The Working of Herbs, Part 6: Herb Actions and the Importance of Family

By Anne Stobart

Previously I considered  issues relating to herb efficacy and how to evaluate herbs and their effectiveness in recipes. Here I review the active constituents and actions of plants in a seventeenth-century recipe for ‘after throwes’ of childbirth; containing hyssop, pennyroyal, groundsel, wild mint and balm. I have been keen to establish how the herbs were viewed then and how they are understood today. In this post I look at herb actions and how knowledge of plant families may be useful.

Herb actions

A herb action indicates the likely effect of a herb in the body – some examples:

  • Carminative: assists digestion and helps reduce/expel wind
  • Diuretic: increases urine amount/flow.
  • Diaphoretic: induces perspiration and has a cooling effect
  • Emmenagogue: promotes menstrual discharge
  • Expectorant: promotes the discharge of phlegm from the chest
  • Febrifuge: reduces fever
  • Pectoral: benefits chest complaint
  • Sedative: has a significant calming effect
  • Spasmolytic: relieves muscle spasm

Herb actions may overlap, for example both a sedative and a spasmolytic herb are likely to reduce pain.

Herb actions and plant families

Particular kinds of phytochemicals often run in plant families, producing similar herb actions. As we saw previously (Working of Herbs, Part 5), the Mint family has aromatic oils which provide both stimulating and calming actions. Other significant plant families include:

  • Daisy family (Asteraceae) – bitter principles with benefits for digestion alongside flavonoids and terpenes with anti-inflammatory actions
  • Lily family (Liliaceae) – steroidal-like constituents with hormonal actions
  • Pea family (Leguminosae) – has steroidal-like and other constituents producing hormonal and anti-inflammatory actions
  • Pine family (Pinaceae) – resinous components with antiseptic and antifungal actions
  • Poppy family (Papaveraceae) – alkaloids which can be sedative and pain-relieving (see the Opium Poppy in Figure 1)
  • Rose family (Rosaceae) – tannins with astringent and anti-inflammatory actions
Poppy (Papaver somniferum)
Figure 1. Opium Poppy (Papaver somniferum)

Getting to know plant families is very important for clinical herbal practitioners. Knowing the plant family can also assist the historical researcher in appreciating the possible effects of herbs. Plants in the same family can often be substituted for each other. But, beware, as not all plant families are consistent – for example the Carrot family (Umbelliferae) includes many beneficial (and edible) plants as well as highly poisonous plants such as Dropwort and Hemlock.

An overview of the recipe herbs and their constituents and actions

  • Groundsel (Senecio spp.) contains pyrrolizidine alkaloids, volatile oils, flavonoids. Once used as a diuretic and diaphoretic and to relieve bilious pains – but due to high concentration of hepatotoxic alkaloids, internal use is not now recommended.[1]
  • Hyssop (Hyssopus officinalis) contains terpenoids, volatile oil, flavonoids  and is carminative, diaphoretic, expectorant, pectoral, sedative and stimulant.[1,2]
  • Pennyroyal (Mentha pulegium), contains volatile oil (mostly pulegone), bitters and tannins and is  carminative, diaphoretic, emmenagogue, spasmolytic, stimulant.[1,2]
  • Wild Mint (Mentha spp.) is not readily identifiable, so I have used several near relatives in the Mint family: Water Mint [Mentha aquatica] contains essential oil including methofuran, menthol, menthyl acetate, pulegone and is stimulant, emetic, astringent.[1]; Peppermint [Mentha x piperita] is carminative, diaphoretic, spasmolytic.[2]
  • Balm (Melissa officinalis) contains volatile oil (mainly neral and geraniol), terpenes, flavonoids, polyphenolics, triterpenic acids and is anti-spasmodic, carminative, diaphoretic, febrifuge, sedative. [1,2]

More detail wanted?

The above listing of constituents and actions is based on several monograph sources. For the fullest detail of constituent phytochemicals, Jim Duke’s online database is very well-referenced and it offers a number of search options for specific ‘chemicals’ or particular ‘plants’. The results of a search can be cross-referenced to all plants with a high content of a particular phytochemical. (See Figure 2 for example of  ‘Hyssop’ which, of all the plants listed, has the 11th highest content of alpha-thujone, a powerful emmenagogue.) [3]

Figure 2. Hyssop query in Duke's Database.
Figure 2. Screenshot of Hyssop query in Duke’s Database.

Plant identification

Note that all of the herbs in the recipe are in the Mint family except one – Groundsel which is in the Daisy family. Of course, we do not have absolute certainty about the identification of these plants – especially since the way we name plant species differs from the seventeenth-century. But the whole topic of plant identification is rather too extensive to deal with here, and I have had to make assumptions about the likeliest plants named. I am active in the Herbal History Research Network which aims to encourage researchers in herbal history through sharing experience and best practice. So if you are interested in issues around herb identification, do check out our next London-based seminar on ‘Illustration and identification in the history of herbal medicineon 18 June 2014.

Next post

In my next post I explore more on how these herbs might take effect together and how the type of recipe preparation may be significant – could it really help the ‘after throwes’?

Notes

[1] R. C. Wren, Elizabeth M. Williamson, and Fred J. Evans, Potter’s New Cyclopaedia of Botanical Drugs and Preparations (Saffron Walden: C. W. Daniel, 1988).

