STUDY OF THE PROTECTIVE ACTIVITY OF NEW SWEET CHERRY CULTIVARS IN NEURON-LIKE SH-SY5Y CELLS

Neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases, are caused by the progressive death of neurons in different regions of the nervous system. Their etiology is multifactorial with oxidative stress as one of the most impacting factors. The brain, due to its high oxygen consumption and high lipid content, is highly vulnerable to the effects of reactive oxygen species. The increase in the generation of free radicals damages the cellular biomolecules and induces necrosis or apoptosis. Sweet cherry fruits are a nutritionally dense food rich in anthocyanins, quercetin, hydroxycinnamates, potassium, fiber, vitamin C, and carotenoids. In the present study, we investigated the antioxidant activity of different sweet cherries (Prunus avium L.), obtained through a natural breeding program at the University of Bologna, in neuron-like SH-SY5Y cells differentiated with retinoic acid. The phytochemical pattern of five different cherry extracts has been characterized by HPLC-DAD/FL analysis. To study the protective effects of the extracts, SH-SY5Y cells were treated with different concentrations of the extracts for 24 h before H2O2 exposure. All the extracts, except one, were able to significantly increase cell viability and decrease ROS levels in respect to cells exposed to H2O2 as measured by MTT and DCFH-DA assays, respectively. Three of the five extracts significantly increased GSH levels in respect to H2O2 exposed cells as measured by monochlorobimane assay. The same extracts that significantly reduced ROS production were also able to up-regulate some important phase II antioxidant enzymes, such as GR and NQO1, as measured by RT-PCR. Our findings support the idea that these new sweet cherries can be considered a new functional food with a high antioxidant and neuroprotective effect and these effects seem to be related to the specific phenolic pattern of the different cherry extracts.