Plant foods contain several bioactive compounds, produced via secondary metabolisms as a defence against predation, herbivores, fungal attack, microbial invasion, UV irradiation, and viral infections. Many evidences point to these bioactive compounds as protective molecules active in the prevention of many degenerative diseases in humans. Polyphenols, in particular anthocyanins and flavonoids contained in vegetables, exhibit remarkable antioxidant and anti-inflammatory activities. In this context, the aim of our project is to test the neuroprotective, antioxidant and anti-inflammatory effects in cellular and animal models of polyphenolic extracts from different plant sources obtained by utilizing a new green chemistry approach based on the Natural Deep Eutectic Solvents (NaDES). Extracts from different ecotypes of Arabidopsis thaliana plants, or from food and spices rich in polyphenols such as olive oil, grapes and Curcuma longa, will be characterized by chromatographic and spectroscopic methods, by comparing the efficiency of the extraction procedure with standard methods (i.e. extraction with organic solvents). The biological activity and anti-inflammatory potential of the extracts will be tested in cellular or animal models of Alzheimer's disease (AD) to evaluate their neuroprotective activity. The molecular mechanism underlying the signal transduction pathways activated by polyphenols will be investigated in neuronal (SH-SY5Y) or microglial (BV2) cells treated with the Abeta 25-35 fragment. The extracts will also be tested to evaluate effects on a mouse model of AD. The extracts will also be tested for their antibacterial activity by standard microbiological tests. These studies will contribute to the elucidation of the role of nutritional therapy in counteracting neurodegenerative and infectious diseases
We consider this project innovative because it will offer a new way of obtaining extracts enriched in antioxidants, antiviral and neuroprotective substances, without the use of harmful organic solvents or other harsh systems. Furthermore, as the NaDES are composed of edible molecules, the extracts are ready-to-use, biocompatible and eco-friendly. The absence of any known toxicity of the principal constituents of NaDES (sugars, aminoacids, organic acids) which are normal components of food or arise from metabolic reactions in our body, makes these solvents extremely promising to the development of new food supplements/nutraceuticals enriched in protective substances.
Furthermore, clarifying the effects of complex mixtures of polyphenols with possible synergistic activity may shed new light on the role nutritional therapy in neurodegenerative disease. The detailed chromatographic characterization of the extracts will also allow a correlation with the biological activity in order to define a fingerprint of bioactive components in complex mixtures.
Disclosing the molecular mechanism of polyphenol action may also provide insights into disease pathway and contribute to identify new pharmacological targets and possible alternative therapeutic interventions. The project involves participants whose scientific expertise spans from biochemistry to molecular biology to microbiology. They will cooperate to develop this project in a highly synergistic way, each providing its own specific sound experience and capacity, and sharing a series of different techniques and experimental settings to obtain fully integrated information on the therapeutic potential of polyphenols in the treatment of AD. All the methods and techniques are already available and in current use. No major technical pitfalls are expected