Sirtuin 1 and Hormonal Regulations in Aging

Aging affects structure and functions of all organs and systems in the organism. Significant changes in the hormonal levels are registered in elderly individuals. They often become a predisposition for chronic diseases, including cardiovascular, neurodegenerative, and metabolic disorders. Therefore, immense scientific efforts are concentrated in the investigation of molecular mechanisms and drugs with potential to diminish the senescent hormonal changes. Sirtuin 1 (SIRT1), a member of the sirtuin deacetylases family, has been extensively studied as regulator of multiple pathways related to antioxidant properties, optimal immune response and metabolism. SIRT1 plays a crucial role in regulating various hormonal pathways and maintaining homeostasis. In the present work we review the interplay between SIRT1 and hormonal regulations, including endocrine role of the hypothalamic-pituitary-thyroid, -adrenal, -gonadal, and -liver axes, of other endocrine glands and of non-endocrine tissues in aging body. The application of natural SIRT1 activators, such as resveratrol, curcumin, paeonol, and Buyang Huanwu Decoction, for treatment of senescence(definition) and aging is discussed. SIRT1 activators improve mitochondrial function, reduce oxidative stress, and promote longevity but their clinical application is limited by low bioavailability and poor permeability across biological barriers. For this reason, advanced delivery strategies, including nose-to-brain drug delivery and nanotechnology-based formulations, are reviewed.