properties are Cold, Cool, Hot and Warm. Herbs have cold or cool properties belongs to Yin herbs which are used to treat hyperactivity of Yang or deficiency of Yin. Herbs have hot or warm properties belongs to Yang herbs which are used to treat Yang deficiency or hyperactivity of Yin.
Properties and Flavours
This simple classification is always neglected
by lots of practitioner, however it is very important in clinical practice e.g. a patient with dry mouth, heatiness, hot feet and high metabolism is using Ginger to treat her arthritis. What is the outcome? The patient may get more thirsty, heatiness or even fever though ginger has antiinflammatory effect but it has HOT property in nature. Thus it is more suitable for patient with Yin syndrome e.g. cold feet, weak pulse.
Properties and Flavours
Flavour refers to the taste of herbs and the
function of the herbs. 5 Flavours are Sour (& Astringent), Bitter, Sweet, Pungent, Salty. Herbs with different compositions & thus different flavours show different pharmacological actions. The flavours do not necessarily refer to the real tastes of the herbs.
Properties and Flavours
Sour Flavour: has the effects of inducing
astringency & arresting discharge. Uses: sweating, chronic cough, diarrhea, dysmenorrhoea etc. Examples: Black Plum, dried opium, Manja Kani. Modern Medicine: Drugs tend to have antimuscarinic effects e.g. loperamide, codeine, tricyclic antidepresants, antihistamines etc.
Properties and Flavours
Bitter Flavour: has the effects of clearing
heat, purging fire, relaxing the bowels, eliminating dampness etc. Uses: syndromes of pathogenic fire (fever), constipation, damp-heat syndromes. Examples: Gentian, Rhubarb, Hempedu Bumi. Modern medicine: Antibiotics may belong to this group.
Properties and Flavours
Sweet Flavour: has the effects of nourishing,
replenishing, tonifying, harmonizing or relieving spasm & pain. Uses: deficiency syndromes, malnutrition, fatigue. Examples: Ginseng, Liquorice, Honey. Modern medicine: Not known apart from vitamins.
Properties and Flavours
Pungent Flavour: has the effects of
dispersing the intruder from superficial body & promoting the circulation of energy & blood. Uses: Superficial and mild illnesses, running nose, cough, asthma. Examples: Diaphoretics, Ephedra, Peppermint, Chrysanthemum etc. Modern medicine: Ephedrine, Aspirin, Paracetamol.
Properties and Flavours
Salty Flavour: has the effects of softening &
resolving hard mass or relieving constipation. Uses: Goiter, chesty cough, mass in abdomen & dry stool. Examples: Mirabilite (hydrated sodium sulphate), Oyster shell, Seaweed. Modern medicine: magnesium sulphate, (Chitosan), Mucolytics e.g. Ambroxol, Bromhexine.
Channel Tropism 归经
Channel Tropism refers to a herb’s selective
therapeutic effects on a certain part of the body. For instance, among the heat-clearing herbs, some only clear the heat either in the lung channel or in the liver channel, etc. Different herbs acting on the same channel have different effects owing to their different properties, flavours & actions of lifting, lowering, floating and sinking. This concept is quite similar to the modern receptor mechanism: Affinity.
Toxicity
There is a saying: “Herbs have 3 degree of toxic”.
This mentions the carefulness of using herbs is important. The concept is similar that why POM or P medicines are call “Poisons/ Racuns” in Malaysia. Some herbs are marked with “toxic”, “slightly toxic”, “extremely poisonous” or “deadly poisonous”. It is advisable to choose herbs & their proper dosage according to their toxicity, S/E, the patient’s constitution, age, severity of the disease.
Toxicity
However, in certain critical or obstinate
diseases, poisonous herbs are needed e.g. Vinca Rosea is used to treat leukemia. In the conservative policy of Malaysia, herbs with undesirable side effects, toxic or tend to be abused are restricted for registration e.g. Ephedra sinica. There are no POM herbal medicines which can be used only by the herbal practitioner.
Classification of CHM
1. Wind Syndrome Expelling Herbs: i) With warm property ii) With cool property Heat Clearing Herbs: i) Heat clearing & Fire-purging ii) Heat clearing & Dampness-drying iii) Heat clearing & Blood-cooling iv) Heat clearing & Detoxicating v) Heat clearing of Deficiency Diaphoretic Antipyretic Emollient Antipyretic Antiseptic Anti-Microbial
2.
3.
4. 5.
