TOTAL PHENOLIC, FLAVONOID AND TANNIN CONTENTS AND ANTIOXIDANT ACTIVITIES OF EXTRACTS OF URTICA DIOICA L. BY DIFFERENT EXTRACTION TECHNIQUES

Abstract

The stinging nettle (Urtica dioïca L.) has been used as a traditional remedy to treat an important range of diseases due to its therapeutic virtues. This work was undertaken to valorize the prospective of extracts of wild Urtica dioica of Algeria as sources of polyphenols and natural antioxidants, as well as the effectiveness of diverse extraction techniques (Soxhlet and maceration) and solvents (ethanol and hexane) on the content of secondary metabolites, and their antioxidant activity were examined by Folin-Ciocalteu, DPPH, FRAP and TAC essays, respectively. The phytochemical screening of aerial part of Urtica dioïca revealed the presence of bioactive compounds: flavonoids, phenols, tannins, anthocyanins and saponosides. Soxhlet with ethanol extracts of Urtica dioica indicated the highest values of total phenolic (13.35 ± 1.06 mg GAE / g DW), flavonoids (3.61 ± 0.46 mg QE / g DW), and tannin (5.37 ± 0.59 mg CE / g DW). Similarly, In terms of IC50, the results clearly showed that the technique of Soxhlet with ethanol was the strongest radical scavenger (0.343 ± 0.012 mg/ml). On another hand, maceration with hexane extracts represented the lowest contents of polyphenols compounds and the antioxidant activity. Subsequently, Soxhlet associated with ethanol exhibited the highest extraction ability for isolation of bioactive ingredients from wild Urtica dioica.

Keywords

• urtica dioïca
• extraction
• soxhlet
• maceration
• solvent
• antioxidant activity