A comparative study on solvent extraction effect on the phytochemical profiling and antioxidant capacity of Zizyphus lotus L and Glycyrrhizaglabra L roots extracts from Algeria

The aim of this research work is the determination of total phenols, flavonoids, condensed tannin levels, and antioxidant power of methanolic and aqueous extracts of Zizyphus lotus L and Glycyrrhiza glabra L roots, using three methods (Test DPPH, bleaching of β-carotene and hemoglobin denaturation protection). The higher levels of total phenols were found in methanol extracts of G. glabra and Z. lotus (58.94 ± 0.05 and 51.80 ± 0.02 mg GAE/ g of extract, respectively), the methanol extract of Z. lotus was the richest in flavonoids and tannins condensed with the content of 16.00 ± 0.01 and 17.22 ± 0.1 mg CE/g of extract respectively. With the DPPH method, the water extract of Z. lotus represents significantly (p <0.05) the most extract active (04.52 ± 0.17 mg/ml). For bleaching of β-carotene, G. glabra aqueous extract showed significantly (P <0.05) a higher antioxidant activity (71.47±01.86%). The methanol extracts of G. glabra and Z. lotus showed inhibition of hemoglobin denaturation with values of 71.80±0.06 and 71.71±0.33%, respectively. Based on these results, it could be concluded that the G. glabra and Z. lotus roots are a rich source of natural antioxidants of high value.