20
2
What You Will Learn in This Chapter
While many of the secondary metabolites produced by plants make them unpalatable or
toxic, the specific capacities of natural plant products have also been exploited by humans
for a long time. In its simplest form, they have been used as spices and aroma compounds
to give flavour to food. While it is rather easy to imagine this development, it is also obvious
that so-called medicinal plants have a long history of use as pharmaceuticals, hallucinogens
or painkillers, even though this often requires careful adjustment of the dose to avoid toxic
effects. Last but not the least, since the onset of modern science and technical development, plant secondary metabolites and their derivatives have been exploited for technical
applications.
2.1 History of Medical Use
Plants are a major nutrient source for humans. Therefore, it has always been important to
distinguish edible plants from inedible and toxic ones. Moreover, people have made use of
plants for purposes beyond eating since prehistoric times (Wadley et al. 2011). Historical
evidence for medicinal and recreational exploitation of plant ingredients dates back to
times more than 70,000 years ago. For example, bedding that was found at Sibudu in South
Africa was made of Cape laurel (Cryptocarya woodii) leaves, a plant still used today in
traditional African medicine. There is some evidence that a substance in this aromatic
plant is toxic to mosquitos and it was therefore suggested by paleoethnobotanists that this
might have been the purpose of its use as bedding material (Wadley et al. 2011).
Written evidence for the medicinal use of plants goes back about 4000 years. These
records include text from China, India, Egypt and Sumeria, indicating that medicinal use
was already widespread at that time. The use of cannabis, for example, is described in the
Hindu scripture Atharva Veda (1200–100 BC), the first Chinese pharmaceutical book (Li
1974) Shennong Bencaojing (ca. 100 AD) as well as by Herodot (500 BC). The Ebers
Papyrus dating to circa 1550 BC is a historic Egyptian medical collection that describes
the use of many plants including Atropa belladonna (Ebbell 1937). Around 50 AD, a Greek
physician, Pedanius Dioscorides, provided a first pharmacopedia De Materia Medica of
about 600 plants and their medical use for the Roman army, which was in use for about
1500 years. Indeed, many of the plants mentioned in these texts are still used today for
herbal medicine or have formed the base for the development of modern drugs.
The advent of modern science was marked by the first books describing specific extraction and distillation methods to obtain medicinal compounds from plants (Brunschwig
1500). Already the first book that described British flora following the Linnaean taxonomy
included “the uses as medicines, or as poisons, as food for men, for brutes and for insects,
with their applications in oeconomy and in the arts” (William Withering 1776). Withering
also discovered common foxglove (Digitalis purpurea) as source of the active compound
found in multi-herbal medicines for the treatment of heart conditions (Withering 1785)
(. Fig. 2.1).
The nineteenth century, due to significant developments of chemical methodology, is
marked by the isolation and identification of many active plant compounds such as morphine (Sertürner 1805), strychnine (Pelletier and Caventou 1818), caffeine (Runge 1820)
or nicotine (Posselt and Reimann 1828). Shortly after, many of these compounds could be
synthesized and chemically altered by chemists to improve their function, e.g. acetylsalicylic acid (aspirin). At the same time, the psychoactive, toxic, antimicrobial, analgesic or
Chapter 2 · Historical and Current Perspective
2
What You Will Learn in This Chapter
While many of the secondary metabolites produced by plants make them unpalatable or
toxic, the specific capacities of natural plant products have also been exploited by humans
for a long time. In its simplest form, they have been used as spices and aroma compounds
to give flavour to food. While it is rather easy to imagine this development, it is also obvious
that so-called medicinal plants have a long history of use as pharmaceuticals, hallucinogens
or painkillers, even though this often requires careful adjustment of the dose to avoid toxic
effects. Last but not the least, since the onset of modern science and technical development, plant secondary metabolites and their derivatives have been exploited for technical
applications.
2.1 History of Medical Use
Plants are a major nutrient source for humans. Therefore, it has always been important to
distinguish edible plants from inedible and toxic ones. Moreover, people have made use of
plants for purposes beyond eating since prehistoric times (Wadley et al. 2011). Historical
evidence for medicinal and recreational exploitation of plant ingredients dates back to
times more than 70,000 years ago. For example, bedding that was found at Sibudu in South
Africa was made of Cape laurel (Cryptocarya woodii) leaves, a plant still used today in
traditional African medicine. There is some evidence that a substance in this aromatic
plant is toxic to mosquitos and it was therefore suggested by paleoethnobotanists that this
might have been the purpose of its use as bedding material (Wadley et al. 2011).
Written evidence for the medicinal use of plants goes back about 4000 years. These
records include text from China, India, Egypt and Sumeria, indicating that medicinal use
was already widespread at that time. The use of cannabis, for example, is described in the
Hindu scripture Atharva Veda (1200–100 BC), the first Chinese pharmaceutical book (Li
1974) Shennong Bencaojing (ca. 100 AD) as well as by Herodot (500 BC). The Ebers
Papyrus dating to circa 1550 BC is a historic Egyptian medical collection that describes
the use of many plants including Atropa belladonna (Ebbell 1937). Around 50 AD, a Greek
physician, Pedanius Dioscorides, provided a first pharmacopedia De Materia Medica of
about 600 plants and their medical use for the Roman army, which was in use for about
1500 years. Indeed, many of the plants mentioned in these texts are still used today for
herbal medicine or have formed the base for the development of modern drugs.
The advent of modern science was marked by the first books describing specific extraction and distillation methods to obtain medicinal compounds from plants (Brunschwig
1500). Already the first book that described British flora following the Linnaean taxonomy
included “the uses as medicines, or as poisons, as food for men, for brutes and for insects,
with their applications in oeconomy and in the arts” (William Withering 1776). Withering
also discovered common foxglove (Digitalis purpurea) as source of the active compound
found in multi-herbal medicines for the treatment of heart conditions (Withering 1785)
(. Fig. 2.1).
The nineteenth century, due to significant developments of chemical methodology, is
marked by the isolation and identification of many active plant compounds such as morphine (Sertürner 1805), strychnine (Pelletier and Caventou 1818), caffeine (Runge 1820)
or nicotine (Posselt and Reimann 1828). Shortly after, many of these compounds could be
synthesized and chemically altered by chemists to improve their function, e.g. acetylsalicylic acid (aspirin). At the same time, the psychoactive, toxic, antimicrobial, analgesic or
Chapter 2 · Historical and Current Perspective