Urtica spp.: Ordinary Plants with Extraordinary Properties

Abstract

Nettles (genus Urtica, family Urticaceae) are of considerable interest as preservatives in foods for both human and animal consumption. They have also been used for centuries in traditional medicine. This paper reviews the properties of nettles that make them suitable for wider applications in the food and pharmaceutical industries. Nettles contain a significant number of biologically-active compounds. For example, the leaves are rich sources of terpenoids, carotenoids and fatty acids, as well as of various essential amino acids, chlorophyll, vitamins, tannins, carbohydrates, sterols, polysaccharides, isolectins and minerals. Extracts from the aerial parts of nettles are rich sources of polyphenols, while the roots contain oleanol acid, sterols and steryl glycosides. Due to the variety of phytochemicals and their proportions they contain, nettles show noticeable activity against both Gram-positive and Gram-negative bacteria. These properties make nettles suitable for a range of possible applications, including functional food, dietary supplements and pharmacological formulations. Despite these benefits, the nettle is still an underestimated plant source. This paper provides a unique overview of the latest research on nettle plants focusing on the possibilities for transforming a common weed into a commercial plant with a wide range of applications. Special attention is paid to the antimicrobial activity of the active compounds in nettles and to possible uses of these valuable plants in food and feed formulations.

A multicomponent herbal feed additive improves somatic cell counts in dairy cows ‐ a two stage, multicentre, placebo‐controlled long‐term on‐farm trial

“…In recent ethnoveterinary studies (Bischoff et al, ; Disler et al, ; Stucki et al, ), common nettle ( Urtica dioica L.) was the most frequently reported herbal drug for “general strengthening.” Flavonoid glycosides and caffeic acid esters seem responsible for its anti‐inflammatory and diuretic effect (ESCOP, ). The relevant properties of nettle are most likely antimicrobial and antioxidative effects (Kregiel, Pawlikowska, & Antonak, ), which are of relevance for udder health. Milk thistle seeds ( Silybum marianum L. GAERTNER) and, in particular, their flavanolignans, possess hepatoprotective properties (ESCOP, ; Saller, Melzer, Reichling, Brignoli, & Meier, ) which might induce positive effects, as the liver is to some degree “causal and contributing to metabolic and related disorders (e.g., fatty liver, ketosis, metritis, lameness)” (van Dorland and Bruckmaier, ).…”

“…Some phytochemicals in HFA may possess antimicrobial activity against udder pathogens (Fratini et al, ; Kregiel et al, ). However, it is unlikely that minimal inhibitory concentrations of essential oils or other phytochemicals in the udder tissue or in the milk could be reached by oral application of HFA.…”

“…The relatively high tannin concentration in HFA-100 was likely due to herbs such as Alchillea millefolium (Fraisse et al, 2007;Jayanegara et al, 2011), Artemisia absinthium (Msaada et al, 2015), Cichorium intybus (Kälber, Meier, Kreuzer, & Leiber, 2011) and Urtica dioica (Kregiel et al, 2018).…”

“…In FT, less cows were culled for udder health reasons in the HFA-100 group compared to PL by tendency (p = .08 Some phytochemicals in HFA may possess antimicrobial activity against udder pathogens (Fratini et al, 2014;Kregiel et al, 2018).…”

Inhibitory Effects of Urtica thunbergiana Ethanol Extract on Atopic Dermatitis-Induced NC/Nga Mice

“…Herbal plant extracts are promising agents in AD treatment because they have fewer side effects and are safer to use compared to chemical medicines. Urtica thunbergiana (UT) is a Korean traditional medicine used to treat a variety of diseases, such as eczema, hematuria, jaundice, menorrhagia, autoimmune disorders, cancer, diabetes, and anemia [10]. However, its effects on AD pathogenesis have not been studied.…”