Grant: Discovery Grants Program - Individual

Polyphenols, such as flavonoids in a variety of plants, have attracted attention due to their potential use as nutraceutical products. In particular, high quantities of polyphenols in some berry species (e.g. blueberries) and their reported antioxidant and anti-inflammatory properties, could be beneficial for brain aging and neurodegenerative disorders. In this research program, our laboratory group will perform detailed analyses of the chemical constituents and neurobiological activity of compounds in various species of wild berries, with a primary focus on species native to Newfoundland and Labrador, in comparison to cultivars from species in this region and commercial extracts. Wild species of berries in the Vaccinium genus (e.g. bilberries, blueberries and lingonberrries) will be collected in Newfoundland and Labrador, while cultivars will be supplied from Agriculture and Agri-Food Canada. Local growers and nutraceutical companies will provide additional samples of berries, such as cloudberry and sea buckthorn. Extracts from berry fruits and leaves will be analyzed by high performance liquid chromatography-mass spectroscopy and a chemical fingerprinting technique will be used to identify and quantify major flavonoids in the leaves and fruits of each species. We will also utilize standard biochemical assays to determine free radical scavenging ability and reducing power of extracts. The major focus of the research program will then be on determining the bioactivity of detected compounds. We will feed rodents diets enriched with berries and measure the polyphenol content in various brain regions. Based on the results of these bioavailability experiments, extracts will be tested at physiologically relevant concentrations for biological activity in cultured cells derived from brain tissue, which will include neurons and microglia. For example, proteins involved in protective cell signaling responses will be measured in cells treated with extracts and in brains of animals fed berry-enriched diets. The effects of extracts on markers of neuroinflammation and brain aging will also be measured. Additionally, we will employ computer-based docking studies to model the interaction between specific flavonoids and proteins whose expression level is altered by extracts, which will aid in determining if the biological effects of polyphenols are due to specific interactions with proteins, or to non-specific effects, such as by truly acting as antioxidants. The continuing results from this research program could have potential economic benefits not only to the province of Newfoundland and Labrador, but to Canada as whole. These benefits could be derived by the development of food products containing berry fruits or compounds derived from the leaves of berry species, as well as the further development of specific chemical constituents into nutraceutical products.