Stress ossidativo e patologie neurodegenerative: ruolo protettivo di antiossidanti naturali e di sintesi su modelli cellulari

Aim: Oxidative stress plays pivotal role in neurodegeneration. An imbalance between antioxidants levels and reactive oxygen species (ROS) production leads to cell damage, particularly in the brain where cells are especially susceptible to oxidative stress. Nowadays, lots of natural and synthetic antioxidant products have been tested for their neuroprotective activities. In this work we tested antioxidant properties of natural and synthetic compounds on two different models of induced-oxidative stress.Methods: Oxidative stress were induced on PC12 cell line by L-DOPA/MnCl2 or H2O2 treatment. Cell viability (MTT-assay; TrypanBlue assay) was evaluated to compare the antioxidant activity of the natural 4-4’dihydroxybiphenyl with its more hydrophilic synthetic analogue AD838. Cell viability (MTT-assay; TrypanBlue; LDH-assays), ROS levels (dichlorfluorescein; GSH-assay) and apoptosis (flow-cytometry analysis) were assessed to study the neuroprotective properties of the synthetic AD838 and the nanostructured cerium oxide (nanoceria).Results: When PC12 cells were pretreated with nanoceria, their viability after L-DOPA/MnCl2 injury raised of 15%. Flow-cytometry indicated that nanoceria reduced the apoptosis ratio of cells insulted by MnCl2. The viability of PC12 cells pretreated with AD838 before exposure to H2O2 was increased of 20%.The preliminary results suggest that its antioxidant activity seemed to be higher than its natural precursor. Moreover, AD838 pretreatment significantly attenuated H2O2-induced apoptotic cell accumulation of 15% and decreased GSH overproduction of 26%.Conclusion: Each compound showed a different antioxidant activity in response to the several used oxidative models. In particular, cerium oxide proved effective on MnCl2/L-DOPA model in PC12 cells. The AD838 compound showed its antioxidant and protective role on H2O2 –induced oxidative stress even more than its structural precursor 4-4’-dihydroxybiphenyl.