On-farm sustainable cultivation techniques of Epilobium angustifolium L. in order to increase the concentration of an innovative functional ingredient
Epilobium angustifolium L., known as fireweed, is a spontaneous perennial herb. Aerial parts of fireweed contain flavonoids, phenolic acids and ellagitannins. Thanks to this rich phytocomplex it is traditionally used in infusions and food supplements for prostatic ailments. Due to population ageing in Western countries, this market segment is increasing every year, however most of the products are based on phytosterols obtained from exotic plants. Therefore, the aim of this work was to cultivate, for the first-time, fireweed setting the best sustainable on-farm practices to respect the agro-environment, facilitate the entomophilous insects’ health and to concentrate one of the most active polyphenols, oenothein B. Fireweed is then used for the production of the first high-value standardized extract.
Epilobium angustifolium L. is native to the temperate Boreal Hemisphere; in Northern America it is typical of coniferous forests, where it grows mainly as a result of forest fires, hence the name fireweed. It prefers acidic and very draining soils (1). It is a perennial herbaceous plant with erect green leaf stems, it can exceed 2 m in height and rejects every spring from buds formed the previous year on lateral roots (2).
Fireweeds may prove to be a good species for artificial revegetation and land rehabilitation projects. It has been described as a dominant natural colonizer of oil spill sites in the arctic and has been found on acidic coal spoils mine wastes and along road cuts (3).
Hundreds of compounds have been identified in Epilobium genus: the most represented secondary metabolites are flavonoids and tannins (4-10). The importance of chemical characterization is linked not only to biological activity, but also to a chemotaxonomic reason since different fireweed species contain a wide variety of flavonoids: myricitrin, isoquercitrin, querci ...