Willow: a natural anti-inflammatory

Salix alba is a tree belonging to the Salicaceae family and is known by the common name of Willow. It is a plant that can reach heights of up to 20 meters, but if cultivated, it is pruned and kept lower.

A dioecious tree with an erect trunk, wide crown, and rapid growth, the Willow thrives in moist soils, marshy areas, and along ponds and watercourses.

The genus name Salix derives from a Celtic word meaning “near water,” while the species described here, namely alba, owes its name to the whitish appearance of its leaves.

The Salix genus includes 300 species, including the famous Weeping Willow (Salix babylonica L.), which is of Oriental origin and mainly used as an ornamental plant.

Salix alba has thin and flexible branches, green, or green-reddish, or even almost yellow depending on the variety. The leaves are deciduous, lanceolate-acuminate, up to 12 cm long and a maximum of 3 cm wide, with a shiny green upper blade, a hairier and whitish lower one, and a serrated margin with very small gray-white teeth.

The buds are pressed against the branches, 6-7 mm long, elongated in shape, and vary in color from reddish to brown. Being a dioecious plant, we will have male and female flowers on separate plants, which in the Willow are organized in catkins or “kittens” about 4-5 cm long. Male flowers have 2 stamens, while female flowers, slimmer than males, have an almost sessile ovary and a minute style. Each flower is found in the axil of a very short bract.

The fruit is a capsule with very small and hairy seeds that, when ripe, release a white “cottony” pappus that floats in the air.

The drug of the Willow is represented by the bark, which is peeled off the branches every 2-3 years and appears smooth, shiny, leathery, and tough to peel off. Internally it is white, and externally the color may vary. The taste is bitter.

It contains tannins, phenolic glycosides (specifically: salicin, salicortin, salicoside, populina, salireposide, picein, tremulacin, triandrin), esters of salicylic acid, polyphenols, catechins, and protoanthocyanidins.

Salicylates have anti-inflammatory, antipyretic, analgesic, and antirheumatic activities, properties known since ancient times; Hippocrates already mentioned them in his De Materia Medica, and Dioscorides (1st century A.D.) also wrote about them. In 1757, Reverend Edward Stone, pastor of a small village in Oxfordshire, used it as an antimalarial, as an alternative to expensive Cinchona. In 1824, the Italians Rigatelli and Fontana demonstrated its antipyretic action and managed to isolate salicin, but the turning point came in 1897 when the young chemist F. Hoffmann synthesized acetylsalicylic acid, leading to the success of the German pharmaceutical company Bayer, becoming the most widespread and popular over-the-counter product in the world.

However, this molecule is the leading cause of hospitalization due to drug abuse. Aspirin indeed has the ability to cause ulceration of the gastric mucosa; a side effect that the natural product, namely Willow bark, does not have, with slower and less targeted therapeutic effects.

The bark is generally used in decoction. The phenolic glycosides of the extract, during the journey from the stomach to the small intestine, are converted into salicin which then, thanks to intestinal bacteria, is converted into salicylic alcohol and in the liver becomes salicylic acid, assuming its pharmacologically more active form. These chemical and enzymatic processes are essential for the conversion of so-called pro-drugs into active molecules (drugs).

The bark is the best-known drug, but the buds, catkins, sap, and bark of young branches can also be used.

The buds act on mood tone, with a sedative action on the nervous system, the catkins act on the female genital system, reducing excessive sexual excitement, and therefore also have a sedative action. The sap is recommended for inflammatory conditions of the eye, namely, in the case of cataracts and degeneration of the vitreous body; while the bark of young branches can be indicated in cases of painful ligamentous osteoarthritis. Depending on the specific cases, in gemmotherapy, the association with another gemmderived product is often recommended to achieve a more complete result.

Willow has been the protagonist of many legends. In the Bible, the Jews sat under a Willow to mourn their captivity. In the Middle Ages, the twigs of the plant were a sign of mourning, while those who had been left or rejected wore garlands of leaves and twigs. According to other legends, it was believed that sorcerers used it to make magic wands, while witches used it for their brooms along with Birch twigs and Ash.

Willow was also considered a protector of the house, as exposing its branches kept evil away. Other legends believed that a secret confessed to a Willow would be safe forever, while another legend tells that by beating its bark, bad luck would be driven away, hence the superstitious expression “touch wood” to ward off a negative event.

ANJA LATINI

Herbalist registered with the RNEP no. GLT0018S