Total phenolic content and antioxidant activity of three Iranian endemic Achillea species

Bioactive compounds such as phenolics and essential oils involved in medicinal plants are beneficial for human health. Medicinal plants are potential sources of natural antioxidants. The genus of Achillea is comprised of more than 100 species worldwide with different medicinal applications. Nineteen species of Achillea have been recognized in Iran. Since the endemic medicinal species are considered as new natural sources of bioactive compounds, in this study, total phenolics and antioxidant activity of three endemic Achillea species (A. pachycephalla, A. aucherii and A. kellalensis) were compared with a synthetic antioxidant butylated hydroxytoluene (BHT). Total phenolic content was determined according to the Folin-Ciocalteu method and varied from 15.55 mg in A. aucherii to 60.65 mg tannic acid/1 g of dry product in A. pachycephalla. Antioxidant activity of methanolic extract evaluated according to 1,1-diphenyl-2-picryl-hydrazyl (DPPH), ferric thiocyanate (FTC) and β-carotene-linoleic acid assay. In DPPH assay, A. aucherii showed the highest IC50 (844 μg/ml), while A. kellalensis and A. pachycephalla possessed 518 μg/ml and 248 μg/ml, respectively. For reducing power, A. pachycephalla had the highest absorbance in 700 nm (2.601), while A. aucherii possessed the lowest one (0.236). The results showed that three studied endemic species had acceptable antioxidant activity and can be introduced as important sources of natural antioxidants for pharmaceutical and medical purposes.