Antioxidant Activity ofIpomoea batatasL. Lam. Leaf Grown in Continental Croatia and Its Effect on Glutathione Level in Glucose-Induced Oxidative Stress

Ethanolic and aqueous extract of Ipomoea batatas (L.) Lam. leaf grown in Croatia were prepared. Antioxidant activity of the extracts, as well as their effect on intracellular glucose-induced oxidative stress, was determined. Antioxidant activity was assayed by DPPH radical scavenging activity, reducing power, activity in β-carotene-linoleic acid assay, and superoxide dismutase-like activity. In addition to being richer in phenols and flavonoids than aqueous extract, ethanolic extract also demonstrated superior antioxidant activity in all the assays. In a concentration of 10 μg/ml, both extracts were able to significantly increase intracellular glutathione levels.