Antioxidant properties and elemental composition of Withania somnifera L.

Withania somnifera (L.) Dunal is popular in the traditional medicine of many areas of the world due to its high biological activity. Research was carried out in order to characterize the plants of this species in terms of antioxidant content and activity, as well as macro- and microelements concentration in leaves and roots plants grown along Crimea sea coast, which receive an intensive element transfer from the sea surface. The leaves of Withania somnifera showed higher levels of polyphenols, flavonoids and total antioxidant activity compared to roots (7.52 mg eq. GA g-1 d.w., 2.30 mg eq. quercetin g-1 d.w. and 38.2 mg eq. GA g-1 d.w. in leaves; 3.83 mg eq. GA g-1 d.w; 0.48 mg eq. quercetin g-1 d.w. and 10.8 mg eq. GA g-1 d.w. in the roots). Withanolides content in roots reached 0.62 %. The determination of 25 macro- and microelements revealed that Withania somnifera intensively accumulated Ca, K, Mg, P, B, I, Li, Mn, Mo, Si and Zn in leaves, whereas the concentration of V, Cr, Fe and Al in roots exceeded those recorded in leaves by 5.5, 5.86, 4.35 and 5.26 times respectively. The highest difference between leaves and roots concentration was detected for Li whose content in leaves was 10 times higher than in roots. Among other cultivated herbs (14 species belonging to Artemisia and Myrthus), Withania somnifera showed the highest levels of Li which makes it suppose this species is a good Li source for humans. Moreover, the leaves of W. somnifera contain high levels of iodine.