Résumé:
In the present work, we explore the biological effects of Cyperus esculentus L. or Hab Alaziz under its aqueous preparation as traditionally used in the Algerian pharmacopoeia or in a water/ethanol ratio of 30v/70v. A first physicochemical analysis was carried out, followed by the analysis of total polyphenols and flavonoid contents. Two biological properties, antioxidant (with calculation of IC50), and antibacterialattributes were also evaluated in vitro. The physicochemical composition of the yellow nutsedge tuber showed a water and volatile matter content of about 8.3% and ash and fat contents of about 3.04 and 26.54%, respectively. Our results also confirmed that a certain amount of water is necessary for the extraction of phenolic compounds from yellow nutsedge flour, as higher amounts of hydrophilic elements pass into water as a pure solvent (12%) compared to a water/ethanol mixture. Also, the aqueous extract (280 mg eq QER/100 g DM) was slightly richer in flavonoids compared to the ethanolic extract (198.18 mg eq QER/100 g DM). Both the aqueous and ethanolic extracts of C. esculentus expressed antioxidant activity with respective IC50 values in the range of 49.96 and 6.22 mg/ml and in the range of 211.5 and 12.15 mg/ml as expressed by DPPH and FRAP methods. On the other hand, the inhibitory activity of the bacteria responsible for toxi-infections showed that the ethanolic extract (30 v water/70 v ethanol) exerts an inhibitory activity at least two times higher than that conferred by the water-soluble constituents.
