The history of herbal medicine is rich and fascinating and is, of course, to a large extent the history of medicine itself. For an engaging and comprehensive account readers are referred to Barbara Griggs’s New Green Pharmacy — The Story of Western Herbal Medicine (1997), from where much of the present information has been sourced.
The oldest written reference to medicinal plants and their use is the Chinese Pen Ts’ao, written about 4800 years ago and listing more than 360 species of herbs. Another ancient manuscript, the Ebers Papyrus from Egypt, dates from about 1500 BCE and mentions a large number of plant and animal remedies. It also contains recipes for many specific formulae as well as magical chants.
Hippocrates (c.460-377 BCE) of Greece is often referred to as ‘the father of medicine’. He could equally be regarded as one of the founders of holistic herbal medicine. He prescribed individualised treatments for his patients, recommended exercise and dietary regimens and selected his herbal treatments from more than 400 species of plants. Hippocrates was also an exponent of humoral medicine and viewed disease as an imbalance of the four humours (black bile, blood, yellow bile and phlegm), which were derived from the concept of the four elements: earth, fire, air and water. Accordingly, Hippocratic treatment aimed at restoring the balance of the four humours.
Diodes, a student of Aristotle, wrote the oldest Greek herbal, the Rbizotomika, in the fourth century BCE. It was a Roman army surgeon by the name of Dioscorides (c. 40-80 CE), however, who wrote the most influential early European manual of medicinal plants, De Materia Medica, in the first century CE. This comprehensive work included illustrations and descriptions of about 600 plant species, along with text detailing their uses, doses and potential toxic effects.
Galen (c. 129-199 CE), like Hippocrates, practised humoral medicine but his approach to therapy was rigid, quite unlike the flexible and individualised approach of Hippocrates. Galen introduced a complex herbal classification system based on the humoral properties of each plant. According to this system each plant was assigned a ‘temperament’ (hot, cold, moist, dry or temperate) and a grading (first, second, third or fourth degree). For example, herbs that were deemed to be strongly heating (e.g. ginger and chillies) were said to be ‘hot in the third degree’.
The works of Galen were translated into Arabic and later Latin, and it is an astounding fact that his ideas had a stranglehold on European medical thought for about 1500 years.
One person who challenged Galenic medical authority was the Swiss-German doctor Philippus Theophrastus Bombastus von Hohenheim (1493-1541), better known as Paracelsus. He had a keen interest in alchemy and introduced the use of chemicals and metals such as mercury into medical practice. He is also credited with being the first to search for ‘active principles’ in plants. Despite his seemingly more modern views on some aspects of medicine, Paracelsus still believed in the Doctrine of Signatures, which states that plants carry ‘labels’ (or signatures) which indicate what they can be used for. Although the Doctrine of Signatures has been part of many different cultures, there is clearly no rational biological explanation for this concept, which is consistent only with creationist or supernatural cosmologies where humans are seen as being provided with (labelled) medicinal plants by a creating power. Numerous examples were cited as ‘evidence’ of the Doctrine of Signatures: plants with yellow flowers such as greater celandine (Cbelidonium majus) for jaundice; plants with small tuberous storage roots such as pilewort (Ranunculus ficaria) for haemorrhoids; and plants that appear to carry leaves with fine holes in them (in fact translucent oil storage cells) such as St John’s wort (Hypericum perforatum) for stab wounds. Despite some correlations, this kind of argument does not stand up to scrutiny and is akin to, say, an idea that the first letter of a plant name should indicate what it might be used for — hence cascara for constipation and foxglove for fibrillations.
In England, John Gerard’s famous Herbal or General Historie of Plantes was published in 1597, and in 1649 the apothecary Nicholas Culpeper (1616-54) translated the London Pharmacopoeia from Latin into English, much to the consternation of the medical establishment, who saw this as a threat to their exclusive medical knowledge. Culpeper also wrote several original herbal works, none more famous than The English Physician (1653), in which he presented herbal medicine in an astrological framework.
Across the Adantic Samuel Thomson (1769-1843) also encountered the ire of the medical establishment. Having been successfully treated with herbs as a child, Thomson was appalled by the bloodletting and heroic medicines of the day, which he believed were counterproductive and dangerous. Having no formal medical training, Thomson was self-taught and his simple but effective herbal medicine practice was dismissed by the medical profession as quackery. Thomson’s theory on medicine was simple and vitalistic: he held that all disease was caused by cold (resulting from obstructions to the flow of vital energy) and accordingly treatment should be heating and aim to restore the flow of vital energy. Thomson’s system of medicine was brought to England by Albert Coffin in 1838, where it became established in the north of the country. After Thomson’s death in 1843 his system of medicine developed into what became known as physiomedicalism.
It was not only lay people like Samuel Thomson who were concerned about the horrors of heroic medicine. Dr Wooster Beach (1794-1868) started a movement of American medical doctors that became known as the eclectics. Eclectic medicine included many herbal medicines and promoted treatments that acted ‘in harmony with physiological laws’. Followers of Thomson, physiomedicalists and eclectics alike used European herbs as well as native North American plants, the use of which was mostly learnt from Native American peoples.
Twentieth-century western herbal medicine arose from the physiomedical and eclectic traditions but was also influenced by European folk medicine, especially from Germany. Over the last couple of decades increasing amounts of scientific information about many herbal medicines has become available, and science is increasingly shaping the practice and future of contemporary herbal medicine.
It should be emphasised that medical knowledge has been exchanged and medicinal plants traded for many centuries, and this type of cross-pollination has influenced all the major schools of medical thought through the ages. Hence medicinal plants from distant parts of the world have been used in western herbal medicine for centuries. The last twenty years, however, have seen an increasing number of Asian medicinal plants in particular incorporated into the western materia medica (literally ‘medicinal materials’ and refers to the medicinal substances used in a given system of medicine). Most of these plants have a long history of use in traditional medical systems such as Traditional Chinese Medicine and Ayurveda.