Phenolic composition and correlation with antioxidant properties of various organic fractions from Hertia cheirifolia extracts.

ABSTRACT

Hertia cheirifolia L. is a medicinal plant that has been used for a long time in folk Mediterranean medicine. The aim of the present study was to analyze and compare the phenolic profile and the antioxidant potential of organic fractions from H. cheirifolia extracts. Crude methanolic extracts were firstly prepared from the different parts of the plant. Then four different organic fractions were obtained by fractioning each extract, using different solvents with increasing polarity (hexane, chloroform, and ethyl acetate). The Phenolic content was analyzed using a UV-Vis colorimetric methods followed by a qualitative and quantitative analysis by high performance liquid chromatography-diode array detector (HPLC-DAD) system. After that, the antioxidant potential of the different organic fractions was evaluated using DPPH and ABTS free radical scavenging assays, reducing power of iron (FRAP) and inhibition of ß-carotene oxidation tests. Our results revealed that ethyl acetate fractions (EA) contained the highest content of total phenolics (100-250 mg GAE/g). Indeed, the ethyl acetate fraction from the flower extract (EA-F) displayed the lowest IC50 values for the scavenging of DPPH and ABTS free radicals (38.83 ± 0.34 µg/ml and 23.76 ± 0.11 µg/ml, respectively). Also, the strongest iron reducing power (2628.87 ± 16.47 µmol Fe2+Eq/ml) and the best rate of inhibition of the ß-carotene oxidation (58.91 ± 5.79 %) were recorded. In sum, the present study suggests that, the organic fractions from H. cherifolia are potential natural antioxidants and this is probably related to their phenolics content and structure.