Antioxidant properties of hydroxytyrosyl acetate compared with hydroxytyrosol and their protective capacity against oxidative stress in human neuroblastoma cells

This study analyses antioxidant activity of synthetic hydroxytyrosol (HTy) and hydroxytyrosyl acetate (HTy-ac) against. different reactive species. Both phenols were found to be able to scavenge superoxide anion as well as hydroxyl radical with comparable efficacy (40% and 80% scavenging activity, respectively). HTy-ac was found to be more effective than HTy or a-tocopherol as hydrogen peroxide scavenger (53%, 29% and 25% scavenging activity, respectively) (p <= 0.05). Human neuroblastoma cell line SH-SY5Y was chosen as an ex vivo model and cellular oxidative stress was assessed through the measurement of total free sulfhydryl groups and protein carbonyls. HTy displayed a high antioxidant ability against thiols oxidation at 10 mu M, whereas HTy-ac showed a great capacity in preventing carbonyl groups generation. Different antioxidant ability showed by tested compounds against oxidative stress in biological system can be attributed to molecular concentration, reducing power and lipophilicity.