*Anthocyanins: Dietary Sources, Bioavailability, Human Metabolic Pathways, and Potential… DOI: http://dx.doi.org/10.5772/intechopen.99927*

example, anthocyanins in vegetables and cereals are chemically more complex in comparison with fruits, but berries are the major source of these compounds. Anthocyanin bioavailability has been reported to be very low, with recovery of less than 1% of the ingested anthocyanin dose. However, nowadays much greater bioavailability values have reported taking into account not only the phase I and phase II metabolites but also the microbiota catabolites. One of the peculiarities of anthocyanin metabolism is their capacity of interconversion between them. For example, dehydroxylation reaction can arise pelargonidin from cyanidin and methylation reactions can convert delphinidin into petunidin and malvidin. For this reason, metabolism data after anthocyanin ingestion is more straight forward to interpret. Regarding metabolism, cyanidin is the most studied anthocyanin due to ubiquitous character in the nature. However, more studies are necessary to better understand the similarities and differences with the other less studied anthocyanins. Even though several papers have reported the potential anti-neuroinflammatory effect of rich anthocyanin extracts, anthocyanins or their metabolites, the number of papers are very scarce. The most important limitation to study the activity of anthocyanin metabolites is the lack of commercial phase II and microbiota catabolites compounds. Thus, the chemical synthesis is the most employed technique to obtain standards although more developments are requires in order to obtain greater quantities. Moreover, little is known about the molecular mechanisms implicated in the observed effects. Furthermore, the majority of works are based on the study of the microglia M1 phenotype, so more studies are necessary to know if anthocyanins and their metabolites are able to induce an anti-inflammatory phenotype. To sum up, more research is necessary to stablish if anthocyanins and their metabolites are efficacious in slowing the progression of brain aging or of neurodegenerative diseases with an inflammatory component.
