Composition of some macro and micro elements, polyphenol content, antimicrobial and antioxidant activity of Achillea millefolium (L.) grown in Kosovo

Abstract

This study aimed to determine the composition of several macro and micronutrients (N, P, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Ni, Cr, Cd and Pb), the composition of polyphenols (total polyphenols, total flavonoids and total phenolic acids), antimicrobial activity and antioxidant activity of the plant Achillea millefolium (L.) grown in Kosovo (the eastern part of Kosovo). The concentrations of the analysed macro and micronutrients are as follows: N 9.95 g/kg, P 6.15 g/kg, K 23.85 g/kg, Ca 21.98 g/kg,
Mg 6.95 g/kg, Fe 59.85 mg/kg, Zn 35.42 mg/kg, Cu 10.75 mg/kg, Mn 31.87 mg/kg, Co 1.15 mg/kg, Ni 3.01 mg/kg, Cr 0.45 mg/kg, Cd 0.035 mg/kg and Pb 0.65 mg/kg. Potassium and calcium were the most abundant macroelements, while iron and zinc were the most abundant micronutrients. The antibacterial efficacy of A. millefolium (L.) was examined using methanol, ethyl acetate, diethyl ether, and water extracts and tested against Staphylococcus aureus (ATTC 25923), Listeria monocytogenes (WSLC 1042) and Escherichia coli (ATCC 25922). Antibacterial activity was determined using the agar disk diffusion meth­od. The inhibition zones from the extracts were compared with that of penicillin G as the standard. Ethyl acetate and diethyl ether extracts showed antibacterial activity against S. aureus and L. monocytogenes, while methanol extracts showed antibacterial activity against S. aureus. The total content of polyphenols (determined using the Folin–Ciocâlteu reagent) was 17.5 ± 0.45 mg GAE/g (GAE-gallic acid equivalent). The total content of flavonoids (determined using the aluminum chloride method) was 8.45 ± 0.65 mg QE/g (QE-quercetin equivalent), and the total phenolic acid content (determined using Arnova reagent) was 13.2 ± 0.17 mg CAE/g (CAE-caffeic acid equivalent). The antioxidant activity determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and phosphomolybdenum methods had values of 9.85 ± 0.15 and 185.7 ± 1.75 mg TE/g, respectively.