Effect of solvent polarity on the content of biomolecules and antioxidant activity of Thapsia garganica (Apiaceae)

Abstract

For the first time, we have evaluated the antioxidant properties of principal secondary metabolites of methanol, ethyl acetate, hexane and water extracts of Thapsia garganica leaves. In this study, phenolic compounds were extracted and isolated l from T. garganica leaves. Phytochemicals and antioxidant capacity of the used extracts were firstly investigated. The ethyl acetate extract exhibited the highest total phenol content (11.72 ± 1.8 mg AGE/g DW), in addition to the flavonoids concentration (3.45 ± 0.06mg CE/g DW) and the anthocyanins (33.56 ± 4.25 mg/l). In the other hand, the highest level of tannins content was measured in the polar aprotic solvent ethyl acetate extract (4.73 ± 0.22 mg CE/g DW). The different extracts of T. garganica were evaluated for their radical scavenging activities by means of the DPPH assay. The strongest scavenging activity was observed in ethyl acetate fraction scavenged radicals effectively with IC50 values of 0.16 ± 0.02 mg/ml of extract. Similarly, the total reducing power of ethyl acetate extract was found higher than other extracts in both potassium ferricyanide reduction (FRAP) and ABTS•+. The present study found that ethyl acetate extracts of T. garganica have effective antioxidant and radical scavenging activities as compared to other extracts.

Keywords

• Antioxidant activity
• Thapsia garganica leaves
• extracting solvents
• phenolic compounds