Spermidine, an Autophagy Inducer, as a Therapeutic Antiaging Strategy

Aging is an ineluctable physiological process that occurs in humans and is often known to progress towards death. It is associated with organ failures, lowered metabolic rate, and a decline in adaptive capabilities of the body. As aging advances, it exerts its effects on the brain, affecting its size, vasculature, structure, and cognitive functions. Multiple factors like oxidative stress, mutation, protein aggregation, reactive oxygen species, and so on have unfolded themselves as contributors to the aging phenomenon. Majorly autophagy is downregulated in the conditions of aging. Therefore, the autophagic processes have marked their prime importance where their modulation could be instrumental in declining the aging pathologies. Spermidine is an autophagy inducer synthesized from diamine putrescine in our body. The age-linked alterations in the spermidine level link autophagy with cellular senescence. Further, recent research highlight the potential of spermidine to delay the aging process. Still, the antiaging mechanisms of spermidine remain unknown. This chapter aims to explore the role of spermidine in the brain and to summarize the epigenetic effects of spermidine linked with aging. We also expose the effects of spermidine on mitochondrial metabolism, lipid metabolism, circadian rhythm, cardioprotection, and anti-inflammatory effects.