Red clover and its phytoestrogens

Trifolium pratense L., belonging to the Fabaceae family, is commonly called Red Clover and is a plant native to Europe, Central Asia, and North Africa; cultivated in numerous countries around the world. Red Clover’s habitat includes meadows, pastures, and uncultivated land; it thrives well in clayey soils from 0 to 2600 meters altitude.

It is a herbaceous plant, not very long-lived, with a woody rhizome wrapped in dark sheaths and on whose lateral branches are inserted numerous nodules a few mm long that have the characteristic of fixing atmospheric nitrogen; Red Clover lives in a symbiotic relationship with bacteria (Rhizobiaceae Family) present in the root nodule from which it obtains nitrogen.

The leaves are long-petioled and, as the name suggests, trifoliate, oval or elliptical, and have a white spot in the shape of a “V”.

The flowers are arranged in globose heads, pedunculated or subsessile, inserted in the axil of the terminal leaves, light red in color tending to pink.

The fruits are defined as pods, indehiscent included in the calyx, with a membranous pericarp containing a single ovoid seed, smooth, yellowish or brown.

The drug consists of the inflorescences that are collected between May and September.

The drug contains flavonoids (isoflavones and flavonols, and in particular formononetin, biochanin A, daidzein, genistein, pratensein, trifoside regarding the former; and quercetin and isorhamnetin glycosides regarding the latter), essential oil (furfural, eugenol, 2-phenylethanol and esters, methyl salicylate, benzyl alcohol and esters), clavamides, coumarins (coumestrol, medicagol, and coumarin), and other substances such as galactoglucomannan, resins, minerals, vitamins, sitosterol, starch, and phytoalexins.

The class of flavonoid compounds, and in particular daidzein and genistein (also present in Glycine max), are also classified as phytoestrogens; these phytoestrogens, thanks to their chemical structure similar to that of female sex hormones, are able to bind to the receptor responsible for endogenous estrogen. They are therefore recommended during menopause to alleviate its symptoms; but they are also useful in premenstrual syndrome and for the prevention of pathologies related to these hormones, such as osteoporosis and endometrial problems, as well as in cardiovascular diseases.

Red Clover was used in the past as an antipyretic, tonic, diuretic, menstruation stimulant, expectorant, anti-inflammatory, glandular secretion regulator, and anti-eczematous.

Extracts of this plant are also used in cosmetic preparations for women in menopausal age, precisely because of its phytoestrogens.

The oldest documents on Red Clover cultivation date back to the 11th century. It is also a well-known forage plant.

Hildegard von Bingen (circa 1098 – 1179) indicated the healing properties of Red Clover in her book “Physica”.

In Ireland, legend has it that St. Patrick was the first to bring the word of Christ to this country and likened the figure of the Christian Trinity to Red Clover (shamrock) so that when Patrick was proclaimed a saint, he was represented as the founder of the Church in Ireland with a clover in his hand or embroidered on his episcopal robes. Still today, Red Clover is a symbol of Ireland, both from a religious and national point of view, and has become a symbol, particularly used on March 17 on the occasion of the national holiday of St. Patrick’s Day.

ANJA LATINI

Herbalist registered with RNEP no. GLT0018S