Antioxidant activity and fructan content in root extracts from elecampane (Inula helenium L.)

Abstract

The purpose of the present study was to investigate the antioxidant activity and fructans content in ethanol and water extracts of roots of elecampane (Inula helenium L.), a Bulgarian medicinal plant. The extraction procedure included 95% (v/v) ethanol extraction and subsequent water treatment. The antioxidant activity was evaluated by several reliable methods such as DPPH-, ABTS-, FRAP- and CUPRAC-assays, as well as the total phenolic content. In addition, the total fructans and sugar content were determinated by spectrophotomeric, TLC and HPLC-RID methods. The level of fructans in ethanol extracts was 14.1 g / 100 g dry weight, as nystose and 1-kestose were only 0.3 g / 100 g dry weight, and 0.5 g / 100g dry weight, respectively. The absence of fructooligosacharides and sugars in water extracts after the ethanol pretreatment was established. Inulin content was evaluated to be 32 g / 100 g dry weight. The metabolites profile of roots revealed their potential application as radical scavengers due to the presence of polyphenols. Therefore, the root extracts of elecampane could be assumed as a rich source of biologically active substance, in particular dietary fiber with potential prebiotic effect, due to the presence of polysaccharide inulin and fructooligosacharides.

Keywords

• Inula helenium L.
• inulin
• total phenolic content
• antioxidant activity