Aušra Adomėnienė, Kristina Gaivelytė, Romualda Gaurylienė
The body’s exposure to oxidative stress is associated with severe health problems such as cardiovascular diseases, autoimmune nervous system disorders, and immune suppression. The use of botanical preparations is one of the measures of oxidative stress reduction. The botanical material of the stinging nettle (Urtica dioica L.) – its leaves (Urticae folium) – is included in the European Pharmacopoeia (Ph.Eur.01/2008:1897). The therapeutic effect and antioxidant activity of substances extracted from the leaves of Urtica dioica L. is being researched worldwide. The data on the qualitative and quantitative chemical composition allow for preparing raw material that meets the requirements set in normative documents, and therefore studies on the qualitative and quantitative variety of biologically active compounds in the organs of plants are promising. The aim of the study was to investigate the quantitative content of phenolic compounds in the leaves of Urtica dioica L. and to evaluate their antioxidant activity depending on changes in the vegetation periods of the plant. The object of the study was leaves of the stinging nettle harvested in Kaunas district during May-August 2015. The content of phenolic compounds in ethanol extracts of Urtica dioica L. leaves was evaluated by applying the Folin-Ciocalteu technique. Antioxidant activity was evaluated by applying the DPPH antioxidant assay. The evaluation of the phenolic content in the leaves of Urtica dioica L. growing in a natural habitat showed that the highest phenolic content was detected in leaves harvested before bloom. We also found that extracts of leaves harvested before bloom had the strongest antioxidant activity.
Keyword(s): Urtica dioica; phenolics; antioxidant.
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