ii Herb of the Month Marianne Hughes, Hazel Brady

Goat’s Rue

(Galega officinalis)

Marianne Hughes, with illustration by Hazel Brady

I had never heard of this herb before I became a student in the RBGE Physic Garden. In the stock bed, one July, I came across a bush covered in white-pink flowers, and alive with bees— this was Goat’s Rue. It was beautiful and flowered all summer long. What I didn’t notice was that bruising the foliage can give a foul smell which, according to Bown (2008) is what gives rise to the name ‘Goat’s Rue’. In German, its name is Pestilenzkraut (ibid.) because Galega officinalis was once an important herb in the treatment of plague, fevers and infectious diseases.

In Greek, however, ‘gala’ means ‘milk’ and ‘ ago ’ means ‘to bring on’, so Galega suggests a powerful galactagogue— a herb for stimulating the production and flow of milk. It was once fed to livestock to increase milk yield (Bailey, 2004) and Hoffman (2002) notes that in humans it can ‘increase milk output by up to 50% in some cases’. Indeed, an Italian study (cited on gaiaherbs.com) found that a combination of Goat's Rue and Milk Thistle (Silybum marianum) supported normal breast milk production in mothers whose babies were born prematurely. As we are all aware, there is increasing scientific interest in the impact of herbal remedies and the Drugs and Lactation Database of the National Library of Medicine in the USA now contains information on Goat’s Rue. Quoting a wide range of studies, the entry concludes that ‘very limited scientific data exist on the safety and efficacy of Goat’s Rue in nursing mothers or infants’. As we also know, an absence of evidence is not necessarily evidence of absence.

Since the Egyptian Ebers papyrus of 1550 BC recommended a high fibre diet of wheat grains and ochre, many traditional plant medicines have been recorded as treatments for diabetes. One established action of Goat’s Rue is that of lowering blood sugar levels (Bartram, 1998), so it can be useful in the treatment of diabetes mellitus (though not as a replacement for insulin treatment). Goat’s Rue was introduced into cultivation in England in 1568 and it seems that Nicolas Culpepper, who published his treatise in 1652, was aware of both diabetes and G. officinalis. Hadden (2005) notes the observation by Paracelsus (1493-1541) that ‘the right dose differentiates a poison from a useful medicine’, and our Goat’s Rue is classed as a Federal Noxious Weed (Class A) in 35 states of the USA. Apparently, Goat’s Rue (or French Lilac or Italian Fitch, as it is also known) contains guanidine from which metformin (trade name: Glucophage, meaning ‘glucose eater’) was derived in the early 1900s and used to treat diabetes (Evidence-Based Medicine Consult, 2015). In 1918, a synthetic form of guanidine was shown to confer hypoglycaemic actions in animals but proved too toxic for clinical use, so an extract of G. officinalis became the preferred antidiabetic agent in the 1920s. Metformin became available in the UK in 1958 for ‘maturity-onset’ (now known as ‘type 2’) diabetes. Hadden (2005) recalls as a junior doctor the friendly approach of a small organisation (Rona), a subsidiary of a small French company (Aron), who marketed metformin in Belfast and Edinburgh. Consequently, clinical studies were undertaken at the Royal Infirmary in Edinburgh and also in Belfast, which demonstrated the efficacy and safety of metformin. Indeed, metformin remains an established leading treatment for people with type 2 diabetes. As Bailey (2004) comments:

'In our high-tech era of drug discovery and development, this first line treatment for type 2 diabetes is little removed from an herbal remedy of the Middle Ages'.

References Bailey, C.J. (2004) ‘Metformin: its botanical background’ , in Practical Diabetes International (21, 3):115-117 Bartram, T. (1998) Bartram’s Encyclopaedia of Herbal Medicine Robinson: London Bown, D. (2008) Encyclopaedia of Herbs, Royal Horticultural Society, Dorling Kindersley: London Drugs and Lactation Database (February, 2021) ‘Goat’s Rue’ (www.ncbi.nim.nih.gov/books/NBK501817/ accessed 23.06.21) Evidence-Based Medicine Consult (2015) ‘The Mechanism of Goat’s Rue or French Lilac in the Treatment of Diabetes Mellitus’, embconsult.com, accessed 25.06.21) Gaia Herbs, www.gaiaherbs.com Hadden, D.R. (2005) ‘Goat’s rue – French lilac – Italian fitch – Spanish sainfoin. Gallega officinalis and Metformin: The Edinburgh connection’, J R Physicians Edinb:35: 258-260, Royal College of Physicians Edinburgh Hoffman, D. (2002) Holistic Herbal, Thorsons: London

Illustration by Hazel Brady