Research update: Lectin enriched fractions of herb and dry extract of Urtica dioica L.

Abstract

Urtica dioica L is a plant rich in flavonoids, carotenoids, caffeoylmalic acid and has an established medical value. Although content of mineral and organic substances of U. dioica L. herb is well characterized, presence of bioactive polypeptides is much less appreciated. Seeds and roots of nettle, have been established as a common source for isolation of lectins. Therefore data on the presence of lectins in herb of nettle is ambiguous. Lectin-enriched protein fractions were isolated from herb (fresh and dry) and dry extract of U. dioica L. by using homogenisation with fluid nitrogen, extraction in 0.01 M phosphate-buffer saline (PBS), concentrating, salting and precipitation. The amount of protein was measured using photometric Bradford method. A proteomic analysis using 2D gel electrophoresis was performed for lectin – enriched protein fractions isolation and analysis. We estimated quantity of protein and lectins, assessed their blood cell agglutinating activity using tests employing rabbit erythrocytes. The highest concentration of protein and specific hemagglutination activity was observed for protein fractions isolated from fresh herb. The highest lectins content was presented in protein fractions isolated from the dry extract. Key words: Urtica dioica L., lectins, hemaglutination, electrophoresis.