Chapter 5: Role of kynurenine pathway in aging

Abstract

Aging is a degenerative process that affects all living organisms and is characterized by physiological and functional changes that drives to numerous aging-related disorders contributing to death. Cellular changes during the aging process involve oxidative stress, infl ammation, mitochondrial dysfunction, and cognitive and immune response decline. In this context, changes in tryptophan metabolism are also found. Tryptophan is an essential amino acid required for the synthesis of proteins, and it is mainly metabolized via the kynurenine pathway generating several metabolites with neuroactive and/or redox properties. Due to kynurenine pathway, metabolites have been related with aging and some aging-related diseases; we review here the alteration in kynurenine pathway components during aging and study the relationship between these metabolites and other factors present during the aging process, with the goal of exploring their therapeutic value, as targets or biomarkers of different age diseases or aging states.