Mechanism of Biological Aging-A Review

Aging is a universal, inherent, natural phenomenon that occurs in all organism. Aging involves morphologicaland functional changes in cellular and extracellular components leading to progressive decline in mostbiological functions. It causes reduction in strength, basal metabolism, sexual activity and the body’sdefenses.Aging is the progressive decline in the maintenance of homeostasis, which leads to decreased response ofthe body against internal and external stress. It involves imbalance between free radicals and the antioxidantmechanism lead to damaged cells, tissues, and organs resulting in age related changes.With age there is modifications in energy metabolism, insulin sensitivity, neuroendocrine function andinduction of hormesis response. Telomere shortening, mitochondrial dysfunction, increase of oxidativestress, alteration of insulin-like growth factor and growth hormone signaling are considered to be importantcontributors of aging process.Recently many genes and changes in gene expression have been found associated with aging which affectsmany biological processes and are associated with senescence and oxidative stress.This review focuses on the underlying mechanism of biological aging. With an increase in the number ofelderly population and the patients of age-related diseases, it is becoming increasingly important to considerthese in the field of research. We have attempted to discuss the different aging mechanism along with thenewer concepts, which can give a direction for the future research studies.