[2] British Herbal Medicine Association. British Herbal Pharmacopoeia (Keighley, West Yorkshire: British Herbal Medicine Association, 1983).

[3] For further detail on phytochemicals see Lisa Ganora, Herbal Constituents: Foundations of Phytochemistry (Louisville, Colorado: Herbalchem Press, 2008).

The Working of Herbs, Part 5: Medicinal Herb Constituents and Actions

By Anne Stobart

In this post I look at some plant constituents and actions. I am especially interested in the plants in a seventeenth-century recipe introduced in Working of Herbs, Part 2. Previously I raised issues related to finding out how medicinal herbs might work (Part 1), and locating modern herbal monographs (Part 4). Here I look at herb constituents and their actions because these are directly relevant to considering how a herb may take effect (or not) in a recipe. Of course, not everyone feels comfortable with the chemistry of plants so I have added some further suggestions in case this topic makes you go ‘AAArgh!’.

Phytochemicals and actions

Phytochemicals, or herb constituents, are fascinating (to me at least!). Knowing the likely effects of some key phytochemicals can be a great help in considering the herbs in recipes. Amongst the  thousands of chemicals in each plant, it is often the ‘secondary metabolites’ produced as a defence against pests and diseases that can be used to some effect in our own bodies.[1] Some have powerful effects, like Groundsel (Senecio vulgaris) which contains toxic alkaloids (Figure 1). Many phytochemicals are surprisingly well-researched so that we know about their likely effects – their herbal actions – even though clinical uses are much less well researched. Here I introduce an important group of plant constituents – the terpenes.

Figure 1. Groundsel (Senecio vulgaris) image from Wikipedia
Figure 1. Groundsel (Senecio vulgaris) image from Wikipedia

What are terpenes?

Terpenes consist of chains of carbon and hydrogen units. They act as a deterrent to insect pests as well as inhibiting fungi and bacteria. The terpenes and related compounds are highly aromatic: many evaporate readily and form the basis of essential oils extracted from plants by distillation.

Plants in the Mint family (Lamiaceae, previously known as Labiatae) contain terpenes which vary considerably in action from stimulant to sedative effects. The simpler stimulant monoterpenes include molecules like menthol with a recognisable minty aroma. Some of these smaller molecules are highly active, often metabolized quickly in the body, with significant neurotoxic effects. Thujone (Figure 2)  is one such monoterpene with a reputation for toxicity. It is found in wormwood (Artemisia absinthum), an extremely bitter-tasting plant in the Daisy family used in the making of absinthe.[2] Thujone is also found in some Mint family members like hyssop (Hyssopus officinalis) and sage (Salvia officinalis). This monoterpene acts on uterine muscle, causing contractions, and hence has a reputation as an abortifacient. Such plant constituents are one reason for caution regarding the use of essential oils in pregnancy.[3]

Figure 2. Thujone
Figure 2. Thujone

Other terpenes, such as diterpenes and sesquiterpenes, have a wide range of therapeutic effects – often particularly anti-spasmodic and calming actions. Both the Mint family (such as lemon balm (Melissa officinalis) and lavender (Lavandula angustifolia)), and the Daisy family (such as chamomile (Matricaria chamomilla) and yarrow (Achillea millefolium)  demonstrate these actions.

 

Other plant constituent groups

Figure 3. Cyanidin, a flavonoid (Wikipedia)
Figure 3. Cyanidin, a flavonoid (Wikipedia)

Another important group of constituents is that of flavonoids which can often be recognised by plant colouring (especially yellows, reds, purples). Flavonoids are polyphenols, consisting of linked rings of carbon atoms (Figure 3), and many are antinflammatory. Some other groups of plant constituents are less obvious, such as the colourless and odourless alkaloids. Alkaloids can significantly affect the nervous system either as stimulants (like caffeine in coffee berries) or as sedatives (morphine-like compounds in poppies). These and other kinds of plant constituents provide for an extensive range of herbal actions.

Conclusion – ask a herbal expert!

I guess some readers will be thinking ‘This is too much chemistry – help!’. If you are not so keen on the chemistry then perhaps you could link up with a clinical herbal practitioner who can help with understanding herb constituents and actions. In the UK you can find a herbalist through a professional organisation like the National Institute of Medical Herbalists. Alternatively you could consider posting a question to HIST-HERB-MED. This is a JISC-MAIL email discussion list which I help to co-ordinate for active researchers in the history of herbal medicine – replies are not guaranteed but might provide useful leads to helpful individuals or sources.

Notes

[1] A standard text on plant constituents is William C. Evans, Trease and Evans’ Pharmacognosy, 16th ed. (Elsevier, 2009). Also see Gunnar Samuelsson, Drugs of Natural Origin: A Textbook of Pharmacognosy (Stockholm: Swedish Pharmaceutical Press, 1992).

[2] However, the toxicity of absinthe may be partly due to the high level of alcohol consumed by regular drinkers, Karin M. Hold, et al., ‘A-thujone (the active component of absinthe): G-aminobutyric acid type a receptor modulation and metabolic detoxification’. Proc. Natl. Acad. Sci. USA 97, no. 8 (2000): 3826–31.

[3] More on herbs with abortifacient actions in John Riddle, Eve’s Herbs: A History of Contraception and Abortion in the West  (Cambridge: Harvard University Press, 1997).