Purgative/ Laxative Herbs
Interior - Warming Herbs Qi-Activating Herbs
Laxatives
Increase Metabolism Antispasmodic Digestant
Classification of CHM
6. 7. 8. 9. Dampness - Dispersing Aromatics Dampness - Excreting Herbs Wind-Dampness Eliminating Herbs Blood - Circulation Activating & Blood Stasis Removing Herbs Hemostatics Cold - Phlegm Warming Herbs Heat - Phlegm Eliminating Herbs Cough and Dyspnea Relieving Herbs Antitussive, Expectorant Antitussive, Expectorant Expectorant, Respiratory Stimulant Antispasmodic Diuretic Antipyretic Antirheumatic Anti-Coagulant
10. 11. 12. 13.
Classification of CHM
14. 15. 16. 17. 18. 19. 20. 21. Liver - Calming Herbs Liver - Calming and Yang Suppressing Herbs Tranquilizers/ Sedatives Analeptics Tonics : Qi Tonic, Yang Tonic, Blood Tonic, Yin Tonic Astringents Digestants Anthelmintics Restorative Stimulant Sedative Sedative
Herbal Processing 炮制
Herbal processing is the process of treating
natural herbs in accordance to the therapeutical, dispensing and pharmaceutical requirements before they are used or further made into various preparations. Processing methods: Primary Processing, Water Processing, Fire Processing, etc.
The Aim of Processing
To facilitate decoction, preparation and preservation. To get rid of impurities, non-medicinal parts and
various bad tastes so as to make drugs clean, pure and easy tp admit. To eliminate or reduce the toxicity, drastic actions and side effects of some herbs. e.g. the toxicity of Dichroa root can be reduced by stir-baking with wine.
The Aim of Processing
To increase the efficacy of herbs e.g.
honey-baked liquorice has a stronger tonic effect. To change the character & function of herbs to meet the therapeutic needs e.g. Rhubarb has strong purgative powder, but this power becomes mild after cooked, and if carbonized, it almost has no purgative effect but is good for stopping bleeding.
Herbal Prescription
Through many years of research,
researcher and health care practitioner concluded that a combination of herbal medicines give a tremendous effect in the treatment of diseases.
1 herb + 1 herb ≠ 2 (Efficacy)
Composition of Herbal Prescription
Monarch 君
- to treat the main disease / symptoms Minister 臣 i) to support the Monarch or sometime its give a synergy effect with Monarch ii) to treat the secondary symptoms /complaints Adjuvant 佐 i) to support the Minister and also Monarch ii) to reduce the side effect of Monarch and Minister or diminish the toxicity of Monarch and Minister Guide 使 i) to direct or guide the drugs to the affected area ii) to harmonize the effect of the above drugs
QI TONIC: SI JUN ZI TANG 四君子汤
The 4 noble ingredients decoction: Monarch: Ginseng 人参 - replenish the primodial qi - tonify the spleen and lung
Minister: Rhizoma Atractylodis macrocephalae 白术 - replenish qi and strengthen the spleen - eliminate dampness and induce diuresis - synergy the tonic effect of Ginseng for the qi
QI TONIC: SI JUN ZI TANG 四君子汤
Adjuvant: Poria 茯苓 - induce diuresis and excrete dampness - invigorate the spleen - Synergy with Minister to enhance the elimination of dampness Guide: Radix Glycyrrhizae 甘草 - harmonize the above drugs Indication: To tonify Qi and strengthen the spleen Treatment: To treat poor appetite, loose stool, abdominal distention, lassitude & asthenia due to deficiency of the spleen-qi and stomach-qi and failure of the spleen in transporting and transforming nutrients
Conclusion
Prescribing pain killer for pain, cough
suppressant for (chesty/dry) cough, antidiarrhoeal for loose stool etc. What do you think? Will this be the right treatment? A responsible doctor will not just provide a R for symptom relieve only. A good doctor must be able to identify the pathology of disease or “explore” the root of the disease. Prescribing, however only a part of TCM; the effective treatment mainly reply on the TCM practitioner’s skill e.g. diagnosis, herbal knowledge, strategy…
Conclusion
Symptom by itself is meaningless; A group of
symptoms reveals the pattern of disease. This makes the diagnosis significant. The system of looking at the symptoms in the context of the whole is why herbs are prescribed for the person, not the illness only. (Holistic Approach) Combination of Chinese Herbal Medicine with modern medicine is the trend. There are a lot of successful cases in China, UK, Australia… Having a TCM department in Malaysia hospitals is the new milestone in the health care system. Hopefully, more people will benefit from the combination of the Orthodox and Holistic treatment.