Ricerc@Sapienza

Henna is the current name of the dye prepared from the dry leaf powder ofLawsonia inermis(Lythraceae). Several studies have focused on the chemistry and pharmacology of the henna dyeingactive compound, lawsone, obtained from the main constituents of leaves, hennosides, during theprocessing of plant material. However, knowledge regarding the biological activity of hennosidesis largely lacking. In this paper, the redox activity of three hennoside isomers is reported. The pro-oxidative activity was confirmed by their ability to induce mild lysis of erythrocytes and to increasethe level of methemoglobin at the concentration≥500μg/mL. The antioxidant activity of hennosides(concentration≥100μg/mL) was determined by FRAP and ABTS assays. At concentration of500μg/mL, antioxidant activity of hennoside isomers was equivalent to 0.46±0.08, 0.62±0.28 and0.35±0.03 mM FeSO4×7H2O, and 0.15±0.01, 0.30±0.01 and 0.09±0.01 mM Trolox. Hennosidesat 100μg/mL concentration did not influence viability of human breast cancer cell lines MDA231and MCF-7 and primary human peripheral blood and periodontal ligament-mesenchymal stem cells,but produced a modest increase in concentration of antioxidants in the cell culture supernatants.The evidenced antioxidant and pro-oxidant activities indicate their potential to act as redox balanceregulator, which opens up the possibility of using hennosides in commercial phytomedicines